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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #16a34a;
    --accent-color: #d97706;
    --text-dark: #1f2937;
    --text-gray: #6b7280;
    --text-light: #9ca3af;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-gray: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    text-decoration: none;
}

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

.nav-link {
    color: var(--text-gray);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

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

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* 教育邮箱按钮 */
.email-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1.25rem;
    margin-left: 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9375rem;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.email-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

.email-btn svg {
    flex-shrink: 0;
}

/* 语言切换器 */
.language-switcher {
    position: relative;
    margin-left: 1rem;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-dark);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.lang-btn:hover {
    background: var(--bg-gray);
    border-color: var(--primary-color);
}

.lang-btn svg {
    flex-shrink: 0;
}

.lang-btn .chevron {
    transition: transform 0.3s ease;
}

.lang-btn.active .chevron {
    transform: rotate(180deg);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    min-width: 150px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    z-index: 1000;
    overflow: hidden;
}

.lang-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-option {
    display: block;
    width: 100%;
    padding: 0.75rem 1rem;
    background: white;
    border: none;
    text-align: left;
    color: var(--text-gray);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.lang-option:hover {
    background: var(--bg-light);
    color: var(--primary-color);
}

.lang-option.active {
    background: var(--bg-light);
    color: var(--primary-color);
    position: relative;
}

.lang-option.active::before {
    content: '✓';
    position: absolute;
    left: 0.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

/* 英雄区 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    z-index: -1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="2" fill="white" opacity="0.1"/></svg>');
    background-size: 50px 50px;
    animation: backgroundMove 60s linear infinite;
}

@keyframes backgroundMove {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: 4rem 20px;
    animation: fadeInUp 1s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-title {
    font-family: 'Playfair Display', serif;
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    max-width: 800px;
    margin: 0 auto 2.5rem;
    opacity: 0.95;
    line-height: 1.8;
}

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

.btn {
    padding: 0.875rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    display: inline-block;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: var(--bg-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

.btn-block {
    width: 100%;
}

/* 统计数据 */
.hero-stats {
    position: relative;
    z-index: 1;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    padding: 2rem 0;
    margin-top: auto;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    text-align: center;
    color: white;
}

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

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

/* 通用区块样式 */
.section {
    padding: 5rem 0;
}

.section:nth-child(even) {
    background: var(--bg-light);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-subtitle {
    display: inline-block;
    color: var(--primary-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.section-title {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-gray);
    max-width: 700px;
    margin: 0 auto;
}

/* 关于我们 */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-image .image-placeholder {
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.about-image .image-placeholder svg {
    width: 100%;
    height: auto;
    display: block;
}

.about-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.about-content p {
    color: var(--text-gray);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feature-item {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.feature-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.feature-text h4 {
    font-size: 1.125rem;
    margin-bottom: 0.25rem;
    color: var(--text-dark);
}

.feature-text p {
    color: var(--text-gray);
    margin: 0;
    font-size: 0.9375rem;
}

/* 课程项目 */
.programs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.program-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.program-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

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

.program-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.program-card > p {
    color: var(--text-gray);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.program-features {
    list-style: none;
    margin-bottom: 1.5rem;
}

.program-features li {
    padding: 0.5rem 0;
    color: var(--text-gray);
    position: relative;
    padding-left: 1.5rem;
}

.program-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: 700;
}

.program-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.program-link:hover {
    color: var(--primary-dark);
    transform: translateX(5px);
    display: inline-block;
}

/* 师资力量 */
.teachers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.teacher-card {
    background: var(--bg-white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    text-align: center;
}

.teacher-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.teacher-image {
    position: relative;
    overflow: hidden;
}

.teacher-placeholder svg {
    width: 100%;
    height: auto;
    display: block;
}

.teacher-card h3 {
    font-size: 1.25rem;
    margin: 1.5rem 1.5rem 0.5rem;
    color: var(--text-dark);
}

.teacher-title {
    color: var(--primary-color);
    font-weight: 600;
    margin: 0 1.5rem 1rem;
    font-size: 0.9375rem;
}

.teacher-bio {
    color: var(--text-gray);
    margin: 0 1.5rem 1.5rem;
    line-height: 1.6;
    font-size: 0.9375rem;
}

/* 新闻动态 */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.news-card {
    background: var(--bg-white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.news-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.news-image {
    position: relative;
}

.news-placeholder svg {
    width: 100%;
    height: auto;
    display: block;
}

.news-date {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-dark);
    box-shadow: var(--shadow-md);
}

.news-content {
    padding: 1.5rem;
}

.news-content h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
    line-height: 1.4;
}

.news-content p {
    color: var(--text-gray);
    margin-bottom: 1rem;
    line-height: 1.7;
}

.news-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.news-link:hover {
    color: var(--primary-dark);
}

/* 联系我们 */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info h3 {
    font-size: 1.75rem;
    margin-bottom: 2rem;
    color: var(--text-dark);
}

.info-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.info-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.info-content h4 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.info-content p {
    color: var(--text-gray);
    line-height: 1.6;
}

/* 表单样式 */
.contact-form {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-dark);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
}

/* 页脚 */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 4rem 0 2rem;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-col p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.footer-col h4 {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
}

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

.footer-col ul li {
    margin-bottom: 0.75rem;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: white;
    padding-left: 5px;
}

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

.social-link {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
    font-size: 0.9375rem;
}

.social-link:hover {
    color: white;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.7);
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
    font-size: 0.9375rem;
}

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

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

/* 响应式设计 */
@media (max-width: 968px) {
    .hero-title {
        font-size: 2.5rem;
    }

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

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }

    .footer-col:first-child {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-white);
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
        gap: 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        padding: 1rem 0;
    }

    .hamburger {
        display: flex;
    }

    .email-btn {
        margin-left: 1rem;
        padding: 0.4rem 1rem;
        font-size: 0.875rem;
    }

    .email-btn span {
        display: none;
    }

    .language-switcher {
        margin-left: 0.75rem;
    }

    .lang-btn {
        padding: 0.4rem 0.75rem;
        font-size: 0.875rem;
    }

    .lang-btn span {
        display: none;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

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

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

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

    .programs-grid,
    .teachers-grid,
    .news-grid {
        grid-template-columns: 1fr;
    }

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

    .footer-col:first-child {
        grid-column: 1;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 1.5rem;
        right: 1.5rem;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.fade-in {
    animation: fadeIn 1s ease-out;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}