/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --shadow-light: 0 4px 12px rgba(0, 0, 0, 0.1);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
}

.logo a {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: inherit;
}

.logo .material-icons {
    font-size: 32px;
    animation: bounce 2s infinite;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

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

.language-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    background: none;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

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

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.btn-primary {
    background: var(--bg-gradient);
    color: white;
    box-shadow: var(--shadow-light);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
}

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

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

.btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

/* Hero 区域 */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 24px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.demo-card {
    background: var(--bg-gradient);
    color: white;
    padding: 32px;
    border-radius: var(--border-radius);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
    max-width: 400px;
    animation: float 6s ease-in-out infinite;
}

.demo-quote {
    display: flex;
    align-items: flex-start;
    gap: 16px;
}

.demo-quote .material-icons {
    font-size: 32px;
    color: rgba(255, 255, 255, 0.8);
}

.demo-quote p {
    font-size: 18px;
    line-height: 1.6;
    font-style: italic;
    margin: 0;
}

/* 功能特色区域 */
.features {
    padding: 80px 0;
    background: var(--bg-primary);
}

.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 60px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.feature-card {
    background: var(--bg-primary);
    padding: 32px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    text-align: center;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: var(--bg-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}

.feature-icon .material-icons {
    font-size: 36px;
    color: white;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

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

/* 下载区域 */
.download {
    padding: 80px 0;
    background: var(--bg-secondary);
}

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

.download-info h3 {
    font-size: 28px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 40px;
}

.steps {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--bg-gradient);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.step-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

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

.download-note {
    margin-top: 16px;
    color: #95a5a6;
    font-size: 14px;
}

/* 隐私政策区域 */
.privacy {
    padding: 80px 0;
    background: var(--bg-primary);
}

.privacy-content {
    max-width: 800px;
    margin: 0 auto;
}

.privacy-content p {
    margin-bottom: 24px;
    line-height: 1.6;
    color: var(--text-secondary);
}

.privacy-details {
    display: grid;
    gap: 32px;
    margin: 40px 0;
}

.privacy-item h4 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.privacy-item p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 隐私政策页面 */
.privacy-page {
    padding: 120px 0 80px;
    background: var(--bg-secondary);
}

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

.privacy-header h1 {
    font-size: 48px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.privacy-date {
    color: #95a5a6;
    font-size: 16px;
}

.privacy-section {
    background: var(--bg-primary);
    padding: 40px;
    border-radius: var(--border-radius);
    margin-bottom: 32px;
    box-shadow: var(--shadow-light);
}

.privacy-section h2 {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.privacy-section h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 24px 0 16px;
}

.privacy-section ul {
    margin: 16px 0;
    padding-left: 24px;
}

.privacy-section li {
    margin-bottom: 8px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 页脚 */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-section h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    display: block;
    margin-bottom: 8px;
    transition: var(--transition);
}

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

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 8px;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 20px;
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* 动画 */
@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        gap: 16px;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .download-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .privacy-header h1 {
        font-size: 36px;
    }
    
    .privacy-section {
        padding: 24px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 16px;
    }
    
    .container {
        padding: 0 16px;
    }
    
    .hero {
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .btn-large {
        padding: 12px 24px;
        font-size: 16px;
    }
    
    .demo-card {
        padding: 24px;
    }
    
    .demo-quote p {
        font-size: 16px;
    }
}