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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    display: flex;
    min-height: 100vh;
}

.content-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.header {
    background-color: #0056b3;
    color: white;
    width: 200px;
    min-height: 100vh;
    padding: 1rem;
    flex-shrink: 0;
}

.header-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.header h1 {
    font-size: 1.2rem;
    text-align: center;
    margin-bottom: 1rem;
}

.nav ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav a {
    color: white;
    text-decoration: none;
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.3s;
    display: block;
}

.nav a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.main {
    flex: 1;
    padding: 2rem;
    display: flex;
    flex-direction: column;
}

.hero {
    background-color: #f8f9fa;
    padding: 4rem 2rem;
    text-align: center;
    margin-bottom: 2rem;
    border-radius: 8px;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #0056b3;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #666;
}

.quick-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background-color: #0056b3;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #004494;
}

.features {
    margin-bottom: 2rem;
}

.features h3 {
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    color: #333;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-item {
    background-color: #f8f9fa;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.feature-item h4 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #0056b3;
}

.feature-item p {
    color: #666;
}

.footer {
    background-color: #333;
    color: white;
    padding: 1rem 0;
    text-align: center;
    margin-top: auto;
}

.footer-content {
    padding: 0 2rem;
}

/* 时间轴样式 */
.timeline {
    position: relative;
    max-width: 1200px;
    margin: 2rem auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 6px;
    background-color: #0056b3;
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -3px;
}

.timeline-item {
    padding: 10px 40px;
    position: relative;
    width: 50%;
    box-sizing: border-box;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 25px;
    right: -12px;
    background-color: white;
    border: 4px solid #0056b3;
    top: 15px;
    border-radius: 50%;
    z-index: 1;
}

.timeline-item.left {
    left: 0;
}

.timeline-item.right {
    left: 50%;
}

.timeline-item.right::after {
    left: -12px;
}

.timeline-content {
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.timeline-content h4 {
    margin-bottom: 10px;
    color: #0056b3;
}

.timeline-content p {
    color: #666;
}

/* 表格样式 */
.table-container {
    overflow-x: auto;
    margin: 2rem 0;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: #0056b3;
    color: white;
    font-weight: bold;
}

tr:hover {
    background-color: #f5f5f5;
}

/* 表单样式 */
.form-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: #f8f9fa;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

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

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: flex-start;
    }

    .nav ul {
        flex-wrap: wrap;
        margin-top: 1rem;
    }

    .timeline::after {
        left: 31px;
    }

    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }

    .timeline-item::after {
        left: 18px;
    }

    .timeline-item.right {
        left: 0;
    }

    .quick-links {
        flex-direction: column;
        align-items: center;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }
}