/* 重置和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #000;
    --secondary-color: #666;
    --accent-color: #0070f3;
    --bg-color: #fff;
    --text-color: #000;
    --border-color: #e5e5e5;
    --max-width: 1200px;
    --spacing: 2rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    /* 移动端滚动优化 */
    -webkit-overflow-scrolling: touch;
    overflow-x: hidden;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 移动端容器优化 */
@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
}

/* 导航栏 */
.header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
    text-decoration: none;
}

.brand-subtitle {
    font-size: 0.875rem;
    color: var(--secondary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 0.9375rem;
    transition: color 0.2s;
}

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

.nav-login {
    color: var(--secondary-color);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.lang-toggle {
    background: none;
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 28px;
    height: 28px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1001;
}

.mobile-menu-toggle span {
    width: 100%;
    height: 2px;
    background: var(--text-color);
    border-radius: 2px;
    transition: all 0.3s;
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding-top: 80px;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
}

.mobile-menu.active {
    transform: translateX(0);
}

.mobile-menu-list {
    list-style: none;
    padding: 2rem;
}

.mobile-menu-list li {
    margin-bottom: 1.5rem;
}

.mobile-menu-list a {
    display: block;
    font-size: 1.125rem;
    color: var(--text-color);
    text-decoration: none;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    transition: color 0.2s;
}

.mobile-menu-list a:hover {
    color: var(--accent-color);
}

.mobile-cta {
    width: 100%;
    margin-top: 1rem;
}

.cta-button {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    /* 移动端触摸优化 */
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    user-select: none;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.cta-button:hover {
    background: #333;
    transform: translateY(-1px);
}

.cta-button:active {
    transform: translateY(0);
    opacity: 0.9;
}

.cta-button.primary {
    background: var(--accent-color);
}

.cta-button.primary:hover {
    background: #0051cc;
}

.cta-button.primary:active {
    background: #0040a3;
}

.cta-button:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

.nav-cta {
    margin-left: 1rem;
}

/* 英雄区域 */
.hero {
    padding: 4rem 0 6rem;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    background: #f5f5f5;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    margin-bottom: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    display: block;
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--secondary-color);
    margin-top: 0.5rem;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--secondary-color);
    max-width: 700px;
    margin: 0 auto 2.5rem;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.member-link {
    font-size: 0.9375rem;
    color: var(--secondary-color);
}

.member-link a {
    color: var(--accent-color);
    text-decoration: none;
    margin-left: 0.5rem;
}

.link {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 0.9375rem;
}

.link:hover {
    text-decoration: underline;
}

/* 特性介绍 */
.features {
    padding: 4rem 0;
    background: #fafafa;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 8px;
    transition: transform 0.2s;
}

.feature-card:hover {
    transform: translateY(-4px);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.feature-card p {
    color: var(--secondary-color);
    font-size: 0.9375rem;
}

/* 欢迎区域 */
.welcome-section {
    padding: 6rem 0;
    text-align: center;
}

.welcome-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.welcome-description {
    font-size: 1.125rem;
    color: var(--secondary-color);
    max-width: 800px;
    margin: 0 auto 2.5rem;
    line-height: 1.8;
}

.welcome-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

/* 社交证明 */
.social-proof {
    padding: 4rem 0;
    background: #fafafa;
}

.proof-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    text-align: center;
}

.proof-number {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.proof-label {
    color: var(--secondary-color);
    font-size: 0.9375rem;
}

/* 早期成员招募 */
.early-bird {
    padding: 6rem 0;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.early-bird-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
}

.early-bird h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.early-bird-description {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    line-height: 1.8;
}

.pricing-comparison {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

.price-old {
    font-size: 2rem;
    text-decoration: line-through;
    opacity: 0.7;
}

.price-new {
    font-size: 3rem;
    font-weight: 700;
}

.price-label {
    font-size: 0.875rem;
    opacity: 0.9;
}

/* 课程部分 */
.courses {
    padding: 6rem 0;
}

.courses h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-align: center;
}

.section-description {
    text-align: center;
    color: var(--secondary-color);
    max-width: 800px;
    margin: 0 auto 2rem;
    font-size: 1.125rem;
}

.courses-section {
    margin-top: 4rem;
}

.courses-section h3 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.course-badge {
    display: inline-block;
    background: #e8f5e9;
    color: #2e7d32;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.course-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    transition: all 0.2s;
}

.course-card:hover {
    border-color: var(--accent-color);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    transform: translateY(-2px);
}

