/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

:root {
    --primary-blue: #4285F4;
    --secondary-blue: #1a73e8;
    --accent-red: #EA4335;
    --accent-yellow: #FBBC05;
    --accent-green: #34A853;
    --light-gray: #f8f9fa;
    --dark-gray: #5f6368;
    --text-color: #202124;
    --border-radius: 8px;
    --box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s ease;
}

body {
    color: var(--text-color);
    line-height: 1.6;
    background-color: #fff;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

/* 头部样式 */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.logo-icon {
    display: flex;
}

.logo-icon span {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    margin-right: 3px;
}

.red { background-color: var(--accent-red); }
.yellow { background-color: var(--accent-yellow); }
.green { background-color: var(--accent-green); }
.blue { background-color: var(--primary-blue); }

.logo h1 {
    font-size: 24px;
    font-weight: 500;
    color: var(--dark-gray);
}

.logo h1 span {
    color: var(--primary-blue);
}

/* 导航菜单 */
nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

nav a {
    text-decoration: none;
    color: var(--dark-gray);
    font-weight: 500;
    transition: var(--transition);
    padding: 5px 0;
    position: relative;
}

nav a:hover, nav a.active {
    color: var(--primary-blue);
}

nav a.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-blue);
}

/* 主按钮样式 */
.btn {
    padding: 10px 25px;
    border-radius: var(--border-radius);
    font-weight: 500;
    cursor: pointer;
    border: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
    text-decoration: none;
    font-size: 16px;
}

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

.primary-btn:hover {
    background-color: var(--secondary-blue);
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(66, 133, 244, 0.3);
}

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

.secondary-btn:hover {
    background-color: #f0f7ff;
    transform: translateY(-3px);
}

/* 页面标题 */
.page-header {
    background: linear-gradient(135deg, #f8f9fa 0%, #e8f0fe 100%);
    padding: 80px 0 50px;
    text-align: center;
    margin-bottom: 50px;
}

.page-title {
    font-size: 48px;
    color: var(--text-color);
    margin-bottom: 15px;
}

.page-subtitle {
    font-size: 20px;
    color: var(--dark-gray);
    max-width: 700px;
    margin: 0 auto;
}

/* 主内容区域 */
.main-content {
    flex: 1;
    padding-bottom: 60px;
}

.section-title {
    font-size: 36px;
    margin-bottom: 40px;
    color: var(--text-color);
    text-align: center;
}

/* 卡片样式 */
.card {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

/* 特性图标样式 */
.feature-icon {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 28px;
    color: white;
}

.speed { background-color: var(--accent-red); }
.security { background-color: var(--primary-blue); }
.sync { background-color: var(--accent-green); }
.extensions { background-color: var(--accent-yellow); }
.privacy { background-color: #8E44AD; }
.devtools { background-color: var(--dark-gray); }

/* 页脚 */
footer {
    background-color: var(--text-color);
    color: white;
    padding: 60px 0 30px;
    margin-top: auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-column h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: white;
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: 10px;
}

.footer-column a {
    color: #ddd;
    text-decoration: none;
    transition: var(--transition);
}

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

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid #444;
    color: #aaa;
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }
    
    .page-title {
        font-size: 36px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .hero-content h2 {
        font-size: 36px;
    }
}