/* 底部导航样式 */
        .bottom-nav {
            position: fixed;
            bottom: 0;
            left: 0;
            right: 0;
            background: white;
            display: flex;
            box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
            z-index: 100;
            height: 65px;
        }
        
        .nav-item {
            flex: 1;
            text-align: center;
            padding: 8px 0;
            color: #666;
            font-size: 12px;
            transition: all 0.3s;
        }
        
        .nav-item.active {
            color: var(--primary);
        }
        
        .nav-icon {
            font-size: 22px;
            margin-bottom: 4px;
        }
/* 新增的中心悬浮按钮 */
        .nav-main {
            position: absolute;
            left: 50%;
            top: -25px;
            transform: translateX(-50%);
            width: 60px;
            height: 60px;
            border-radius: 30px;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            display: flex;
            justify-content: center;
            align-items: center;
            box-shadow: 0 4px 20px rgba(108, 92, 231, 0.3);
            z-index: 101;
            transition: all 0.3s;
        }
        
        .nav-main:active {
            transform: translateX(-50%) scale(0.95);
        }
        
        .nav-icon-main {
            position: relative;
            color: white;
            font-size: 24px;
        }
        
        .pulse-effect {
            position: absolute;
            width: 100%;
            height: 100%;
            border-radius: 50%;
            background: rgba(255,255,255,0.2);
            animation: pulse 2s infinite;
        }
        
        @keyframes pulse {
            0% { transform: scale(0.8); opacity: 0.8; }
            70% { transform: scale(1.3); opacity: 0; }
            100% { opacity: 0; }
        }