:root {
        /* Christmas Theme */
        --primary: #c62828; 
        --secondary: #2e7d32;
        --bg-body: #f0f2f5;
        --bg-white: #ffffff;
        --text-dark: #1c1e21;
        --text-gray: #65676b;
        --border: #ddd;
        --sidebar-width: 250px;
        --selection-width: 320px;
        --header-height: 70px;
    }

    /* Black Friday Theme */
    body.theme-bfcm {
        --primary: #212121;
        --secondary: #673ab7;
    }

    /* 全局重置与字体优化 */
    * { 
        box-sizing: border-box; 
        margin: 0; 
        padding: 0; 
        -webkit-tap-highlight-color: transparent; /* 移除手机点击高亮块 */
    }

    body {
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
        background-color: var(--bg-body);
        color: var(--text-dark);
        height: 100vh;
        height: 100dvh; /* 适配移动端动态地址栏 */
        display: flex;
        flex-direction: column;
        overflow: hidden;
        transition: background-color 0.3s;
        -webkit-font-smoothing: antialiased; /* Mac 字体抗锯齿 */
        -moz-osx-font-smoothing: grayscale;
    }

    /* --- 滚动条美化 (跨浏览器) --- */
    /* Firefox */
    * {
        scrollbar-width: thin;
        scrollbar-color: #ccc transparent;
    }
    /* Chrome, Edge, Safari */
    ::-webkit-scrollbar {
        width: 8px;
        height: 8px;
    }
    ::-webkit-scrollbar-track {
        background: transparent;
    }
    ::-webkit-scrollbar-thumb {
        background-color: #ccc;
        border-radius: 4px;
        border: 2px solid transparent;
        background-clip: content-box;
    }
    ::-webkit-scrollbar-thumb:hover {
        background-color: #bbb;
    }

    /* --- Header --- */
   header {
    background-color: var(--bg-white);
    /* height: 70px;  <-- 删除固定高度 */
    min-height: 70px; /* 改为最小高度 */
    height: auto;     /* 允许高度随内容撑开 */
    display: flex;
    align-items: center;
    padding: 10px 20px; /* 增加上下内边距，防止换行后贴边 */
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    z-index: 20;
    gap: 15px; /* 元素之间的间距 */
    row-gap: 10px; /* 换行后的行间距 */
    flex-wrap: wrap; /* 关键：空间不足时允许自动换行 */
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

    /* Brand */
    .brand {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 8px;
    /* min-width: 180px; <-- 删除这一行，不要强制占位 */
    min-width: auto;     /* 改为自动宽度 */
    text-decoration: none;
    white-space: nowrap;
    margin-right: 5px;   /* 给右边留点余地 */
}
    .brand i { font-size: 1.3rem; }

    /* Topic Switcher */
    .topic-switch { display: flex; background: #f0f2f5; padding: 4px; border-radius: 10px; gap: 5px; flex-shrink: 0; }
    .topic-btn {
        padding: 8px 16px; border: none; border-radius: 8px; cursor: pointer; font-weight: 700; font-size: 0.9rem;
        background: transparent; color: var(--text-gray); transition: all 0.2s; display: flex; align-items: center; gap: 8px; white-space: nowrap;
    }
    .topic-btn:hover { background: #e4e6eb; }
    .topic-btn.active { background: white; color: var(--text-dark); box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
    .topic-btn.active.xmas { color: #c62828; }
    .topic-btn.active.bfcm { color: #212121; }

    /* Country Switcher */
    .country-switch {
        display: flex;
        border: 1px solid var(--border);
        border-radius: 8px;
        flex-shrink: 0;
    }

    .country-btn {
        padding: 6px 12px;
        border: none;
        cursor: pointer;
        font-weight: 600;
        font-size: 0.85rem;
        background: white;
        color: var(--text-gray);
        border-right: 1px solid var(--border);
        transition: all 0.2s;
        position: relative;
    }

