/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Segoe UI", "Roboto", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #3c4043;
    background-color: #fff;
}

/* 导航栏 */
header {
    background-color: #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 20px;
    font-weight: 500;
    text-decoration: none;
    color: #5f6368;
}

.logo svg {
    margin-right: 8px;
}

.nav-links {
    display: flex;
    gap: 24px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: #5f6368;
    font-size: 14px;
    font-weight: 500;
    padding: 8px 0;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
}

.nav-links a:hover {
    color: #1a73e8;
}

.nav-links a.active {
    color: #1a73e8;
    border-bottom-color: #1a73e8;
}

/* 布局容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
}

/* 英雄板块 */
.hero {
    text-align: center;
    padding: 100px 20px;
    background: linear-gradient(180deg, #f8f9fa 0%, #fff 100%);
}

.hero h1 {
    font-size: 56px;
    color: #202124;
    margin-bottom: 24px;
    font-weight: 400;
}

.hero p {
    font-size: 20px;
    color: #5f6368;
    max-width: 700px;
    margin: 0 auto 40px;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 32px;
    font-size: 16px;
    font-weight: 500;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
}

.btn-primary {
    background-color: #1a73e8;
    color: #fff;
}

.btn-primary:hover {
    background-color: #185abc;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.btn-outline {
    background-color: #fff;
    color: #1a73e8;
    border: 1px solid #dadce0;
}

.btn-outline:hover {
    background-color: #f8f9fa;
}

/* 网格系统 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin-top: 60px;
}

.card {
    padding: 32px;
    border-radius: 8px;
    background: #f8f9fa;
    text-align: center;
}

.card h3 {
    font-size: 22px;
    margin: 16px 0;
    color: #202124;
}

.card p {
    color: #5f6368;
}

/* FAQ 板块 */
.faq {
    margin-top: 80px;
}

.faq h2 {
    text-align: center;
    font-size: 32px;
    margin-bottom: 48px;
}

.faq-item {
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid #dadce0;
}

.faq-item h4 {
    font-size: 18px;
    color: #202124;
    margin-bottom: 8px;
}

/* 页脚 */
footer {
    background-color: #f8f9fa;
    padding: 60px 20px;
    text-align: center;
    border-top: 1px solid #dadce0;
    margin-top: 100px;
}

.footer-info {
    font-size: 14px;
    color: #5f6368;
    line-height: 2;
}

.security-badge {
    color: #1e8e3e;
    font-weight: bold;
    margin-bottom: 16px;
}

/* 动画 */
@keyframes spin { 
    from { transform: rotate(0deg); } 
    to { transform: rotate(360deg); } 
}

/* 响应式 */
@media (max-width: 768px) {
    .hero h1 { font-size: 36px; }
    .nav-links { display: none; }
}