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

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: #f5f5f5;
    line-height: 1.6;
}

header {
    background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    color: white;
    padding: 15px;
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

header .logo h1 {
    font-size: 24px;
    margin-bottom: 2px;
}

header .logo p {
    font-size: 12px;
    opacity: 0.9;
}

header nav {
    margin-top: 10px;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
}

header nav a {
    color: white;
    text-decoration: none;
    font-size: 14px;
    padding: 5px 10px;
    border-radius: 5px;
    transition: background 0.3s;
}

header nav a:hover {
    background: rgba(255, 255, 255, 0.2);
}

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 20px;
    text-align: center;
}

.hero-content h2 {
    font-size: 28px;
    margin-bottom: 15px;
}

.hero-content p {
    font-size: 16px;
    margin-bottom: 25px;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    background: #e74c3c;
    color: white;
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
}

.btn:hover {
    background: #c0392b;
    transform: scale(1.05);
}

.about, .services, .contact, .products-header, .buy-tips {
    padding: 30px 20px;
    background: white;
    margin: 15px;
    border-radius: 15px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.about h3, .services h3, .contact h3, .products-header h2, .buy-tips h3 {
    color: #2c3e50;
    font-size: 22px;
    margin-bottom: 20px;
    text-align: center;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}

.about-content p {
    color: #666;
    margin-bottom: 12px;
    font-size: 15px;
    text-align: justify;
}

.service-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.service-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    transition: transform 0.3s;
}

.service-item:hover {
    transform: translateY(-5px);
}

.service-icon {
    font-size: 36px;
    margin-bottom: 10px;
}

.service-item h4 {
    color: #2c3e50;
    margin-bottom: 8px;
    font-size: 16px;
}

.service-item p {
    color: #666;
    font-size: 13px;
    line-height: 1.5;
}

.contact-info p {
    color: #666;
    font-size: 16px;
    margin-bottom: 10px;
    text-align: center;
}

footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 20px;
    margin-top: 15px;
}

footer p {
    font-size: 13px;
    margin-bottom: 5px;
    opacity: 0.8;
}

.products-header {
    text-align: center;
}

.products-header h2 {
    font-size: 26px;
}

.products-header p {
    color: #666;
    margin-top: 10px;
}

.products {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    padding: 0 20px;
}

.product-card {
    background: white;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
    position: relative;
    transition: transform 0.3s, box-shadow 0.3s;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 5px 25px rgba(0,0,0,0.15);
}

.product-card.featured {
    border: 2px solid #3498db;
}

.featured-badge {
    position: absolute;
    top: -10px;
    right: 20px;
    background: #e74c3c;
    color: white;
    padding: 3px 12px;
    border-radius: 10px;
    font-size: 12px;
    font-weight: bold;
}

.product-card .price {
    font-size: 36px;
    font-weight: bold;
    color: #e74c3c;
    margin-bottom: 15px;
}

.product-card h3 {
    color: #2c3e50;
    font-size: 20px;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
}

.product-card ul {
    list-style: none;
    margin-bottom: 20px;
}

.product-card li {
    color: #666;
    font-size: 14px;
    padding: 8px 0;
    border-bottom: 1px dashed #eee;
    position: relative;
    padding-left: 20px;
}

.product-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #27ae60;
    font-weight: bold;
}

.buy-btn {
    width: 100%;
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    color: white;
    border: none;
    padding: 15px;
    border-radius: 30px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
}

.buy-btn:hover {
    background: linear-gradient(135deg, #2980b9 0%, #2c3e50 100%);
    transform: scale(1.02);
}

.buy-tips ul {
    list-style: none;
}

.buy-tips li {
    color: #666;
    font-size: 14px;
    padding: 10px 0;
    border-bottom: 1px dashed #eee;
    position: relative;
    padding-left: 25px;
}

.buy-tips li::before {
    content: '💡';
    position: absolute;
    left: 0;
}

.product-detail {
    padding: 20px;
}

.detail-header {
    background: white;
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    margin-bottom: 15px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
    position: relative;
}

.featured-badge-detail {
    position: absolute;
    top: -10px;
    right: 30px;
    background: #e74c3c;
    color: white;
    padding: 3px 15px;
    border-radius: 10px;
    font-size: 12px;
    font-weight: bold;
}

.detail-header .price {
    font-size: 48px;
    font-weight: bold;
    color: #e74c3c;
    margin-bottom: 10px;
}

.detail-header h2 {
    color: #2c3e50;
    font-size: 28px;
}

.detail-features {
    background: white;
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 15px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
}

.detail-features h3 {
    color: #2c3e50;
    font-size: 20px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}

.detail-features ul {
    list-style: none;
}

.detail-features li {
    color: #666;
    font-size: 15px;
    padding: 12px 0;
    border-bottom: 1px dashed #eee;
    position: relative;
    padding-left: 25px;
}

.detail-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #27ae60;
    font-weight: bold;
    font-size: 16px;
}

.detail-form {
    background: white;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
}

.detail-form h3 {
    color: #2c3e50;
    font-size: 20px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}

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

.form-group label {
    display: block;
    color: #333;
    font-size: 15px;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #ddd;
    border-radius: 10px;
    font-size: 15px;
    font-family: inherit;
    transition: border-color 0.3s;
    background: #fafafa;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #3498db;
    background: white;
}

.form-group textarea {
    resize: none;
    min-height: 100px;
}

.submit-btn {
    width: 100%;
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    color: white;
    border: none;
    padding: 16px;
    border-radius: 30px;
    font-size: 17px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
    margin-top: 10px;
}

.submit-btn:hover {
    background: linear-gradient(135deg, #2980b9 0%, #2c3e50 100%);
    transform: scale(1.02);
}

@media (min-width: 768px) {
    body {
        max-width: 600px;
        margin: 0 auto;
        background: #e8ecef;
    }
    
    .hero-content h2 {
        font-size: 32px;
    }
    
    .service-list {
        grid-template-columns: repeat(4, 1fr);
    }
}