/* ========================================
   DESIGN TOKENS (Variables)
   ======================================== */

:root {
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8fafc; 
    --color-bg-elevated: #ffffff;
    --color-bg-overlay: rgba(0, 0, 0, 0.5);
    
    --color-text-primary: #1e293b; 
    --color-text-secondary: #475569; 
    --color-text-tertiary: #94a3b8; 
    
    --color-border: #e2e8f0; 
    --color-border-strong: #cbd5e1;
    
    
    --color-primary: #3b82f6;
    --color-primary-hover: #2563eb;
    --color-primary-glow: rgba(59, 130, 246, 0.4); 
    
    --color-accent: #8b5cf6;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --color-info: #06b6d4;
    
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    
    --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', Monaco, 'Cascadia Code', monospace;
    
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-glow: 0 0 20px var(--color-primary-glow);
    
    
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);
    
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
}


[data-theme="dark"] {
    --color-bg-primary: #0f172a; 
    --color-bg-secondary: #1e293b; 
    --color-bg-elevated: #1e293b;
    --color-bg-overlay: rgba(0, 0, 0, 0.7);
    
    --color-text-primary: #f8fafc; 
    --color-text-secondary: #cbd5e1; 
    --color-text-tertiary: #64748b; 
    
    --color-border: #334155; 
    --color-border-strong: #475569;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 25px rgba(59, 130, 246, 0.25);
}/* ========================================
   BASE & TYPOGRAPHY
   ======================================== */

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}


.error-message {
    color: var(--color-danger);
    padding: 20px;
    text-align: center;
}

.error-message h2 {
    margin-bottom: 1rem;
}

.error-message p {
    margin-bottom: 0.5rem;
}

html {
    font-size: 100%;
    scroll-behavior: smooth;
    width: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    min-height: 100dvh;
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
    position: relative;
}


body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 2px,
        rgba(0, 0, 0, 0.02) 2px,
        rgba(0, 0, 0, 0.02) 4px
    );
    pointer-events: none;
    z-index: var(--z-modal, 100);
    opacity: 0.4;
}


.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--color-primary);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    z-index: 1000;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 6px;
}


a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: 2px;
}


h1, h2, h3, h4, h5, h6 {
    color: var(--color-text-primary);
    font-weight: 700;
    line-height: 1.2;
}/* ========================================
   LAYOUT & STRUCTURE
   ======================================== */

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-lg);
    overflow-x: hidden;
    width: 100%;
}


.header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.logo-icon {
    width: 2.5rem;
    height: 2.5rem;
    color: var(--color-primary);
    filter: drop-shadow(0 0 8px var(--color-primary-glow));
}

.logo-text {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: var(--color-primary); 
    letter-spacing: -0.02em;
}

.tagline {
    color: var(--color-text-secondary);
    font-size: var(--font-size-lg);
}


.settings-panel {
    position: fixed;
    top: 0;
    right: 0;
    width: 100%;
    max-width: 400px;
    height: 100dvh;
    background: var(--color-bg-elevated);
    box-shadow: var(--shadow-xl);
    z-index: 2000;
    transform: translateX(100%);
    transition: transform var(--transition-base);
    overflow-y: auto;
    overscroll-behavior: contain;
}

.settings-panel[data-open="true"] {
    transform: translateX(0);
}

.settings-toggle {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1000;
    width: 3rem;
    height: 3rem;
    border-radius: var(--radius-full);
    border: 1px solid var(--color-border);
    background: var(--color-bg-elevated);
    color: var(--color-text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}

.settings-toggle[data-custom="true"]::after {
    content: attr(data-count);
    position: absolute;
    top: -4px;
    right: -4px;
    width: 18px;
    height: 18px;
    background: var(--color-danger);
    color: white;
    border-radius: var(--radius-full);
    font-size: 0.625rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--color-bg-primary);
}

@media (max-width: 768px) {
    .settings-panel {
        top: auto;
        bottom: 0;
        max-width: 100%;
        height: auto;
        max-height: 80vh;
        border-radius: var(--radius-xl) var(--radius-xl) 0 0;
        transform: translateY(100%);
    }
    
    .settings-panel[data-open="true"] {
        transform: translateY(0);
    }
    
    .settings-panel::before {
        content: '';
        position: fixed;
        inset: 0;
        background: var(--color-bg-overlay);
        backdrop-filter: blur(4px);
        z-index: -1;
        opacity: 0;
        transition: opacity var(--transition-base);
        pointer-events: auto;
    }
    
    .settings-panel[data-open="true"]::before {
        opacity: 1;
    }
}




.footer {
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
    border-top: 1px solid var(--color-border);
    margin-top: var(--spacing-3xl);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.footer-info-grid.collapsed {
    max-height: 600px;
    overflow: hidden;
    position: relative;
}

.footer-info-grid.collapsed::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(to bottom, transparent, var(--color-bg-primary));
    pointer-events: none;
}

.footer-toggle-btn {
    display: block;
    margin: 0 auto var(--spacing-xl);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    color: var(--color-text-primary);
    cursor: pointer;
    font-size: var(--font-size-base);
    font-weight: 600;
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}

.footer-toggle-btn:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.footer-info-grid.collapsed .info-card:nth-child(n+4) {
    display: none;
}

.footer-show-more {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    color: var(--color-text-primary);
    font-weight: 600;
    cursor: pointer;
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
    margin-bottom: var(--spacing-xl);
}

.footer-show-more:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

/* =========================================
   RESULTS MATRIX HIERARCHY
   ========================================= */
.results-matrix {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto;
    gap: var(--spacing-lg);
}


.matrix-card[data-metric="download"],
.matrix-card[data-metric="upload"] {
    grid-column: span 1;
    min-height: 180px;
    padding: var(--spacing-xl);
}

.matrix-card[data-metric="download"] .matrix-number,
.matrix-card[data-metric="upload"] .matrix-number {
    font-size: 3rem;
    font-weight: 800;
}


.matrix-card[data-metric="latency"],
.matrix-card[data-metric="jitter"] {
    grid-column: span 1;
    padding: var(--spacing-lg);
}

.matrix-card[data-metric="latency"] .matrix-number,
.matrix-card[data-metric="jitter"] .matrix-number {
    font-size: 2rem;
    font-weight: 700;
}



