/* 基础设置 */
:root {
    --primary-color: #0088cc;
    --primary-dark: #0077b5;
    --primary-light: #e6f4fa;
    --secondary-color: #333333;
    --text-color: #333333;
    --text-light: #666666;
    --text-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --success-color: #4caf50;
    --warning-color: #ff9800;
    --error-color: #f44336;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s ease;
    --container-padding: 1rem;
    --border-radius: 8px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.5;
    color: var(--text-color);
    background-color: var(--bg-white);
}

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

ul {
    list-style: none;
}

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

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

/* 常见类样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

.btn svg {
    margin-right: 0.5rem;
}

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

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

.btn-secondary {
    background-color: var(--bg-white);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

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

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

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

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

/* 头部导航样式 */
#header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    transition: var(--transition);
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
}

#header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    padding-bottom: 1rem;
}

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

.logo a {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background-color: var(--primary-color);
    color: var(--text-white);
    border-radius: 50%;
    margin-right: 0.5rem;
    font-weight: 700;
}

.desktop-nav {
    display: none;
}

.desktop-nav li {
    display: inline-block;
    margin-left: 2rem;
}

.desktop-nav a {
    color: var(--text-color);
    font-weight: 500;
}

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

.mobile-menu-icon {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    cursor: pointer;
}

.mobile-menu-icon span {
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.mobile-nav {
    display: none;
    background-color: var(--bg-white);
    padding: 1rem 0;
    box-shadow: var(--shadow-md);
}

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

.mobile-nav li {
    padding: 0.75rem 1rem;
}

.mobile-nav a {
    color: var(--text-color);
    font-weight: 500;
    display: block;
}

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

/* 英雄区域样式 */
#hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, #e6f4fa 0%, #ffffff 100%);
}

#hero .container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-content {
    text-align: center;
    margin-bottom: 3rem;
}

.hero-content h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.25rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    max-width: 600px;
}

.cta-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

.hero-image {
    position: relative;
    width: 100%;
    max-width: 500px;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.stat-badge {
    position: absolute;
    padding: 0.75rem 1rem;
    border-radius: var(--border-radius);
    color: var(--text-white);
    text-align: center;
    box-shadow: var(--shadow-md);
    display: none;
}

.users-badge {
    background-color: var(--primary-color);
    bottom: -20px;
    left: -20px;
}

.countries-badge {
    background-color: var(--success-color);
    top: -20px;
    right: -20px;
}

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

.stat-label {
    font-size: 0.875rem;
}

/* 功能特点样式 */
#features {
    padding: 5rem 0;
    background-color: var(--bg-light);
}

.features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.feature-card {
    background-color: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    color: var(--primary-color);
    margin-bottom: 1.25rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--text-light);
}

/* 隐私安全部分样式 */
#privacy {
    padding: 5rem 0;
    background-color: var(--bg-white);
}

.privacy-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3rem;
}

.privacy-image {
    width: 100%;
    max-width: 500px;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.privacy-features {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    width: 100%;
}

.privacy-feature {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.25rem;
    background-color: var(--bg-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.privacy-feature:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-sm);
}

.privacy-icon {
    color: var(--primary-color);
    flex-shrink: 0;
}

.privacy-text h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.privacy-text p {
    color: var(--text-light);
    font-size: 0.9375rem;
}

/* 产品对比样式 */
#comparison {
    padding: 5rem 0;
    background-color: var(--bg-light);
}

.comparison-table-wrapper {
    overflow-x: auto;
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9375rem;
    box-shadow: var(--shadow-md);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.comparison-table th,
.comparison-table td {
    padding: 1rem;
    text-align: center;
}

.comparison-table th {
    background-color: var(--primary-color);
    color: var(--text-white);
    font-weight: 600;
}

.comparison-table th:first-child,
.comparison-table td:first-child {
    text-align: left;
    font-weight: 500;
}

