 * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
        }
        
        body {
            background-color: #f5f5f5;
            color: #333;
            line-height: 1.5;
        }
        
        /* 顶部标题区 */
        .header {
            position: sticky;
            top: 0;
            background-color: #fff;
            padding: 12px 16px;
            text-align: center;
            font-size: 18px;
            font-weight: 600;
            box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05);
            z-index: 10;
        }
        
        /* 按钮功能区 */
        .button-area {
            display: flex;
            background-color: #fff;
            padding: 12px 16px;
            margin-bottom: 8px;
            border-bottom: 1px solid #f0f0f0;
        }
        
        .action-button {
            flex: 1;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 8px;
            background: none;
            border: none;
            color: #666;
            font-size: 14px;
            cursor: pointer;
            transition: all 0.2s;
        }
        
        .action-button:hover {
            color: #1a73e8;
        }
        
        .action-button .icon {
            font-size: 20px;
            margin-bottom: 4px;
        }
        
        .action-button.active {
            color: #1a73e8;
        }
        
        /* 消息卡片区 */
        .message-list {
            padding: 0 16px;
        }
        
        .message-card {
            display: flex;
            background-color: #fff;
            padding: 12px;
            margin-bottom: 8px;
            border-radius: 8px;
            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
            transition: transform 0.2s;
        }
        
        .message-card:active {
            transform: scale(0.98);
        }
        
        .message-card.unread {
            background-color: #f8f9fa;
        }
        
        .avatar {
            width: 48px;
            height: 48px;
            border-radius: 50%;
            margin-right: 12px;
            object-fit: cover;
            background-color: #e9ecef;
        }
        
        .message-content {
            flex: 1;
        }
        
        .message-header {
            display: flex;
            justify-content: space-between;
            margin-bottom: 6px;
        }
        
        .username {
            font-weight: 600;
            color: #333;
        }
        
        .time {
            font-size: 12px;
            color: #999;
        }
        
        .message-text {
            overflow: hidden;
            text-overflow: ellipsis;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            line-clamp: 2;
            -webkit-box-orient: vertical;
        }
        
        /* 未读标记 */
        .unread-badge {
            align-self: center;
            width: 8px;
            height: 8px;
            background-color: #1a73e8;
            border-radius: 50%;
            margin-left: 8px;
        }