:root[data-theme="dark"] {
            --bg-base: #0f0f0f;
            --bg-sidebar: #0f0f0f;
            --bg-card: #1f1f1f;
            --bg-hover: #272727;
            --text-main: #f1f1f1;
            --text-sub: #aaaaaa;
            --border-color: #272727;
            --brand-red: #ff0000;
            --input-bg: #121212;
            --input-border: #303030;
            --chip-bg: #272727;
            --chip-active-bg: #f1f1f1;
            --chip-active-text: #0f0f0f;
            --card-glow-border: rgba(255, 255, 255, 0.18);
            --card-glow-shadow: rgba(0, 0, 0, 0.7);
        }

        :root[data-theme="light"] {
            --bg-base: #ffffff;
            --bg-sidebar: #ffffff;
            --bg-card: #f9f9f9;
            --bg-hover: #e5e5e5;
            --text-main: #0f0f0f;
            --text-sub: #606060;
            --border-color: #e5e5e5;
            --brand-red: #ff0000;
            --input-bg: #ffffff;
            --input-border: #ccc;
            --chip-bg: #0000000d;
            --chip-active-bg: #0f0f0f;
            --chip-active-text: #ffffff;
            --card-glow-border: rgba(0, 0, 0, 0.12);
            --card-glow-shadow: rgba(0, 0, 0, 0.12);
        }

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

        body {
            background-color: var(--bg-base);
            color: var(--text-main);
            font-family: "Roboto", "Arial", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
            font-size: 14px;
            min-height: 100vh;
            overflow-x: hidden;
            transition: background-color 0.3s, color 0.3s;
        }

        a {
            color: inherit;
            text-decoration: none;
        }

        /* 顶栏 Header */
        .yt-header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            height: 56px;
            background-color: var(--bg-base);
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 16px;
            z-index: 1000;
            border-bottom: 1px solid var(--border-color);
        }

        .header-left {
            display: flex;
            align-items: center;
            gap: 16px;
        }

        .menu-toggle {
            background: none;
            border: none;
            color: var(--text-main);
            font-size: 18px;
            cursor: pointer;
            padding: 8px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background-color 0.2s;
        }

        .menu-toggle:hover {
            background: var(--bg-hover);
        }

        .yt-logo {
            display: flex;
            align-items: center;
            gap: 6px;
            font-weight: 700;
            font-size: 18px;
            letter-spacing: -0.5px;
        }

        .yt-logo i {
            color: var(--brand-red);
            font-size: 24px;
        }

        .header-center {
            flex: 1;
            max-width: 640px;
            display: flex;
            align-items: center;
            margin: 0 20px;
        }

        .search-form {
            display: flex;
            width: 100%;
        }

        .search-input {
            width: 100%;
            height: 40px;
            padding: 0 16px;
            background-color: var(--input-bg);
            border: 1px solid var(--input-border);
            border-radius: 40px 0 0 40px;
            color: var(--text-main);
            font-size: 14px;
            outline: none;
            transition: border-color 0.2s;
        }

        .search-input:focus {
            border-color: #1c62b9;
        }

        .search-btn {
            width: 64px;
            height: 40px;
            background-color: var(--bg-hover);
            border: 1px solid var(--input-border);
            border-left: none;
            border-radius: 0 40px 40px 0;
            color: var(--text-main);
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 16px;
            transition: background-color 0.2s;
        }

        .search-btn:hover {
            background-color: var(--input-border);
        }

        .header-right {
            display: flex;
            align-items: center;
            gap: 10px;
        }

        /* 默认隐藏移动端专属搜索图标 (PC端隐形) */
        .mobile-search-btn {
            display: none;
        }

        .icon-btn {
            background: none;
            border: none;
            color: var(--text-main);
            font-size: 18px;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.2s;
        }

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

        .theme-toggle-btn {
            background: var(--bg-hover);
            border: 1px solid var(--border-color);
            color: var(--text-main);
            padding: 6px 14px;
            border-radius: 20px;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 6px;
            font-size: 13px;
            font-weight: 500;
            transition: background-color 0.2s, border-color 0.2s;
        }

        .theme-toggle-btn:hover {
            background-color: var(--input-border);
        }

