body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 40px;
    background-color: #6272A4;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    width: 80%;
    max-width: 800px;
    margin: 20px;
    text-align: center;
}

.paper {
    background-color: white;
    padding: 20px;
    /* margin: auto; */
    margin-bottom: 5vh;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    text-align: left;
}

h1 {
    color: #000;
    text-align: center;
}

.unit-title {
    background-color: #87CEFA;
    color: white;
    padding: 10px;
    margin-top: 20px;
    text-align: left;
    font-size: 18px;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.unit-title:hover {
    background-color: #79bcea;
}

.topic-list {
    list-style: none;
    padding: 0;
    margin: 0;
    text-align: left;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-out;
}

.topic-list.show {
    max-height: 2000px; /* Assume max content height for the animation */
}

.topic-list li {
    padding: 10px;
    margin-bottom: 5px;
    border-bottom: 1px solid #ddd;
    transition: background-color 0.3s ease;
}

.topic-list li:hover {
    background-color: #f1f1f1;
}

.topic-list li a {
    text-decoration: none;
    color: #0056b3;
}

.topic-list li a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    .container {
        width: 90%;
        padding: 0 10px;
    }
    .paper {
        margin: 10px 0;
    }
}