/* ========================================
   爱思助手官网 - 样式表
   ======================================== */

/* CSS 变量 */
:root {
    --primary: #007AFF;
    --primary-dark: #0056CC;
    --secondary: #5856D6;
    --success: #34C759;
    --warning: #FF9500;
    --danger: #FF3B30;
    --gray: #8E8E93;
    --gray-light: #F2F2F7;
    --gray-dark: #1C1C1E;
    --white: #FFFFFF;
    --black: #000000;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-dark);
    background: 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;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* 容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========================================
   头部导航
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    transition: var(--transition);
}

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

.header-small {
    position: relative;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

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

.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--primary);
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-dark);
}

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

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--gray);
    padding: 8px 0;
    position: relative;
}

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

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

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

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--gray-dark);
    transition: var(--transition);
}

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

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--white);
    padding: 20px;
    box-shadow: var(--shadow-md);
    transform: translateY(-100%);
    opacity: 0;
    transition: var(--transition);
    z-index: 999;
}

.mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
}

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

.mobile-nav-link {
    font-size: 16px;
    font-weight: 500;
    color: var(--gray-dark);
    padding: 12px 0;
    border-bottom: 1px solid var(--gray-light);
}

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

/* ========================================
   按钮样式
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 15px;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

.btn-icon {
    width: 20px;
    height: 20px;
}

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

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

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

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

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

.btn-white:hover {
    background: var(--gray-light);
    transform: translateY(-2px);
}

.btn-large {
    padding: 16px 32px;
    font-size: 16px;
}

.btn-download {
    width: 100%;
}

.link-secondary {
    color: var(--gray);
    font-size: 14px;
    margin-left: 16px;
}

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

/* ========================================
   Hero 区域
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 72px;
    background: linear-gradient(135deg, #f5f7ff 0%, #e8f0fe 50%, #f0f7ff 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 150%;
    background: radial-gradient(ellipse, rgba(0, 122, 255, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.hero .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-title {
    font-size: 52px;
    font-weight: 800;
    line-height: 1.2;
    color: var(--gray-dark);
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--gray);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    gap: 48px;
}

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

.stat-number {
    display: block;
    font-size: 32px;
    font-weight: 800;
    color: var(--primary);
}

.stat-label {
    font-size: 14px;
    color: var(--gray);
}

/* 手机模型 */
.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: linear-gradient(145deg, #1a1a1a 0%, #2d2d2d 100%);
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.phone-mockup::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 24px;
    background: #1a1a1a;
    border-radius: 12px;
    z-index: 1;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #667eea 0%, #764ba2 100%);
    border-radius: 30px;
    padding: 40px 16px 16px;
}

.app-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    padding: 20px;
}

.app-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.app-icon svg {
    width: 28px;
    height: 28px;
    color: var(--white);
}

.app-icon.green { background: linear-gradient(135deg, #11998e, #38ef7d); }
.app-icon.blue { background: linear-gradient(135deg, #2193b0, #6dd5ed); }
.app-icon.orange { background: linear-gradient(135deg, #f12711, #f5af19); }
.app-icon.purple { background: linear-gradient(135deg, #667eea, #764ba2); }
.app-icon.red { background: linear-gradient(135deg, #ec008c, #fc6767); }
.app-icon.teal { background: linear-gradient(135deg, #02aab0, #00cdac); }

/* ========================================
   功能区域
   ======================================== */
.features {
    padding: 100px 0;
    background: var(--white);
}

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

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--gray-dark);
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--gray);
}

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

.feature-card {
    background: var(--white);
    padding: 40px 32px;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

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

.feature-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.1), rgba(88, 86, 214, 0.1));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.feature-icon svg {
    width: 32px;
    height: 32px;
    color: var(--primary);
}

.feature-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-dark);
    margin-bottom: 12px;
}

.feature-desc {
    font-size: 15px;
    color: var(--gray);
    line-height: 1.7;
}

/* ========================================
   下载区域
   ======================================== */
.download-section {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

.download-content {
    text-align: center;
}

.download-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 16px;
}

.download-subtitle {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 32px;
}

