/* 公告部分美化 */
        #announcements {
            max-width: 1200px;
            margin: 0 auto;
            padding: 30px 20px;
        }
        
        .announcement-latest, .announcement-history {
            margin-bottom: 40px;
        }
        
        .announcement-latest h3, .announcement-history h3 {
            position: relative;
            margin-bottom: 25px;
            padding-bottom: 10px;
            font-weight: 600;
            color: #3498db;
        }
        
        .announcement-latest h3::after, .announcement-history h3::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 50px;
            height: 3px;
            background: linear-gradient(90deg, #3498db, #2ecc71);
            border-radius: 3px;
        }
        
        /* 最新公告卡片 */
        .latest-card {
            background: linear-gradient(135deg, #f8f9fa, #e9ecef);
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            transition: all 0.3s ease;
            border: none;
            margin-bottom: 30px;
        }
        
        .latest-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.12);
        }
        
        .latest-card .card-header {
            background: linear-gradient(90deg, #3498db, #2ecc71);
            color: white;
            padding: 15px 20px;
            font-weight: 600;
            font-size: 1.1rem;
            border: none;
        }
        
        .latest-card .card-body {
            padding: 25px;
        }
        
        .latest-card .card-title {
            font-size: 1.4rem;
            margin-bottom: 15px;
            color: #2c3e50;
            font-weight: 700;
        }
        
        .latest-card .card-text {
            color: #555;
            line-height: 1.8;
            font-size: 1.05rem;
        }
        
        .latest-card .card-footer {
            background: rgba(236, 240, 241, 0.7);
            padding: 12px 20px;
            font-size: 0.9rem;
            color: #7f8c8d;
            border-top: 1px solid rgba(0,0,0,0.05);
        }
        
        /* 历史公告网格 */
        .history-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 25px;
        }
        
        .history-card {
            background: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
            height: 100%;
            display: flex;
            flex-direction: column;
            border: 1px solid rgba(0,0,0,0.06);
        }
        
        .history-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 25px rgba(0,0,0,0.1);
        }
        
        .history-card .card-header {
            background: #f8f9fa;
            padding: 12px 15px;
            font-size: 0.9rem;
            color: #7f8c8d;
            border-bottom: 1px solid rgba(0,0,0,0.05);
        }
        
        .history-card .card-body {
            padding: 20px;
            flex-grow: 1;
        }
        
        .history-card .card-title {
            font-size: 1.15rem;
            margin-bottom: 10px;
            color: #2c3e50;
            font-weight: 600;
        }
        
        .history-card .card-text {
            color: #555;
            font-size: 0.95rem;
            line-height: 1.6;
        }
        
        /* 响应式调整 */
        @media (max-width: 768px) {
            .history-grid {
                grid-template-columns: 1fr;
            }
            
            .latest-card .card-title {
                font-size: 1.2rem;
            }
        }
        
        /* 动画效果 */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .latest-card {
            animation: fadeIn 0.6s ease-out;
        }
        
        .history-card {
            animation: fadeIn 0.6s ease-out;
            animation-fill-mode: backwards;
        }
        
        .history-card:nth-child(1) { animation-delay: 0.1s; }
        .history-card:nth-child(2) { animation-delay: 0.2s; }
        .history-card:nth-child(3) { animation-delay: 0.3s; }
        .history-card:nth-child(4) { animation-delay: 0.4s; }
        .history-card:nth-child(5) { animation-delay: 0.5s; }