:root {
    --primary-color: #0052d9;
    --primary-hover: #003cab;
    --primary-light: #e6f0ff;
    --secondary-color: #00a870;
    --danger-color: #e34d59;
    --warning-color: #ed7b2f;
    --success-color: #00a870;
    --text-primary: #1d2129;
    --text-secondary: #4e5969;
    --text-tertiary: #86909c;
    --text-disabled: #c9cdd4;
    --border-color: #e5e6eb;
    --bg-color: #f2f3f5;
    --bg-white: #ffffff;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-white);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-hover);
}

img {
    max-width: 100%;
    height: auto;
}

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

.page-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.main {
    flex: 1;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 16px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    color: white;
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: white;
}

.btn-lg {
    padding: 12px 24px;
    font-size: 16px;
}

.btn-sm {
    padding: 4px 12px;
    font-size: 12px;
}

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
}

.header-top {
    background-color: #f8f9fa;
    border-bottom: 1px solid var(--border-color);
    padding: 8px 0;
    font-size: 12px;
}

.header-top-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-top-left {
    display: flex;
    gap: 20px;
    color: var(--text-secondary);
}

.header-top-left i {
    margin-right: 4px;
    color: var(--primary-color);
}

.header-top-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.header-top-right a {
    color: var(--text-secondary);
}

.header-top-right a:hover {
    color: var(--primary-color);
}

.btn-register {
    background-color: var(--primary-color);
    color: white !important;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
}

.btn-register:hover {
    background-color: var(--primary-hover);
}

.navbar {
    padding: 12px 0;
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-brand a {
    display: flex;
    align-items: center;
    gap: 10px;
}

.navbar-brand .logo {
    height: 40px;
}

.navbar-brand .brand-name {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
}

.navbar-menu {
    flex: 1;
    display: flex;
    justify-content: center;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-item {
    position: relative;
}

.nav-item > a {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 8px 0;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

.nav-item > a:hover,
.nav-item.active > a {
    color: var(--primary-color);
}

.nav-item > a i {
    font-size: 12px;
    transition: var(--transition);
}

.nav-item.has-dropdown:hover > a i {
    transform: rotate(180deg);
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    min-width: 600px;
    background-color: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    padding: 24px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    margin-top: 10px;
}

.nav-item.has-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    margin-top: 0;
}

.dropdown-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.dropdown-column h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.dropdown-column a {
    display: block;
    padding: 6px 0;
    color: var(--text-secondary);
    font-size: 13px;
}

.dropdown-column a:hover {
    color: var(--primary-color);
}

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-primary);
}

.hero {
    position: relative;
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,154.7C960,171,1056,181,1152,165.3C1248,149,1344,107,1392,85.3L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: cover;
    background-position: bottom;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
}

.hero-subtitle {
    font-size: 20px;
    opacity: 0.9;
    margin-bottom: 32px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 40px;
}

.hero-actions .btn-outline {
    border-color: white;
    color: white;
}

.hero-actions .btn-outline:hover {
    background-color: white;
    color: var(--primary-color);
}

.hero-features {
    display: flex;
    gap: 32px;
    justify-content: center;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.feature-item i {
    color: #00d4aa;
}

.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
}

.products {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.product-card {
    background-color: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    border: 1px solid var(--border-color);
}

.product-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.product-card.featured {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.product-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    background-color: var(--danger-color);
    color: white;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 12px;
}

.product-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-light) 0%, #d6e4ff 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.product-icon i {
    font-size: 32px;
    color: var(--primary-color);
}

.product-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.product-desc {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.6;
}

.product-features {
    list-style: none;
    text-align: left;
    margin-bottom: 24px;
}

.product-features li {
    padding: 6px 0;
    color: var(--text-secondary);
    font-size: 13px;
}

.product-features i {
    color: var(--success-color);
    margin-right: 8px;
}

.stats {
    padding: 60px 0;
    background-color: var(--bg-white);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    text-align: center;
}

.stat-item {
    padding: 24px;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 16px;
    color: var(--text-secondary);
}

.advantages {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.advantage-item {
    background-color: var(--bg-white);
    padding: 32px;
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
}

.advantage-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.advantage-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-light) 0%, #d6e4ff 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.advantage-icon i {
    font-size: 32px;
    color: var(--primary-color);
}

.advantage-item h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.advantage-item p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta-content h2 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 12px;
}

.cta-content p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 32px;
}

.cta-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}

.cta-actions .btn-outline {
    border-color: white;
    color: white;
}

.cta-actions .btn-outline:hover {
    background-color: white;
    color: var(--primary-color);
}

.footer {
    background-color: #2c2c2c;
    color: #999;
    font-size: 13px;
}

.footer-top {
    background-color: #2c2c2c;
    padding: 40px 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr 1fr 1.5fr;
    gap: 40px;
}

.footer-section {
    margin-bottom: 20px;
}

.footer-brand .footer-logo {
    height: 40px;
    margin-bottom: 12px;
}

.footer-brand h4 {
    color: #fff;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
}

.footer-brand p {
    font-size: 13px;
    margin-bottom: 16px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background-color: #444;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    transition: var(--transition);
}

.social-link:hover {
    background-color: var(--primary-color);
    color: white;
}

.footer-section h5 {
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 1px solid #444;
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: #999;
    transition: var(--transition);
    font-size: 13px;
}

.footer-section ul li a:hover {
    color: var(--primary-color);
}

.contact-section .contact-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 16px;
}

.contact-section .contact-item i {
    font-size: 18px;
    color: var(--primary-color);
    margin-top: 2px;
}

.contact-section .contact-item div {
    display: flex;
    flex-direction: column;
}

.contact-label {
    font-size: 12px;
    color: #777;
    margin-bottom: 2px;
}

.contact-value {
    color: #fff;
    font-size: 14px;
}

.footer-middle {
    background-color: #252525;
    padding: 16px 0;
}

.payment-methods {
    display: flex;
    align-items: center;
    gap: 20px;
}

.payment-label {
    color: #777;
    font-size: 13px;
}

.payment-icons {
    display: flex;
    gap: 16px;
}

.payment-icon {
    display: flex;
    align-items: center;
    gap: 6px;
    color: #999;
    font-size: 13px;
}

.payment-icon i {
    font-size: 18px;
}

.footer-bottom {
    background-color: #1a1a1a;
    padding: 20px 0;
}

.footer-bottom-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.footer-links {
    display: flex;
    align-items: center;
    gap: 12px;
}

.footer-links a {
    color: #777;
    font-size: 13px;
}

.footer-links a:hover {
    color: var(--primary-color);
}

.footer-links .divider {
    color: #555;
}

.footer-legal {
    text-align: center;
}

.footer-legal p {
    margin: 4px 0;
    font-size: 12px;
}

.footer-legal a {
    color: #777;
}

.footer-legal a:hover {
    color: var(--primary-color);
}

@media (max-width: 1024px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-top {
        display: none;
    }
    
    .navbar-menu {
        display: none;
    }
    
    .navbar-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-features {
        flex-direction: column;
        gap: 16px;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .advantages-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}