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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    text-decoration: none;
    color: #fff;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

nav ul li a:hover {
    opacity: 0.8;
}

/* 主要内容区域 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 80px 20px;
    text-align: center;
    margin-bottom: 60px;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-button {
    display: inline-block;
    padding: 15px 40px;
    background: #fff;
    color: #667eea;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

/* 卡片布局 */
.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 40px 0;
}

.card {
    background: #fff;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.card h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

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

/* 统计信息 */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin: 60px 0;
}

.stat-item {
    text-align: center;
    padding: 2rem;
    background: #fff;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.stat-number {
    font-size: 3rem;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: #666;
    font-size: 1.1rem;
}

/* 课程网格 */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 40px 0;
}

.course-card {
    background: #fff;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.course-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: #fff;
}

.course-content {
    padding: 1.5rem;
}

.course-title {
    color: #333;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.course-description {
    color: #666;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    color: #999;
    font-size: 0.9rem;
}

/* 表单样式 */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #333;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

.submit-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 15px 40px;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
}

.submit-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

/* 页脚 */
footer {
    background: #2c3e50;
    color: #fff;
    text-align: center;
    padding: 3rem 2rem;
    margin-top: 80px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 2rem 0;
}

.social-links a {
    color: #fff;
    font-size: 1.5rem;
    text-decoration: none;
    transition: opacity 0.3s;
}

.social-links a:hover {
    opacity: 0.7;
}

.footer-bottom {
    border-top: 1px solid #444;
    padding-top: 2rem;
    margin-top: 2rem;
    color: #aaa;
    font-size: 0.9rem;
}

/* 关于我们样式 */
.about-section {
    background: #fff;
    padding: 3rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    margin: 40px 0;
}

.about-section h2 {
    color: #667eea;
    margin-bottom: 1.5rem;
    font-size: 2.5rem;
}

.about-section p {
    color: #666;
    line-height: 1.8;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
    }

    nav ul {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1.1rem;
    }

    .cards,
    .courses-grid {
        grid-template-columns: 1fr;
    }

    .stats {
        grid-template-columns: 1fr;
    }
}

/* 页内标题 */
.page-header {
    text-align: center;
    padding: 60px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    margin-bottom: 40px;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* 特色区域 */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 60px 0;
}

.feature {
    text-align: center;
    padding: 2rem;
    background: #fff;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.feature-icon {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.feature h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.feature p {
    color: #666;
    line-height: 1.6;
}

/* 面包屑导航 */
.breadcrumb {
    padding: 1rem 0;
    color: #666;
}

.breadcrumb a {
    color: #667eea;
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

/* 联系信息卡片 */
.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 40px 0;
}

.contact-card {
    background: #fff;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
}

.contact-card h3 {
    color: #667eea;
    margin-bottom: 1rem;
}

.contact-card p {
    color: #666;
    line-height: 1.8;
}