/* ============================================
   沃伦培优 - 教育培训机构官方网站样式
   ============================================ */

/* ---------- 基础变量 ---------- */
:root {
    /* 主色调 */
    --primary-color: #0056D2;
    --primary-dark: #003d94;
    --primary-light: #e0e7ff;
    
    /* 辅助色 */
    --secondary-color: #FF9F1C;
    --secondary-dark: #e68a00;
    --secondary-light: #fff3e0;
    
    /* 中性色 */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    
    /* 字体 */
    --font-primary: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Montserrat', 'Noto Sans SC', sans-serif;
    
    /* 尺寸 */
    --header-height: 80px;
    --container-width: 1200px;
    --border-radius: 12px;
    --border-radius-lg: 20px;
    --border-radius-full: 9999px;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    
    /* 过渡 */
    --transition: all 0.3s ease;
    --transition-fast: all 0.15s ease;
}

/* ---------- 重置样式 ---------- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--gray-700);
    background-color: var(--white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul, ol {
    list-style: none;
}

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

button, input, select, textarea {
    font-family: inherit;
    font-size: inherit;
    outline: none;
    border: none;
}

button {
    cursor: pointer;
    background: none;
}

/* ---------- 通用类 ---------- */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section__header {
    text-align: center;
    margin-bottom: 60px;
}

.section__subtitle {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.section__title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 16px;
    line-height: 1.2;
}

.section__description {
    font-size: 1.125rem;
    color: var(--gray-500);
    max-width: 600px;
    margin: 0 auto;
}

/* ---------- 按钮样式 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--border-radius-full);
    transition: var(--transition);
    cursor: pointer;
}

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

.btn--primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn--secondary:hover {
    background: var(--secondary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

.btn--small {
    padding: 8px 16px;
    font-size: 0.875rem;
}

.btn--large {
    padding: 16px 40px;
    font-size: 1.125rem;
}

.btn--block {
    width: 100%;
}

/* ---------- 导航栏 ---------- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: transparent;
    z-index: 1000;
    transition: var(--transition);
}

.header.scrolled {
    background: var(--white);
    box-shadow: var(--shadow);
}

.header.scrolled .nav__link {
    color: var(--gray-700);
}

.header.scrolled .nav__link:hover,
.header.scrolled .nav__link.active {
    color: var(--primary-color);
}

.header.scrolled .nav__logo .logo-text {
    color: var(--primary-color);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav__logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    z-index: 1001;
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 45px;
    height: 45px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    font-size: 1.5rem;
    font-weight: 900;
    border-radius: 12px;
}

.logo-img {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.header.scrolled .logo-img {
    filter: none;
}

.logo-text {
    color: var(--white);
    transition: var(--transition);
}

.header.scrolled .logo-text {
    color: var(--primary-color);
}

.nav__menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav__link {
    padding: 10px 18px;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--white);
    border-radius: var(--border-radius-full);
    transition: var(--transition);
}

.nav__link:hover,
.nav__link.active {
    color: var(--secondary-color);
}

.nav__buttons {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav__toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--white);
    cursor: pointer;
    z-index: 1001;
}

.header.scrolled .nav__toggle {
    color: var(--gray-700);
}

/* ---------- 首屏英雄区域 ---------- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.unsplash.com/photo-1427504494785-3a9ca7044f45?w=1920&h=1080&fit=crop') center/cover no-repeat;
    opacity: 0.15;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 200px;
    background: linear-gradient(to top, var(--white), transparent);
}

.hero__overlay {
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: radial-gradient(circle at center, rgba(255, 159, 28, 0.15), transparent 70%);
}

.hero__content {
    position: relative;
    z-index: 10;
    padding: 120px 0 80px;
    max-width: 800px;
}

.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 20px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-full);
    color: var(--white);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 24px;
    backdrop-filter: blur(10px);
}

.hero__title {
    font-size: 3.5rem;
    font-weight: 900;
    color: var(--white);
    line-height: 1.2;
    margin-bottom: 24px;
}

.hero__title .highlight {
    background: linear-gradient(90deg, var(--secondary-color), #ffd93d);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero__description {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 40px;
    max-width: 600px;
}

.hero__cta {
    margin-bottom: 40px;
}

.hero__form {
    display: flex;
    gap: 12px;
    max-width: 520px;
}

.hero__input {
    flex: 1;
    padding: 16px 24px;
    background: var(--white);
    border-radius: var(--border-radius-full);
    font-size: 1rem;
    color: var(--gray-800);
}

.hero__input::placeholder {
    color: var(--gray-400);
}

.hero__features {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
}

.hero__feature {
    display: flex;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.9375rem;
}