    .country-btn:first-child { border-top-left-radius: 7px; border-bottom-left-radius: 7px; }
    .country-btn:last-child { border-right: none; border-top-right-radius: 7px; border-bottom-right-radius: 7px; }
    .country-btn:hover { background: #f9f9f9; z-index: 1; }
    .country-btn.active { background: #e8f5e9; color: var(--secondary); font-weight: bold; }
    body.theme-bfcm .country-btn.active { background: #ede7f6; }

    /* Search */
    .search-container {
    flex: 1;
    max-width: 400px;
    position: relative;
    /* margin-left: auto; <-- 删除这行，让 flex-wrap 自动处理位置 */
    min-width: 200px; /* 保证搜索框最小宽度 */
}
    .search-input {
        width: 100%; padding: 10px 15px 10px 40px; border-radius: 20px; border: 1px solid var(--border);
        background: #f0f2f5; outline: none; transition: all 0.2s; -webkit-appearance: none; /* 移除iOS默认圆角 */
    }
    .search-input:focus { background: #fff; border-color: var(--secondary); box-shadow: 0 0 0 2px rgba(0,0,0, 0.05); }
    .search-icon { position: absolute; left: 15px; top: 50%; transform: translateY(-50%); color: var(--text-gray); pointer-events: none; }

    /* Header Actions */
    .header-actions {
        display: flex; align-items: center; gap: 8px;
        border-left: 1px solid var(--border); padding-left: 15px; flex-shrink: 0;
    }
    .action-btn {
        background: none; border: none; cursor: pointer; color: var(--text-gray);
        width: 36px; height: 36px; border-radius: 50%;
        display: flex; align-items: center; justify-content: center;
        transition: all 0.2s; text-decoration: none; font-size: 1.1rem;
    }
    .action-btn:hover { background: #f0f2f5; color: var(--text-dark); }
    
    /* --- Layout Container --- */
    .layout { display: flex; flex: 1; overflow: hidden; position: relative; }

    /* --- Sidebar --- */
    .sidebar { width: var(--sidebar-width); background: var(--bg-white); border-right: 1px solid var(--border); overflow-y: auto; flex-shrink: 0; padding: 10px 0; }
    
    /* Sidebar Stats */
    .sidebar-stats {
        padding: 15px 20px; border-bottom: 1px solid var(--border); margin-bottom: 10px;
        background: linear-gradient(to right, var(--bg-white), #fafafa);
    }
    .stats-label { font-size: 0.75rem; color: var(--text-gray); text-transform: uppercase; letter-spacing: 1px; font-weight: 600; margin-bottom: 4px; }
    .stats-number { font-size: 1.6rem; font-weight: 800; color: var(--text-dark); display: flex; align-items: baseline; gap: 8px; }
    .stats-number small { font-size: 0.9rem; font-weight: 400; color: var(--text-gray); }

    .nav-item { padding: 12px 20px; cursor: pointer; display: flex; align-items: center; justify-content: space-between; color: var(--text-gray); font-size: 0.9rem; border-left: 4px solid transparent; }
    .nav-content { display: flex; align-items: center; gap: 12px; }
    .nav-count { font-size: 0.75rem; background: #eee; padding: 2px 8px; border-radius: 10px; color: #666; }
    .nav-item:hover { background-color: #f5f5f5; color: var(--text-dark); }
    .nav-item.active { background-color: #ffebee; color: #c62828; border-left-color: #c62828; font-weight: 600; }
    .nav-item.active .nav-count { background: #ffcdd2; color: #c62828; }
    body.theme-bfcm .nav-item.active { background-color: #ede7f6; color: #673ab7; border-left-color: #673ab7; }
    body.theme-bfcm .nav-item.active .nav-count { background: #d1c4e9; color: #673ab7; }
    .nav-content i { width: 20px; text-align: center; }

