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

body {
    font-family: 'PingFang SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f7fa;
}

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

/* 导航栏 */
.navbar {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    padding: 1rem 0;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.navbar-brand {
    display: flex;
    align-items: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 600;
}

.logo {
    font-size: 1.8rem;
    margin-right: 8px;
}

.navbar-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 20px;
}

.nav-link:hover,
.nav-link.active {
    background-color: rgba(255, 255, 255, 0.2);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    z-index: 999;
}

.mobile-menu ul {
    list-style: none;
    padding: 1rem;
}

.mobile-menu li {
    margin: 0.5rem 0;
}

.mobile-menu a {
    color: white;
    text-decoration: none;
    display: block;
    padding: 0.75rem;
    border-radius: 8px;
    transition: background-color 0.3s;
}

.mobile-menu a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    padding: 120px 0 80px;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn-primary {
    background-color: white;
    color: #4facfe;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(255, 255, 255, 0.3);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: white;
    color: #4facfe;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-top: 4rem;
    flex-wrap: wrap;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* 通用区块样式 */
.section {
    padding: 60px 0;
}

.section-title {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 0.5rem;
}

.section-desc {
    text-align: center;
    color: #666;
    margin-bottom: 3rem;
}

.bg-light {
    background-color: #f5f7fa;
}

/* 卡片网格 */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.12);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.card-desc {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.6;
}

/* 学习路径 */
.steps {
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    margin-bottom: 2rem;
    padding: 2rem;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.step-number {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #333;
}

.step-content p {
    color: #666;
    margin-bottom: 1rem;
}

.step-tips {
    list-style: none;
    padding-left: 0;
}

.step-tips li {
    color: #4facfe;
    padding: 0.25rem 0;
    position: relative;
    padding-left: 1rem;
}

.step-tips li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #4facfe;
}

/* 学习资源 */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.resource-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.resource-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.resource-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.resource-list {
    list-style: none;
    padding-left: 0;
}

.resource-list li {
    color: #666;
    padding: 0.5rem 0;
    border-bottom: 1px solid #eee;
}

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

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

.faq-item {
    background: white;
    border-radius: 12px;
    margin-bottom: 1rem;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.faq-question {
    width: 100%;
    padding: 1.25rem;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: #333;
    display: flex;
    align-items: center;
    position: relative;
}

.faq-question::after {
    content: "+";
    position: absolute;
    right: 1rem;
    font-size: 1.5rem;
    transition: transform 0.3s;
}

.faq-question.active::after {
    transform: rotate(45deg);
}

.faq-question span {
    color: #4facfe;
    margin-right: 0.5rem;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-answer.active {
    max-height: 200px;
}

.faq-answer p {
    padding: 0 1.25rem 1.25rem;
    color: #666;
    line-height: 1.8;
}

/* 页脚 */
.footer {
    background: #333;
    color: white;
    padding: 40px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    gap: 2rem;
    flex-wrap: wrap;
}

.footer-section {
    flex: 1;
    min-width: 200px;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: #4facfe;
}

.footer-section p {
    color: #aaa;
    margin: 0.25rem 0;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    text-decoration: none;
    transition: background-color 0.3s;
}

.social-link:hover {
    background: rgba(255, 255, 255, 0.2);
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #aaa;
    font-size: 0.9rem;
}

.copyright-info {
    font-size: 0.75rem;
    color: #666;
    margin-top: 0.5rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar-menu {
        display: none;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-stats {
        gap: 2rem;
    }
    
    .stat-number {
        font-size: 1.75rem;
    }
    
    .step {
        flex-direction: column;
        gap: 1rem;
    }
    
    .step-number {
        align-self: flex-start;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .social-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .section {
        padding: 40px 0;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .cards-grid,
    .resources-grid {
        grid-template-columns: 1fr;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 高亮颜色 */
.muted {
    color: #999;
}