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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: #333;
    line-height: 1.6;
    background: #f8f9ff;
}

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

/* 品牌色板 */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --bg-light: #f0f0ff;
    --text-primary: #333;
    --text-secondary: #666;
    --text-light: #999;
    --border-color: #e5e5e5;
    --card-shadow: 0 4px 6px rgba(99, 102, 241, 0.1);
    --card-hover-shadow: 0 8px 25px rgba(99, 102, 241, 0.2);
}

/* 字体层级 */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

p { font-size: 1rem; color: var(--text-secondary); }

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

.navbar {
    padding: 0.8rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 40px;
    height: 40px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 1rem;
    transition: color 0.3s;
    padding: 5px 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s;
}

.nav-link:hover, .nav-link.active {
    color: var(--primary-color);
}

.nav-link:hover::after, .nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
}

/* Hero 区域 */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 50%, var(--accent-color) 100%);
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 20px 60px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: heroGlow 6s ease-in-out infinite alternate;
}

@keyframes heroGlow {
    0% { transform: translate(0, 0); }
    100% { transform: translate(10%, 10%); }
}

.hero-container {
    position: relative;
    z-index: 1;
    max-width: 800px;
    width: 100%;
}

.hero-logo {
    width: 200px;
    margin-bottom: 20px;
}

.hero-title {
    font-size: 3rem;
    color: #fff;
    margin-bottom: 15px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.hero-subtitle {
    font-size: 1.2rem;
    color: rgba(255,255,255,0.9);
    margin-bottom: 30px;
}

.hero-search {
    display: flex;
    max-width: 500px;
    margin: 0 auto;
    gap: 10px;
}

.search-input {
    flex: 1;
    padding: 15px 20px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    outline: none;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.search-btn {
    background: #fff;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--primary-color);
    font-size: 1.2rem;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.search-btn:hover {
    transform: scale(1.1);
    background: var(--primary-color);
    color: #fff;
}

/* 特色区域 */
.features {
    padding: 80px 0;
    background: #fff;
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    margin: 10px auto;
    border-radius: 2px;
}

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

.feature-card {
    background: var(--bg-light);
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

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

.feature-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-title {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.feature-desc {
    color: var(--text-secondary);
}

/* 课程列表 */
.courses {
    padding: 80px 0;
    background: var(--bg-light);
}

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

.course-card {
    background: #fff;
    border-radius: 20px;
    padding: 30px;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

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

.course-title {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

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

.course-status {
    display: inline-block;
    padding: 5px 15px;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
}

.course-status.active {
    background: #d1fae5;
    color: #059669;
}

.course-status.inactive {
    background: #fee2e2;
    color: #dc2626;
}

/* 数据统计 */
.stats {
    padding: 60px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    text-align: center;
}

.stat-item {
    padding: 20px;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 5px;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
}

/* 行动号召 */
.cta {
    padding: 80px 0;
    text-align: center;
    background: #fff;
}

.cta h2 {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.cta p {
    margin-bottom: 30px;
    font-size: 1.1rem;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: var(--bg-light);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: #fff;
}

/* 页脚 */
.footer {
    background: #1e1e2f;
    color: #ccc;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo {
    width: 150px;
    margin-bottom: 15px;
}

.footer-desc {
    color: #aaa;
    line-height: 1.6;
}

.footer h4 {
    color: #fff;
    margin-bottom: 15px;
    font-size: 1.1rem;
}

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

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

.footer-links a {
    color: #aaa;
    text-decoration: none;
    transition: color 0.3s;
}

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

.footer-contact p {
    margin-bottom: 10px;
    color: #aaa;
}

.footer-contact i {
    margin-right: 10px;
    color: var(--accent-color);
}

.social-icons {
    display: flex;
    gap: 15px;
    margin-top: 15px;
}

.social-icons a {
    color: #aaa;
    font-size: 1.5rem;
    transition: color 0.3s;
}

