元の HTML 構造を変更せずに、HTML と CSS を使用して 3 列のレイアウトを作成するにはどうすればよいですか?

<div class="container">
  <div class="column-center">Column center</div>
  <div class="column-left">Column left</div>
  <div class="column-right">Column right</div>
</div>

----------------------------------------------------
|              |                   |               |
| Column left  |   Column center   | Column right  |
|              |                   |               |
----------------------------------------------------

.column-left {
  float: left;
  width: 33.333%;
}

.column-right {
  float: right;
  width: 33.333%;
}

.column-center {
  display: inline-block;
  width: 33.333%;
}

.column {
  float: left;
  position: relative;
  width: 20%;
}

.column-offset-1 {
  left: 20%;
}

.column-offset-2 {
  left: 40%;
}

.column-offset-3 {
  left: 60%;
}

.column-offset-4 {
  left: 80%;
}

.column-inset-1 {
  left: -20%;
}

.column-inset-2 {
  left: -40%;
}

.column-inset-3 {
  left: -60%;
}

.column-inset-4 {
  left: -80%;
}

<div class="container">
  <div class="column column-one column-offset-2">Column one</div>
  <div class="column column-two column-inset-1">Column two</div>
  <div class="column column-three column-offset-1">Column three</div>
  <div class="column column-four column-inset-2">Column four</div>
  <div class="column column-five">Column five</div>
</div>