.hero__feature i {
    color: var(--secondary-color);
}

.hero__scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

.hero__scroll a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    color: var(--white);
    font-size: 1.25rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

/* ---------- 数据统计区 ---------- */
.stats {
    padding: 80px 0;
    background: var(--white);
    position: relative;
    z-index: 20;
    margin-top: -100px;
}

.stats__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    background: var(--white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    padding: 50px 40px;
}

.stats__item {
    text-align: center;
    padding: 20px;
    position: relative;
}

.stats__item:not(:last-child)::after {
    content: '';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 1px;
    height: 60px;
    background: var(--gray-200);
}

.stats__icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    margin: 0 auto 16px;
    background: var(--primary-light);
    border-radius: 50%;
    color: var(--primary-color);
    font-size: 1.5rem;
}

.stats__number {
    display: inline;
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    color: var(--gray-900);
}

.stats__suffix {
    display: inline;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.stats__label {
    font-size: 1rem;
    color: var(--gray-500);
    margin-top: 8px;
}

/* ---------- 教学特色 ---------- */
.features {
    padding: 100px 0;
    background: var(--gray-50);
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature__card {
    position: relative;
    background: var(--white);
    border-radius: var(--border-radius-lg);
    padding: 40px 30px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    overflow: hidden;
}

.feature__card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.feature__card--highlight {
    background: linear-gradient(135deg, var(--primary-color), #1e40af);
    color: var(--white);
}

.feature__card--highlight .feature__title,
.feature__card--highlight .feature__description,
.feature__card--highlight .feature__list li {
    color: var(--white);
}

.feature__card--highlight .feature__icon {
    background: rgba(255, 255, 255, 0.2);
    color: var(--white);
}

.feature__card--highlight .feature__list i {
    color: var(--secondary-color);
}

.feature__badge {
    position: absolute;
    top: 20px;
    right: -30px;
    background: var(--secondary-color);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 600;
    padding: 6px 40px;
    transform: rotate(45deg);
}

.feature__icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 70px;
    height: 70px;
    background: var(--primary-light);
    border-radius: var(--border-radius);
    color: var(--primary-color);
    font-size: 1.75rem;
    margin-bottom: 24px;
}

.feature__title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.feature__description {
    font-size: 0.9375rem;
    color: var(--gray-500);
    margin-bottom: 20px;
    line-height: 1.7;
}

.feature__list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.feature__list li {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.875rem;
    color: var(--gray-600);
}

.feature__list li i {
    color: var(--success);
    font-size: 0.75rem;
}

/* ---------- 精品课程 ---------- */
.courses {
    padding: 100px 0;
    background: var(--white);
}

.courses__tabs {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 50px;
}

.courses__tab {
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-600);
    background: var(--gray-100);
    border-radius: var(--border-radius-full);
    transition: var(--transition);
}

.courses__tab:hover {
    color: var(--primary-color);
    background: var(--primary-light);
}

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

.courses__panel {
    display: none;
}

.courses__panel.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.courses__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.course__card {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.course__image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.course__image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.course__card:hover .course__image img {
    transform: scale(1.1);
}

.course__badge {
    position: absolute;
    top: 16px;
    left: 16px;
    padding: 6px 14px;
    background: var(--primary-color);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--border-radius-full);
}

.course__badge--hot {
    background: var(--danger);
}

.course__badge--new {
    background: var(--success);
}

.course__content {
    padding: 24px;
}

.course__title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 10px;
}

.course__description {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-bottom: 16px;
    line-height: 1.6;
}

.course__meta {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--gray-100);
}

.course__meta span {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.875rem;
    color: var(--gray-500);
}

.course__meta i {
    color: var(--primary-color);
}

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

.course__price {
    font-size: 1rem;
    font-weight: 700;
    color: var(--secondary-color);
}

/* ---------- 师资力量 ---------- */
.teachers {
    padding: 100px 0;
    background: var(--gray-50);
}

.teachers__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.teacher__card {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.teacher__card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.teacher__image {
    position: relative;
    height: 280px;
    overflow: hidden;
}

.teacher__image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.teacher__card:hover .teacher__image img {
    transform: scale(1.1);
}

.teacher__overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0, 86, 210, 0.95), transparent 60%);
    display: flex;
    align-items: flex-end;
    padding: 24px;
    opacity: 0;
    transition: var(--transition);
}

.teacher__card:hover .teacher__overlay {
    opacity: 1;
}

.teacher__quote {
    color: var(--white);
    font-size: 0.875rem;
    font-style: italic;
    line-height: 1.6;
}

