Two-column layout, the second column width is fixed, I use float second column why not go up?

https://codepen.io/niusz/pen/. and I empty the margin-right in the first column. Can the elements under the vacant margin-right go up?

Mar.10,2021

left is a block-level element station right how to get up
put right in front of left before right floats and then leaves the layout left goes up

<div class="ct">
  <div class="right">right</div>
  <div class="left">left</div>
</div>

because left is a block-level element that does not float, it already occupies a full line, so there is no room for this line to float. Add a float to left and right goes up

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