@media (max-width: 374px) {
    
    .results-matrix {
        grid-template-columns: 1fr;
    }
    
    .logo-text {
        font-size: var(--font-size-xl);
    }
    
    .matrix-card {
        padding: var(--spacing-md);
    }
}

@media (max-width: 600px) {
    .app-container {
        padding: var(--spacing-md) var(--spacing-sm);
    }
    
    .logo-text {
        font-size: var(--font-size-2xl);
    }
    
    .footer-info-grid {
        grid-template-columns: 1fr !important;
    }
    
    .settings-toggle {
        width: 2.5rem !important;
        height: 2.5rem !important;
        top: var(--spacing-md) !important;
        right: var(--spacing-md) !important;
    }
    
    .gauge-wrapper {
        max-width: 280px;
    }
    
    
    .btn-primary, .btn-secondary {
        min-height: 44px;
        padding: var(--spacing-lg) var(--spacing-xl);
        font-size: var(--font-size-base);
    }
    
    
    .controls {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: stretch;
    }
    
    .controls .btn-primary {
        margin-left: 0;
        margin-top: var(--spacing-sm);
    }
    
    
    .results-matrix {
        gap: var(--spacing-md);
        padding: var(--spacing-lg) 0;
    }
    
    .matrix-card {
        padding: var(--spacing-lg);
        border-radius: var(--radius-lg);
    }
    
    
    .gauge-container {
        padding: var(--spacing-xl) var(--spacing-md);
    }
}

@media (min-width: 601px) and (max-width: 768px) {
    
    .gauge-wrapper {
        max-width: 320px;
    }
}

@media (min-width: 769px) {
    
}

@media (min-width: 1024px) {
    
    .app-container {
        padding: var(--spacing-3xl) var(--spacing-xl);
        max-width: 1400px;
    }
}

@media (min-width: 1440px) {
    
    .app-container {
        max-width: 1600px;
    }
}/* ========================================
   COMPONENTS & UI ELEMENTS (Refined)
   ======================================== */

/* --- Edge Location Banner --- */
.smart-banner {
    display: none;
    position: relative;
    width: 100%;
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.smart-banner-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    max-width: 1400px;
    margin: 0 auto;
}

.smart-banner-content span {
    color: var(--color-text-primary);
    font-size: var(--font-size-sm);
    font-weight: 500;
    flex: 1;
}

.smart-banner-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-primary);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 600;
    transition: transform var(--transition-fast), background-color var(--transition-fast);
    white-space: nowrap;
    flex-shrink: 0;
}

.smart-banner-btn:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
}

.smart-banner-close {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    line-height: 1;
    color: var(--color-text-secondary);
    cursor: pointer;
    padding: var(--spacing-xs);
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast), color var(--transition-fast);
    flex-shrink: 0;
    margin-left: var(--spacing-md);
}

.smart-banner-close:hover {
    background: var(--color-bg-elevated);
    color: var(--color-text-primary);
}

@media (max-width: 768px) {
    .smart-banner-content {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .smart-banner-content span {
        font-size: 0.8125rem;
        flex-basis: 100%;
        text-align: center;
    }
    
    .smart-banner-btn {
        flex: 1;
    }
    
    .smart-banner-close {
        margin-left: 0;
    }
}

/* --- Buttons --- */
.btn-primary, .btn-secondary, .cta-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-2xl);
    font-size: var(--font-size-lg);
    font-weight: 600;
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-base);
    text-decoration: none !important;
    position: relative;
    overflow: hidden;
}

.btn-primary:active, .btn-secondary:active, .cta-button:active {
    transform: translateY(1px);
}

.btn-primary, .cta-button {
    background: var(--color-primary);
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: white !important;
    box-shadow: 0 4px 12px var(--color-primary-glow);
}

.btn-primary:hover:not(:disabled), .cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px var(--color-primary-glow);
    filter: brightness(1.1);
}

.btn-secondary {
    background: var(--color-bg-elevated);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    border-color: var(--color-border-strong);
    background: var(--color-bg-secondary);
    box-shadow: var(--shadow-md);
}

.btn-primary:focus-visible,
.btn-secondary:focus-visible,
.cta-button:focus-visible,
.btn-icon:focus-visible,
.btn-icon-small:focus-visible {
    outline: none;
    box-shadow: 0 0 0 4px var(--color-bg-primary), 0 0 0 6px var(--color-primary);
}

/* --- Icons --- */
.btn-icon-small {
    width: 2.75rem; 
    height: 2.75rem;
    border: 1px solid var(--color-border);
    background: var(--color-bg-elevated);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

.btn-icon-small:hover {
    background: var(--color-bg-secondary);
    color: var(--color-primary);
    border-color: var(--color-primary);
    transform: translateY(-1px);
}

.metric-info-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    width: 2rem;
    height: 2rem;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.matrix-card:hover .metric-info-btn {
    opacity: 1;
}

/* --- Confidence Indicators --- */
.confidence-indicator {
    margin-top: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.confidence-bar {
    flex: 1;
    height: 4px;
    background: var(--color-border);
    border-radius: var(--radius-full);
    overflow: hidden;
    position: relative;
}

.confidence-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-warning), var(--color-success));
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

.confidence-text {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
}


.confidence-fill[data-level="high"] {
    background: var(--color-success);
}

.confidence-fill[data-level="medium"] {
    background: var(--color-primary);
}

.confidence-fill[data-level="low"] {
    background: var(--color-warning);
}

.confidence-fill[data-level="very-low"] {
    background: var(--color-danger);
}

/* --- Cards / Info Boxes (General Styling) --- */
.info-card {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.info-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-border-strong);
}

/* --- Data Strip Components --- */
.data-strip {
    
}

.data-group {
    
}

.data-item {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-sm) var(--spacing-md);
    transition: transform var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
    text-align: center;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.data-item.active {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
    background: var(--color-bg-elevated);
}

.data-item .label {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

.data-item .value {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-primary);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.03em;
}

.data-item .unit {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.data-item.hero-data {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    gap: var(--spacing-md);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-xl);
    min-width: 180px;
    box-shadow: var(--shadow-md);
}

