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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    background-color: #f4f4f4;
    color: #333;
    transition: background-color 0.5s ease; /* Smooth background color transition */
}

header {
    background: #4CAF50;
    color: white;
    padding: 20px;
    text-align: center;
    transition: background-color 0.5s ease; /* Smooth header background transition */
}

main {
    padding: 20px;
    text-align: center;
}

h2 {
    margin: 20px 0;
    transition: color 0.3s ease; /* Smooth color transition for the heading */
}

.button-container {
    display: flex;
    flex-wrap: wrap; /* Allow buttons to wrap in small screens */
    justify-content: center;
    gap: 20px;
    margin-top: 20px;
}

.semester-button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 15px 25px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s, transform 0.2s, box-shadow 0.3s; /* Added box-shadow transition */
    flex: 1 1 200px; /* Flex property to allow buttons to grow and shrink */
    max-width: 200px; /* Set a maximum width for buttons */
}

.semester-button:hover {
    background-color: #45a049;
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2); /* Add shadow on hover */
}

footer {
    text-align: center;
    padding: 10px;
    background: #333;
    color: white;
    position: relative;
    bottom: 0;
    width: 100%;
    transition: background-color 0.5s ease; /* Smooth footer background transition */
}

/* Responsive Design */
@media (max-width: 600px) {
    header {
        padding: 15px;
    }

    .semester-button {
        font-size: 14px; /* Smaller font size on small screens */
        padding: 10px 20px; /* Adjust padding for smaller buttons */
    }

    footer {
        padding: 8px;
    }
}

/* Background color change on hover */
body:hover {
    background-color: #e9e9e9; /* Lighten background on hover */
}

header:hover {
    background-color: #388e3c; /* Darken header on hover */
}

h2:hover {
    color: #333; /* Change heading color on hover */
}