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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.8;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* 导航栏 */
header {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #0088cc;
    text-decoration: none;
}

.logo span {
    color: #764ba2;
}

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

.nav-links a {
    text-decoration: none;
    color: #555;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #0088cc;
}

.nav-links a.active {
    color: #0088cc;
}

/* 移动端菜单 */
.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    transition: 0.3s;
}

/* 主容器 */
.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

/* 内容卡片 */
.content-card {
    background: white;
    border-radius: 20px;
    padding: 3rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

/* 标题样式 */
h1 {
    font-size: 2.5rem;
    color: #0088cc;
    margin-bottom: 1.5rem;
    line-height: 1.3;
}

h2 {
    font-size: 1.8rem;
    color: #333;
    margin: 2rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid #0088cc;
}

h3 {
    font-size: 1.3rem;
    color: #555;
    margin: 1.5rem 0 0.8rem;
}

/* 段落样式 */
p {
    margin-bottom: 1rem;
    text-align: justify;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, #0088cc, #764ba2);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    margin: 0.5rem;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 136, 204, 0.4);
}

.btn-secondary {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

/* 特色卡片 */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.feature-card {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

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

/* 下载卡片 */
.download-card {
    background: #f8f9fa;
    border-left: 4px solid #0088cc;
    padding: 1.5rem;
    margin: 1rem 0;
    border-radius: 0 10px 10px 0;
}

.download-link {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background: #0088cc;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    margin-top: 0.5rem;
}

.download-link:hover {
    background: #006699;
}

/* 列表样式 */
ul, ol {
    margin: 1rem 0 1rem 2rem;
}

li {
    margin-bottom: 0.5rem;
}

/* 页脚 */
footer {
    background: rgba(0, 0, 0, 0.8);
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 3rem;
}

footer a {
    color: #0088cc;
    text-decoration: none;
}

/* 面包屑导航 */
.breadcrumb {
    margin-bottom: 2rem;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: #0088cc;
    text-decoration: none;
}

.breadcrumb span {
    margin: 0 0.5rem;
    color: #999;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        padding: 1rem;
        box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        display: flex;
    }

    .menu-toggle {
        display: flex;
    }

    h1 {
        font-size: 1.8rem;
    }

    h2 {
        font-size: 1.4rem;
    }

    .content-card {
        padding: 1.5rem;
    }

    .container {
        padding: 0 1rem;
    }
}

/* 关键词高亮 */
.keyword {
    color: #0088cc;
    font-weight: 600;
}

/* 统计数字 */
.stats {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    margin: 2rem 0;
    text-align: center;
}

.stat-item {
    padding: 1rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #0088cc;
}

.stat-label {
    color: #666;
    font-size: 0.9rem;
}

/* 教程步骤 */
.step {
    display: flex;
    align-items: flex-start;
    margin: 1.5rem 0;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
}

.step-number {
    background: #0088cc;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    margin-right: 1rem;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

/* 表单样式 */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #0088cc;
}

/* 警告框 */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
}

.alert-info {
    background: #d1ecf1;
    border-left: 4px solid #0088cc;
    color: #0c5460;
}

.alert-warning {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    color: #856404;
}