.data-item.hero-data .icon-wrapper {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.data-item.hero-data .icon-wrapper i {
    width: 20px;
    height: 20px;
    color: white;
}

.data-item.hero-data .icon-wrapper.download {
    background: var(--color-primary);
}
.data-item.hero-data .icon-wrapper.upload {
    background: var(--color-accent);
}

.data-item.hero-data .text-wrapper {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    flex-grow: 1;
}

.data-item.hero-data .value-row {
    display: flex;
    align-items: baseline;
    gap: var(--spacing-xs);
}

.data-item.hero-data .value {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    line-height: 1;
}

/* --- Header Status Pill --- */
.server-status-pill {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    font-weight: 500;
    transition: transform var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

.server-status-pill .status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--color-info); 
    display: inline-block;
    flex-shrink: 0;
}

/* --- Gauge Specifics (Overrides from layout.css if needed) --- */
.gauge-start-button {
    width: 100%; 
    aspect-ratio: 1 / 1;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: white;
    border: none; 
    outline: none; 
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    font-weight: 700;
    font-size: var(--font-size-2xl);
    box-shadow: 0 8px 32px rgba(59, 130, 246, 0.4); 
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
    position: relative;
    overflow: hidden;
    margin: 0 auto;
}

.gauge-start-button::before {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    opacity: 0;
    transition: opacity var(--transition-base);
    animation: pulse-ring 2s ease-out infinite;
}

@keyframes pulse-ring {
    0% {
        transform: scale(1);
        opacity: 0.5;
    }
    100% {
        transform: scale(1.2);
        opacity: 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    .gauge-start-button::before {
        animation: none;
    }
}

.gauge-start-button:hover {
    transform: scale(1.05);
    box-shadow: 0 12px 48px rgba(59, 130, 246, 0.5); 
}

.gauge-start-button:active {
    transform: scale(0.98);
}

.start-button-text {
    font-size: var(--font-size-3xl); 
    font-weight: 800;
    letter-spacing: 0.1em;
}

.start-button-subtitle {
    font-size: var(--font-size-xs); 
    font-weight: 500;
    opacity: 0.9;
    letter-spacing: 0.02em;
}


.gauge-start-button::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: scale(0);
    opacity: 0;
}

.gauge-start-button:active::after {
    animation: ripple 0.6s ease-out;
}

@keyframes ripple {
    0% {
        transform: scale(0);
        opacity: 1;
    }
    100% {
        transform: scale(2);
        opacity: 0;
    }
}


@media (prefers-reduced-motion: reduce) {
    .gauge-start-button::before {
        animation: none;
    }
    .gauge-start-button:active::after {
        animation: none;
    }
    .gauge-start-button:hover {
        transform: none;
    }
    .gauge-start-button:active {
        transform: none;
    }
}

/* --- Typography Fixes --- */

.gauge-value-live, .data-item .value, #timerValue {
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.04em;
    font-weight: 800;
}
.gauge-unit, .data-item .unit {
    font-weight: 600;
    text-transform: uppercase;
}
.gauge-phase-pill {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}


/* --- Loading Skeletons --- */
.loading-skeleton {
    padding: var(--spacing-2xl);
    max-width: 1200px;
    margin: 0 auto;
}

.skeleton-gauge {
    width: 340px;
    height: 340px;
    margin: 0 auto var(--spacing-2xl);
    border-radius: 50%;
    background: var(--color-bg-secondary);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.skeleton-gauge::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    animation: shimmer 2s infinite;
}

@media (prefers-reduced-motion: reduce) {
    .skeleton-gauge::after { animation: none; }
}

.skeleton-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
    max-width: 600px;
    margin: 0 auto;
}

.skeleton-card {
    height: 110px;
    border-radius: var(--radius-xl);
    background: var(--color-bg-secondary);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.skeleton-card::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    animation: shimmer 2s infinite;
}

@media (prefers-reduced-motion: reduce) {
    .skeleton-card::after { animation: none; }
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* --- Input Ranges (Sliders) --- */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: var(--color-border);
    border-radius: var(--radius-full);
    outline: none;
    border: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--color-bg-elevated);
    border: 2px solid var(--color-primary);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    margin-top: -7px;
}

input[type="range"]::-webkit-slider-runnable-track {
    width: 100%;
    height: 6px;
    cursor: pointer;
    background: var(--color-border);
    border-radius: var(--radius-full);
}

input[type="range"]:focus::-webkit-slider-thumb {
    box-shadow: 0 0 0 4px var(--color-primary-glow);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}


input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--color-bg-elevated);
    border: 2px solid var(--color-primary);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

input[type="range"]::-moz-range-track {
    width: 100%;
    height: 6px;
    cursor: pointer;
    background: var(--color-border);
    border-radius: var(--radius-full);
}

/* --- Modals --- */
.help-modal, .share-modal, .settings-panel::before {
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
.help-modal-content, .share-modal-content {
    background: var(--color-bg-elevated);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--color-border);
}
.settings-content {
    padding: var(--spacing-xl);
}

.settings-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.settings-header h2 {
    color: var(--color-text-primary);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin: 0;
}

.settings-body {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.setting-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.setting-section-title {
    color: var(--color-text-primary);
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin: 0 0 var(--spacing-sm) 0;
}

.setting-section-description {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    margin: 0 0 var(--spacing-md) 0;
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.setting-group-row {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
}

.setting-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.setting-info label {
    color: var(--color-text-primary);
    font-weight: 600;
    font-size: var(--font-size-base);
}

.setting-description {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    margin: 0;
}

.setting-control {
    width: 100%;
}

.setting-control-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.setting-control input[type="range"] {
    flex: 1;
    height: 6px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    outline: none;
    border: 1px solid var(--color-border);
}

.setting-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: var(--radius-full);
    background: var(--color-primary);
    cursor: pointer;
    border: 2px solid var(--color-bg-elevated);
    box-shadow: var(--shadow-md);
}

.setting-control input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: var(--radius-full);
    background: var(--color-primary);
    cursor: pointer;
    border: 2px solid var(--color-bg-elevated);
    box-shadow: var(--shadow-md);
}

.setting-value {
    color: var(--color-primary);
    font-weight: 600;
    font-size: var(--font-size-base);
    min-width: 3rem;
    text-align: right;
}

