body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f5f5f5;
}
.portal-header {
    text-align: center;
    background-color: #0078d7;
    color: white;
    padding: 30px;
    border-radius: 8px;
    margin-bottom: 30px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}
.portal-title {
    font-size: 32px;
    margin: 0;
}
.portal-subtitle {
    font-size: 18px;
    margin-top: 10px;
    font-weight: normal;
}
.chapters-container {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
}
.chapter-card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    padding: 20px;
    width: 100%;
    max-width: 450px;
    transition: transform 0.2s, box-shadow 0.2s;
}
.chapter-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}
.chapter-title {
    color: #0078d7;
    font-size: 22px;
    margin-top: 0;
    border-bottom: 2px solid #0078d7;
    padding-bottom: 10px;
}
.chapter-date {
    color: #666;
    font-size: 14px;
    margin-bottom: 15px;
}
.chapter-content {
    margin-bottom: 20px;
}
.chapter-button {
    display: inline-block;
    background-color: #0078d7;
    color: white;
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 4px;
    transition: background-color 0.2s;
}
.chapter-button:hover {
    background-color: #0056b3;
}
.portal-footer {
    text-align: center;
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #ddd;
    color: #666;
}
.github-link {
    display: inline-flex;
    align-items: center;
    color: #0078d7;
    text-decoration: none;
    margin-left: 5px;
}
.github-link svg {
    margin-right: 5px;
}
.coming-soon {
    background-color: #f8f9fa;
    border: 1px dashed #ccc;
    opacity: 0.8;
}
.coming-soon .chapter-title {
    color: #666;
    border-bottom-color: #ccc;
}
.badge {
    display: inline-block;
    background-color: #28a745;
    color: white;
    font-size: 12px;
    padding: 3px 8px;
    border-radius: 20px;
    margin-left: 10px;
}