.course-badge-small {
    display: inline-block;
    background: #fff3e0;
    color: #e65100;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    margin-bottom: 0.75rem;
}

.course-card h4 {
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.course-card p {
    color: var(--secondary-color);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* 团队介绍 */
.team {
    padding: 6rem 0;
    background: #fafafa;
    text-align: center;
}

.team h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.team-member {
    text-align: center;
}

.team-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 600;
    margin: 0 auto 1rem;
}

.team-member h4 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.team-member p {
    color: var(--secondary-color);
    font-size: 0.875rem;
}

/* 故事部分 */
.story {
    padding: 6rem 0;
}

.story h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.story h3 {
    font-size: 1.75rem;
    margin: 2rem 0 1rem;
}

.story p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
}

/* 社区部分 */
.community {
    padding: 6rem 0;
    background: #fafafa;
}

.community h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 1rem;
}

.community-badge {
    text-align: center;
    color: #2e7d32;
    font-weight: 500;
    margin-bottom: 3rem;
}

.community-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.community-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
}

.community-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.community-card h4 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.community-card p {
    color: var(--secondary-color);
    font-size: 0.9375rem;
}

/* 定价部分 */
.pricing {
    padding: 6rem 0;
}

.pricing h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 1rem;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.pricing-card {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: all 0.2s;
}

.pricing-card.featured {
    border-color: var(--accent-color);
    transform: scale(1.05);
}

.pricing-badge {
    display: inline-block;
    background: #fff3e0;
    color: #e65100;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.pricing-price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 0.25rem;
    margin: 1.5rem 0;
}

.pricing-price .currency {
    font-size: 1.5rem;
}

.pricing-price .amount {
    font-size: 3rem;
    font-weight: 700;
}

.pricing-price .period {
    font-size: 1.25rem;
    color: var(--secondary-color);
}

.pricing-label {
    color: var(--secondary-color);
    font-size: 0.9375rem;
    margin-bottom: 1.5rem;
}

.pricing-features {
    list-style: none;
    text-align: left;
    margin: 2rem 0;
}

.pricing-features li {
    padding: 0.75rem 0;
    color: var(--secondary-color);
    border-bottom: 1px solid var(--border-color);
}

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

/* FAQ */
.faq {
    padding: 6rem 0;
    background: #fafafa;
}

.faq h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
}

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

.faq-item {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.faq-item h4 {
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
}

.faq-item p {
    color: var(--secondary-color);
    line-height: 1.6;
}

/* 最终CTA */
.final-cta {
    padding: 6rem 0;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.final-cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.final-cta p {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    line-height: 1.8;
}

/* 页脚 */
.footer {
    padding: 4rem 0 2rem;
    background: #1a1a1a;
    color: white;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-brand .logo-text {
    color: white;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.footer-brand .brand-subtitle {
    color: #999;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.footer-brand p {
    color: #999;
    font-size: 0.9375rem;
}

.footer-links h4 {
    margin-bottom: 1rem;
}

.footer-links a {
    display: block;
    color: #999;
    text-decoration: none;
    margin-bottom: 0.5rem;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: white;
}

.footer-copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #333;
    color: #999;
    font-size: 0.875rem;
}

/* 响应式设计 */

/* 平板和移动端 (768px 及以下) */
@media (max-width: 768px) {
    .nav {
        padding: 0.75rem 1rem;
    }
    
    .nav-menu {
        display: none;
    }
    
    .nav-actions {
        gap: 0.5rem;
    }
    
    .lang-toggle {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .mobile-menu {
        display: block;
    }
    
    .nav-cta {
        display: none;
    }
    
    /* 英雄区域优化 */
    .hero {
        padding: 2rem 0 4rem;
    }
    
    .hero-badge {
        font-size: 0.75rem;
        padding: 0.4rem 0.8rem;
        margin-bottom: 1.5rem;
    }
    
    .hero-title {
        font-size: 2rem;
        line-height: 1.3;
        margin-bottom: 1rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
        margin-top: 0.5rem;
    }
    
    .hero-description {
        font-size: 1rem;
        margin-bottom: 2rem;
        padding: 0 0.5rem;
    }
    
    .hero-actions {
        gap: 1rem;
    }
    
    .cta-button {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
        min-height: 44px; /* 触摸目标优化 */
    }
    
    /* 特性网格 */
    .features {
        padding: 3rem 0;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .feature-card {
        padding: 1.5rem;
    }
    