.theme-toggle-inline {
    width: 3rem;
    height: 3rem;
    border-radius: var(--radius-full);
    border: 1px solid var(--color-border);
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}

.theme-toggle-inline:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
    transform: scale(1.05);
}

.settings-close {
    width: 2.75rem; 
    height: 2.75rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}

.settings-close:hover {
    background: var(--color-danger);
    color: white;
    border-color: var(--color-danger);
}

.btn-reset {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xl);
}

.btn-reset:hover {
    background: var(--color-danger);
    color: white;
    border-color: var(--color-danger);
}

/* --- Progress Bar --- */
.progress-container {
    width: 100%;
    max-width: 600px;
    margin-top: var(--spacing-xl);
    height: 10px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
    border: 1px solid var(--color-border);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    border-radius: var(--radius-full);
    transition: width 0.3s ease-out;
}

/* --- History Section --- */
.history-section {
    max-width: 900px;
    margin: var(--spacing-3xl) auto;
    padding: var(--spacing-xl);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}
.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
}
.history-header h2 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-primary);
}
.history-actions {
    display: flex;
    gap: var(--spacing-sm);
}
.history-chart-container {
    height: 200px;
    margin-bottom: var(--spacing-xl);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}
.history-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}
.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
}
.history-item-data span {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text-primary);
    margin-right: var(--spacing-md);
}
.history-item-time {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

/* --- PWA Update Banner --- */
.update-banner {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 16px 24px;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    z-index: 10000;
    display: flex;
    align-items: center;
    gap: 16px;
    max-width: 90%;
    animation: slideDown 0.3s ease-out;
}
.update-banner span {
    flex: 1;
    font-weight: 500;
}
.update-banner button {
    background: white;
    color: #667eea;
    border: none;
    padding: 8px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}
.update-banner button:hover {
    transform: scale(1.05);
}
.update-banner button#dismiss-btn {
    background: transparent;
    color: white;
    border: 2px solid white;
}

@keyframes slideDown {
    from { transform: translateX(-50%) translateY(-20px); opacity: 0; }
    to { transform: translateX(-50%) translateY(0); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
    .update-banner {
        animation: none;
    }
}

.history-privacy-notice {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    margin-top: 16px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
}

.history-privacy-notice i {
    flex-shrink: 0;
    color: var(--color-success);
    width: 16px;
    height: 16px;
}


.matrix-number,
.metric-value,
.history-value {
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
}


.learn-link-tooltip {
    position: relative;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    color: var(--color-accent);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s ease;
}

.learn-link-tooltip:hover {
    color: var(--color-primary);
}

.learn-link-tooltip i {
    width: 16px;
    height: 16px;
}


.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width 0.6s ease, height 0.6s ease;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

.btn:not(:disabled):hover {
    transform: translateY(-1px);
}

.btn:not(:disabled):active {
    transform: translateY(0);
}

/* =========================================
/* =========================================
   VARIANCE GRAPH - LEGACY (Removed, replaced by Stage Speed Curve)
   ========================================= */

/* =========================================
   QUALITY BADGES FOR LATENCY/JITTER
   ========================================= */
.quality-badge-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    width: fit-content;
}

.quality-label {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text-primary);
}

.latency-context {
    margin-top: var(--spacing-sm);
}

.context-list {
    list-style: none;
    padding: 0;
    margin: var(--spacing-xs) 0 0 0;
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

.context-list li {
    padding-left: var(--spacing-md);
    position: relative;
}

.context-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-success);
}

/* =========================================
   FOOTER ACCORDION
   ========================================= */
.footer-accordion {
    margin: var(--spacing-2xl) 0;
}

.accordion-intro {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    padding: 0 var(--spacing-lg);
}

.accordion-intro h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.accordion-intro p {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.accordion-item {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    background: var(--color-bg-elevated);
    transition: box-shadow var(--transition-base);
}

.accordion-item:hover {
    box-shadow: var(--shadow-md);
}

.accordion-header {
    width: 100%;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    background: transparent;
    border: none;
    cursor: pointer;
    text-align: left;
    transition: background-color var(--transition-base);
}

.accordion-header:hover {
    background: var(--color-bg-secondary);
}

.accordion-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    background: var(--color-bg-secondary);
    color: var(--color-primary);
    flex-shrink: 0;
}

.accordion-icon i {
    width: 1rem;
    height: 1rem;
}

.accordion-title {
    flex: 1;
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text-primary);
}

.accordion-chevron {
    color: var(--color-text-tertiary);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.accordion-header[aria-expanded="true"] .accordion-chevron {
    transform: rotate(180deg);
}

.accordion-content {
    padding: 0 var(--spacing-lg) var(--spacing-lg) var(--spacing-lg);
    color: var(--color-text-secondary);
    line-height: 1.6;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                opacity 0.3s ease-out,
                padding 0.3s ease-out;
}

.accordion-content:not([hidden]) {
    max-height: 1000px;
    opacity: 1;
    padding: 0 var(--spacing-lg) var(--spacing-lg) var(--spacing-lg);
}

.accordion-content p {
    margin-bottom: var(--spacing-md);
}

.accordion-content p:last-child {
    margin-bottom: 0;
}

.accordion-content ul {
    margin: var(--spacing-sm) 0;
    padding-left: var(--spacing-xl);
}

.accordion-content li {
    margin-bottom: var(--spacing-sm);
}

.accordion-content strong {
    color: var(--color-text-primary);
    font-weight: 600;
}

/* --- Why Amsterdam Banner --- */
.why-amsterdam-banner {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin: var(--spacing-3xl) 0;
    border: 1px solid var(--color-border);
}

.banner-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.banner-icon {
    color: var(--color-primary);
    font-size: 2rem;
}

.banner-icon i {
    width: 2.5rem;
    height: 2.5rem;
}

.banner-text h3 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.banner-text p {
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-secondary);
}

.banner-text strong {
    color: var(--color-text-primary);
    font-weight: 600;
}

.banner-cta {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--color-primary);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-full);
    font-size: var(--font-size-base);
    font-weight: 600;
    transition: transform var(--transition-fast), background-color var(--transition-fast);
    align-self: flex-start;
    margin-top: var(--spacing-sm);
}

