/* ===== 全屏搜索遮罩层 ===== */
        .search-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            background: rgba(0, 0, 0, 0.8);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 11000;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.4s ease, visibility 0.4s ease;
        }

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

        .search-overlay-content {
            width: 600px;
            max-width: 90%;
            position: relative;
        }

        .overlay-search-box {
            display: flex;
            align-items: center;
            background: #fff;
            border-radius: 50px;
            padding: 6px 6px 6px 24px;
            box-shadow: 0 10px 40px rgba(0,0,0,0.3);
            transition: box-shadow 0.3s ease;
        }

        .overlay-search-box:focus-within {
            box-shadow: 0 10px 50px rgba(0,0,0,0.5), 0 0 0 3px rgba(26, 58, 92, 0.3);
        }

        .overlay-search-box input[type="text"] {
            flex: 1;
            border: none;
            outline: none;
            font-size: 18px;
            color: #333;
            padding: 12px 0;
            background: transparent;
        }

        .overlay-search-box input[type="text"]::placeholder {
            color: #999;
        }

        .overlay-search-btn {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background: #1a3a5c;
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.3s ease, transform 0.2s ease;
            flex-shrink: 0;
        }

        .overlay-search-btn:hover {
            background: #2a4a6c;
            transform: scale(1.05);
        }

        .overlay-search-btn svg {
            width: 22px;
            height: 22px;
            fill: #fff;
        }

        /* 关闭按钮 */
        .overlay-close {
            position: absolute;
            top: -60px;
            right: 0;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: rgba(255,255,255,0.5);
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.3s ease;
        }

        .overlay-close:hover {
            background: rgba(255,255,255,0.8);
        }

        .overlay-close svg {
            width: 20px;
            height: 20px;
            fill: #fff;
        }

        /* 提示文字 */
        .overlay-hint {
            text-align: center;
            color: rgba(255,255,255,0.6);
            margin-top: 20px;
            font-size: 14px;
            letter-spacing: 2px;
        }

        /* ===== 页面内容（用于演示滚动） ===== */
        .page-content {
            padding: 40px 20px;
            max-width: 1200px;
            margin: 0 auto;
        }

        .page-content h1 {
            color: #1a3a5c;
            margin-bottom: 20px;
        }

        .page-content p {
            line-height: 2;
            color: #666;
            margin-bottom: 16px;
        }

        .demo-section {
            background: #fff;
            padding: 30px;
            margin-bottom: 20px;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
        }

        .demo-section h2 {
            color: #1a3a5c;
            margin-bottom: 15px;
            border-left: 4px solid #1a3a5c;
            padding-left: 12px;
        }

        /* 滚动条样式 */
        ::-webkit-scrollbar {
            width: 8px;
        }

        ::-webkit-scrollbar-track {
            background: #f1f1f1;
        }

        ::-webkit-scrollbar-thumb {
            background: #c1c1c1;
            border-radius: 4px;
        }

        ::-webkit-scrollbar-thumb:hover {
            background: #a1a1a1;
        }