/* ============================================
   童鱼宝宝学粤语 - 产品介绍页面样式
   ============================================ */

/* CSS变量 */
:root {
    --primary-color: #FF6B6B;
    --primary-light: #FF8E8E;
    --primary-dark: #E85555;
    --secondary-color: #4ECDC4;
    --secondary-light: #6ED9D2;
    --accent-color: #FFE66D;
    --accent-orange: #FFA94D;
    --accent-purple: #9775FA;
    --accent-blue: #74C0FC;

    --text-primary: #2D3436;
    --text-secondary: #636E72;
    --text-light: #B2BEC3;

    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FA;
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.16);
    --shadow-xl: 0 16px 60px rgba(0, 0, 0, 0.2);

    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;

    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;

    --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

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

body {
    font-family: var(--font-family);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================================
   导航栏
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.98);
    transition: box-shadow var(--transition-fast);
}

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

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon {
    font-size: 1.75rem;
}

.logo img {
    width: 2.2rem
}

.logo-text {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width var(--transition-normal);
}

.nav-links a:hover {
    color: var(--primary-color);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    padding: 10px 24px;
    border-radius: 50px;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(255, 107, 107, 0.4);
    transition: all var(--transition-normal);
}

.nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 107, 0.5);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-normal);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: white;
    padding: 24px;
    box-shadow: var(--shadow-md);
    z-index: 999;
}

.mobile-menu.active {
    display: block;
}

.mobile-menu ul {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.mobile-menu a {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-primary);
    padding: 8px 0;
}

.mobile-menu .download-btn {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 12px 24px;
    border-radius: 50px;
    margin-top: 8px;
}

/* ============================================
   主视觉区域
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: linear-gradient(135deg, #FFF5F5 0%, #FFF9E6 50%, #E6FFF5 100%);
    overflow: hidden;
    padding-top: 80px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.wave {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 320'%3E%3Cpath fill='%23ffffff' fill-opacity='1' d='M0,224L48,213.3C96,203,192,181,288,181.3C384,181,480,203,576,218.7C672,235,768,245,864,234.7C960,224,1056,192,1152,181.3C1248,171,1344,181,1392,186.7L1440,192L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z'%3E%3C/path%3E%3C/svg%3E") no-repeat bottom;
    background-size: cover;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-text {
    max-width: 600px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 16px;
}

.hero-title .highlight {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-weight: 500;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-btns {
    display: flex;
    gap: 16px;
    margin-bottom: 40px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    box-shadow: 0 4px 20px rgba(255, 107, 107, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(255, 107, 107, 0.5);
}

.btn-secondary {
    background: white;
    color: var(--text-primary);
    box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.stat-item {
    text-align: center;
}

.stat-num {
    font-size: 2rem;
    font-weight: 900;
    color: var(--primary-color);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.hero-phone {
    display: flex;
    justify-content: center;
    perspective: 1000px;
}

.phone-frame {
    width: 280px;
    height: 580px;
    background: linear-gradient(145deg, #2D3436, #636E72);
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-xl);
    position: relative;
}

.phone-frame::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 24px;
    background: #1a1a1a;
    border-radius: 20px;
    z-index: 10;
}

.phone-frame img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 32px;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.mouse {
    width: 24px;
    height: 40px;
    border: 2px solid var(--text-secondary);
    border-radius: 12px;
    position: relative;
}

.wheel {
    width: 4px;
    height: 8px;
    background: var(--text-secondary);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll 2s ease-in-out infinite;
}

@keyframes scroll {
    0%, 100% { opacity: 1; transform: translateX(-50%) translateY(0); }
    50% { opacity: 0.5; transform: translateX(-50%) translateY(12px); }
}

/* 动画类 */
.animate-fade-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeUp 0.8s ease forwards;
}

.animate-fade-up:not([style*="animation"]) {
    animation: fadeUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.1s !important; }
.delay-2 { animation-delay: 0.2s !important; }
.delay-3 { animation-delay: 0.3s !important; }
.delay-4 { animation-delay: 0.4s !important; }

@keyframes fadeUp {
    0% {
        opacity: 0;
        transform: translateY(30px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 确保动画完成后保持状态 */
.animate-fade-up {
    animation-fill-mode: forwards;
}

/* ============================================
   产品特色
   ============================================ */
.features {
    padding: 100px 0;
    background: white;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: 16px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, #FFF5F5, #FFF9E6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    transition: all var(--transition-normal);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

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

/* ============================================
   内容展示
   ============================================ */
.content-section {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.content-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    margin-bottom: 100px;
}

.content-block:last-child {
    margin-bottom: 0;
}

.content-block.reverse {
    direction: rtl;
}

.content-block.reverse > * {
    direction: ltr;
}

.content-tag {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-orange));
    color: white;
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.content-text h3 {
    font-size: 2rem;
    font-weight: 900;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.content-text p {
    font-size: 1.0625rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 24px;
}

.content-features {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.content-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 500;
}

.content-features .check {
    width: 24px;
    height: 24px;
    background: linear-gradient(135deg, var(--secondary-color), var(--secondary-light));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
}

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

.phone-mockup {
    width: 220px;
    height: 460px;
    background: linear-gradient(145deg, #2D3436, #636E72);
    border-radius: 30px;
    padding: 8px;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
}