.banner-cta:hover {
    background: var(--color-primary-hover);
    transform: translateY(-2px);
}

.banner-cta i {
    width: 1.25rem;
    height: 1.25rem;
}

@media (max-width: 768px) {
    .why-amsterdam-banner {
        padding: var(--spacing-xl);
        margin: var(--spacing-xl) 0;
    }
    
    .banner-text h3 {
        font-size: var(--font-size-xl);
    }
    
    .banner-text p {
        font-size: var(--font-size-sm);
    }
}

/* --- Matrix Context --- */
.matrix-context {
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
    margin-top: var(--spacing-xs);
    font-weight: 500;
}

/* --- Config Summary --- */
.config-summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    margin-bottom: var(--spacing-md);
}

.config-summary-text {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.config-summary-text strong {
    color: var(--color-text-primary);
    font-weight: 600;
}

.config-summary[hidden] {
    display: none;
}

@media (max-width: 768px) {
    .config-summary {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-sm);
    }
}

/* --- Status Bar --- */
.status-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--color-info);
    color: white;
    z-index: var(--z-header, 30);
    transform: translateY(-100%);
    transition: transform var(--transition-base);
}

.status-bar:not([hidden]) {
    transform: translateY(0);
}

.status-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    max-width: 1400px;
    margin: 0 auto;
}

.status-icon {
    width: 1.25rem;
    height: 1.25rem;
    flex-shrink: 0;
}

.status-text {
    font-size: var(--font-size-sm);
    font-weight: 500;
}

/* --- Footer Elements --- */
.footer-note {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin: var(--spacing-2xl) 0;
}

.footer-note p {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin: 0;
}

.footer-note i {
    color: var(--color-warning);
    flex-shrink: 0;
    margin-top: 0.125rem;
}

.footer-copyright {
    text-align: center;
    padding: var(--spacing-xl) 0;
    border-top: 1px solid var(--color-border);
    margin-top: var(--spacing-2xl);
}

.footer-copyright p {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin: 0;
}

/* --- Server Info --- */
.server-info {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-md) 0;
    margin-bottom: var(--spacing-xl);
}

.server-info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.info-icon {
    width: 1rem;
    height: 1rem;
    color: var(--color-text-tertiary);
}

.server-info[hidden] {
    display: none;
}

/* --- Modal Elements --- */
.shortcut-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.shortcut-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
}

.shortcut-item span {
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
}

.shortcut-item kbd {
    padding: 0.25rem 0.5rem;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--color-text-primary);
    box-shadow: 0 1px 0 var(--color-border-strong);
}

.share-options {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.share-option-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
    text-align: left;
    width: 100%;
}

.share-option-btn:hover {
    background: var(--color-bg-elevated);
    border-color: var(--color-border-strong);
    transform: translateX(4px);
}

.share-option-btn i {
    width: 1.5rem;
    height: 1.5rem;
    color: var(--color-primary);
    flex-shrink: 0;
}

.share-option-btn span {
    font-size: var(--font-size-base);
    font-weight: 500;
    color: var(--color-text-primary);
}

@media (min-width: 769px) and (max-width: 1024px) {
    .results-tray {
        gap: var(--spacing-md);
    }
    
    .active-stage {
        height: clamp(400px, 55vh, 550px);
    }
}


@media (min-width: 1440px) {
    .active-stage {
        max-width: 1600px;
        margin-left: auto;
        margin-right: auto;
    }
    
    .results-tray {
        max-width: 1600px;
        margin-left: auto;
        margin-right: auto;
    }
}


@media (prefers-reduced-motion: reduce) {
    .stage-graph,
    .live-status,
    .tray-card {
        transition: none;
    }
    
    .tray-card:hover {
        transform: none;
    }
}
.gauge-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-2xl) var(--spacing-xl);
}


.gauge-container-split {
    position: relative;
    width: 100%;
    background: transparent;
    border: none;
    box-shadow: none;
}

.gauge-wrapper,
.gauge-container-split {
    position: relative;
    width: 100%;
    max-width: 240px;
    aspect-ratio: 1 / 1;
    background: transparent;
    border: none;
    box-shadow: none;
}.gauge-circle {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: conic-gradient(
        from -135deg,
        transparent 0deg,
        var(--color-border) 0deg,
        var(--color-border) 270deg,
        transparent 270deg
    );
    mask: radial-gradient(circle, transparent 0%, transparent 55%, black 55%, black 100%);
    -webkit-mask: radial-gradient(circle, transparent 0%, transparent 55%, black 55%, black 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.gauge-circle[hidden] {
    pointer-events: none;
}

.gauge-progress {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    z-index: 1;
    background: conic-gradient(
        from -135deg,
        transparent 0deg,
        #3b82f6 0deg,
        #8b5cf6 135deg,
        #ec4899 270deg,
        transparent 270deg
    );
    mask: radial-gradient(circle, transparent 0%, transparent 55%, black 55%, black 100%);
    -webkit-mask: radial-gradient(circle, transparent 0%, transparent 55%, black 55%, black 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
    will-change: opacity, background;
    transform: translateZ(0);
}

.gauge-inner {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 65%;
    height: 65%;
    border-radius: 50%;
    background: var(--color-bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    z-index: 2;
    box-shadow: none;
}

.gauge-inner[hidden] {
    pointer-events: none;
}

.gauge-value-live {
    font-size: clamp(2rem, 6vw, 3rem); 
    font-weight: 300;
    letter-spacing: -0.03em;
    color: var(--color-text-primary);
    font-variant-numeric: tabular-nums;
    line-height: 1;
    margin-bottom: var(--spacing-xs);
}

@keyframes softPulse {
    0% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.7); }
    70% { box-shadow: 0 0 0 15px rgba(59, 130, 246, 0); }
    100% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0); }
}



.gauge-start-button:focus-visible {
    outline: 4px solid var(--color-primary);
    outline-offset: 4px;
    box-shadow: var(--shadow-xl), 0 0 0 8px rgba(59, 130, 246, 0.3);
}

.start-button-subtitle {
    font-size: var(--font-size-sm);
    font-weight: 400;
    opacity: 0.9;
    letter-spacing: normal;
}

