body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  margin: 0;
}

header,
footer {
  background-color: sandybrown;
}

.middler {
  display: flex;
  flex-direction: row;
  flex-grow: 1;
}

aside {
  flex-basis: 150px;
  background-color: cornsilk;
}

main {
  flex-grow: 1;
  flex-basis: 0;
}

main,
aside,
header,
footer {
  padding: 10px;
}