/* ===== CSS Variables & Design Tokens - Nordic Silver White Theme ===== */
:root {
    /* Colors - Nordic Light Theme */
    --bg-primary: #f9f8f6;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e9ecef;
    --bg-card: rgba(255, 255, 255, 0.9);
    --bg-glass: rgba(0, 0, 0, 0.03);
    --bg-glass-hover: rgba(0, 0, 0, 0.06);

    /* Accent Colors - Soft Nordic */
    --accent-primary: #57534E;
    --accent-secondary: #6c8ea0;
    --accent-tertiary: #868e96;
    --accent-highlight: #339af0;

    /* Text Colors */
    --text-primary: #212529;
    --text-secondary: #495057;
    --text-tertiary: #6c757d;
    --text-muted: #adb5bd;

    /* Border Colors */
    --border-primary: rgba(0, 0, 0, 0.08);
    --border-secondary: rgba(0, 0, 0, 0.04);
    --border-accent: rgba(108, 142, 160, 0.3);

    /* Shadows - Subtle */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-glow: 0 0 0 3px rgba(108, 142, 160, 0.15);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius - Softer */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang TC', 'Noto Sans TC', 'Microsoft JhengHei', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;

    /* Z-index */
    --z-toolbar: 100;
    --z-overlay: 200;
    --z-modal: 300;
    --z-toast: 400;

    /* Layout */
    --toolbar-height: 64px;
    --grid-gap: 6px;
}

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

html {
    font-size: 16px;
}

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.5;
}

.toolbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--toolbar-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-primary);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-lg);
    z-index: var(--z-toolbar);
    transition: transform var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.toolbar.hidden {
    transform: translateY(-100%);
}

.toolbar-left,
.toolbar-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.toolbar-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

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

.logo-icon {
    width: 28px;
    height: 28px;
    color: var(--accent-tertiary);
}

.logo-text {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-glass);
    border-radius: var(--radius-full);
    border: 1px solid var(--border-primary);
}

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

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.5;
    }
}

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

.toolbar-btn {
    min-width: 44px;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-glass);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.toolbar-btn svg {
    width: 18px;
    height: 18px;
}

.toolbar-btn:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
}

.toolbar-btn.primary {
    background: var(--accent-primary);
    border-color: transparent;
    color: #ffffff;
}

.toolbar-btn.primary:hover {
    background: #44403c;
    box-shadow: var(--shadow-md);
}

.toolbar-btn.muted svg {
    opacity: 0.5;
}

.video-grid-container {
    padding-top: var(--toolbar-height);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(2, 1fr);
    gap: var(--grid-gap);
    width: 100%;
    height: calc(100vh - var(--toolbar-height));
    padding: var(--grid-gap);
}

.video-cell {
    position: relative;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.video-cell::before {
    content: '';
    position: absolute;
    inset: 0;
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-sm);
    pointer-events: none;
    z-index: 1;
}

.video-cell:hover::before {
    border-color: var(--accent-secondary);
}

.video-cell iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.video-cell.empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    cursor: pointer;
}

.video-cell.empty:hover {
    background: var(--bg-tertiary);
}

.empty-icon {
    width: 48px;
    height: 48px;
    color: var(--text-muted);
}

.video-cell.empty:hover .empty-icon {
    color: var(--accent-secondary);
}

.empty-text {
    font-size: var(--font-size-sm);
    /* 原用 --text-muted (#adb5bd) 在白底上對比度僅 2.07:1，未達 WCAG AA
       4.5:1 門檻；改用 --text-secondary 使其可正常閱讀（實測 8.18:1）。 */
    color: var(--text-secondary);
}

.video-number {
    position: absolute;
    top: var(--spacing-sm);
    left: var(--spacing-sm);
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.9);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--text-primary);
    z-index: 2;
    opacity: 0;
    transition: opacity var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.video-cell:hover .video-number {
    opacity: 1;
}

.expand-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    cursor: pointer;
    z-index: 2;
    opacity: 0;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.expand-btn svg {
    width: 16px;
    height: 16px;
}

.video-cell:hover .expand-btn {
    opacity: 1;
}

.expand-btn:hover {
    background: var(--accent-secondary);
    color: #ffffff;
}

/* Settings Panel */
.settings-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(8px);
    z-index: var(--z-overlay);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.settings-overlay.active {
    opacity: 1;
    visibility: visible;
}

.settings-panel {
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-primary);
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    transform: translateY(20px) scale(0.95);
    transition: transform var(--transition-normal);
    overflow: hidden;
}

.settings-overlay.active .settings-panel {
    transform: translateY(0) scale(1);
}

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

.settings-header h2 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-xl);
}

.settings-header h2 svg {
    width: 24px;
    height: 24px;
    color: var(--accent-secondary);
}

.close-btn {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-glass);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.close-btn svg {
    width: 18px;
    height: 18px;
}

.close-btn:hover {
    background: var(--bg-tertiary);
    color: var(--accent-primary);
}

.settings-content {
    flex: 1;
    padding: var(--spacing-lg);
    overflow-y: auto;
}

.settings-description {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

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

.video-input-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.video-input-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.video-input-label .number-badge {
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-secondary);
    color: #ffffff;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 600;
}