.test-timer {
    display: none !important;
}

.start-button-subtitle {
    font-size: var(--font-size-xs);
    font-weight: 400;
    opacity: 0.9;
    letter-spacing: 0.02em;
}

.test-timer {
    text-align: center;
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.test-timer strong {
    color: var(--color-primary);
    font-weight: 600;
}

.history-section {
    margin-bottom: var(--spacing-2xl);
}

.history-chart-container {
    width: 100%;
    height: 250px;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

canvas#historyChart {
    width: 100%;
    height: 100%;
    display: block;
}


.test-context-panel {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
}

.test-context-panel h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.context-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin: 0;
}

.context-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
}

.context-item:last-child {
    border-bottom: none;
}

.context-item dt {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.context-item dt i {
    width: 16px;
    height: 16px;
    color: var(--color-primary);
}

.context-item dd {
    font-weight: 600;
    color: var(--color-text-primary);
    font-variant-numeric: tabular-nums;
    text-align: right;
}

.context-learn-prompt {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-primary);
}

.context-learn-prompt p {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin: 0 0 var(--spacing-sm) 0;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.context-learn-prompt p i {
    width: 18px;
    height: 18px;
    color: var(--color-primary);
}

.learn-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary);
    font-weight: 600;
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: gap var(--transition-fast);
}

.learn-link:hover {
    gap: var(--spacing-sm);
}


.modal {
    position: fixed;
    inset: 0;
    z-index: 3000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: var(--color-bg-overlay);
    backdrop-filter: blur(4px);
    animation: fadeIn 0.2s ease;
}

.modal-content {
    position: relative;
    background: var(--color-bg-elevated);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    max-width: 600px;
    width: 100%;
    max-height: 80vh;
    overflow: hidden;
    animation: slideUp 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.modal-header h3 {
    margin: 0;
    font-size: var(--font-size-xl);
}

.modal-close {
    width: 2.5rem;
    height: 2.5rem;
    border: none;
    background: transparent;
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

.modal-close:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

.modal-body {
    padding: var(--spacing-lg);
    overflow-y: auto;
    max-height: calc(80vh - 80px);
}

.measurement-detail {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
}

.measurement-detail:last-child {
    border-bottom: none;
}

.measurement-detail h4 {
    margin: 0 0 var(--spacing-sm) 0;
    font-size: var(--font-size-base);
    color: var(--color-text-primary);
}

.measurement-detail dl {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-xs) var(--spacing-lg);
    margin: 0;
    font-size: var(--font-size-sm);
}

.measurement-detail dt {
    color: var(--color-text-secondary);
    font-weight: 500;
}

.measurement-detail dd {
    color: var(--color-text-primary);
    font-weight: 600;
    text-align: right;
    font-variant-numeric: tabular-nums;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes countUp {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}


.skeleton {
    background: linear-gradient(
        90deg,
        var(--bg-secondary) 25%,
        var(--bg-tertiary) 50%,
        var(--bg-secondary) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: 4px;
}

@keyframes shimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.skeleton-text {
    height: 16px;
    margin-bottom: 8px;
}

.skeleton-number {
    height: 48px;
    width: 120px;
}


.counting {
    animation: countUp 0.3s ease;
}


.tooltip {
    position: absolute;
    background: var(--bg-primary);
    color: var(--text-primary);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 0.75rem;
    white-space: nowrap;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    border: 1px solid var(--border-color);
    z-index: 1000;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.tooltip.visible {
    opacity: 1;
}

.tooltip::before {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
    width: 8px;
    height: 8px;
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

@media (max-width: 768px) {
    .test-context-panel {
        padding: var(--spacing-md);
    }
    
    .modal-content {
        max-height: 90vh;
        margin: var(--spacing-md);
    }
    
    .context-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }
    
    .context-item dd {
        text-align: left;
    }
}

.history-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: transform var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

.history-item:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.sparkline-container {
    margin-top: 8px;
    height: 30px;
    width: 100%;
    opacity: 0.5;
    transition: opacity 0.3s ease;
}

.matrix-card:hover .sparkline-container {
    opacity: 1;
}

.sparkline-path {
    vector-effect: non-scaling-stroke;
    stroke: var(--color-primary);
    fill: none;
}

.matrix-card::before {
    content: '';
    position: absolute;
    inset: -3px;
    border-radius: var(--radius-xl);
    background: conic-gradient(
        from -90deg,
        var(--color-primary) calc(var(--progress) * 1%),
        transparent calc(var(--progress) * 1%)
    );
    -webkit-mask: linear-gradient(black 0 0) content-box, linear-gradient(black 0 0);
    -webkit-mask-composite: xor;
    mask: linear-gradient(black 0 0) content-box, linear-gradient(black 0 0);
    mask-composite: exclude;
    padding: 3px;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s, background 0.1s ease-out;
    z-index: -1; 
}

.matrix-card[data-status="measuring"]::before {
    opacity: 1;
}

.progress-bar {
    height: 8px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    overflow: hidden;
    margin-bottom: var(--spacing-lg);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    border-radius: var(--radius-full);
    transition: width var(--transition-base);
    width: 0%;
}

.phase-dot {
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: var(--color-border-strong);
    transition: transform var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}

.phase[data-status="active"] .phase-dot {
    background: var(--color-primary);
    box-shadow: 0 0 0 4px var(--color-primary-glow);
    animation: pulse 2s infinite;
}

.phase[data-status="complete"] .phase-dot {
    background: var(--color-success);
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}


@media (max-width: 600px) {
    .gauge-container {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .gauge-wrapper {
        max-width: 260px;
    }
    
    .gauge-value-live {
        font-size: clamp(2.5rem, 10vw, 4rem);
    }
    
    .gauge-unit {
        font-size: var(--font-size-lg);
    }
    
    .gauge-phase-label {
        font-size: var(--font-size-sm);
    }
    
    
    .progress-phases {
        gap: var(--spacing-md);
    }
    
    .phase-label {
        font-size: var(--font-size-sm);
    }
}
}

@keyframes countUp {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.counting {
    animation: countUp 0.3s ease;
}


@keyframes shimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.skeleton {
    background: linear-gradient(
        90deg,
        var(--color-bg-secondary) 25%,
        var(--color-bg-elevated) 50%,
        var(--color-bg-secondary) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-md);
}