    .feature-icon {
        font-size: 2.5rem;
    }
    
    /* 欢迎区域 */
    .welcome-section {
        padding: 4rem 0;
    }
    
    .welcome-section h2 {
        font-size: 1.75rem;
        margin-bottom: 1rem;
    }
    
    .welcome-description {
        font-size: 1rem;
        margin-bottom: 2rem;
    }
    
    /* 社交证明 */
    .social-proof {
        padding: 3rem 0;
    }
    
    .proof-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .proof-number {
        font-size: 2rem;
    }
    
    /* 早期成员 */
    .early-bird {
        padding: 4rem 0;
    }
    
    .early-bird h2 {
        font-size: 1.75rem;
    }
    
    .early-bird-description {
        font-size: 1rem;
        padding: 0 1rem;
    }
    
    .pricing-comparison {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .price-new {
        font-size: 2.5rem;
    }
    
    /* 课程部分 */
    .courses {
        padding: 4rem 0;
    }
    
    .courses h2 {
        font-size: 1.75rem;
    }
    
    .section-description {
        font-size: 1rem;
        padding: 0 0.5rem;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }
    
    .course-card {
        padding: 1.25rem;
    }
    
    .course-card h4 {
        font-size: 1rem;
    }
    
    /* 团队 */
    .team {
        padding: 4rem 0;
    }
    
    .team h2 {
        font-size: 1.75rem;
    }
    
    .team-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
    
    .team-avatar {
        width: 60px;
        height: 60px;
        font-size: 1.5rem;
    }
    
    /* 故事 */
    .story {
        padding: 4rem 0;
    }
    
    .story h2 {
        font-size: 1.75rem;
    }
    
    .story h3 {
        font-size: 1.5rem;
    }
    
    .story p {
        font-size: 1rem;
    }
    
    /* 社区 */
    .community {
        padding: 4rem 0;
    }
    
    .community h2 {
        font-size: 1.75rem;
    }
    
    .community-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    /* 定价 */
    .pricing {
        padding: 4rem 0;
    }
    
    .pricing h2 {
        font-size: 1.75rem;
    }
    
    .pricing-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .pricing-card {
        padding: 1.5rem;
    }
    
    .pricing-card.featured {
        transform: none;
        border-width: 3px;
    }
    
    .pricing-price .amount {
        font-size: 2.5rem;
    }
    
    /* FAQ */
    .faq {
        padding: 4rem 0;
    }
    
    .faq h2 {
        font-size: 1.75rem;
    }
    
    .faq-item {
        padding: 1.25rem;
    }
    
    .faq-item h4 {
        font-size: 1rem;
    }
    
    /* 最终CTA */
    .final-cta {
        padding: 4rem 0;
    }
    
    .final-cta h2 {
        font-size: 1.75rem;
    }
    
    .final-cta p {
        font-size: 1rem;
        padding: 0 1rem;
    }
    
    /* 页脚 */
    .footer {
        padding: 3rem 0 1.5rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

/* 小屏手机 (480px 及以下) */
@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .hero-subtitle {
        font-size: 0.9rem;
    }
    
    .hero-description {
        font-size: 0.9375rem;
    }
    
    .welcome-section h2,
    .early-bird h2,
    .courses h2,
    .team h2,
    .story h2,
    .community h2,
    .pricing h2,
    .faq h2,
    .final-cta h2 {
        font-size: 1.5rem;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
    }
    
    .pricing-price .amount {
        font-size: 2rem;
    }
    
    .proof-number {
        font-size: 1.75rem;
    }
    
    .feature-card,
    .course-card,
    .community-card,
    .pricing-card {
        padding: 1rem;
    }
}

/* 横屏优化 */
@media (max-width: 768px) and (orientation: landscape) {
    .hero {
        padding: 2rem 0 3rem;
    }
    
    .mobile-menu {
        padding-top: 60px;
    }
}

/* 触摸设备优化 */
@media (hover: none) and (pointer: coarse) {
    .cta-button,
    .link,
    .nav-menu a {
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }
    
    .feature-card:hover,
    .course-card:hover {
        transform: none;
    }
    
    /* 移动端链接触摸反馈 */
    a {
        -webkit-tap-highlight-color: rgba(0, 112, 243, 0.2);
    }
    
    /* 移除移动端悬停效果 */
    .feature-card:hover,
    .course-card:hover,
    .community-card:hover {
        box-shadow: none;
        transform: none;
    }
    
    /* 添加点击反馈 */
    .feature-card:active,
    .course-card:active,
    .community-card:active {
        opacity: 0.8;
        transform: scale(0.98);
    }
}