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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    background-color: #f4f4f4;
    color: #333;
}

header,
footer {
    background: #333;
    color: #fff;
    padding: 1rem;
    text-align: center;
}

nav {
    background: #444;
    color: #fff;
    padding: 0.5rem;
    text-align: center;
}

nav ul {
    list-style: none;
}

nav ul li {
    display: inline-block;
    margin: 0 15px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
}

.container {
    display: block;
    overflow: hidden;
    padding: 20px;
}

.sidebar {
    width: 20%;
    background: #ccc;
    padding: 15px;
    min-height: 200px;
}

.sidebar.left {
    float: left;
}

.sidebar.right {
    float: right;
}

.content {
    width: 75%;
    display: inline-block;
    background: #fff;
    padding: 15px;
    min-height: 200px;
    border: 1px solid #ddd;
    margin: 0 2.5%;
}

footer {
    clear: both;
    background: #333;
    color: #fff;
    text-align: center;
    padding: 1rem;
    margin-top: 20px;
}