.skeleton-text {
    height: 16px;
    margin-bottom: 8px;
}

.skeleton-number {
    height: 48px;
    width: 120px;
}


.tooltip {
    position: absolute;
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    padding: 8px 12px;
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    white-space: nowrap;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
    z-index: 1000;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.tooltip.visible {
    opacity: 1;
}

.tooltip::before {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
    width: 8px;
    height: 8px;
    background: var(--color-bg-primary);
    border-right: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}


@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}


.history-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-bottom: 24px;
}

.history-stat-card {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 16px;
    text-align: center;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-primary);
    font-variant-numeric: tabular-nums;
}

.stat-unit {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--color-text-secondary);
}
/* ========================================
   PAGE-SPECIFIC STYLES
   ======================================== */

/* --- Learn Layout with Sidebar --- */
.learn-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 3rem;
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    align-items: start;
}

.learn-sidebar {
    position: sticky;
    top: 2rem;
    height: fit-content;
    max-height: calc(100dvh - 4rem);
    overflow-y: auto;
    overflow-x: hidden;
}

.sidebar-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.sidebar-section {
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--color-border);
}

.sidebar-section:last-child {
    border-bottom: none;
}

.sidebar-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-tertiary);
    margin-bottom: 1rem;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.625rem 0.875rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    border-radius: var(--radius-md);
    transition: transform 0.2s ease, opacity 0.2s ease, background 0.2s ease;
    border-left: 2px solid transparent;
}

.sidebar-link:hover {
    color: var(--color-primary);
    background: var(--color-bg-secondary);
    border-left-color: var(--color-primary);
    padding-left: 1.125rem;
}

.sidebar-link.active {
    color: var(--color-primary);
    background: var(--color-bg-secondary);
    font-weight: 600;
    border-left-color: var(--color-primary);
}

.sidebar-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.toc-nav-sidebar {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toc-link {
    display: block;
    padding: 0.5rem 0.75rem;
    color: var(--color-text-tertiary);
    text-decoration: none;
    font-size: 0.875rem;
    border-left: 2px solid transparent;
    transition: transform 0.2s ease, opacity 0.2s ease, background 0.2s ease;
}

.toc-link:hover,
.toc-link.active {
    color: var(--color-primary);
    border-left-color: var(--color-primary);
    padding-left: 1rem;
}

.sidebar-back {
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
}


.learn-article {
    max-width: 800px;
    padding: 0;
}

.learn-article .article-header {
    text-align: left;
    margin-bottom: 3rem;
    padding-bottom: 2rem;
}

.learn-article .article-header h1 {
    text-align: left;
    background: none;
    -webkit-text-fill-color: unset;
    color: var(--color-text-primary);
}

.article-meta-bar {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--color-border);
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
}

.meta-item i {
    width: 16px;
    height: 16px;
}


.article-navigation {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.nav-card {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding: 1.5rem;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    transition: transform 0.25s ease, opacity 0.25s ease, background 0.25s ease;
}

.nav-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.nav-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-tertiary);
    font-weight: 600;
}

.nav-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.nav-next {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05), rgba(139, 92, 246, 0.05));
    border-color: var(--color-primary);
}

.nav-next .nav-label {
    color: var(--color-primary);
}


@media (max-width: 1024px) {
    .learn-layout {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .learn-sidebar {
        position: static;
        max-height: none;
        order: 2;
        margin-top: 3rem;
        padding-top: 3rem;
        border-top: 2px solid var(--color-border);
    }
    
    .learn-article {
        order: 1;
    }
}

/* --- Table of Contents --- */
.toc-nav {
    position: sticky;
    top: 2rem;
    height: fit-content;
    margin-bottom: 2rem;
    z-index: 10;
}

.toc-content {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(8px);
}

.toc-content h2 {
    font-size: 1rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
    color: var(--color-text-tertiary);
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-list li {
    margin-bottom: 0.25rem;
}

.toc-list a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    padding: 0.5rem 0.75rem;
    display: block;
    border-radius: var(--radius-md);
    transition: transform var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
    border-left: 2px solid transparent;
}

.toc-list a:hover {
    color: var(--color-primary);
    background: var(--color-bg-secondary);
    border-left-color: var(--color-primary);
    padding-left: 1rem;
}

.toc-list a:focus-visible {
    outline: none;
    box-shadow: 0 0 0 3px var(--color-primary-glow);
}


@media (max-width: 768px) {
    .toc-nav {
        position: static;
        margin-bottom: 2rem;
    }
    
    .toc-content {
        padding: 1.25rem;
        background: var(--color-bg-secondary);
    }
    
    .article-content {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* --- Learn Page (Article Layout) --- */
body.page-learn {
    background: var(--color-bg-primary);
    scroll-behavior: smooth;
}

.learn-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0;
}

.article-intro {
    max-width: 900px;
    margin: 0 auto;
}

.lead-paragraph {
    font-size: 1.35rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
    font-weight: 400;
    margin-bottom: 3rem;
}


.article-links-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin: 2rem 0;
}

.article-link-card {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 1.75rem;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    color: inherit;
    transition: transform 0.25s ease, opacity 0.25s ease, background 0.25s ease;
}

.article-link-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
    background: var(--color-bg-secondary);
}

.article-link-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
}

.article-link-content {
    flex: 1;
}

.article-link-content h3 {
    margin: 0 0 0.5rem 0;
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.article-link-content p {
    margin: 0 0 0.75rem 0;
    color: var(--color-text-secondary);
    font-size: 1rem;
    line-height: 1.6;
}

.article-meta {
    display: inline-block;
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
    font-weight: 500;
}


.callout-info {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05), rgba(139, 92, 246, 0.05));
    border-left-color: var(--color-primary);
}

.callout-info h3 {
    color: var(--color-primary);
}


.learn-cta {
    text-align: center;
    margin: 5rem auto 4rem;
    padding: 3rem 1.5rem;
    border-top: 1px solid var(--color-border);
}

.btn-lg {
    padding: 1rem 2.5rem;
    font-size: 1.125rem;
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
}

.article-content {
    max-width: 800px; 
    margin: 0 auto;
    padding: 4rem 1.5rem;
}