.download-version {
    margin-top: 16px;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
}

/* ========================================
   关于区域
   ======================================== */
.about {
    padding: 100px 0;
    background: var(--gray-light);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-text {
    font-size: 16px;
    color: var(--gray);
    line-height: 1.9;
    margin-bottom: 48px;
}

.about-stats {
    display: flex;
    justify-content: center;
    gap: 80px;
}

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

.about-stat-num {
    display: block;
    font-size: 42px;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 8px;
}

.about-stat-label {
    font-size: 15px;
    color: var(--gray);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--gray-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 48px;
    margin-bottom: 48px;
}

.footer-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--white);
    margin-bottom: 20px;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
}

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

.social-links {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.social-link svg {
    width: 20px;
    height: 20px;
}

.social-link:hover {
    background: var(--primary);
}

.footer-qr {
    width: 100px;
    height: 100px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.qr-code {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
    text-align: center;
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.copyright,
.ICP {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.4);
}

/* ========================================
   下载页面样式
   ======================================== */
.download-hero {
    padding: 140px 0 60px;
    background: linear-gradient(135deg, #f5f7ff 0%, #e8f0fe 100%);
    text-align: center;
}

.page-title {
    font-size: 42px;
    font-weight: 700;
    color: var(--gray-dark);
    margin-bottom: 12px;
}

.page-subtitle {
    font-size: 18px;
    color: var(--gray);
}

.download-options {
    padding: 60px 0 100px;
    background: var(--gray-light);
}

.download-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 32px;
    overflow: hidden;
    transition: var(--transition);
}

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

.download-card-header {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 32px;
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.05), rgba(88, 86, 214, 0.05));
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.platform-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.platform-icon svg {
    width: 36px;
    height: 36px;
}

.platform-icon.windows {
    background: linear-gradient(135deg, #00a4ef, #00bcf5);
    color: var(--white);
}

.platform-icon.mac {
    background: linear-gradient(135deg, #666666, #999999);
    color: var(--white);
}

.platform-icon.mobile {
    background: linear-gradient(135deg, #007AFF, #5856D6);
    color: var(--white);
}

.platform-info {
    flex: 1;
}

.platform-name {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-dark);
    margin-bottom: 4px;
}

.platform-version {
    font-size: 14px;
    color: var(--gray);
}

.platform-badge {
    background: var(--warning);
    color: var(--white);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
}

.download-card-body {
    padding: 32px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
}

.download-info {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.info-row {
    display: flex;
    gap: 8px;
}

.info-label {
    font-size: 14px;
    color: var(--gray);
    min-width: 80px;
}

.info-value {
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-dark);
}

.download-changelog {
    background: var(--gray-light);
    padding: 20px;
    border-radius: var(--radius-md);
}

.download-changelog h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--gray-dark);
    margin-bottom: 12px;
}

.download-changelog ul {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.download-changelog li {
    font-size: 14px;
    color: var(--gray);
    padding-left: 16px;
    position: relative;
}

.download-changelog li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
}

.download-card-footer {
    padding: 24px 32px;
    background: var(--gray-light);
    display: flex;
    align-items: center;
}

.download-steps {
    background: rgba(0, 122, 255, 0.05);
    padding: 20px;
    border-radius: var(--radius-md);
    border: 1px solid rgba(0, 122, 255, 0.1);
}

.download-steps h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--gray-dark);
    margin-bottom: 12px;
}

.download-steps ol {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.download-steps li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 14px;
    color: var(--gray);
}

.step-num {
    width: 24px;
    height: 24px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
    flex-shrink: 0;
}

/* 系统要求 */
.system-requirements {
    padding: 80px 0;
    background: var(--white);
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 48px;
}

.requirement-card {
    background: var(--gray-light);
    padding: 32px;
    border-radius: var(--radius-lg);
}

.requirement-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-dark);
    margin-bottom: 20px;
}

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

.requirement-card li {
    font-size: 14px;
    color: var(--gray);
    padding-left: 20px;
    position: relative;
}

.requirement-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success);
    font-weight: bold;
}

