*{
    box-sizing: border-box;
}
.container{
    width: 960px;
    background-color: deepskyblue;
    margin: 0 auto;
    padding: 20px;
}
.box{
    background-color: red;
    width: 700px;
    height: 200px;
    padding: 20px;
    border: 10px solid blue;
    margin: 20px;
    max-width: 500px;
    min-width: 250px;
    padding-top: 100px;
    
}