/* ========================================
   顾老师英语 - 品牌样式表
   ======================================== */

/* CSS 变量 - 品牌色板 */
:root {
    /* 主色 */
    --primary: #4F46E5;
    --primary-dark: #4338CA;
    --primary-light: #6366F1;

    /* 辅色 */
    --secondary: #7C3AED;
    --secondary-light: #A78BFA;
    --accent: #06B6D4;

    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
    --gradient-hero: linear-gradient(135deg, #EEF2FF 0%, #F5F3FF 50%, #ECFEFF 100%);

    /* 中性色 */
    --text-primary: #1E293B;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    --border: #E2E8F0;
    --bg-light: #F8FAFC;
    --bg-white: #FFFFFF;

    /* 功能色 */
    --success: #10B981;
    --warning: #F59E0B;
    --error: #EF4444;

    /* 字体 */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    /* 字号 */
    --text-xs: 0.75rem;   /* 12px */
    --text-sm: 0.8125rem; /* 13px */
    --text-base: 0.9375rem; /* 15px */
    --text-md: 1.0625rem; /* 17px */
    --text-lg: 1.25rem;   /* 20px */
    --text-xl: 1.5rem;    /* 24px */
    --text-2xl: 2rem;     /* 32px */
    --text-3xl: 2.5rem;   /* 40px */
    --text-4xl: 3rem;     /* 48px */

    /* 间距 */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;

    /* 圆角 */
    --radius-sm: 0.375rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.25rem;
    --radius-full: 9999px;

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* ========================================
   基础重置与通用样式
   ======================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-family);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--primary-dark);
}

ul {
    list-style: none;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* ========================================
   排版
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-primary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-title {
    font-size: var(--text-2xl);
    font-weight: 800;
    margin-bottom: var(--space-md);
}

@media (min-width: 768px) {
    .section-title {
        font-size: var(--text-3xl);
    }
}

.section-desc {
    font-size: var(--text-md);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.brand-highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.highlight {
    color: var(--primary);
}

/* ========================================
   按钮
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.75rem 1.75rem;
    font-family: var(--font-family);
    font-size: var(--text-base);
    font-weight: 600;
    line-height: 1;
    border: 2px solid transparent;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.25s ease;
    text-decoration: none;
    white-space: nowrap;
}

.btn:active {
    transform: scale(0.97);
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    box-shadow: 0 4px 14px rgba(79, 70, 229, 0.35);
}

.btn-primary:hover {
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.5);
    transform: translateY(-2px);
    color: #fff;
}

.btn-secondary {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

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

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--border);
    border-radius: var(--radius-full);
}

.btn-outline:hover {
    border-color: var(--primary);
    background: rgba(79, 70, 229, 0.05);
}

.btn-lg {
    padding: 1rem 2.5rem;
    font-size: var(--text-lg);
}

.btn-block {
    width: 100%;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    border-bottom-color: var(--border);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.logo-text {
    font-size: var(--text-lg);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.nav-link {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-secondary);
    padding: var(--space-sm) 0;
    position: relative;
    transition: color 0.2s;
}

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

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

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

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    transition: background 0.2s;
}

.hamburger:hover {
    background: var(--bg-light);
}

.hamburger-line {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hamburger.active .hamburger-line:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

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

.hamburger.active .hamburger-line:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--space-xl);
        gap: var(--space-md);
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 0.3s ease;
    }

    .nav-menu.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }

    .nav-link {
        font-size: var(--text-md);
        padding: var(--space-sm) 0;
    }
}

/* ========================================
   Hero 区域
   ======================================== */
.hero {
    padding: 120px 0 80px;
    background: var(--gradient-hero);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(79, 70, 229, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

.hero-logo {
    width: 180px;
    margin-bottom: var(--space-xl);
}

.hero-title {
    font-size: var(--text-3xl);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--space-lg);
}

@media (min-width: 768px) {
    .hero-title {
        font-size: var(--text-4xl);
    }
}

.hero-subtitle {
    font-size: var(--text-md);
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
    max-width: 480px;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.hero-illustration {
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
}

.hero-illustration svg {
    width: 100%;
    height: auto;
}

@media (max-width: 768px) {
    .hero {
        padding: 100px 0 60px;
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
        text-align: center;
    }