.comparison-table tr:nth-child(even) {
    background-color: var(--bg-white);
}

.comparison-table tr:nth-child(odd) {
    background-color: var(--primary-light);
}

.comparison-table .yes {
    color: var(--success-color);
    font-weight: 600;
}

.comparison-table .no {
    color: var(--error-color);
}

.comparison-table .partial {
    color: var(--warning-color);
}

/* 下载部分样式 */
#download {
    padding: 5rem 0;
    background-color: var(--bg-white);
}

.download-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3rem;
}

.devices-image {
    width: 100%;
    max-width: 500px;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.download-options {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    width: 100%;
}

.download-card {
    background-color: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.download-card:hover {
    box-shadow: var(--shadow-lg);
}

.download-platform-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: var(--text-white);
    margin-bottom: 1rem;
}

.download-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.download-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1rem;
    border-radius: var(--border-radius);
    color: var(--text-white);
    font-weight: 500;
    transition: var(--transition);
}

.download-btn svg {
    margin-right: 0.5rem;
}

.ios-btn, .android-btn {
    background-color: #5A5A5A;
}

.ios-btn:hover, .android-btn:hover {
    background-color: #333333;
}

.desktop-btn {
    background-color: #0078D7;
}

.desktop-btn:hover {
    background-color: #106EBE;
}

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

.web-btn:hover {
    background-color: var(--primary-dark);
}

/* 常见问题样式 */
#faq {
    padding: 5rem 0;
    background-color: var(--bg-light);
}

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

.faq-item {
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    background-color: var(--bg-white);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
}

.faq-question h3 {
    font-size: 1.125rem;
    font-weight: 600;
}

.arrow-icon {
    transition: var(--transition);
}

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

.faq-answer {
    padding: 0 1.25rem 1.25rem;
    color: var(--text-light);
    display: none;
}

.faq-item.active .faq-answer {
    display: block;
}

/* 页脚样式 */
#footer {
    padding: 5rem 0 1rem;
    background-color: var(--secondary-color);
    color: var(--text-white);
}

.footer-top {
    display: flex;
    flex-direction: column;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-logo {
    margin-bottom: 1rem;
}

.footer-logo a {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 0.75rem;
}

.footer-logo p {
    color: #aaa;
    font-size: 0.9375rem;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 2rem;
}

.footer-links-column h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
    color: var(--text-white);
}

.footer-links-column ul li {
    margin-bottom: 0.75rem;
}

.footer-links-column a {
    color: #aaa;
    font-size: 0.9375rem;
    transition: var(--transition);
}

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

.footer-bottom {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: #aaa;
    font-size: 0.875rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text-white);
    transition: var(--transition);
}

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

/* 响应式设计 */
@media (min-width: 640px) {
    .cta-buttons {
        flex-direction: row;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .download-options {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .download-buttons {
        flex-direction: row;
        justify-content: center;
    }
    
    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
    }
    
    .stat-badge {
        display: block;
    }
}

@media (min-width: 768px) {
    .desktop-nav {
        display: flex;
    }
    
    .mobile-menu-icon {
        display: none;
    }
    
    #hero .container {
        flex-direction: row;
        align-items: center;
        gap: 2rem;
    }
    
    .hero-content {
        text-align: left;
        flex: 1;
        margin-bottom: 0;
    }
    
    .hero-image {
        flex: 1;
    }
    
    .cta-buttons {
        justify-content: flex-start;
    }
    
    .privacy-content {
        flex-direction: row;
    }
    
    .privacy-image, .privacy-features {
        flex: 1;
    }
    
    .download-content {
        flex-direction: row;
    }
    
    .devices-image {
        flex: 1;
    }
    
    .download-options {
        flex: 1;
    }
}

@media (min-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .footer-top {
        flex-direction: row;
    }
    
    .footer-logo {
        flex: 1;
    }
    
    .footer-links {
        flex: 2;
    }
}