    /* --- Content --- */
    .content { flex: 1; overflow-y: auto; padding: 25px; scroll-behavior: smooth; }
    .category-section { margin-bottom: 40px; }
    .category-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 15px; padding-bottom: 10px; border-bottom: 2px solid #e0e0e0; }
    .category-title { font-size: 1.4rem; color: var(--text-dark); display: flex; align-items: center; gap: 12px; }
    .cat-count-badge { font-size: 0.9rem; color: var(--text-gray); font-weight: normal; }
    .btn-copy-list {
        background-color: white; border: 1px solid var(--border); color: var(--text-dark);
        padding: 6px 12px; border-radius: 6px; cursor: pointer; font-size: 0.85rem;
        display: flex; align-items: center; gap: 6px; transition: all 0.2s; white-space: nowrap;
    }
    .btn-copy-list:hover { background-color: var(--text-dark); color: white; }
    
    .keywords-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }

    /* --- Letter Header --- */
    .letter-header {
        grid-column: 1 / -1; font-size: 1.2rem; font-weight: 700; color: var(--text-dark);
        background-color: transparent; padding: 20px 0 10px 5px; border-bottom: 2px solid var(--border);
        margin-top: 10px; display: flex; align-items: center;
    }
    .letter-header:first-child { margin-top: 0; }

    /* --- Chips --- */
    .keyword-chip {
        background: white; border: 1px solid var(--border); border-radius: 8px;
        padding: 12px 14px; cursor: pointer; transition: transform 0.15s, box-shadow 0.15s;
        display: flex; align-items: center; justify-content: space-between;
        user-select: none; position: relative; min-height: 50px;
    }
    
    /* 仅在支持 hover 的设备上启用 hover 效果，避免手机端点击卡住 */
    @media (hover: hover) {
        .keyword-chip:hover { border-color: #999; box-shadow: 0 2px 5px rgba(0,0,0,0.05); transform: translateY(-1px); }
    }
    
    .keyword-chip:active { transform: translateY(0); background-color: #f5f5f5; }
    .keyword-chip.selected { background-color: #e8f5e9; border-color: var(--secondary); }
    body.theme-bfcm .keyword-chip.selected { background-color: #ede7f6; }
    .chip-text-group { display: flex; flex-direction: column; line-height: 1.2; word-break: break-word; }
    .chip-main { font-size: 0.95rem; color: var(--text-dark); font-weight: 500; }
    .keyword-chip.selected .chip-main { color: var(--secondary); }
    .chip-sub { font-size: 0.75rem; color: #888; margin-top: 2px; }
    .keyword-chip i { font-size: 0.8rem; color: #ccc; flex-shrink: 0; margin-left: 10px;}
    .keyword-chip.selected i { color: var(--secondary); }

    /* --- Right Selection Panel --- */
    .selection-panel {
        width: var(--selection-width); background: var(--bg-white); border-left: 1px solid var(--border);
        display: flex; flex-direction: column; z-index: 15; box-shadow: -2px 0 5px rgba(0,0,0,0.02);
        transition: transform 0.3s ease;
    }
    .panel-header { padding: 15px 20px; border-bottom: 1px solid var(--border); background: #fafafa; }
    .selected-list { flex: 1; overflow-y: auto; padding: 10px; list-style: none; }
    .selected-item {
        display: flex; justify-content: space-between; align-items: center;
        padding: 10px 15px; border-bottom: 1px solid #f0f0f0; font-size: 0.9rem;
        animation: fadeIn 0.2s; background: white; margin-bottom: 5px; border-radius: 6px;
    }
    .selected-item:hover { background-color: #f9f9f9; }
    @keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }
    .remove-btn { color: #999; cursor: pointer; padding: 5px; }
    .remove-btn:hover { color: var(--primary); }
    .panel-footer { padding: 20px; border-top: 1px solid var(--border); display: flex; gap: 10px; background: white; }
    .btn { flex: 1; padding: 12px; border: none; border-radius: 8px; cursor: pointer; font-weight: 600; display: flex; justify-content: center; align-items: center; gap: 8px; }
    .btn-copy-selected { background-color: var(--secondary); color: white; }
    .btn-copy-selected:hover { opacity: 0.9; }
    .btn-clear { background-color: #f5f5f5; color: var(--text-dark); }
    .btn-clear:hover { background-color: #e0e0e0; }