    .hero-logo {
        margin: 0 auto var(--space-xl);
    }

    .hero-subtitle {
        margin: 0 auto var(--space-2xl);
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-illustration {
        max-width: 280px;
    }
}

/* ========================================
   特色服务
   ======================================== */
.features {
    padding: var(--space-4xl) 0;
    background: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.feature-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
    transition: all 0.3s ease;
    cursor: default;
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
}

.feature-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin: 0 auto var(--space-lg);
}

.feature-icon.purple {
    background: #EEF2FF;
}

.feature-icon.teal {
    background: #ECFEFF;
}

.feature-icon.orange {
    background: #FFF7ED;
}

.feature-icon.pink {
    background: #FDF2F8;
}

.feature-card h3 {
    font-size: var(--text-lg);
    margin-bottom: var(--space-sm);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    line-height: 1.7;
}

/* ========================================
   课程
   ======================================== */
.courses {
    padding: var(--space-4xl) 0;
    background: var(--bg-light);
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--space-xl);
}

.course-card {
    background: var(--bg-white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.course-card-image {
    height: 160px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: rgba(255, 255, 255, 0.9);
}

.course-card:nth-child(2) .course-card-image {
    background: linear-gradient(135deg, #06B6D4, #3B82F6);
}

.course-card:nth-child(3) .course-card-image {
    background: linear-gradient(135deg, #F59E0B, #EF4444);
}

.course-card:nth-child(4) .course-card-image {
    background: linear-gradient(135deg, #10B981, #059669);
}

.course-card:nth-child(5) .course-card-image {
    background: linear-gradient(135deg, #8B5CF6, #EC4899);
}

.course-card:nth-child(6) .course-card-image {
    background: linear-gradient(135deg, #F97316, #DC2626);
}

.course-card-body {
    padding: var(--space-lg);
}

.course-card-body h3 {
    font-size: var(--text-lg);
    margin-bottom: var(--space-xs);
}

.course-card-body p {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    margin-bottom: var(--space-md);
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border);
}

.course-price {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--primary);
}

.course-price .original {
    font-size: var(--text-sm);
    color: var(--text-muted);
    text-decoration: line-through;
    font-weight: 400;
}

.course-level {
    font-size: var(--text-xs);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    background: #EEF2FF;
    color: var(--primary);
    font-weight: 600;
}

.section-footer {
    text-align: center;
    margin-top: var(--space-3xl);
}

/* ========================================
   数据统计
   ======================================== */
.stats {
    padding: var(--space-4xl) 0;
    background: var(--gradient-primary);
    color: #fff;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-xl);
    text-align: center;
}

.stat-item {
    padding: var(--space-lg);
}

.stat-number {
    display: block;
    font-size: var(--text-3xl);
    font-weight: 800;
    margin-bottom: var(--space-xs);
    font-variant-numeric: tabular-nums;
}

.stat-label {
    font-size: var(--text-sm);
    opacity: 0.85;
}

@media (max-width: 768px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-lg);
    }

    .stat-number {
        font-size: var(--text-2xl);
    }
}

/* ========================================
   学员评价
   ======================================== */
.testimonials {
    padding: var(--space-4xl) 0;
    background: var(--bg-light);
}

.testimonials-slider {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--space-xl);
}

.testimonial-card {
    background: var(--bg-white);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.testimonial-card:hover {
    box-shadow: var(--shadow-md);
}

.testimonial-stars {
    color: #F59E0B;
    font-size: var(--text-lg);
    margin-bottom: var(--space-md);
}

.testimonial-text {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-lg);
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.testimonial-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: var(--text-lg);
}

.testimonial-name {
    font-weight: 600;
    font-size: var(--text-sm);
}

.testimonial-role {
    font-size: var(--text-xs);
    color: var(--text-muted);
}

/* ========================================
   CTA 区域
   ======================================== */
.cta {
    padding: var(--space-4xl) 0;
}

.cta-card {
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    padding: var(--space-4xl) var(--space-2xl);
    text-align: center;
    color: #fff;
    box-shadow: 0 20px 40px rgba(79, 70, 229, 0.3);
}

