    <style>
        * {
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        /* 整体布局调整 */
        body {
            margin: 0;
            padding: 0;
            background: #f5f5f5;
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }
        
        /* Header容器 */
        .header-container {
            width: 100%;
        }
        
        /* 主内容区 */
        .main-content {
            flex: 1;
            width: 100%;
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
            box-sizing: border-box;
        }
        
        .calculator {
            background: white;
            border-radius: 10px;
            padding: 25px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        }
        
        h1 {
            color: #2c3e50;
            text-align: center;
            margin-bottom: 30px;
        }
        
        .tabs {
            display: flex;
            overflow-x: auto;
            margin-bottom: 20px;
            border-bottom: 1px solid #ddd;
        }
        
        .tab {
            padding: 10px 20px;
            cursor: pointer;
            border-bottom: 3px solid transparent;
            white-space: nowrap;
        }
        
        .tab.active {
            border-bottom: 3px solid #3498db;
            font-weight: 600;
            color: #3498db;
        }
        
        .tab-content {
            display: none;
        }
        
        .tab-content.active {
            display: block;
        }
        
        .converter {
            display: flex;
            gap: 15px;
            align-items: center;
            margin-bottom: 20px;
        }
        
        .input-group {
            flex: 1;
        }
        
        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: #34495e;
        }
        
        input, select {
            width: 100%;
            padding: 12px;
            border: 1px solid #ddd;
            border-radius: 6px;
            font-size: 16px;
        }
        
        .swap-btn {
            background: #3498db;
            color: white;
            border: none;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: background 0.3s;
        }
        
        .swap-btn:hover {
            background: #2980b9;
        }
        
        .result {
            margin-top: 20px;
            padding: 15px;
            background: #f8f9fa;
            border-radius: 8px;
            font-size: 18px;
        }
        
        .result-value {
            font-weight: 600;
            color: #2c3e50;
        }
        
        .common-conversions {
            margin-top: 30px;
        }
        
        .common-conversions h3 {
            color: #34495e;
            margin-bottom: 15px;
        }
        
        .common-list {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 10px;
        }
        
        .common-item {
            padding: 10px;
            background: #f8f9fa;
            border-radius: 6px;
            cursor: pointer;
            transition: background 0.2s;
        }
        
        .common-item:hover {
            background: #e9ecef;
        }
        
        /* Footer容器 */
        .footer-container {
            width: 100%;
        }
    </style>