    /* --- Modal --- */
    .modal-overlay {
        position: fixed; top: 0; left: 0; width: 100%; height: 100%;
        background: rgba(0, 0, 0, 0.5); z-index: 3000;
        display: flex; justify-content: center; align-items: center;
        opacity: 0; pointer-events: none; transition: opacity 0.3s;
        padding: 20px; /* 防止手机端贴边 */
    }
    .modal-overlay.open { opacity: 1; pointer-events: auto; }
    .modal-box {
        background: var(--bg-white); width: 100%; max-width: 450px; max-height: 90vh; overflow-y: auto;
        border-radius: 12px; box-shadow: 0 10px 25px rgba(0,0,0,0.2);
        padding: 25px; transform: translateY(20px); transition: transform 0.3s; color: var(--text-dark);
    }
    .modal-overlay.open .modal-box { transform: translateY(0); }
    .modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; border-bottom: 1px solid var(--border); padding-bottom: 15px; }
    .modal-title { font-size: 1.25rem; font-weight: 700; color: var(--primary); display: flex; align-items: center; gap: 10px; }
    .modal-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text-gray); }
    .modal-close:hover { color: var(--text-dark); }
    .modal-body h4 { margin-top: 15px; margin-bottom: 8px; color: var(--secondary); font-size: 1rem; }
    .modal-body p { font-size: 0.95rem; color: #555; line-height: 1.5; margin-bottom: 10px; }
    .modal-body ul { padding-left: 20px; font-size: 0.95rem; color: #555; }
    .author-profile { text-align: center; padding: 10px 0; }
/* 修改 .author-icon 容器样式 */
.author-profile .author-icon { 
    margin-bottom: 15px; 
    display: flex;
    justify-content: center; /* 图片居中 */
}

/* 新增：专门控制二维码图片的样式 */
.author-profile .author-icon img {
    width: 120px;       /* 控制二维码大小 */
    height: 120px;
    border-radius: 8px; /* 圆角 */
    padding: 5px;       /* 内边距 */
    background: #fff;   /*以此确保二维码背景是白的 */
    border: 1px solid var(--border); /* 边框 */
    box-shadow: 0 4px 10px rgba(0,0,0,0.08); /* 阴影 */
}    .version-badge { background: #eee; padding: 4px 10px; border-radius: 12px; font-size: 0.8rem; color: #666; }

    /* --- Tooltip --- */
    /* 仅在支持 hover 的设备显示 Tooltip，防止手机点击显示 */
    @media (hover: hover) {
        [data-tooltip] { position: relative; }
        [data-tooltip]:hover::after {
            content: attr(data-tooltip); position: absolute; top: 100%; left: 50%; transform: translateX(-50%); margin-top: 8px;
            background-color: #333; color: #fff; padding: 6px 10px; border-radius: 4px; font-size: 0.75rem; white-space: nowrap;
            z-index: 1000; box-shadow: 0 4px 6px rgba(0,0,0,0.15); pointer-events: none; opacity: 0; animation: tooltipFadeIn 0.2s forwards;
        }
    }
    @keyframes tooltipFadeIn { from { opacity: 0; transform: translateX(-50%) translateY(-5px); } to { opacity: 1; transform: translateX(-50%) translateY(0); } }

    /* --- Toast --- */
    .toast {
        position: fixed; top: 80px; right: 50%; transform: translateX(50%);
        background-color: #323232; color: white; padding: 12px 24px; border-radius: 50px;
        box-shadow: 0 4px 15px rgba(0,0,0,0.2); opacity: 0; transition: opacity 0.3s, transform 0.3s;
        z-index: 2000; pointer-events: none; display: flex; align-items: center; gap: 8px; white-space: nowrap;
    }
    .toast.show { opacity: 1; transform: translateX(50%) translateY(10px); }

