html{
    background: rgb(244, 244, 244);
}
*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
#codeHtml{
    width: 360px;
    height: 520px;
    border: 2px solid black;
    overflow: auto;
    margin-left: 20px;
    margin-top: 20px;
    border-radius: 5px;
}
#codeCss{
    width: 360px;
    height: 520px;
    border: 1px solid red;
    overflow: auto;
}
#code {
    float: left;
}
#main {
    float: right;;
    height: 100vh;
    overflow: auto;
    padding-left: 20px;
}
.clearfix::after{
    content: '';
    display: block;
    clear:both;
}