body{
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header{
    background-color: #444;
    color: white;
    padding: 20px;
    text-align: center;
    border-bottom: 3px solid #222; 
    position: relative; 
}
nav{
    background-color: #eee;
    padding: 10px;
    border-bottom: 2px solid #ccc; 
}
nav ul{
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex; 
    gap: 10px;
}
nav li{
    padding: 5px;
}
section{
    float: left; 
    width: 60%; 
    padding: 15px; 
    box-sizing: border-box;
    border-right: 2px solid #ccc;
}
aside{
    float: right; 
    width: 30%; 
    padding: 15px; 
    box-sizing: border-box;
    border-left: 2px solid #ccc; 
}
article{
    clear: both; 
    padding: 20px;
    margin: 10px; 
    border-top: 2px solid #aaa; 
    background-color: #f9f9f9;
}  
footer {
    text-align: center;
    padding: 15px;
    background-color: #333;
    color: white;
    border-top: 3px solid #222; 
}