    /* --- Responsive & Mobile --- */
    .mobile-bar { display: none; }

    /* Tablet (900px down) */
    @media (max-width: 900px) {
        .sidebar { width: 70px; }
        .nav-item span, .cat-count-badge, .sidebar-stats { display: none; } /* Hide text and stats */
        .nav-item { justify-content: center; padding: 15px 5px; }
        .nav-item i { font-size: 1.4rem; width: auto; }
        .nav-count { position: absolute; top: 5px; right: 5px; font-size: 0.7rem; }
        .nav-item { position: relative; }
    }

    /* Mobile (768px down) */
    @media (max-width: 768px) {
        .layout { flex-direction: column; position: relative; }
        header { padding: 10px; height: auto; flex-wrap: wrap; gap: 10px; justify-content: space-between; }
        
        /* Mobile Header Ordering */
        .brand { order: 1; width: auto; font-size: 1.1rem; }
        .header-actions { order: 2; padding-left: 10px; border-left: none; }
        .topic-switch { width: 100%; justify-content: center; order: 3; margin-top: 5px; overflow-x: auto; }
        .country-switch { order: 4; width: 100%; justify-content: center; overflow-x: auto; padding-bottom: 2px; }
        .search-container { order: 5; width: 100%; max-width: none; margin: 0; }
        
        .sidebar { width: 100%; height: auto; display: flex; overflow-x: auto; border-right: none; border-bottom: 1px solid var(--border); padding: 0; order: 2; background: white; -webkit-overflow-scrolling: touch; }
        .nav-item { flex-shrink: 0; padding: 12px 20px; border-left: none; border-bottom: 3px solid transparent; border-radius: 0; }
        .nav-item.active { border-left: none; border-bottom-color: var(--primary); background: none; }
        .sidebar-stats { display: none; } /* 移动端隐藏侧边栏统计 */
        
        .content { order: 3; padding: 15px; padding-bottom: 80px; }
        .keywords-grid { grid-template-columns: repeat(auto-fill, minmax(100%, 1fr)); } /* 手机端单列或双列 */
        
        .selection-panel {
            position: fixed; bottom: 0; left: 0; width: 100%; height: 70vh; border-left: none; border-top: 1px solid var(--border);
            transform: translateY(110%); box-shadow: 0 -5px 20px rgba(0,0,0,0.15); border-radius: 15px 15px 0 0;
        }
        .selection-panel.open { transform: translateY(0); }

        .mobile-bar {
            display: flex; position: fixed; bottom: 0; left: 0; width: 100%; background: white;
            padding: 12px 20px; border-top: 1px solid #ddd; align-items: center; justify-content: space-between;
            z-index: 30; box-shadow: 0 -2px 10px rgba(0,0,0,0.05); padding-bottom: max(12px, env(safe-area-inset-bottom));
        }
        .mobile-bar-info { font-weight: bold; color: var(--secondary); }
        .mobile-bar-btn { background: var(--text-dark); color: white; border: none; padding: 8px 20px; border-radius: 20px; font-weight: 600; }
        .mobile-close-btn { display: block !important; }
    }

    /* Small Mobile (480px down) */
    @media (max-width: 480px) {
        .topic-btn { padding: 6px 12px; font-size: 0.8rem; }
        .country-btn { padding: 6px 10px; font-size: 0.8rem; }
        .keywords-grid { grid-template-columns: 1fr; } /* 强制单列 */
    }
        /* --- 平板/窄屏笔记本优化 --- */
@media (max-width: 1100px) {
    header {
        justify-content: space-between; /* 元素分散对齐 */
    }
    
    /* 让搜索框在窄屏下独占一行，或者排在最后 */
    .search-container {
        order: 5; 
        min-width: 300px;
        margin-left: 0;
        margin-top: 5px;
    }
    
    /* 稍微缩小标题字体 */
    .brand {
        font-size: 1.1rem;
    }
}
    @media (min-width: 769px) { .mobile-close-btn { display: none; } }