Xuân Dinh Trần

Thử cách này nhé bạn https://codepen.io/xuandinhgl/pen/EJgLxR

html,body{
  margin: 0;
  padding: 0
}
body{
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.header {
  background: #595959;
  top: 0;
  width: 100%;
  height: 90px;
}
.content{
  border:solid ;
  padding: 15px;
  overflow-y: auto;
}
.footer {
  width: 100%;
  background-color: blue;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  padding: 10px;
  box-sizing: border-box;
}

.layout{
  height: 70px;
  width: 45%;
}
.layout-1{
  background: red;
}
.layout-2{
  background: green;
}

@media only screen and (max-width: 600px) {
  .layout{
    width: 100%;
    margin-bottom:15px;
  }
}