.social-icons a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    border-top: 1px solid #333;
    padding-top: 20px;
    text-align: center;
    color: #666;
}

/* 页面标题 */
.page-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 120px 0 60px;
    text-align: center;
    color: #fff;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.page-header p {
    color: rgba(255,255,255,0.9);
    font-size: 1.2rem;
}

/* 关于页 */
.about-story {
    padding: 80px 0;
    background: #fff;
}

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

.story-content h2 {
    margin-bottom: 20px;
    color: var(--text-primary);
}

.story-content p {
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-mission {
    padding: 60px 0;
    background: var(--bg-light);
}

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

.mission-card {
    background: #fff;
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    box-shadow: var(--card-shadow);
}

.mission-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.mission-card h3 {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.team {
    padding: 80px 0;
    background: #fff;
}

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

.team-card {
    background: var(--bg-light);
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    transition: all 0.3s;
}

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

.team-avatar {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 2rem;
    color: #fff;
}

.team-card h3 {
    margin-bottom: 5px;
    color: var(--text-primary);
}

.team-card p {
    color: var(--text-secondary);
    margin-bottom: 5px;
}

/* 联系页 */
.contact-section {
    padding: 80px 0;
    background: #fff;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}

.contact-info h2 {
    margin-bottom: 30px;
    color: var(--text-primary);
}

.info-item {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
}

.info-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    width: 40px;
    text-align: center;
}

.info-item p {
    color: var(--text-secondary);
}

.social-links {
    margin-top: 30px;
}

.social-links h3 {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.contact-form-container h2 {
    margin-bottom: 30px;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 后台管理 */
.admin-login {
    padding: 120px 0 60px;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

.login-card {
    max-width: 400px;
    margin: 0 auto;
    background: #fff;
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--card-shadow);
}

.login-card h2 {
    text-align: center;
    margin-bottom: 30px;
}

.admin-panel {
    padding: 120px 0 60px;
}

.admin-panel h2 {
    margin-bottom: 30px;
}

.admin-toolbar {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.admin-table-container {
    overflow-x: auto;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
}

.admin-table th,
.admin-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.admin-table th {
    background: var(--bg-light);
    color: var(--text-primary);
    font-weight: 600;
}

.admin-table tr:hover {
    background: var(--bg-light);
}

.admin-actions {
    display: flex;
    gap: 10px;
}

.admin-actions button {
    padding: 5px 15px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s;
}

.btn-edit {
    background: #dbeafe;
    color: #2563eb;
}

.btn-edit:hover {
    background: #2563eb;
    color: #fff;
}

.btn-delete {
    background: #fee2e2;
    color: #dc2626;
}

.btn-delete:hover {
    background: #dc2626;
    color: #fff;
}

.btn-toggle {
    background: var(--bg-light);
    color: var(--text-secondary);
}

.btn-toggle:hover {
    background: var(--primary-color);
    color: #fff;
}

.data-status {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    background: var(--bg-light);
    color: var(--text-secondary);
    text-align: center;
}

/* 模态框 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.modal-content {
    background: #fff;
    padding: 40px;
    border-radius: 20px;
    max-width: 500px;
    width: 90%;
    position: relative;
    max-height: 90vh;
    overflow-y: auto;
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.close-modal:hover {
    color: var(--text-primary);
}

/* 响应式设计 */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.6rem; }
    h3 { font-size: 1.3rem; }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

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

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-logo {
        width: 150px;
    }

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

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

    .footer-links ul,
    .social-icons {
        justify-content: center;
    }

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

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

    .modal-content {
        padding: 30px 20px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 100px 15px 40px;
    }

    .hero-title {
        font-size: 1.6rem;
    }

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

    .search-input {
        width: 100%;
    }

    .search-btn {
        width: 100%;
        border-radius: 50px;
        margin-top: 10px;
    }

    .features,
    .courses,
    .cta {
        padding: 60px 0;
    }

    .feature-card,
    .course-card {
        padding: 30px 20px;
    }
}