/* 頁面底色（無全版漸層）；內容區塊內漸層保留 */
body.page-btu {
  margin: 0;
  font-family: 'Microsoft JhengHei', Arial, sans-serif;
  background: #ececec;
  min-height: 100vh;
}
body.page-btu * {
  box-sizing: border-box;
}

/* Main Content */
        .container {
            max-width: 1000px;
            margin: 0 auto;
            padding: 1.5rem 1rem;
        }
        
        .card {
            background: white;
            border-radius: 1rem;
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
            padding: 1.5rem;
            margin-bottom: 1.5rem;
        }
        
        .card-title {
            font-size: 1.75rem;
            font-weight: bold;
            text-align: center;
            margin-bottom: 1.5rem;
            color: #1f2937;
        }
        
        .section-title {
            font-size: 1.25rem;
            font-weight: bold;
            color: #374151;
            margin: 1.5rem 0 1rem 0;
            padding: 0.5rem;
            background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%);
            border-radius: 0.5rem;
            border-left: 4px solid #0ea5e9;
        }
        
        .input-table {
            width: 100%;
            border-collapse: collapse;
            margin-bottom: 1rem;
        }
        
        .input-table th,
        .input-table td {
            padding: 0.75rem;
            border: 1px solid #e5e7eb;
            text-align: center;
        }
        
        .input-table th {
            background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
            font-weight: 600;
            color: #374151;
        }
        
        .input-table input[type="text"],
        .input-table input[type="number"] {
            width: 100%;
            padding: 0.5rem;
            border: 2px solid #d1d5db;
            border-radius: 0.375rem;
            font-size: 1rem;
            transition: border-color 0.3s;
        }
        
        .input-table input[type="text"]:focus,
        .input-table input[type="number"]:focus {
            outline: none;
            border-color: #0ea5e9;
        }
        
        .input-table select {
            width: 100%;
            padding: 0.5rem;
            border: 2px solid #d1d5db;
            border-radius: 0.375rem;
            font-size: 1rem;
            background: white;
        }
        
        .highlight-input {
            background-color: #fef3c7 !important;
        }
        
        .result-input {
            background-color: #dfe3ee !important;
            font-weight: 600;
        }
        
        .btn-calculate {
            background: linear-gradient(135deg, #0ea5e9 0%, #06b6d4 100%);
            color: white;
            border: none;
            padding: 1rem 2rem;
            font-size: 1.125rem;
            font-weight: bold;
            border-radius: 0.75rem;
            cursor: pointer;
            transition: transform 0.2s, box-shadow 0.2s;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
            width: 100%;
            margin: 1rem 0;
        }
        
        .btn-calculate:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 12px rgba(0,0,0,0.15);
        }
        
        .btn-calculate:active {
            transform: translateY(0);
        }
        
        .result-box {
            background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%);
            border: 2px solid #0ea5e9;
            border-radius: 0.75rem;
            padding: 1.5rem;
            margin: 1rem 0;
        }
        
        .result-item {
            margin: 0.75rem 0;
        }
        
        .result-item input {
            width: 100%;
            padding: 0.75rem;
            font-size: 1.25rem;
            font-weight: bold;
            text-align: center;
            border: 2px solid #0284c7;
            border-radius: 0.5rem;
            background: white;
        }
        
        .converter-card {
            background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
            border-radius: 1rem;
            padding: 1.5rem;
            margin-bottom: 1.5rem;
        }
        
        .converter-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 1rem;
            margin-top: 1rem;
        }
        
        .converter-item {
            display: flex;
            align-items: center;
            gap: 1rem;
        }
        
        .converter-label {
            font-size: 1.25rem;
            font-weight: bold;
            min-width: 80px;
            color: #92400e;
        }
        
        .converter-item input {
            flex: 1;
            padding: 0.75rem;
            font-size: 1.125rem;
            border: 2px solid #d97706;
            border-radius: 0.5rem;
        }
        
        .info-box {
            background: #f0fdf4;
            border-left: 4px solid #22c55e;
            border-radius: 0.5rem;
            padding: 1.5rem;
            margin: 1.5rem 0;
        }
        
        .info-box h3 {
            color: #166534;
            font-size: 1.25rem;
            margin-bottom: 1rem;
        }
        
        .info-box ul {
            list-style: none;
            padding-left: 0;
        }
        
        .info-box li {
            padding: 0.5rem 0;
            padding-left: 1.5rem;
            position: relative;
        }
        
        .info-box li:before {
            content: "✓";
            position: absolute;
            left: 0;
            color: #22c55e;
            font-weight: bold;
        }
        
        .knowledge-box {
            background: linear-gradient(135deg, #fef3c7 0%, #fed7aa 100%);
            border-radius: 0.75rem;
            padding: 1.5rem;
            margin: 1rem 0;
        }
        
        .knowledge-box h4 {
            color: #92400e;
            font-size: 1.125rem;
            margin-bottom: 0.75rem;
        }
        
        .knowledge-box p {
            color: #451a03;
            line-height: 1.6;
            margin: 0.5rem 0;
        }
        
        .links-section {
            background: white;
            border-radius: 0.75rem;
            padding: 1.5rem;
            margin: 1.5rem 0;
        }
        
        .links-section h3 {
            color: #1f2937;
            margin-bottom: 1rem;
        }
        
        .links-section a {
            display: block;
            padding: 0.75rem;
            margin: 0.5rem 0;
            background: #f3f4f6;
            border-radius: 0.5rem;
            text-decoration: none;
            color: #0ea5e9;
            transition: background 0.3s;
        }
        
        .links-section a:hover {
            background: #e5e7eb;
        }
        
        .note {
            font-size: 0.875rem;
            color: #6b7280;
            font-style: italic;
            margin-top: 0.5rem;
        }
        
            .hero {
            text-align: center;
            color: white;
            margin-bottom: 3rem;
        }
        .hero h1 {
            font-size: 3rem;
            margin-bottom: 1rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
        }

        .hero p {
            font-size: 1.2rem;
            opacity: 0.9;
        }

        .calculator-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
            gap: 2rem;
            margin-top: 2rem;
        }
        

        .calculator-card {
            background: #eae6dd;
            border-radius: 15px;
            padding: 1rem;
            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
            transition: all 0.3s ease;
            cursor: pointer;
        }

        .calculator-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 40px rgba(0,0,0,0.3);
        }
.calculator-card a {
    text-decoration: none; /* 去除底線 */
    font-weight: bold;     /* 粗體 */
    color: #222;           /* 顏色 #222 */
}
   .calculator-card h3 {
            color: #222;
            margin-bottom: 1rem;
            font-size: 1rem;
        }

        .calculator-card p {
            color: #666;
            line-height: 1;
        }

        .icon {
            font-size: 2rem;
            margin-bottom: 0rem;
        }
              /* Mobile Responsive */
        @media (max-width: 767px) {
            .card {
                padding: 1rem;
            }
            
            .card-title {
                font-size: 1.5rem;
            }
            
            .section-title {
                font-size: 1.125rem;
            }
            
            .input-table {
                font-size: 0.875rem;
            }
            
            .input-table th,
            .input-table td {
                padding: 0.5rem 0.25rem;
            }
            
            .converter-item {
                flex-direction: column;
                align-items: stretch;
            }
            
            .converter-label {
                min-width: auto;
            }
        }
        
        @media (min-width: 768px) {
            .container {
                padding: 2.5rem 1.5rem;
            }
            
            .converter-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        
        @media (min-width: 1024px) {
            .input-table th,
            .input-table td {
                padding: 1rem;
            }
        }