/* 全局样式 */
:root {
    --primary-color: #6366f1;
    --background-color: #0f172a;
    --surface-color: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* 导航栏 */
.navbar {
    background-color: var(--surface-color);
    padding: 20px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.nav-brand {
    font-size: 28px;
    font-weight: 800;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-brand i {
    font-size: 32px;
}

.nav-menu {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 18px;
    font-weight: 500;
    padding: 10px 15px;
    border-radius: 10px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link:hover {
    color: var(--primary-color);
    background-color: rgba(99, 102, 241, 0.1);
}

/* 英雄区域 */
.hero {
    padding: 120px 20px;
    text-align: center;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 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%, rgba(99, 102, 241, 0.2) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(139, 92, 246, 0.2) 0%, transparent 50%);
}

.hero-title {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 24px;
    line-height: 1.2;
    position: relative;
}

.hero-subtitle {
    font-size: 22px;
    color: var(--text-secondary);
    margin-bottom: 50px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
    color: white;
    padding: 18px 36px;
    border: none;
    border-radius: 12px;
    font-size: 20px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 12px;
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(99, 102, 241, 0.6);
}

/* 功能区域 */
.features {
    padding: 100px 40px;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 60px;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 100px;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), #8b5cf6);
    margin: 20px auto 0;
    border-radius: 5px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
}

.feature-card {
    background: var(--surface-color);
    padding: 40px 30px;
    border-radius: 20px;
    border: 2px solid rgba(255, 255, 255, 0.05);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-color);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), #8b5cf6);
}

.feature-icon {
    font-size: 50px;
    color: var(--primary-color);
    margin-bottom: 25px;
}

.feature-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.7;
}

/* 页脚 */
.footer {
    background: var(--surface-color);
    padding: 60px 20px;
    text-align: center;
    border-top: 2px solid rgba(255, 255, 255, 0.05);
}

.footer p {
    color: var(--text-secondary);
    margin-bottom: 10px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar {
        padding: 20px;
        flex-direction: column;
        gap: 20px;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }
    
    .hero-title {
        font-size: 42px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .features {
        padding: 60px 20px;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}