.video-input-wrapper {
    position: relative;
    display: flex;
    gap: var(--spacing-sm);
}

.video-input {
    flex: 1;
    padding: var(--spacing-md);
    padding-left: 44px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: var(--font-size-sm);
    font-family: inherit;
    transition: all var(--transition-fast);
}

.video-input::placeholder {
    color: var(--text-muted);
}

.video-input:focus {
    outline: none;
    border-color: var(--accent-secondary);
    box-shadow: 0 0 0 3px rgba(108, 142, 160, 0.15);
}

.input-icon {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    height: 18px;
    color: var(--text-muted);
    pointer-events: none;
}

.clear-input-btn {
    width: 44px;
    min-width: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-glass);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
}

.clear-input-btn svg {
    width: 16px;
    height: 16px;
}

.clear-input-btn:hover {
    background: var(--bg-tertiary);
    color: var(--accent-primary);
}

.settings-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xl);
    flex-wrap: wrap;
}

.action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.action-btn svg {
    width: 16px;
    height: 16px;
}

.action-btn.secondary {
    background: var(--bg-glass);
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
}

.action-btn.secondary:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
}

.action-btn.primary {
    flex: 1;
    background: var(--accent-primary);
    border: none;
    color: #ffffff;
}

.action-btn.primary:hover {
    background: #44403c;
    box-shadow: var(--shadow-md);
}

.settings-footer {
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-glass);
    border-top: 1px solid var(--border-primary);
}

.tip {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-xs);
    /* 原用 --text-muted 在 settings-footer 的實際合成背景上對比度僅 1.94:1，
       未達 WCAG AA 4.5:1 門檻；改用 --text-secondary（實測 ≈7.6:1）。 */
    color: var(--text-secondary);
}

.tip svg {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}

/* Expanded Overlay */
.expanded-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.95);
    z-index: var(--z-modal);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.expanded-overlay.active {
    opacity: 1;
    visibility: visible;
}

.expanded-close {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    color: var(--text-primary);
    cursor: pointer;
    z-index: 1;
    transition: all var(--transition-fast);
}

.expanded-close svg {
    width: 24px;
    height: 24px;
}

.expanded-close:hover {
    background: var(--accent-secondary);
    color: #ffffff;
}

.expanded-video {
    width: 100%;
    max-width: 1280px;
    aspect-ratio: 16 / 9;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.expanded-video iframe {
    width: 100%;
    height: 100%;
    border: none;
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    font-size: var(--font-size-sm);
    animation: slideUp 0.3s ease;
}

.toast.success {
    border-color: var(--accent-secondary);
}

.toast.success::before {
    content: '✓';
    color: var(--accent-secondary);
    font-weight: bold;
}

.toast.error {
    border-color: var(--accent-primary);
}

.toast.error::before {
    content: '✕';
    color: var(--accent-primary);
    font-weight: bold;
}

.toast.info {
    border-color: var(--accent-secondary);
}

.toast.info::before {
    content: 'ℹ';
    color: var(--accent-secondary);
    font-weight: bold;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 1024px) {
    .toolbar-center {
        display: none;
    }

    .btn-text {
        display: none;
    }

    .video-grid {
        grid-template-columns: repeat(2, 1fr);
        grid-template-rows: repeat(3, 1fr);
    }
}

@media (max-width: 900px) and (orientation: landscape) {
    :root {
        --toolbar-height: 48px;
    }

    .logo-text {
        display: none;
    }

    .video-grid {
        grid-template-columns: repeat(3, 1fr);
        grid-template-rows: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --toolbar-height: 56px;
        --grid-gap: 2px;
    }

    .logo-text {
        display: none;
    }

    .toolbar-btn {
        padding: var(--spacing-sm);
    }

    .btn-text {
        display: none;
    }

    /* 桌機／平板橫向刻意把 6 格塞滿單一螢幕高度（video-wall 免捲動）；
       但窄螢幕直向硬塞 6 列在固定高度內，會把每格壓成僅約 100~160px 高
       的細條（實測寬高比 3.7:1～4.8:1，遠非 16:9，等同看不清楚）。
       改為讓格子維持 16:9、grid 依內容自然增高，容器改直向捲動。 */
    .video-grid-container {
        align-items: flex-start;
    }

    .video-grid {
        grid-template-columns: 1fr;
        grid-template-rows: none;
        grid-auto-rows: auto;
        height: auto;
        min-height: calc(100vh - var(--toolbar-height));
    }

    .video-cell {
        aspect-ratio: 16 / 9;
    }

    .settings-panel {
        max-height: 100vh;
        border-radius: 0;
    }

    .settings-overlay {
        padding: 0;
    }
}

@media (max-width: 480px) {
    .settings-actions {
        flex-direction: column;
    }

    .action-btn.secondary {
        width: 100%;
    }
}

body.fullscreen-mode .toolbar {
    transform: translateY(-100%);
}

body.fullscreen-mode .video-grid-container {
    padding-top: 0;
}

body.fullscreen-mode .video-grid {
    height: 100vh;
}

body.fullscreen-mode:hover .toolbar {
    transform: translateY(0);
}

::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
}

:focus-visible {
    outline: 2px solid var(--accent-tertiary);
    outline-offset: 2px;
}

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