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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px 0;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

header h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 10px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.1rem;
    color: #666;
}

.calculator-card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.calculator-form h2 {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid #667eea;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: #2c3e50;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-group small {
    display: block;
    margin-top: 5px;
    color: #666;
    font-size: 0.875rem;
}

.calculate-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.3);
}

.result-card {
    margin-top: 30px;
    padding: 25px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

.result-card.error {
    border-left-color: #e74c3c;
    background: linear-gradient(135deg, #fdf2f2 0%, #fde8e8 100%);
}

.result-card h2 {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 20px;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 25px;
}

.result-item {
    background: white;
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.result-item h3 {
    font-size: 1rem;
    color: #666;
    margin-bottom: 10px;
}

.result-value {
    font-size: 1.4rem;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 5px;
}

.result-note {
    font-size: 0.875rem;
    color: #888;
}

.checkup-list {
    list-style: none;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.checkup-list li {
    padding: 10px 0;
    border-bottom: 1px solid #eee;
}

.checkup-list li:last-child {
    border-bottom: none;
}

.info-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.info-card {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.info-card h3 {
    font-size: 1.3rem;
    color: #2c3e50;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #667eea;
}

.info-card h4 {
    font-size: 1.1rem;
    color: #2c3e50;
    margin: 20px 0 10px;
}

.info-card ul {
    margin-left: 20px;
    margin-bottom: 15px;
}

.info-card li {
    margin-bottom: 8px;
}

footer {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.footer-links h3 {
    font-size: 1.2rem;
    color: #2c3e50;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid #eee;
}

.links-container {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

.links-container a {
    color: #667eea;
    text-decoration: none;
    padding: 5px 10px;
    border-radius: 4px;
    transition: background-color 0.2s ease;
}

.links-container a:hover {
    background-color: #f0f2ff;
}

.copyright {
    text-align: center;
    margin-top: 25px;
    padding-top: 20px;
    border-top: 1px solid #eee;
    color: #666;
}

.copyright a {
    color: #667eea;
    text-decoration: none;
}

.copyright a:hover {
    text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .info-section {
        grid-template-columns: 1fr;
    }
    
    .result-grid {
        grid-template-columns: 1fr;
    }
    
    .calculator-card, .info-card, footer {
        padding: 20px;
    }
}