.teacher__info {
    padding: 24px;
    text-align: center;
}

.teacher__name {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 6px;
}

.teacher__title {
    font-size: 0.875rem;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 12px;
}

.teacher__tags {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.teacher__tag {
    padding: 4px 12px;
    background: var(--primary-light);
    color: var(--primary-color);
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--border-radius-full);
}

.teacher__bio {
    font-size: 0.8125rem;
    color: var(--gray-500);
    line-height: 1.6;
}

/* ---------- 学员见证 ---------- */
.testimonials {
    padding: 100px 0;
    background: var(--white);
}

.testimonials__slider {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.testimonial__card {
    background: var(--gray-50);
    border-radius: var(--border-radius-lg);
    padding: 32px;
    transition: var(--transition);
}

.testimonial__card:hover {
    background: var(--white);
    box-shadow: var(--shadow-lg);
}

.testimonial__quote {
    color: var(--primary-light);
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.testimonial__quote i {
    color: var(--primary-color);
    opacity: 0.3;
}

.testimonial__text {
    font-size: 0.9375rem;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 24px;
}

.testimonial__author {
    display: flex;
    align-items: center;
    gap: 16px;
}

.testimonial__author img {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    object-fit: cover;
}

.testimonial__info h5 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 4px;
}

.testimonial__info span {
    font-size: 0.8125rem;
    color: var(--gray-500);
}

.testimonial__result {
    margin-top: 8px;
}

.result__badge {
    display: inline-block;
    padding: 4px 12px;
    background: var(--success);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--border-radius-full);
}

.testimonials__nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
}

.testimonial__btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--gray-100);
    border-radius: 50%;
    color: var(--gray-600);
    transition: var(--transition);
}

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

.testimonials__dots {
    display: flex;
    gap: 8px;
}

.dot {
    width: 10px;
    height: 10px;
    background: var(--gray-300);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    width: 30px;
    background: var(--primary-color);
    border-radius: var(--border-radius-full);
}

/* ---------- CTA转化区 ---------- */
.cta {
    position: relative;
    padding: 100px 0;
    background: linear-gradient(135deg, var(--primary-color), #1e3a8a);
    overflow: hidden;
}

.cta__overlay {
    position: absolute;
    inset: 0;
    background: url('https://images.unsplash.com/photo-1523050854058-8df90110c9f1?w=1920&h=600&fit=crop') center/cover no-repeat;
    opacity: 0.1;
}

.cta__content {
    position: relative;
    z-index: 10;
    text-align: center;
}

.cta__title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 16px;
}

.cta__description {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 40px;
}

.cta__buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
}

/* ---------- 联系我们 ---------- */
.contact {
    padding: 100px 0;
    background: var(--gray-50);
}

.contact__grid {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 60px;
}

.contact__form-wrapper {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    padding: 40px;
    box-shadow: var(--shadow);
}

.contact__form {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.form__group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form__group--full {
    grid-column: span 2;
}

.form__group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-700);
}

.form__group input,
.form__group select,
.form__group textarea {
    padding: 14px 18px;
    background: var(--gray-50);
    border: 2px solid var(--gray-200);
    border-radius: var(--border-radius);
    font-size: 1rem;
    color: var(--gray-800);
    transition: var(--transition);
}

.form__group input:focus,
.form__group select:focus,
.form__group textarea:focus {
    border-color: var(--primary-color);
    background: var(--white);
}

.form__group textarea {
    resize: vertical;
    min-height: 120px;
}

.contact__form .btn {
    grid-column: span 2;
    margin-top: 10px;
}

.contact__info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact__info-item {
    display: flex;
    gap: 20px;
}

.contact__icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    border-radius: var(--border-radius);
    color: var(--white);
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact__details h4 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.contact__details p {
    font-size: 0.9375rem;
    color: var(--gray-600);
    margin-bottom: 4px;
}

.qrcode {
    margin-top: 12px;
}

.qrcode__img {
    width: 120px;
    height: 120px;
    object-fit: cover;
    border-radius: var(--border-radius);
    border: 2px solid var(--gray-200);
    box-shadow: var(--shadow-sm);
}

.qrcode__placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 120px;
    height: 120px;
    background: var(--white);
    border: 2px dashed var(--gray-300);
    border-radius: var(--border-radius);
    color: var(--gray-400);
    font-size: 0.875rem;
}

.qrcode__placeholder i {
    font-size: 2rem;
    margin-bottom: 8px;
    color: var(--success);
}

