* {

    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4CAF50;
    --secondary-color: #2196F3;
    --accent-color: #FF9800;
    --danger-color: #f44336;
    --success-color: #4CAF50;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-light: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    background: #f0f2f5;
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 10px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

header {
    text-align: center;
    margin-bottom: 30px;
    animation: fadeInDown 0.6s ease;
}

header h1 {
    color: #333;
    font-size: 1.3rem;
    margin-bottom: 6px;
    font-weight: 600;
}

main {
    background: #ffffff;
    border-radius: 10px;
    padding: 15px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    animation: fadeInUp 0.6s ease;
}

.calculator-section {
    margin-bottom: 30px;
}

.calculator-section h2 {
    color: #2c3e50;
    font-size: 1rem;
    margin-bottom: 8px;
    padding-bottom: 6px;
    border-bottom: 2px solid #3498db;
    font-weight: 600;
}

/* 表单样式 */
form {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 10px;
    margin-bottom: 10px;
}

.input-group {
    display: flex;
    flex-direction: column;
}

.input-group label {
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 4px;
    font-size: 0.8rem;
}

.input-group input {
    padding: 8px 10px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    font-size: 16px; /* 至少 16px 防止 iOS 自动放大 */
    transition: all 0.3s ease;
    background: #fafafa;
}

.input-group input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
    background: #ffffff;
}

.input-group input:hover {
    border-color: #3498db;
}

/* 按钮样式 */
.btn-calculate,
.btn-reset {
    padding: 9px 20px;
    border: none;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    grid-column: 1 / -1;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-calculate {
    background: #3498db;
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(52, 152, 219, 0.3);
}

.btn-calculate:hover {
    background: #2980b9;
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.4);
}

.btn-calculate:active {
    transform: translateY(0);
}

.btn-reset {
    background: #95a5a6;
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(149, 165, 166, 0.3);
}

.btn-reset:hover {
    background: #7f8c8d;
    box-shadow: 0 4px 12px rgba(149, 165, 166, 0.4);
}

/* 结果展示区域 */
.results {
    background: #f8f9fa;
    border-radius: 6px;
    padding: 12px;
    margin-top: 10px;
    animation: fadeIn 0.5s ease;
}

.results h3 {
    color: #2c3e50;
    font-size: 1rem;
    margin-bottom: 10px;
    text-align: center;
    font-weight: 600;
}

.results h4 {
    color: #2c3e50;
    font-size: 0.9rem;
    margin: 12px 0 8px 0;
    font-weight: 600;
    padding-left: 8px;
    border-left: 3px solid #3498db;
}

.results h4:first-child {
    margin-top: 0;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 8px;
}

.result-item {
    background: linear-gradient(135deg, #ffffff, #f0f8ff);
    padding: 10px;
    border-radius: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: all 0.3s ease;
    border-left: 3px solid #3498db;
}

.result-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.2);
}

.result-item.highlight {
    border-left-color: #f39c12;
    background: linear-gradient(135deg, #fffaf3, #fff5e6);
}

.result-item.highlight:hover {
    box-shadow: 0 4px 12px rgba(243, 156, 18, 0.2);
}

.result-item.highlight-positive {
    border-left-color: #27ae60;
    background: linear-gradient(135deg, #e8f8f0, #f0fff5);
    box-shadow: 0 3px 10px rgba(39, 174, 96, 0.15);
}

.result-item.highlight-positive:hover {
    box-shadow: 0 5px 15px rgba(39, 174, 96, 0.3);
}

.result-label {
    font-size: 0.7rem;
    color: var(--text-light);
    margin-bottom: 5px;
    font-weight: 500;
}

.result-value {
    font-size: 1.2rem;
    font-weight: 700;
    color: #2c3e50;
    margin-bottom: 3px;
}

.result-unit {
    font-size: 0.7rem;
    color: var(--text-light);
    font-weight: 500;
}

/* 输入数据展示样式 */
.input-summary {
    background: #ffffff;
    border-radius: 6px;
    padding: 12px;
    margin-bottom: 10px;
}

.input-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 10px;
}

.input-item {
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
    padding: 10px;
    border-radius: 6px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    border-left: 3px solid #6c757d;
    transition: all 0.3s ease;
}

.input-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(108, 117, 125, 0.2);
}

.input-label {
    font-size: 0.75rem;
    color: #495057;
    margin-bottom: 5px;
    font-weight: 600;
}

.input-value {
    font-size: 1.2rem;
    font-weight: 700;
    color: #343a40;
    margin-bottom: 2px;
}

.input-unit {
    font-size: 0.7rem;
    color: #6c757d;
    font-weight: 500;
}

/* 页脚 */
footer {
    text-align: center;
    margin-top: 15px;
    padding: 10px;
}

footer p {
    font-size: 0.75rem;
    color: #7f8c8d;
}

.friend-link {
    margin-top: 8px;
}

.friend-link a {
    display: inline-block;
    padding: 8px 16px;
    background: #3498db;
    color: #ffffff;
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.8rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(52, 152, 219, 0.3);
}

.friend-link a:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.4);
}

/* 动画效果 */

/* 响应式设计 */
@media screen and (max-width: 768px) {
    body {
        padding: 6px;
    }

    header h1 {
        font-size: 1.2rem;
        margin-bottom: 5px;
    }

    main {
        padding: 10px;
    }

    .calculator-section h2 {
        font-size: 0.95rem;
        margin-bottom: 7px;
    }

    form {
        grid-template-columns: 1fr;
        gap: 8px;
        margin-bottom: 8px;
    }

    .input-group input {
        padding: 7px 9px;
        font-size: 16px; /* 移动端保持 16px 防止自动放大 */
    }

    .btn-calculate,
    .btn-reset {
        padding: 8px 16px;
        font-size: 0.8rem;
    }

    .results {
        padding: 10px;
        margin-top: 8px;
    }

    .results h3 {
        font-size: 0.9rem;
        margin-bottom: 8px;
    }

    .result-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 6px;
    }
    
    .result-item {
        padding: 6px;
    }
    
    .result-label {
        font-size: 0.65rem;
    }
    
    .result-value {
        font-size: 1.1rem;
    }
    
    .input-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 6px;
    }
    
    .input-item {
        padding: 6px;
    }
    
    .input-label {
        font-size: 0.65rem;
    }
    
    .input-value {
        font-size: 1rem;
    }
}

@media screen and (max-width: 480px) {
    header h1 {
        font-size: 1.1rem;
    }

    main {
        padding: 8px;
    }

    .calculator-section h2 {
        font-size: 0.9rem;
    }

    .result-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 5px;
    }
    
    .result-item {
        padding: 5px;
    }
    
    .result-label {
        font-size: 0.6rem;
    }
    
    .result-value {
        font-size: 1rem;
    }

    .btn-calculate,
    .btn-reset {
        padding: 7px 14px;
        font-size: 0.75rem;
    }

    footer p {
        font-size: 0.65rem;
    }

    .friend-link a {
        padding: 5px 10px;
        font-size: 0.7rem;
    }
    
    .input-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 5px;
    }
    
    .input-item {
        padding: 5px;
    }
    
    .input-label {
        font-size: 0.6rem;
    }
    
    .input-value {
        font-size: 0.95rem;
    }
}

/* 打印样式 */
@media print {
    body {
        background: #ffffff;
        padding: 0;
    }

    .container {
        max-width: 100%;
    }

    header h1 {
        color: #333333;
        text-shadow: none;
    }

    main {
        box-shadow: none;
    }

    .btn-calculate,
    .btn-reset {
        display: none;
    }
}