/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-blue: #0066cc;
    --secondary-blue: #0052a3;
    --light-blue: #e6f2ff;
    --dark-blue: #003366;
    --text-primary: #333;
    --text-secondary: #666;
    --text-light: #999;
    --white: #ffffff;
    --gray-light: #f5f5f5;
    --gray-medium: #e0e0e0;
    --success-green: #28a745;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--white);
}

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

/* 导航栏 */
.navbar {
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.nav-logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-blue);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: var(--primary-blue);
}

.nav-btn {
    background: var(--primary-blue);
    color: var(--white);
    border: none;
    padding: 10px 24px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 500;
    transition: background 0.3s;
}

.nav-btn:hover {
    background: var(--secondary-blue);
}

/* 首屏横幅 */
.hero-section {
    background: linear-gradient(135deg, var(--light-blue) 0%, #cce7ff 100%);
    padding: 100px 0;
    text-align: center;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    color: var(--dark-blue);
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 50px;
}

.btn {
    padding: 15px 35px;
    border-radius: 30px;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

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

.btn-primary:hover {
    background: var(--secondary-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-secondary:hover {
    background: var(--primary-blue);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-large {
    padding: 18px 40px;
    font-size: 18px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 80px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 42px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 5px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-secondary);
}

/* 板块通用样式 */
section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 700;
    color: var(--dark-blue);
    margin-bottom: 50px;
}

/* 核心功能板块 */
.features-section {
    background: var(--gray-light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 22px;
    color: var(--dark-blue);
    margin-bottom: 15px;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 安全承诺板块 */
.security-section {
    background: var(--white);
}

.security-content {
    max-width: 800px;
    margin: 0 auto;
}

.security-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 30px;
    padding: 25px;
    background: var(--light-blue);
    border-radius: 10px;
}

.security-check {
    font-size: 24px;
    font-weight: bold;
    color: var(--success-green);
    min-width: 30px;
}

.security-text h3 {
    font-size: 20px;
    color: var(--dark-blue);
    margin-bottom: 10px;
}

.security-text p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 用户评价板块 */
.reviews-section {
    background: var(--gray-light);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.review-card {
    background: var(--white);
    padding: 35px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.review-stars {
    color: #ffc107;
    font-size: 20px;
    margin-bottom: 15px;
}

.review-text {
    color: var(--text-secondary);
    line-height: 1.8;
    font-style: italic;
    margin-bottom: 25px;
}

.review-author {
    display: flex;
    align-items: center;
    gap: 15px;
}

.author-avatar {
    width: 50px;
    height: 50px;
    background: var(--primary-blue);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: bold;
}

.author-name {
    font-weight: 600;
    color: var(--dark-blue);
    margin-bottom: 3px;
}

.author-title {
    font-size: 13px;
    color: var(--text-light);
}

/* 套餐选择板块 */
.pricing-section {
    background: var(--white);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    align-items: stretch;
}

.pricing-card {
    background: var(--white);
    border: 2px solid var(--gray-medium);
    border-radius: 15px;
    padding: 40px 30px;
    text-align: center;
    transition: all 0.3s;
    position: relative;
}

.pricing-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.pricing-popular {
    border-color: var(--primary-blue);
    box-shadow: var(--shadow-lg);
}

.popular-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-blue);
    color: var(--white);
    padding: 5px 20px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
}

.pricing-title {
    font-size: 24px;
    color: var(--dark-blue);
    margin-bottom: 20px;
}

.pricing-price {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.pricing-price span {
    font-size: 18px;
    font-weight: normal;
    color: var(--text-secondary);
}

.pricing-save {
    color: var(--success-green);
    font-weight: 600;
    margin-bottom: 25px;
}

.pricing-features {
    list-style: none;
    margin-bottom: 30px;
    text-align: left;
}

.pricing-features li {
    padding: 10px 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--gray-light);
}

.pricing-features li:last-child {
    border-bottom: none;
}

.pricing-card .btn {
    width: 100%;
    justify-content: center;
}

/* 常见问题板块 */
.faq-section {
    background: var(--gray-light);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--white);
    margin-bottom: 15px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.faq-question {
    padding: 25px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: background 0.3s;
}

.faq-question:hover {
    background: var(--light-blue);
}

.faq-question h3 {
    font-size: 18px;
    color: var(--dark-blue);
    margin: 0;
    flex: 1;
}

.faq-icon {
    font-size: 24px;
    color: var(--primary-blue);
    font-weight: bold;
    transition: transform 0.3s;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background: var(--light-blue);
}

.faq-answer p {
    padding: 0 30px 25px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

/* 页脚 */
.footer {
    background: var(--dark-blue);
    color: var(--white);
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 24px;
    margin-bottom: 15px;
}

.footer-section h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--light-blue);
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
}

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

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

.footer-section ul a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s;
}

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

/* 友情链接 */
.friendly-links {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 30px 0;
    margin-bottom: 20px;
}

.friendly-links h4 {
    font-size: 18px;
    color: var(--light-blue);
    margin-bottom: 20px;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 15px;
}

.links-grid a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    padding: 8px 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    text-align: center;
    transition: all 0.3s;
    display: block;
}

.links-grid a:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav-menu {
        flex-direction: column;
        align-items: center;
        gap: 15px;
    }

    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .hero-stats {
        flex-direction: column;
        gap: 30px;
    }

    .section-title {
        font-size: 28px;
    }

    .features-grid,
    .reviews-grid,
    .pricing-grid {
        grid-template-columns: 1fr;
    }

    .security-item {
        flex-direction: column;
        text-align: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-section {
        padding: 60px 0;
    }

    .hero-title {
        font-size: 24px;
    }

    section {
        padding: 50px 0;
    }
}