/* 公共样式文件 - 所有页面共用 */

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f7fa;
}

/* 导航栏 */
nav {
    background: white;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: #667eea;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s;
    position: relative;
}

.nav-links a:hover {
    color: #667eea;
}

.nav-links a.active {
    color: #667eea;
    font-weight: bold;
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background: #667eea;
}

/* 页面头部 */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 20px;
    text-align: center;
}

.page-header h1 {
    font-size: 42px;
    margin-bottom: 15px;
}

.page-header p {
    font-size: 18px;
    opacity: 0.9;
}

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

.section {
    background: white;
    padding: 40px;
    margin-bottom: 30px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.section h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 28px;
    border-bottom: 2px solid #e8eaf6;
    padding-bottom: 10px;
}

.section h3 {
    color: #333;
    margin: 20px 0 10px;
    font-size: 20px;
}

.section p {
    color: #666;
    line-height: 1.8;
    margin-bottom: 15px;
}

.section ul {
    margin: 15px 0;
}

.section ul li {
    color: #666;
    line-height: 1.8;
    margin-bottom: 8px;
}

.section a {
    color: #667eea;
    text-decoration: none;
}

.section a:hover {
    text-decoration: underline;
}

/* 页脚 */
footer {
    background: #2c3e50;
    color: white;
    padding: 40px 20px 20px;
    margin-top: 60px;
}

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

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3 {
    margin-bottom: 15px;
    color: #667eea;
}

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

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

.footer-section a {
    color: #bbb;
    text-decoration: none;
    transition: color 0.3s;
}

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

.footer-bottom {
    border-top: 1px solid #444;
    padding-top: 20px;
    text-align: center;
    color: #999;
    font-size: 14px;
}

.footer-bottom a {
    color: #667eea;
    text-decoration: none;
    margin: 0 5px;
}

.footer-bottom a:hover {
    text-decoration: underline;
}

.beian {
    margin-top: 10px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        gap: 15px;
        font-size: 14px;
    }

    .page-header h1 {
        font-size: 32px;
    }

    .page-header {
        padding: 40px 20px;
    }

    .section {
        padding: 25px;
    }

    .section h2 {
        font-size: 24px;
    }

    .container {
        padding: 30px 15px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

/* 按钮样式 */
.button {
    display: inline-block;
    padding: 12px 30px;
    background: #667eea;
    color: white;
    text-decoration: none;
    border-radius: 25px;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.button:hover {
    background: #764ba2;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

/* 提示框 */
.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin: 20px 0;
}

.alert-info {
    background: #e3f2fd;
    color: #1976d2;
    border-left: 4px solid #1976d2;
}

.alert-warning {
    background: #fff3e0;
    color: #f57c00;
    border-left: 4px solid #f57c00;
}

.alert-danger {
    background: #ffebee;
    color: #c62828;
    border-left: 4px solid #c62828;
}

/* 加载动画 */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}