/* 重置样式和基础设置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #4285f4;
    --primary-dark: #3367d6;
    --secondary: #34a853;
    --accent: #ea4335;
    --text: #202124;
    --text-light: #5f6368;
    --background: #ffffff;
    --surface: #f8f9fa;
    --border: #dadce0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Google Sans', 'Segoe UI', system-ui, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--background);
    min-height: 100vh;
    transition: opacity 0.3s ease;
    opacity: 0;
}

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

/* 导航栏样式 */
.navbar {
    background: var(--background);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--primary);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

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

/* 英雄区域样式 */
.hero {
    text-align: center;
    padding: 6rem 0 4rem;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 400;
    color: var(--text);
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.3rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto 3rem;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
}

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

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

.btn-secondary {
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--background);
    border-color: var(--primary);
    transform: translateY(-2px);
}

/* 特性区域样式 */
.features {
    padding: 4rem 0;
    background: var(--surface);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 400;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: var(--background);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
    text-align: center;
}

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 0.5rem;
}

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

/* 下载区域样式 */
.download-section {
    padding: 4rem 0;
    background: var(--background);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.download-card {
    background: var(--surface);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.download-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.download-card h3 {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.download-card p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

.download-btn {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
    border: 1px solid var(--primary);
}

.download-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

/* 页脚样式 */
.footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
}

.footer p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .hero {
        padding: 4rem 0 2rem;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .feature-grid,
    .download-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .feature-card,
    .download-card {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .feature-card,
    .download-card {
        padding: 1rem;
    }
}

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

.animate {
    animation: fadeInUp 0.6s ease forwards;
}