section

header, footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
header ul, footer ul {
  display: flex;
  justify-content: space-around;
  width: 50%;
}
main {
  display: flex;
}
aside {
  width: 200px;
}
section {
  width: calc(960px - 200px);
}