html {

  box-sizing: border-box;

}

​

*, *:before, *:after {

  box-sizing: inherit;

}

​

body{

  margin: 0;

  height: 3000px;

}

​

div {

  padding-right: 15px;

  padding-left: 15px;

  margin-right: auto;

  margin-left: auto;

  background: blue;

  height: 100%;

}

@media (min-width: 768px) {

  div {

    width: 768px;

    background: silver;

  }

}

@media (min-width: 992px) {

  div {

    width: 992px;

    background: yellow;

  }

}

@media (min-width: 1200px) {

  div {

    width: 1200px;

    background: red;

  }

}