/* ============================================
   比特币中文介绍平台 - 全局样式表
   ============================================ */

/* 全局CSS变量 */
:root {
    --primary-color: #F7931A;
    --primary-dark: #E8820F;
    --secondary-color: #1F2937;
    --text-dark: #1F2937;
    --text-light: #6B7280;
    --background-light: #F9FAFB;
    --background-white: #FFFFFF;
    --border-color: #E5E7EB;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --error-color: #EF4444;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   重置与基础样式
   ============================================ */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--background-white);
    overflow-x: hidden;
}

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

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

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

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

/* ============================================
   导航栏样式
   ============================================ */

.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--background-white);
    box-shadow: var(--shadow-md);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.logo {
    flex-shrink: 0;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    margin: 0;
}

.nav-menu li {
    margin: 0;
}

.nav-link {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-dark);
    padding: var(--spacing-sm) 0;
    border-bottom: 2px solid transparent;
    transition: all var(--transition-fast);
}

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

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

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--text-dark);
    margin: 5px 0;
    transition: all var(--transition-fast);
    border-radius: 2px;
}

/* ============================================
   Hero 首屏
   ============================================ */

.hero {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--background-light) 0%, var(--background-white) 100%);
}

.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-dark);
    margin: 0;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--text-light);
    margin: 0;
    line-height: 1.5;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.btn {
    padding: 12px 32px;
    font-size: 16px;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: center;
    display: inline-block;
    text-decoration: none;
}

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

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

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

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

.hero-image {
    position: relative;
}

.hero-image img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

/* ============================================
   通用Section样式
   ============================================ */

.section {
    padding: var(--spacing-2xl) 0;
    background-color: var(--background-white);
}

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

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-dark);
    text-align: center;
    margin: 0 0 var(--spacing-sm) 0;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-light);
    text-align: center;
    margin: 0 0 var(--spacing-2xl) 0;
}

/* ============================================
   比特币是什么 - Features Grid
   ============================================ */

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

.feature-card {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

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

.feature-icon {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md) auto;
    background-color: var(--background-light);
    border-radius: 50%;
    color: var(--primary-color);
}

.feature-icon svg {
    width: 60px;
    height: 60px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.feature-card p {
    margin: 0;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   比特币如何运作 - Timeline
   ============================================ */

.process-timeline {
    margin: var(--spacing-xl) 0;
    position: relative;
}

.timeline-item {
    display: flex;
    gap: var(--spacing-lg);
    position: relative;
    padding: var(--spacing-lg) 0;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    width: 12px;
    height: 12px;
    background-color: var(--primary-color);
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: 0 0 0 3px var(--primary-color);
    z-index: 1;
}

.timeline-content {
    margin-left: 60px;
    padding-bottom: var(--spacing-lg);
}

.timeline-content h3 {
    font-size: 20px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.timeline-content p {
    margin: 0;
    color: var(--text-light);
    line-height: 1.6;
}

.timeline-divider {
    position: absolute;
    left: 26px;
    top: 52px;
    width: 2px;
    height: var(--spacing-xl);
    background-color: var(--primary-color);
}

.timeline-item:last-child .timeline-divider {
    display: none;
}

.tech-image {
    margin-top: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.tech-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   使用指南 - Guide Cards
   ============================================ */

.guide-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.guide-card {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border-left: 4px solid var(--primary-color);
}

.guide-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
}

.guide-icon {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 60px;
    height: 60px;
    background-color: var(--background-light);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
}

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

.guide-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.guide-card p {
    margin: 0;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   钱包与安全 - Security Grid
   ============================================ */

.security-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin: var(--spacing-xl) 0;
}

.security-item {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

.security-item:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.security-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
}

.security-item h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.security-item p {
    margin: 0;
    color: var(--text-light);
    line-height: 1.6;
    font-size: 14px;
}

/* 安全高亮框 */
.security-highlight {
    background: linear-gradient(135deg, #FFF3E0 0%, #FFE0B2 100%);
    border-left: 4px solid var(--warning-color);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    margin-top: var(--spacing-2xl);
}

.security-highlight h3 {
    font-size: 20px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.security-tips {
    list-style: none;
    margin: 0;
    padding: 0;
}

.security-tips li {
    margin: var(--spacing-sm) 0;
    padding: var(--spacing-sm) 0;
    color: var(--text-dark);
    line-height: 1.6;
}

.security-tips li::before {
    content: '⚠️ ';
    margin-right: var(--spacing-sm);
    font-weight: 600;
}

/* ============================================
   应用场景 - Application Grid
   ============================================ */

.application-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.app-card {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

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

.app-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
}

.app-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.app-card p {
    margin: 0;
    color: var(--text-light);
    line-height: 1.6;
    font-size: 14px;
}

/* ============================================
   FAQ - 常见问题
   ============================================ */

.faq-container {
    margin-top: var(--spacing-xl);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.faq-item {
    margin-bottom: var(--spacing-lg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background-color: white;
}

.faq-question {
    width: 100%;
    padding: var(--spacing-lg);
    background-color: var(--background-light);
    border: none;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-dark);
    transition: all var(--transition-fast);
}

