body{
    width: 80%;
    margin: 0px auto;
}
.header{
    width: 100%;
    height: 200px;
    border: 4px solid red;
    text-align: center;
    line-height: 200px;
    font-size: 30px;
    border-bottom: none;
}
.menu{
    width: 100%;
    height: 50px;
    border: 4px solid red;
    text-align: center;
    line-height: 50px;
    font-size: 30px;
    border-bottom: none;
}
.main{
    width: 100%;
    height: 500px;
    border: 4px solid red;
    display: flex;
}
.content{
    width: 70%;
    height: 500px;
    border: 1px solid red;
    text-align: center;
    line-height: 500px;
    font-size: 30px;
    border-left: none;
}
.sidebar{
    width: 30%;
    height: 500px;
    border: 1px solid red;
    text-align: center;
    line-height: 500px;
    font-size: 30px;
    border-right: none;
}
.footer{
    width: 100%;
    height: 100px;
    border: 4px solid red;
    text-align: center;
    line-height: 100px;
    font-size: 30px;
    border-top: none;
}