        /* 侧边栏 Sidebar */
        .yt-sidebar {
            position: fixed;
            top: 56px;
            left: 0;
            bottom: 0;
            width: 240px;
            background-color: var(--bg-sidebar);
            padding: 12px 8px;
            overflow-y: auto;
            border-right: 1px solid var(--border-color);
            z-index: 900;
            transition: width 0.25s ease, transform 0.25s ease;
        }

        .sidebar-item {
            display: flex;
            align-items: center;
            gap: 24px;
            padding: 10px 12px;
            border-radius: 10px;
            color: var(--text-main);
            font-size: 14px;
            margin-bottom: 2px;
            white-space: nowrap;
            transition: background-color 0.2s;
        }

        .sidebar-item i {
            font-size: 18px;
            width: 24px;
            text-align: center;
            flex-shrink: 0;
        }

        .sidebar-item span {
            transition: opacity 0.2s;
        }

        .sidebar-item:hover {
            background-color: var(--bg-hover);
        }

        .sidebar-item.active {
            background-color: var(--bg-hover);
            font-weight: 600;
        }

        .sidebar-divider {
            height: 1px;
            background-color: var(--border-color);
            margin: 12px 0;
        }

        .sidebar-title {
            padding: 8px 12px;
            font-size: 13px;
            font-weight: 700;
            color: var(--text-sub);
            white-space: nowrap;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }

        .yt-sidebar.collapsed {
            width: 72px;
            padding: 8px 4px;
        }

        .yt-sidebar.collapsed .sidebar-item {
            flex-direction: column;
            gap: 6px;
            padding: 14px 0;
            justify-content: center;
            border-radius: 10px;
        }

        .yt-sidebar.collapsed .sidebar-item i {
            font-size: 20px;
            width: auto;
        }

        .yt-sidebar.collapsed .sidebar-item span {
            font-size: 10px;
            line-height: 1;
            font-weight: normal;
        }

        .yt-sidebar.collapsed .sidebar-divider,
        .yt-sidebar.collapsed .sidebar-title {
            display: none;
        }

        /* 主内容 Main */
        .yt-main {
            margin-top: 56px;
            margin-left: 240px;
            padding: 10px 12px 24px 12px;
            transition: margin-left 0.25s ease;
            display: flex;
            flex-direction: column;
            min-height: calc(100vh - 56px);
        }

        .yt-main.expanded {
            margin-left: 72px;
        }

        .chips-bar {
            display: flex;
            gap: 8px;
            overflow-x: auto;
            padding-bottom: 8px;
            margin-bottom: 12px;
            position: sticky;
            top: 56px;
            background-color: var(--bg-base);
            z-index: 800;
            scrollbar-width: none;
            scroll-behavior: smooth;
        }
        .chips-bar::-webkit-scrollbar { display: none; }

        .chip {
            padding: 6px 14px;
            background-color: var(--chip-bg);
            color: var(--text-main);
            border-radius: 8px;
            white-space: nowrap;
            font-size: 13px;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.2s ease;
            user-select: none;
        }

        .chip:hover {
            background-color: var(--bg-hover);
        }

        .chip.active {
            background-color: var(--chip-active-bg);
            color: var(--chip-active-text);
        }

        .tab-panel {
            display: none;
            flex: 1;
        }

        .tab-panel.active {
            display: block;
        }

        .video-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 10px 8px;
        }

        .video-card {
            display: flex;
            flex-direction: column;
            cursor: pointer;
            padding: 4px;
            border-radius: 10px;
            border: 1px solid transparent;
            background-color: transparent;
            transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1),
                        border-color 0.25s ease,
                        background-color 0.25s ease,
                        box-shadow 0.25s ease;
            will-change: transform, box-shadow, border-color;
        }

        .video-card:hover {
            transform: scale(1.025);
            background-color: var(--bg-card);
            border-color: var(--card-glow-border);
            box-shadow: 0 6px 18px var(--card-glow-shadow);
            z-index: 10;
        }

        .thumbnail-box {
            position: relative;
            width: 100%;
            aspect-ratio: 16 / 9;
            border-radius: 8px;
            overflow: hidden;
            background-color: var(--bg-card);
            display: block;
        }

        .thumbnail-img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.35s ease, opacity 0.25s ease;
        }