.faq-question:hover {
    background-color: #E8E8E8;
}

.faq-toggle {
    font-size: 20px;
    transition: transform var(--transition-normal);
    display: inline-block;
}

.faq-item.active .faq-question {
    background-color: var(--primary-color);
    color: white;
}

.faq-item.active .faq-toggle {
    transform: rotate(45deg);
    color: white;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
    background-color: white;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: var(--spacing-lg);
    margin: 0;
    color: var(--text-light);
    line-height: 1.8;
}

/* ============================================
   平台声明
   ============================================ */

.platform-notice {
    background-color: #F5F5F5;
}

.notice-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
}

.notice-item {
    background-color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
}

.notice-item h3 {
    font-size: 16px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.notice-item p {
    margin: 0;
    color: var(--text-light);
    font-size: 14px;
    line-height: 1.6;
}

/* ============================================
   联系我们
   ============================================ */

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.contact-item {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.contact-item h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.contact-item p {
    margin: 0;
    font-size: 16px;
}

.contact-item a {
    color: var(--primary-color);
    font-weight: 600;
}

.contact-item a:hover {
    text-decoration: underline;
}

/* ============================================
   页脚
   ============================================ */

.footer {
    background-color: var(--text-dark);
    color: white;
    padding: var(--spacing-2xl) 0 var(--spacing-lg) 0;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: white;
}

.footer-section ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer-section li {
    margin: var(--spacing-sm) 0;
}

.footer-section a {
    color: #D1D5DB;
    font-size: 14px;
    transition: color var(--transition-fast);
}

.footer-section a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    font-size: 14px;
    color: #9CA3AF;
}

.footer-bottom p {
    margin: 0;
}

/* ============================================
   返回顶部按钮
   ============================================ */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-fast);
    z-index: 999;
}

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

.back-to-top.show {
    display: flex;
}

/* ============================================
   响应式设计 - 平板
   ============================================ */

@media (max-width: 1024px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .hero {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
        padding: var(--spacing-xl) 0;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .section-title {
        font-size: 28px;
    }

    .features-grid,
    .guide-cards,
    .security-grid,
    .application-grid {
        gap: var(--spacing-lg);
    }

    .feature-card,
    .guide-card,
    .security-item,
    .app-card {
        padding: var(--spacing-lg);
    }
}

/* ============================================
   响应式设计 - 手机
   ============================================ */

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

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: white;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        box-shadow: var(--shadow-md);
        max-height: 0;
        overflow: hidden;
        transition: max-height var(--transition-normal);
    }

    .nav-menu.active {
        max-height: 500px;
    }

    .hero {
        padding: var(--spacing-xl) 0;
    }

    .hero-title {
        font-size: 28px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

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

    .btn {
        width: 100%;
    }

    .section {
        padding: var(--spacing-xl) 0;
    }

    .section-title {
        font-size: 24px;
    }

    .section-subtitle {
        font-size: 14px;
    }

    .features-grid,
    .guide-cards,
    .security-grid,
    .application-grid,
    .notice-content,
    .contact-info {
        grid-template-columns: 1fr;
    }

    .timeline-item {
        margin-left: 0;
    }

    .timeline-item::before {
        left: -12px;
    }

    .timeline-content {
        margin-left: 30px;
    }

    .timeline-divider {
        left: -6px;
    }

    .faq-container {
        padding: 0;
    }

    .faq-question {
        font-size: 14px;
        padding: var(--spacing-md);
    }

    .faq-answer p {
        padding: var(--spacing-md);
        font-size: 14px;
    }

    .feature-card,
    .guide-card,
    .security-item,
    .app-card,
    .notice-item,
    .contact-item {
        padding: var(--spacing-md);
    }

    .feature-card h3,
    .guide-card h3,
    .security-item h3,
    .app-card h3,
    .notice-item h3,
    .contact-item h3 {
        font-size: 16px;
    }

    .feature-card p,
    .guide-card p,
    .security-item p,
    .app-card p,
    .notice-item p,
    .contact-item p {
        font-size: 13px;
    }

    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-lg);
    }

    .footer-section h4 {
        font-size: 14px;
    }

    .footer-section a {
        font-size: 12px;
    }
}

@media (max-width: 480px) {
    .logo-text {
        font-size: 16px;
    }

    .logo-img {
        width: 40px;
        height: 40px;
    }

    .nav-menu {
        padding: var(--spacing-md);
    }

    .nav-link {
        font-size: 13px;
    }

    .hero-title {
        font-size: 24px;
    }

    .hero-subtitle {
        font-size: 14px;
    }

    .section-title {
        font-size: 20px;
    }

    .hero-buttons {
        gap: var(--spacing-sm);
    }

    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }

    .gallery-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: var(--spacing-md);
    }

    .gallery-item img {
        height: 120px;
    }

    .gallery-item h3 {
        font-size: 12px;
        padding: var(--spacing-sm);
    }

    .wallet-list {
        grid-template-columns: 1fr;
    }

    .wallet-buttons {
        flex-direction: column;
    }

    .wallet-btn {
        width: 100%;
    }

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

    .footer-trust {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

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

    .security-highlight {
        padding: var(--spacing-lg);
    }

    .security-highlight h3 {
        font-size: 16px;
    }
}

/* ============================================
   Logo样式
   ============================================ */