.phone-mockup:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.phone-mockup img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 24px;
}

/* ============================================
   下载区域
   ============================================ */
.download-section {
    padding: 100px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    position: relative;
    overflow: hidden;
}

.download-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.download-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.download-content h2 {
    font-size: 2.5rem;
    font-weight: 900;
    color: white;
    margin-bottom: 16px;
}

.download-content > p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 40px;
}

.download-btns {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    background: white;
    color: var(--text-primary);
    padding: 12px 28px;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
    cursor: pointer;
}

.download-btn:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.download-btn .btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
}

.download-btn .btn-text {
    text-align: left;
}

.download-btn .btn-text small {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.download-btn .btn-text strong {
    font-size: 1.25rem;
}

.download-qrcode {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.qrcode-placeholder {
    width: 150px;
    height: 150px;
    background: white;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.download-qrcode p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
}

/* ============================================
   下载弹窗
   ============================================ */
.download-modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease;
}

.download-modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: white;
    border-radius: var(--radius-lg);
    padding: 32px;
    max-width: 360px;
    width: 90%;
    text-align: center;
    box-shadow: var(--shadow-xl);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
}

.modal-header h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.modal-close {
    width: 32px;
    height: 32px;
    border: none;
    background: var(--bg-secondary);
    border-radius: 50%;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

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

.modal-body {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.qrcode-wrapper {
    width: 200px;
    height: 200px;
    background: white;
    border-radius: var(--radius-md);
    padding: 16px;
    box-shadow: var(--shadow-md);
    margin-bottom: 16px;
}

.qrcode-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.modal-body p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ============================================
   关于我们
   ============================================ */
.about-section {
    padding: 80px 0 100px;
    background: linear-gradient(180deg, #fff 0%, #FFF9F5 100%);
}

/* 品牌故事 */
.about-story {
    max-width: 800px;
    margin: 0 auto 60px;
    text-align: center;
}

.story-content {
    background: white;
    padding: 48px 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.story-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
}

.story-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.story-content h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.story-content p {
    font-size: 1.0625rem;
    color: var(--text-secondary);
    line-height: 1.9;
}

/* 核心理念 */
.about-values {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 60px;
}

.value-item {
    background: white;
    padding: 32px 24px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.value-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.value-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #FFF5F5, #FFF9E6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
}

.value-item h4 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.value-item p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 数据展示 */
.about-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    padding: 40px;
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.stat-card {
    text-align: center;
    padding: 20px;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--primary-color);
    line-height: 1;
    margin-bottom: 8px;
}

.stat-number span {
    font-size: 1.25rem;
    font-weight: 700;
}

.stat-label {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

/* ============================================
   页脚
   ============================================ */
.footer {
    background: #1a1a2e;
    color: white;
    padding: 60px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .logo {
    margin-bottom: 16px;
}

.footer-brand .logo-text {
    color: white;
    background: none;
    -webkit-text-fill-color: white;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-column h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: white;
}

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

.footer-column a {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9375rem;
    transition: all var(--transition-fast);
}

.footer-column a:hover {
    color: var(--primary-color);
    padding-left: 4px;
}

.footer-bottom {
    padding: 20px 0;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.875rem;
}

/* ============================================
   回到顶部
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

/* ============================================
   滚动动画
   ============================================ */
[data-aos="fade-up"] {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="fade-up"].aos-animate {
    opacity: 1 !important;
    transform: translateY(0) !important;
    transition: none;
}

/* ============================================
   响应式设计
   ============================================ */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-text {
        max-width: 100%;
    }

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

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

    .hero-phone {
        order: -1;
    }

    .phone-frame {
        width: 220px;
        height: 460px;
    }

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

    .content-block {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .content-block.reverse {
        direction: ltr;
    }

    .content-images {
        justify-content: center;
    }

    .about-values {
        grid-template-columns: repeat(3, 1fr);
    }

    .about-stats {
        grid-template-columns: repeat(4, 1fr);
    }

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

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .nav-links,
    .nav-btn {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .hero-stats {
        flex-wrap: wrap;
        gap: 24px;
    }

    .stat-item {
        flex: 1 1 100px;
    }

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

    .about-values {
        grid-template-columns: 1fr;
    }

    .about-stats {
        grid-template-columns: repeat(2, 1fr);
        padding: 24px;
    }

    .stat-number {
        font-size: 2rem;
    }

    .phone-mockup {
        width: 180px;
        height: 380px;
    }

    .download-btns {
        flex-direction: column;
        align-items: center;
    }

    .download-btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }

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

    .scroll-indicator {
        display: none;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero {
        padding-top: 60px;
    }

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

    .hero-btns {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .phone-frame {
        width: 180px;
        height: 380px;
    }

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

    .about-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
        padding: 16px;
    }

    .stat-card {
        padding: 12px;
    }

    .stat-number {
        font-size: 1.75rem;
    }

    .content-images {
        flex-direction: column;
        align-items: center;
    }

    .phone-mockup {
        width: 200px;
        height: 420px;
    }

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

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}

/* 打印样式 */
@media print {
    .navbar,
    .back-to-top,
    .scroll-indicator,
    .hero-bg {
        display: none !important;
    }

    .hero {
        min-height: auto;
        padding: 40px 0;
    }

    body {
        color: #000;
        background: #fff;
    }
}