/* ---------- 页脚 ---------- */
.footer {
    background: var(--gray-900);
    padding: 80px 0 0;
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 60px;
    padding-bottom: 60px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer__logo .logo-img {
    width: 55px;
    height: 55px;
    object-fit: contain;
    padding: 5px;
    background: var(--white);
    border-radius: 10px;
}

.footer__logo .logo-text {
    color: var(--white);
}

.footer__tagline {
    font-size: 1rem;
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 16px;
}

.footer__description {
    font-size: 0.9375rem;
    color: var(--gray-400);
    line-height: 1.7;
    margin-bottom: 24px;
}

.footer__social {
    display: flex;
    gap: 12px;
}

.social__link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: var(--white);
    font-size: 1.125rem;
    transition: var(--transition);
}

.social__link:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer__links h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--white);
    margin-bottom: 24px;
}

.footer__links ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer__links a {
    font-size: 0.9375rem;
    color: var(--gray-400);
    transition: var(--transition);
}

.footer__links a:hover {
    color: var(--white);
    padding-left: 5px;
}

.footer__bottom {
    padding: 24px 0;
    text-align: center;
}

.footer__bottom p {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.footer__bottom a {
    color: var(--gray-400);
}

.footer__bottom a:hover {
    color: var(--white);
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
    position: fixed;
    bottom: 100px;
    right: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    border-radius: 50%;
    color: var(--white);
    font-size: 1.125rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 100;
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-5px);
}

/* ---------- 移动端固定按钮 ---------- */
.mobile__cta {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.1);
    z-index: 100;
    padding: 12px 20px;
}

.mobile__cta {
    display: none;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.mobile__btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px;
    border-radius: var(--border-radius);
    font-size: 0.9375rem;
    font-weight: 600;
}

.mobile__btn--call {
    background: var(--gray-100);
    color: var(--gray-700);
}

.mobile__btn--book {
    background: var(--secondary-color);
    color: var(--white);
}

/* ---------- 响应式设计 ---------- */
@media (max-width: 1200px) {
    .features__grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .teachers__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 992px) {
    .hero__title {
        font-size: 2.75rem;
    }
    
    .stats__grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stats__item:nth-child(2)::after {
        display: none;
    }
    
    .courses__grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .testimonials__slider {
        grid-template-columns: 1fr;
    }
    
    .contact__grid {
        grid-template-columns: 1fr;
    }
    
    .footer__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 70px;
    }
    
    .nav__menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: var(--white);
        flex-direction: column;
        justify-content: center;
        gap: 0;
        box-shadow: var(--shadow-xl);
        transition: var(--transition);
    }
    
    .nav__menu.show {
        right: 0;
    }
    
    .nav__link {
        color: var(--gray-700);
        padding: 16px 30px;
        width: 100%;
        border-radius: 0;
    }
    
    .nav__link:hover,
    .nav__link.active {
        color: var(--primary-color);
        background: var(--primary-light);
    }
    
    .nav__buttons {
        display: none;
    }
    
    .nav__toggle {
        display: block;
    }
    
    .hero__title {
        font-size: 2rem;
    }
    
    .hero__form {
        flex-direction: column;
    }
    
    .hero__features {
        flex-direction: column;
        gap: 12px;
    }
    
    .section__title {
        font-size: 1.75rem;
    }
    
    .stats__grid {
        grid-template-columns: 1fr;
        padding: 30px 20px;
    }
    
    .stats__item::after {
        display: none !important;
    }
    
    .features__grid,
    .courses__grid,
    .teachers__grid {
        grid-template-columns: 1fr;
    }
    
    .courses__tabs {
        flex-wrap: wrap;
    }
    
    .cta__title {
        font-size: 1.75rem;
    }
    
    .cta__buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .contact__form {
        grid-template-columns: 1fr;
    }
    
    .form__group--full {
        grid-column: span 1;
    }
    
    .contact__form .btn {
        grid-column: span 1;
    }
    
    .footer__grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .mobile__cta {
        display: grid;
    }
    
    .back-to-top {
        bottom: 90px;
        right: 20px;
    }
    
    body {
        padding-bottom: 80px;
    }
}

@media (max-width: 480px) {
    .hero__title {
        font-size: 1.75rem;
    }
    
    .hero__description {
        font-size: 1rem;
    }
    
    .stats__number {
        font-size: 2.5rem;
    }
    
    .feature__card {
        padding: 30px 20px;
    }
    
    .contact__form-wrapper {
        padding: 24px;
    }
}

/* ---------- 动画效果 ---------- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 平滑滚动 */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
    
    .fade-in {
        transition: none;
    }
}