/* CSS Custom Properties */
:root {
    /* Colors */
    --color-primary: #0ea5e9;
    --color-primary-dark: #0284c7;
    --color-primary-light: #38bdf8;
    --color-success: #22c55e;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --color-danger-dark: #dc2626;

    /* Neutrals */
    --color-bg: #0f172a;
    --color-bg-light: #1e293b;
    --color-bg-lighter: #334155;
    --color-text: #f1f5f9;
    --color-text-muted: #94a3b8;
    --color-text-dim: #64748b;
    --color-border: #475569;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --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: 2rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.3);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;

    /* Layout */
    --sidebar-width: 420px;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    height: 100%;
    overflow: hidden;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
}

/* App Container */
.app-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Video Section */
.video-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    background: var(--color-bg);
    min-width: 0;
    overflow: hidden;
}

.video-wrapper {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #000;
    overflow: hidden;
}

.video-wrapper video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transform: scaleX(-1);
}

.video-wrapper canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

/* Detection Overlay */
.detection-overlay {
    position: absolute;
    top: var(--space-md);
    left: var(--space-md);
    z-index: 10;
}

.detection-status {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(8px);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity var(--transition-base), transform var(--transition-base);
}

.detection-status.visible {
    opacity: 1;
    transform: translateY(0);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-success);
    animation: pulse-dot 2s ease-in-out infinite;
}

.detection-status.warning .status-dot {
    background: var(--color-warning);
}

.detection-status.danger .status-dot {
    background: var(--color-danger);
    animation: pulse-dot-danger 0.5s ease-in-out infinite;
}

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

@keyframes pulse-dot-danger {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.3); }
}

/* Alert Flash */
.alert-flash {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at center, transparent 0%, rgba(239, 68, 68, 0.3) 100%);
    pointer-events: none;
    opacity: 0;
    transition: opacity 100ms ease;
    z-index: 5;
}

.alert-flash.active {
    opacity: 1;
    animation: flash-pulse 400ms ease-out;
}

@keyframes flash-pulse {
    0% { opacity: 1; }
    100% { opacity: 0; }
}

/* Welcome Content */
.welcome-content {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
    text-align: center;
    z-index: 20;
    overflow-y: auto;
}

.welcome-content.hidden {
    display: none;
}

.welcome-content h1 {
    font-size: clamp(var(--font-size-xl), 4vw, var(--font-size-2xl));
    font-weight: 700;
    margin-bottom: var(--space-xs);
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    flex-shrink: 0;
}

.welcome-content .tagline {
    font-size: var(--font-size-base);
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
    flex-shrink: 0;
}

.features {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
    flex-wrap: wrap;
    justify-content: center;
    flex-shrink: 0;
}

.feature {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-bg-light);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 500;
}

.feature-icon {
    font-size: var(--font-size-base);
}

.welcome-content .description {
    max-width: 450px;
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
    line-height: 1.6;
    font-size: var(--font-size-sm);
    flex-shrink: 0;
}

.privacy-note {
    font-size: var(--font-size-xs);
    color: var(--color-text-dim);
    margin-top: var(--space-sm);
    flex-shrink: 0;
}

/* Loading State */
.loading-state {
    position: absolute;
    inset: 0;
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.95);
    z-index: 25;
}

.loading-state.visible {
    display: flex;
}

.loader-ring {
    width: 60px;
    height: 60px;
    border: 4px solid var(--color-bg-lighter);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--space-lg);
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-state p {
    font-size: var(--font-size-lg);
    font-weight: 500;
}

.loader-subtitle {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm) !important;
    font-weight: 400 !important;
    margin-top: var(--space-sm);
}

/* Dashboard Sidebar */
.dashboard {
    width: var(--sidebar-width);
    height: 100vh;
    max-height: 100vh;
    background: var(--color-bg-light);
    border-left: 1px solid var(--color-border);
    overflow-y: auto;
    overflow-x: hidden;
    flex-shrink: 0;
}

.dashboard-content {
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.dashboard-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.dashboard-header h2 {
    font-size: var(--font-size-lg);
    font-weight: 600;
}

.connection-status {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.connection-status .pulse {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-text-dim);
}

.connection-status.active .pulse {
    background: var(--color-success);
    animation: pulse-dot 2s ease-in-out infinite;
}

/* Stats Section */
.stats-section h3,
.controls-section h3 {
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-sm);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xs);
}

.stat-card {
    background: var(--color-bg);
    border-radius: var(--radius-md);
    padding: var(--space-sm);
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.stat-value {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-primary-light);
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

/* Controls */
.controls-section {
    border-top: 1px solid var(--color-border);
    padding-top: var(--space-md);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

/* Toggle Control */
.toggle-control {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    cursor: pointer;
    padding: var(--space-xs) 0;
}

.toggle-control input {
    display: none;
}

.toggle-slider {
    position: relative;
    width: 44px;
    height: 24px;
    background: var(--color-bg-lighter);
    border-radius: var(--radius-full);
    transition: background var(--transition-fast);
    flex-shrink: 0;
}

