body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #007bff; /* Blue background */
    padding: 15px 0;
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    text-align: center; /* Center the navigation menu */
}

nav ul li {
    display: inline-block;
    margin: 0 15px; /* Gap between tabs */
}

nav ul li a {
    color: #fff; /* White text */
    text-decoration: none;
    padding: 12px 25px; /* Padding for tabs */
    display: block;
    background-color: #d40027; /* Aqua background */
    border-radius: 5px;
    font-weight: bold; /* Bold text */
    transition: background-color 0.3s ease, color 0.3s ease, transform 0.3s ease;
    border: 2px solid #007bff; /* Blue border */
    cursor: pointer; /* Pointer cursor */
}

nav ul li a:hover {
    background-color: #fde806; /* Darker aqua on hover */
    color: #930000; /* Darker text color */
    transform: scale(1.1); /* Zoom effect */
    border-color: #0056b3; /* Darker blue border on hover */
}

.class-content {
    display: none;
    padding: 20px;
    border: 1px solid #007bff;
    border-radius: 5px;
    margin-top: 10px;
}

.class-content.active {
    display: block;
}

.subject {
    cursor: pointer; /* Pointer cursor for subjects */
    padding: 10px;
    margin: 5px 0;
    background-color: #d40027; /* Aqua background for subjects */
    color: #fff; /* White text */
    border-radius: 5px;
    text-align: center; /* Center-align subject names */
    transition: background-color 0.3s ease, color 0.3s ease, transform 0.3s ease;
}

.subject:hover {
    background-color: #fde806; /* Darker aqua on hover */
    color: #930000; /* Darker text color */
    transform: scale(1.05); /* Slight zoom effect */
}
.unit-list {
    margin-top: 5px; /* Space between subject and unit list */
    padding: 5px;
    background-color: #f0f0f0; /* Light background for contrast */
    border-radius: 5px;
}

.unit-list h4 {
    margin-bottom: 5px; /* Space between subject name and unit list */
}

.unit {
    display: block; /* Ensure units appear as block-level elements */
    margin: 5px 0; /* Reduced space between units */
    padding: 8px;
    background-color: #007bff;
    color: #fff;
    border-radius: 5px;
    text-align: left;
}

.unit a {
    color: #fff;
    text-decoration: none;
}

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