.cta-title {
    font-size: var(--text-2xl);
    font-weight: 800;
    margin-bottom: var(--space-md);
    color: #fff;
}

.cta-desc {
    font-size: var(--text-md);
    opacity: 0.9;
    margin-bottom: var(--space-2xl);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.cta-card .btn-primary {
    background: #fff;
    color: var(--primary);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
}

.cta-card .btn-primary:hover {
    background: #f0f0f0;
    color: var(--primary-dark);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--text-primary);
    color: rgba(255, 255, 255, 0.8);
    padding-top: var(--space-4xl);
}

.footer-container {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: var(--space-4xl);
    padding-bottom: var(--space-3xl);
}

.footer-logo {
    width: 140px;
    margin-bottom: var(--space-md);
}

.footer-desc {
    font-size: var(--text-sm);
    line-height: 1.7;
    opacity: 0.7;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
}

.footer-col h4 {
    color: #fff;
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-lg);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-col ul li {
    margin-bottom: var(--space-sm);
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.6);
    font-size: var(--text-sm);
    transition: color 0.2s;
}

.footer-col ul li a:hover {
    color: #fff;
}

.footer-col ul li {
    color: rgba(255, 255, 255, 0.6);
    font-size: var(--text-sm);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--space-lg) 0;
    text-align: center;
}

.footer-bottom p {
    font-size: var(--text-xs);
    opacity: 0.5;
}

@media (max-width: 768px) {
    .footer-container {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }

    .footer-links {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-xl);
    }
}

@media (max-width: 480px) {
    .footer-links {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   页面通用样式（内页）
   ======================================== */
.page-hero {
    padding: 120px 0 60px;
    background: var(--gradient-hero);
    text-align: center;
}

.page-title {
    font-size: var(--text-3xl);
    font-weight: 800;
    margin-bottom: var(--space-md);
}

@media (min-width: 768px) {
    .page-title {
        font-size: var(--text-4xl);
    }
}

.page-desc {
    font-size: var(--text-md);
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

/* ========================================
   关于页
   ======================================== */
.story {
    padding: var(--space-4xl) 0;
}

.story-content {
    max-width: 800px;
    margin: 0 auto var(--space-3xl);
}

.story-text {
    font-size: var(--text-md);
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-md);
}

.mission-vision {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
    margin-top: var(--space-2xl);
}

.mv-card {
    background: var(--bg-light);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.mv-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.mv-card h3 {
    font-size: var(--text-lg);
    margin-bottom: var(--space-sm);
}

.mv-card p {
    color: var(--text-secondary);
    font-size: var(--text-sm);
}

@media (max-width: 768px) {
    .mission-vision {
        grid-template-columns: 1fr;
    }
}

/* 发展历程 */
.timeline {
    padding: var(--space-4xl) 0;
    background: var(--bg-light);
}

.timeline-grid {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
}

.timeline-grid::before {
    content: '';
    position: absolute;
    left: 100px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.timeline-item {
    display: flex;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
    position: relative;
}

.timeline-year {
    width: 80px;
    text-align: right;
    font-weight: 700;
    color: var(--primary);
    font-size: var(--text-lg);
    flex-shrink: 0;
    padding-top: 4px;
}

.timeline-content {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    border: 1px solid var(--border);
    flex: 1;
    position: relative;
}

.timeline-content::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 16px;
    width: 14px;
    height: 14px;
    background: var(--primary);
    border-radius: 50%;
    border: 3px solid var(--bg-white);
    box-shadow: 0 0 0 2px var(--primary);
}

.timeline-content h4 {
    font-size: var(--text-md);
    margin-bottom: var(--space-xs);
}

.timeline-content p {
    color: var(--text-secondary);
    font-size: var(--text-sm);
}

/* 团队 */
.team {
    padding: var(--space-4xl) 0;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--space-xl);
}

.team-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
    transition: all 0.3s;
}

.team-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.team-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-lg);
    color: #fff;
    font-size: 2rem;
    font-weight: 700;
}

.team-card h3 {
    font-size: var(--text-lg);
    margin-bottom: var(--space-xs);
}