        .video-card:hover .thumbnail-img {
            transform: scale(1.04);
        }

        .preview-layer {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            opacity: 0;
            display: none;
            pointer-events: none;
            transition: opacity 0.25s ease;
            background: #000;
        }

        .preview-layer video {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .video-card:hover .preview-layer {
            opacity: 1;
        }

        .preview-progress-bar {
            position: absolute;
            bottom: 0;
            left: 0;
            height: 3px;
            background: var(--brand-red);
            width: 0%;
            z-index: 3;
            transition: width 0.1s linear;
        }

        .badge-duration {
            position: absolute;
            bottom: 5px;
            right: 5px;
            background-color: rgba(0, 0, 0, 0.85);
            color: #fff;
            font-size: 11px;
            font-weight: 500;
            padding: 2px 5px;
            border-radius: 4px;
            z-index: 2;
            letter-spacing: 0.2px;
        }

        .badge-remarks {
            position: absolute;
            top: 5px;
            left: 5px;
            background-color: var(--brand-red);
            color: #fff;
            font-size: 10px;
            font-weight: bold;
            padding: 2px 5px;
            border-radius: 4px;
            z-index: 2;
            box-shadow: 0 2px 4px rgba(0,0,0,0.3);
        }

        .video-info {
            display: flex;
            gap: 8px;
            margin-top: 8px;
        }

        .channel-avatar {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            background-color: var(--bg-hover);
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 13px;
            color: var(--text-sub);
            flex-shrink: 0;
            text-transform: uppercase;
        }

        .video-details {
            flex: 1;
            min-width: 0;
        }

        .video-title {
            font-size: 13px;
            font-weight: 600;
            line-height: 1.35;
            color: var(--text-main);
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            margin-bottom: 3px;
            transition: color 0.2s ease;
        }

        .video-card:hover .video-title {
            color: #3ea6ff;
        }

        .video-meta {
            font-size: 11px;
            color: var(--text-sub);
            line-height: 1.35;
        }

        .yt-footer {
            margin-top: 36px;
            padding: 20px 0 16px 0;
            border-top: 1px solid var(--border-color);
            color: var(--text-sub);
            font-size: 12px;
            line-height: 1.6;
        }

        .footer-links {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            margin-bottom: 12px;
        }

        .footer-links a {
            color: var(--text-sub);
            transition: color 0.2s;
        }

        .footer-links a:hover {
            color: var(--text-main);
            text-decoration: underline;
        }

        .footer-disclaimer {
            margin-bottom: 12px;
            max-width: 900px;
            opacity: 0.85;
        }

        .footer-copyright {
            font-size: 11px;
            color: var(--text-sub);
            opacity: 0.6;
        }

        /* 移动端响应式适配 */
        @media (max-width: 768px) {
            .header-center {
                display: none !important;
            }

            /* 移动端显现搜索按钮 */
            .mobile-search-btn {
                display: flex !important;
            }

            .yt-sidebar { 
                transform: translateX(-100%);
                width: 240px !important;
                box-shadow: 4px 0 16px rgba(0,0,0,0.3);
            }
            .yt-sidebar.mobile-open {
                transform: translateX(0);
            }
            
            .yt-main { 
                margin-left: 0 !important; 
                padding: 6px 6px 20px 6px; 
            }

            #themeText {
                display: none;
            }

            .theme-toggle-btn {
                padding: 6px 10px;
            }
            
            .chips-bar {
                gap: 6px;
                margin-bottom: 8px;
                padding-bottom: 6px;
            }

            .video-grid {
                grid-template-columns: repeat(2, 1fr) !important;
                gap: 8px 6px !important;
            }

            .video-card {
                padding: 2px;
            }

            .video-title {
                font-size: 12px;
                line-height: 1.3;
                margin-bottom: 2px;
            }

            .channel-avatar {
                width: 26px;
                height: 26px;
                font-size: 11px;
            }

            .video-info {
                gap: 6px;
                margin-top: 5px;
            }

            .video-meta {
                font-size: 10px;
            }

            .badge-duration, .badge-remarks {
                font-size: 9px;
                padding: 1px 4px;
            }

            .yt-footer {
                margin-top: 20px;
                padding: 14px 0;
            }
        }

        @media (max-width: 480px) {

        }