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

/* Header */
header {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 20px;
}

/* Navigation - left column */
nav {
    float: left;
    width: 25%;
    background-color: #f2f2f2;
    padding: 20px;
    box-sizing: border-box;

    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    overflow-y: auto;
}

/* Main content - right column */
main {
    float: right;
    width: 70%;
    padding: 20px;
    box-sizing: border-box;
    margin-left: 25%;
}

/* Nav list styling */
nav ul {
    list-style-type: none;
    padding: 0;
}

nav li {
    margin-bottom: 10px;
}

nav a {
    text-decoration: none;
    color: black;
    font-weight: bold;
}

/* Hover effect */
nav a:hover {
    color: blue;
}

/* Footer */
footer {
    clear: both;
    background-color: #333;
    color: white;
    text-align: center;
    padding: 15px;
    margin-left: 25%;
}