.toggle-slider::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: var(--color-text);
    border-radius: 50%;
    transition: transform var(--transition-fast);
}

.toggle-control input:checked + .toggle-slider {
    background: var(--color-primary);
}

.toggle-control input:checked + .toggle-slider::after {
    transform: translateX(20px);
}

.toggle-label {
    font-size: var(--font-size-sm);
    color: var(--color-text);
}

/* Section Hint */
.section-hint {
    font-size: var(--font-size-xs);
    color: var(--color-text-dim);
    margin-bottom: var(--space-sm);
}

/* Zone-specific toggle colors */
.zone-hint {
    font-size: var(--font-size-xs);
    color: var(--color-text-dim);
}

.toggle-control input:checked + .toggle-slider.zone-mouth {
    background: #ef4444;
}

.toggle-control input:checked + .toggle-slider.zone-nose {
    background: #f59e0b;
}

.toggle-control input:checked + .toggle-slider.zone-eyes {
    background: #0ea5e9;
}

.toggle-control input:checked + .toggle-slider.zone-cheeks {
    background: #8b5cf6;
}

.toggle-control input:checked + .toggle-slider.zone-chin {
    background: #22c55e;
}

/* Input Group */
.input-group {
    margin-top: var(--space-sm);
}

.input-group label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--space-sm);
}

.input-with-unit {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.input-with-unit input {
    width: 80px;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-size: var(--font-size-sm);
    font-family: inherit;
}

.input-with-unit input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.input-with-unit .unit {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

/* Slider Control */
.slider-control {
    padding: var(--space-xs) 0;
}

.slider-control input[type="range"] {
    width: 100%;
    height: 6px;
    background: var(--color-bg);
    border-radius: var(--radius-full);
    appearance: none;
    cursor: pointer;
}

.slider-control input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 18px;
    height: 18px;
    background: var(--color-primary);
    border-radius: 50%;
    cursor: grab;
    transition: transform var(--transition-fast);
}

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

.slider-control input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--color-primary);
    border-radius: 50%;
    border: none;
    cursor: grab;
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    margin-top: var(--space-sm);
    font-size: var(--font-size-xs);
    color: var(--color-text-dim);
}

.slider-labels span:nth-child(2) {
    color: var(--color-primary-light);
    font-weight: 600;
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-danger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-family: inherit;
    font-size: var(--font-size-base);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

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

.btn-secondary {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-bg-lighter);
}

.btn-danger {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    background: transparent;
    color: var(--color-danger);
    border: 1px solid var(--color-danger);
}

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

/* Actions Section */
.actions-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    margin-top: auto;
    padding-top: var(--space-sm);
    border-top: 1px solid var(--color-border);
}

/* Dashboard Footer */
.dashboard-footer {
    padding-top: var(--space-sm);
    border-top: 1px solid var(--color-border);
    font-size: var(--font-size-xs);
    color: var(--color-text-dim);
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    align-items: center;
}

.dashboard-footer p {
    margin: 0;
}

.dashboard-footer a {
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color var(--transition-fast);
}

/* GitHub Badge */
.github-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: var(--font-size-xs);
    font-weight: 500;
    color: var(--color-text-muted);
    transition: all var(--transition-fast);
}

.github-badge:hover {
    background: var(--color-bg-lighter);
    color: var(--color-text);
    border-color: var(--color-text-dim);
}

.github-badge svg {
    flex-shrink: 0;
}

.author-credit {
    font-size: var(--font-size-xs);
    color: var(--color-text-dim);
}

.author-credit a {
    color: var(--color-primary-light);
    font-weight: 500;
}

.author-credit a:hover {
    text-decoration: underline;
}

.dashboard-footer a:hover {
    color: var(--color-primary-light);
}

/* Responsive Design */
@media (max-width: 1200px) {
    :root {
        --sidebar-width: 360px;
    }
}

@media (max-width: 900px) {
    :root {
        --sidebar-width: 320px;
    }
}

@media (max-width: 768px) {
    html, body {
        overflow: auto;
    }

    .app-container {
        flex-direction: column;
        height: auto;
        min-height: 100vh;
    }

    .video-section {
        height: 50vh;
        min-height: 300px;
    }

    .video-wrapper {
        position: relative;
        height: 100%;
    }

    .dashboard {
        width: 100%;
        height: auto;
        border-left: none;
        border-top: 1px solid var(--color-border);
        overflow: visible;
    }

    .dashboard-content {
        min-height: auto;
    }

    .stats-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .stat-card {
        padding: var(--space-sm);
    }

    .stat-value {
        font-size: var(--font-size-lg);
    }

    .welcome-content {
        padding: var(--space-md);
    }

    .features {
        flex-direction: row;
        gap: var(--space-sm);
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .dashboard-content {
        padding: var(--space-md);
    }

    .btn-primary {
        width: 100%;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Styles */
button:focus-visible,
input:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Selection */
::selection {
    background: var(--color-primary);
    color: white;
}