.article-header {
    text-align: center;
    margin-bottom: 5rem;
    padding-bottom: 3rem;
    border-bottom: 1px solid var(--color-border);
}

.article-header h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: var(--color-primary);
    letter-spacing: -0.02em;
}

.article-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    max-width: 650px;
    margin: 0 auto;
    line-height: 1.6;
}

.article-body {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text-primary);
}

.article-section {
    margin-bottom: 4rem;
}

.article-section h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-top: 0;
    margin-bottom: 1.5rem;
    color: var(--color-text-primary);
    letter-spacing: -0.01em;
    position: relative;
    display: inline-block;
}

.article-section h2::after {
    content: '';
    display: block;
    width: 40%;
    height: 4px;
    background: var(--color-primary);
    margin-top: 0.5rem;
    border-radius: 2px;
    opacity: 0.3;
}

.article-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    color: var(--color-text-primary);
}

.article-body p {
    margin-bottom: 1.5rem;
    color: var(--color-text-secondary);
}

.article-body ul {
    margin: 1.5rem 0;
    padding-left: 1.5rem;
}

.article-body li {
    margin-bottom: 0.75rem;
    position: relative;
    padding-left: 0.5rem;
}

.article-body li::marker {
    color: var(--color-primary);
}

.article-body strong {
    font-weight: 600;
    color: var(--color-text-primary);
}

.callout-box {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-primary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    margin: 3rem 0;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.callout-box::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--color-primary-glow) 0%, transparent 100%);
    opacity: 0.1;
    pointer-events: none;
}

.callout-box h3 {
    margin-top: 0;
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.article-footer {
    margin-top: 6rem;
    padding-top: 3rem;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

/* --- 404 Page --- */
.page-404 {
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    text-align: center;
    background: var(--color-bg-secondary);
}

.page-404 .error-code {
    font-size: clamp(8rem, 20vw, 12rem);
    font-weight: 900;
    line-height: 1;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: var(--color-primary);
    margin-bottom: 1rem;
    opacity: 0.9;
}

.page-404 h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--color-text-primary);
}

.page-404 p {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: 2rem;
    max-width: 500px;
}

@media (max-width: 768px) {
    .article-content {
        padding: 3rem 1.25rem;
    }
    
    .article-header h1 {
        font-size: 2.5rem;
    }
    
    .callout-box {
        padding: 1.5rem;
    }
    
    .article-links-list {
        gap: 1rem;
    }
    
    .article-link-card {
        flex-direction: column;
        padding: 1.5rem;
    }
    
    .article-link-icon {
        width: 50px;
        height: 50px;
        font-size: 2rem;
    }
    
    .lead-paragraph {
        font-size: 1.125rem;
    }
}

/* --- Data Tables --- */
.data-table-wrapper {
    overflow-x: auto;
    margin: 2rem 0;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    background: var(--color-bg-elevated);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.data-table thead {
    background: linear-gradient(135deg, 
        var(--color-primary-dim) 0%, 
        var(--color-accent-dim) 100%);
    color: var(--color-text-primary);
}

.data-table th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 2px solid var(--color-primary);
}

.data-table tbody tr {
    border-bottom: 1px solid var(--color-border);
    transition: background-color var(--transition-base);
}

.data-table tbody tr:hover {
    background: var(--color-bg-secondary);
}

.data-table tbody tr:last-child {
    border-bottom: none;
}

.data-table td {
    padding: 0.875rem 1rem;
    color: var(--color-text-primary);
}

.data-table td:first-child {
    font-weight: 500;
}

.data-table td:nth-child(2),
.data-table td:nth-child(3) {
    font-family: 'Courier New', monospace;
    color: var(--color-accent);
    font-weight: 600;
}

.data-table td:last-child {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}


.conversion-table tbody tr:nth-child(4) {
    background: var(--color-primary-dim);
    font-weight: 600;
}

.conversion-table tbody tr:nth-child(7) {
    background: var(--color-accent-dim);
    font-weight: 600;
}


.conversion-callout {
    text-align: center;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.conversion-formula {
    font-size: 1.1rem;
    line-height: 1.8;
}

.conversion-formula strong {
    font-size: 1.3rem;
    color: var(--color-primary);
    display: block;
    margin-bottom: 0.5rem;
}


@media (max-width: 768px) {
    .data-table {
        font-size: 0.85rem;
    }
    
    .data-table th,
    .data-table td {
        padding: 0.75rem 0.5rem;
    }
    
    .data-table th {
        font-size: 0.8rem;
    }
}

@media (max-width: 600px) {
    .data-table thead {
        display: none;
    }
    
    .data-table tbody tr {
        display: block;
        margin-bottom: 1rem;
        border: 1px solid var(--color-border);
        border-radius: var(--radius-md);
    }
    
    .data-table td {
        display: flex;
        justify-content: space-between;
        padding: 0.75rem 1rem;
        border-bottom: 1px solid var(--color-border-subtle);
    }
    
    .data-table td:last-child {
        border-bottom: none;
    }
}
/* ========================================
   UTILITIES
   ======================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

[hidden] {
    display: none !important;
}


.performance-warning {
    position: fixed;
    top: 20px;
    right: 20px;
    background: rgba(255, 152, 0, 0.95);
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 0.875rem;
    z-index: var(--z-modal, 100);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    animation: slideInRight 0.3s ease;
}

.performance-warning.hiding {
    animation: slideOutRight 0.3s ease;
}

@keyframes slideInRight {
    from { transform: translateX(400px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes slideOutRight {
    from { transform: translateX(0); opacity: 1; }
    to { transform: translateX(400px); opacity: 0; }
}


.app-container-loading {
    opacity: 0;
    transition: opacity 0.3s;
}


.hidden-display {
    display: none;
}


.share-btn-positioned {
    margin-left: auto;
}

/* PWA Update Banner */
.update-banner-wrapper {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 16px 24px;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    z-index: 10000;
    display: flex;
    align-items: center;
    gap: 16px;
    max-width: 90%;
    animation: slideDown 0.3s ease-out;
}

.update-banner-message {
    flex: 1;
    font-weight: 500;
}

.update-banner-btn-primary {
    background: white;
    color: #667eea;
    border: none;
    padding: 8px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

.update-banner-btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
    padding: 8px 16px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}