:root {
    /* 亮色主题 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-card: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
    --accent-color: #667eea;
    --hover-bg: #f1f5f9;
}

[data-theme="dark"] {
    /* 暗色主题 */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border-color: #334155;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --gradient-start: #818cf8;
    --gradient-end: #a855f7;
    --accent-color: #818cf8;
    --hover-bg: #334155;
}

* {
    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;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* 头部导航 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--bg-card);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

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

.logo-text {
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--accent-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    transition: width 0.3s ease;
}

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

/* 主题切换按钮 */
.theme-toggle {
    background: none;
    border: 2px solid var(--border-color);
    border-radius: 50px;
    padding: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    color: var(--text-secondary);
}

.theme-toggle:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.theme-toggle .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: block;
}

/* 主要内容 */
main {
    padding-top: 64px;
}

/* 英雄区域 */
.hero {
    padding: 120px 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 50%, var(--gradient-start) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, var(--gradient-end) 0%, transparent 50%);
    opacity: 0.1;
    pointer-events: none;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.8;
}

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

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 500;
}

.hero-actions {
    display: flex;
    gap: 20px;
    align-items: center;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 16px 32px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    box-shadow: 0 4px 20px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.btn-large {
    padding: 20px 40px;
    font-size: 18px;
}

/* 应用预览 */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.app-preview {
    position: relative;
    width: 100%;
    max-width: 400px;
}

.preview-svg {
    width: 100%;
    height: auto;
    filter: drop-shadow(0 20px 40px var(--shadow-color));
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

/* 功能特点 */
.features {
    padding: 100px 0;
    background-color: var(--bg-secondary);
}

.section-title {
    font-size: 40px;
    font-weight: 800;
    text-align: center;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 60px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 32px;
}

.feature-card {
    background: var(--bg-card);
    border-radius: 16px;
    padding: 40px 32px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px var(--shadow-color);
}

.feature-card:hover::before {
    opacity: 1;
}

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

.feature-title {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 16px;
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 下载区域 */
.download {
    padding: 100px 0;
    background-color: var(--bg-primary);
}

.download-card {
    background: var(--bg-card);
    border-radius: 24px;
    padding: 60px;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 60px var(--shadow-color);
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 60px;
    align-items: center;
}

.download-title {
    font-size: 32px;
    font-weight: 800;
    margin-bottom: 16px;
}

.download-description {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.download-specs {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.spec {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.spec:last-child {
    border-bottom: none;
}

.spec-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.spec-value {
    font-weight: 700;
    color: var(--text-primary);
}

.download-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.download-note {
    font-size: 14px;
    color: var(--text-muted);
    text-align: center;
}

/* 关于我们 */
.about {
    padding: 100px 0;
    background-color: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-text {
    color: var(--text-secondary);
    line-height: 1.8;
}

.about-text p {
    margin-bottom: 24px;
}

.about-links {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.about-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 20px 24px;
    background: var(--bg-card);
    border-radius: 12px;
    text-decoration: none;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    font-weight: 500;
}

.about-link:hover {
    transform: translateX(8px);
    border-color: var(--accent-color);
    color: var(--accent-color);
}

/* 页脚 */
.footer {
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-top: 16px;
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}

.footer-copyright {
    margin-bottom: 8px;
}

.footer-icp a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-icp a:hover {
    color: var(--accent-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        gap: 20px;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-stats {
        justify-content: center;
        gap: 24px;
    }
    
    .hero-actions {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .download-card {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 40px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .container {
        padding: 0 16px;
    }
    
    .nav-container {
        padding: 0 16px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 80px 0;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-description {
        font-size: 16px;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 16px;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .download-card {
        padding: 24px;
    }
    
    .feature-card {
        padding: 24px;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card {
    animation: fadeInUp 0.6s ease forwards;
}

.feature-card:nth-child(1) { animation-delay: 0.1s; }
.feature-card:nth-child(2) { animation-delay: 0.2s; }
.feature-card:nth-child(3) { animation-delay: 0.3s; }
.feature-card:nth-child(4) { animation-delay: 0.4s; }
.feature-card:nth-child(5) { animation-delay: 0.5s; }
.feature-card:nth-child(6) { animation-delay: 0.6s; }

/* 安全提示 */
.security-notice {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    padding: 16px 24px;
    border-radius: 8px;
    margin: 20px 0;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 500;
}

.security-notice svg {
    flex-shrink: 0;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--accent-color);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}