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

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

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-color);
}

/* ============================================
   比特币图片库
   ============================================ */

.bitcoin-gallery {
    background: linear-gradient(135deg, #F5F5F5 0%, #FFFFFF 100%);
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.gallery-item {
    background-color: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

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

.gallery-item img {
    width: 100%;
    height: 200px;
    object-fit: contain;
    padding: var(--spacing-md);
    background-color: #F9FAFB;
}

.gallery-item h3 {
    padding: var(--spacing-md);
    margin: 0;
    font-size: 15px;
    font-weight: 600;
    color: var(--text-dark);
    text-align: center;
    border-top: 1px solid var(--border-color);
}

/* ============================================
   钱包下载板块
   ============================================ */

.wallet-download {
    background-color: var(--background-light);
}

.wallet-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin: var(--spacing-xl) 0;
}

.wallet-category {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.wallet-category h3 {
    font-size: 22px;
    font-weight: 600;
    margin: 0 0 var(--spacing-lg) 0;
    color: var(--text-dark);
}

.wallet-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.wallet-card {
    background: linear-gradient(135deg, #F9FAFB 0%, #FFFFFF 100%);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

.wallet-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    transform: translateY(-4px);
}

.wallet-card h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 0 0 var(--spacing-sm) 0;
    color: var(--text-dark);
}

.wallet-card p {
    font-size: 14px;
    color: var(--text-light);
    margin: 0 0 var(--spacing-md) 0;
    line-height: 1.5;
}

.wallet-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.wallet-btn {
    display: inline-block;
    padding: 6px 12px;
    background-color: var(--primary-color);
    color: white;
    font-size: 12px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    text-align: center;
    flex: 1;
    min-width: 60px;
}

.wallet-btn:hover {
    background-color: var(--primary-dark);
    transform: scale(1.05);
}

.wallet-warning {
    background: linear-gradient(135deg, #FFF3E0 0%, #FFE0B2 100%);
    border-left: 4px solid var(--warning-color);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    margin-top: var(--spacing-xl);
}

.wallet-warning h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: var(--text-dark);
}

.wallet-warning ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.wallet-warning li {
    margin: var(--spacing-sm) 0;
    padding: var(--spacing-sm) 0;
    color: var(--text-dark);
    line-height: 1.6;
}

.wallet-warning li::before {
    content: '👉 ';
    margin-right: var(--spacing-sm);
    font-weight: 600;
}

/* ============================================
   新页脚样式
   ============================================ */

.footer-trust {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    padding: var(--spacing-xl) 0;
    margin-bottom: var(--spacing-xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.trust-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.trust-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.trust-content h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 0 0 var(--spacing-sm) 0;
    color: white;
}

.trust-content p {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.8);
    margin: 0;
    line-height: 1.5;
}

.footer-divider {
    height: 1px;
    background-color: rgba(255, 255, 255, 0.1);
    margin: var(--spacing-xl) 0;
}

.footer-bottom-top {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-disclaimer {
    background: rgba(255, 255, 255, 0.05);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    border-left: 3px solid #FF6B6B;
}

.footer-disclaimer h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: #FF6B6B;
}

.footer-disclaimer p {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.9);
    margin: var(--spacing-sm) 0;
    line-height: 1.6;
}

.footer-disclaimer strong {
    color: white;
}

.footer-security-badge {
    background: rgba(16, 185, 129, 0.1);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    border-left: 3px solid #10B981;
}

.footer-security-badge h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 0 0 var(--spacing-md) 0;
    color: #10B981;
}

.footer-security-badge ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer-security-badge li {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.9);
    margin: var(--spacing-sm) 0;
    padding-left: var(--spacing-md);
}

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

.footer-copyright p {
    margin: var(--spacing-sm) 0;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.8);
}

.footer-copyright a {
    color: var(--primary-color);
    text-decoration: underline;
    transition: color var(--transition-fast);
}

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

/* ============================================
   打印样式
   ============================================ */

@media print {
    .navbar,
    .back-to-top,
    .hero-buttons {
        display: none;
    }

    body {
        color: black;
        background: white;
    }

    a {
        color: black;
    }

    .container {
        max-width: 100%;
    }
}

/* ============================================
   暗黑模式支持（可选）
   ============================================ */

@media (prefers-color-scheme: dark) {
    :root {
        --text-dark: #F3F4F6;
        --text-light: #D1D5DB;
        --background-white: #111827;
        --background-light: #1F2937;
        --border-color: #374151;
    }

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

    .feature-card,
    .guide-card,
    .security-item,
    .app-card,
    .notice-item,
    .contact-item,
    .faq-item {
        background-color: var(--background-light);
        border-color: var(--border-color);
    }

    .faq-question {
        background-color: var(--background-light);
        color: var(--text-dark);
    }

    .faq-answer {
        background-color: var(--background-light);
    }

    .security-highlight {
        background: rgba(245, 158, 11, 0.1);
    }
}