.team-role {
    font-size: var(--text-sm);
    color: var(--primary);
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.team-desc {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========================================
   联系页
   ======================================== */
.contact-section {
    padding: var(--space-4xl) 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--space-3xl);
    align-items: start;
}

.contact-info h2,
.contact-form-wrapper h2 {
    font-size: var(--text-xl);
    margin-bottom: var(--space-xl);
}

.info-item {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    align-items: flex-start;
}

.info-icon {
    font-size: 1.5rem;
    width: 48px;
    height: 48px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.info-item h4 {
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: 2px;
}

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

.social-links {
    margin-top: var(--space-2xl);
}

.social-links h4 {
    font-size: var(--text-sm);
    margin-bottom: var(--space-md);
}

.social-icons {
    display: flex;
    gap: var(--space-sm);
}

.social-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all 0.2s;
}

.social-icon:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-2px);
}

/* 联系表单 */
.contact-form-wrapper {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
}

.form-group {
    margin-bottom: var(--space-lg);
}

.form-group label {
    display: block;
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    font-family: var(--font-family);
    font-size: var(--text-base);
    border: 2px solid var(--border);
    border-radius: var(--radius-md);
    transition: border-color 0.2s, box-shadow 0.2s;
    background: var(--bg-white);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-success {
    text-align: center;
    padding: var(--space-3xl) var(--space-xl);
}

.success-icon {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: var(--success);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0 auto var(--space-lg);
}

.form-success h3 {
    font-size: var(--text-xl);
    margin-bottom: var(--space-sm);
}

.form-success p {
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

/* ========================================
   课程列表页
   ======================================== */
.courses-list {
    padding: var(--space-4xl) 0;
}

.filter-bar {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-2xl);
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: 0.5rem 1.25rem;
    font-family: var(--font-family);
    font-size: var(--text-sm);
    font-weight: 600;
    border: 2px solid var(--border);
    border-radius: var(--radius-full);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.filter-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.filter-btn.active {
    background: var(--gradient-primary);
    color: #fff;
    border-color: transparent;
}

/* ========================================
   师资页
   ======================================== */
.teachers-list {
    padding: var(--space-4xl) 0;
}

.teachers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.teacher-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
    transition: all 0.3s;
}

.teacher-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.teacher-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-lg);
    color: #fff;
    font-size: 2.5rem;
    font-weight: 700;
}

.teacher-card:nth-child(2) .teacher-avatar {
    background: linear-gradient(135deg, #06B6D4, #3B82F6);
}

.teacher-card:nth-child(3) .teacher-avatar {
    background: linear-gradient(135deg, #F59E0B, #EF4444);
}

.teacher-card:nth-child(4) .teacher-avatar {
    background: linear-gradient(135deg, #10B981, #059669);
}

.teacher-card:nth-child(5) .teacher-avatar {
    background: linear-gradient(135deg, #8B5CF6, #EC4899);
}

.teacher-card h3 {
    font-size: var(--text-lg);
    margin-bottom: var(--space-xs);
}

.teacher-title {
    font-size: var(--text-sm);
    color: var(--primary);
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.teacher-desc {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--space-md);
}

.teacher-tags {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
    justify-content: center;
}

.teacher-tag {
    font-size: var(--text-xs);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    background: #EEF2FF;
    color: var(--primary);
    font-weight: 500;
}

/* ========================================
   响应式调整
   ======================================== */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--space-md);
    }

    .hero-title {
        font-size: var(--text-2xl);
    }

    .features-grid,
    .courses-grid,
    .testimonials-slider,
    .team-grid,
    .teachers-grid {
        grid-template-columns: 1fr;
    }

    .section-title {
        font-size: var(--text-xl);
    }
}

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.course-card,
.testimonial-card,
.team-card,
.teacher-card {
    animation: fadeInUp 0.6s ease forwards;
}

.feature-card:nth-child(2),
.course-card:nth-child(2),
.testimonial-card:nth-child(2) {
    animation-delay: 0.1s;
}

.feature-card:nth-child(3),
.course-card:nth-child(3),
.testimonial-card:nth-child(3) {
    animation-delay: 0.2s;
}

.feature-card:nth-child(4),
.course-card:nth-child(4),
.testimonial-card:nth-child(4) {
    animation-delay: 0.3s;
}