.topic-page {
    max-width: 900px;
    margin: 0 auto;
    background-color: #34495e;
    border-radius: 8px;
    padding: 40px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
}

.topic-page h1 {
    color: #3498db;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}

.topic-page h2 {
    color: #3498db;
    margin: 25px 0 15px 0;
}

.topic-page h3 {
    color: #5dade2;
    margin: 20px 0 10px 0;
}

.topic-page p {
    line-height: 1.7;
    margin-bottom: 15px;
}

.topic-page pre {
    background-color: #2c3e50;
    padding: 15px;
    border-radius: 4px;
    overflow-x: auto;
    margin: 15px 0;
}

.topic-page code {
    font-family: 'Consolas', 'Monaco', monospace;
    color: #e67e22;
}

.topic-page ul, .topic-page ol {
    margin-left: 25px;
    margin-bottom: 15px;
}

.topic-page li {
    margin-bottom: 8px;
    line-height: 1.5;
}

.topic-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #2c3e50;
}

.topic-nav-btn {
    padding: 10px 20px;
    background-color: #3498db;
    color: #ecf0f1;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.topic-nav-btn:hover {
    background-color: #2980b9;
}

.topic-nav-btn:disabled {
    background-color: #7f8c8d;
    cursor: not-allowed;
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    color: #3498db;
    text-decoration: none;
    cursor: pointer;
}

.back-link:hover {
    text-decoration: underline;
}