Square DIV where height is equal to viewport

user_844668 0
Viewed 49963

I need to create a DIV where width=height, and height=100% of the viewport (which, obviously, is variable).

In other words, a perfectly square DIV that calculates it's dimensions based on the height of the viewport. Elements within that DIV will take their dimensions as percentages of the parent-DIV's height & width.

It seems to me like this should be simple to do in CSS, but I've gotten stuck with it! Any pointers would be much appreciated.

css-shapes aspect-ratio css html
8 Answers

This is interesting...

For those who may be looking for a pure CSS way to contain a square div with the maximum dimensions:

The key takeaway here is that you set max-width and max-height while setting width and height to the opposite values.

HTML

<div>
</div>

CSS

html, body {
  margin: 0;
  padding: 0;
  width: 100vw;
  height: 100vh;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
}

div {
  background-color: red;
  width: 100vh;
  height: 100vw;
  max-width: 100vw;
  max-height: 100vh;
}

Live running example: https://jsfiddle.net/resistdesign/szrv5o19/

user_8778600
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