/* FAQ */
.faq {
    padding: 100px 0;
    background: var(--gray-light);
}

.faq-list {
    max-width: 800px;
    margin: 48px auto 0;
}

.faq-item {
    background: var(--white);
    margin-bottom: 12px;
    border-radius: var(--radius-md);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 16px;
    font-weight: 600;
    color: var(--gray-dark);
    text-align: left;
}

.faq-icon {
    width: 24px;
    height: 24px;
    transition: var(--transition);
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 200px;
}

.faq-answer p {
    padding: 0 24px 20px;
    font-size: 15px;
    color: var(--gray);
    line-height: 1.7;
}

/* 模态框 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
}

.modal-content {
    position: relative;
    background: var(--white);
    padding: 48px;
    border-radius: var(--radius-lg);
    text-align: center;
    max-width: 400px;
    animation: modalIn 0.3s ease;
}

@keyframes modalIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.modal-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}

.modal-icon svg {
    width: 40px;
    height: 40px;
    color: var(--white);
}

.modal-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-dark);
    margin-bottom: 12px;
}

.modal-text {
    font-size: 15px;
    color: var(--gray);
    margin-bottom: 24px;
}

.modal-close {
    padding: 12px 32px;
}

/* ========================================
   404 页面样式
   ======================================== */
.error-page {
    min-height: calc(100vh - 72px);
    padding: 140px 0 80px;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #f5f7ff 0%, #e8f0fe 100%);
}

.error-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.error-illustration {
    margin-bottom: 32px;
}

.error-icon {
    width: 200px;
    height: 200px;
    color: var(--primary);
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.crack {
    animation: crackAnim 2s ease-in-out infinite;
}

@keyframes crackAnim {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.error-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--gray-dark);
    margin-bottom: 16px;
}

.error-desc {
    font-size: 16px;
    color: var(--gray);
    margin-bottom: 32px;
    line-height: 1.7;
}

.error-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 48px;
}

.error-search {
    background: var(--white);
    padding: 24px 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.search-hint {
    font-size: 14px;
    color: var(--gray);
    margin-bottom: 16px;
}

.search-suggestions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.search-suggestions li a {
    font-size: 14px;
    color: var(--primary);
    padding: 8px 16px;
    background: rgba(0, 122, 255, 0.1);
    border-radius: 20px;
    transition: var(--transition);
}

.search-suggestions li a:hover {
    background: var(--primary);
    color: var(--white);
}

/* 热门页面推荐 */
.popular-pages {
    padding: 80px 0;
    background: var(--white);
}

.pages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.page-card {
    background: var(--gray-light);
    padding: 32px 24px;
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
}

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

.page-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.1), rgba(88, 86, 214, 0.1));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.page-icon svg {
    width: 32px;
    height: 32px;
    color: var(--primary);
}

.page-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-dark);
    margin-bottom: 8px;
}

.page-desc {
    font-size: 14px;
    color: var(--gray);
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1024px) {
    .hero .container {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-title {
        font-size: 40px;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .phone-mockup {
        width: 240px;
        height: 480px;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .download-card-body {
        grid-template-columns: 1fr;
    }
    
    .requirements-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .pages-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .mobile-menu {
        display: block;
    }
    
    .hero {
        padding-top: 100px;
        min-height: auto;
        padding-bottom: 60px;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        flex-direction: column;
        gap: 32px;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
    
    .download-hero {
        padding-top: 120px;
    }
    
    .page-title {
        font-size: 32px;
    }
    
    .requirements-grid {
        grid-template-columns: 1fr;
    }
    
    .error-actions {
        flex-direction: column;
    }
    
    .pages-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 28px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .phone-mockup {
        width: 200px;
        height: 400px;
    }
    
    .app-grid {
        gap: 12px;
    }
    
    .app-icon {
        width: 44px;
        height: 44px;
    }
    
    .app-icon svg {
        width: 22px;
        height: 22px;
    }
    
    .download-card-header {
        flex-direction: column;
        text-align: center;
    }
    
    .platform-badge {
        order: -1;
    }
    
    .download-card-footer {
        flex-direction: column;
        gap: 16px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

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

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}