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

.box1 {
    width: 400px;
    padding: 10px;
    margin: 30px;
    border: 4px solid #000;
    background-color: #ffd6d6;
}

.box2 {
    width: 400px;
    padding: 30px;
    margin: 50px;
    border: 6px dashed #333;
    background-color: #d6f5ff;
}

#box3 {
    width: 400px;
    padding: 5px;
    margin: 50px;
    border: 6px double #444;
}

.box4 {
    width: 400px;
    padding: 30px;
    margin: 50px;
    border: 6px dashed #333;
    background-color: #d6f5ff;

    box-sizing: border-box;
}