Responsive SVG sizing

Question

I have the following SVG:

body {
    background-color: #dad9c7;
    svg {
        position: absolute;
        width: 100%;
        height: 400px;
        margin: 0 auto;
        display: block;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
    }
}

.

Which looks like this:

How can I do the following?

Keep heights of colored strips the same when scaling the window (not scale).
Stretch colored strips horizontally to the edges of the viewport on either side left and right.
Stretch the top-most rectangle to the top of the screen so the upper third of the viewport is orange and stretch the bottom-most rectangle to the bottom of the viewport so that the lower third of the viewport is purple.
Always keep the "square" centered vertically which already works with CSS, but however the SVG is manipulated to solve would have to keep this into account.

Here is an example of how this would look: As the window gets taller, the colored rectangles will stay in the middle, but the top orange and bottom purple would be cut off based on the height of the viewport.

Paul LeBeau · Accepted Answer

How can I do the following?

Keep heights of colored strips the same when scaling the window (not scale).

You are already doing this by setting height to 400px.

Stretch colored strips horizontally to the edges of the viewport on either side left and right.

Set preserveAspectRatio="none" on the SVG. See below.

body {
    background-color: #dad9c7;
}

svg {
    position: absolute;
    width: 100%;
    height: 400px;
    margin: 0 auto;
    display: block;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

Stretch the top-most rectangle to the top of the screen so the upper third of the viewport is orange and stretch the bottom-most rectangle to the bottom of the viewport so that the lower third of the viewport is purple.

You cannot automatically stretch the rectangle itself with CSS. But one way you could do it is to use pseudo elements to colour the top and bottom halves of the parent element with matching colours.

body {
    background-color: #dad9c7;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 0;
    margin: 0;
}

svg {
    position: absolute;
    width: 100%;
    height: 400px;
    margin: 0 auto;
    display: block;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

body::before {
  content: "";
  display: block;
  position: absolute;
  width: 100%;
  top: 0;
  bottom: 50%;
  background-color: #d5835b;
}

body::after {
  content: "";
  display: block;
  position: absolute;
  width: 100%;
  top: 50%;
  bottom: 0;
  background-color: #313d53;
  z-index: -1;
}

Always keep the "square" centered vertically which already works with CSS, but however the SVG is manipulated to solve would have to keep this into account.

N/A here.

Alternate pure-SVG solution

There is also a pure SVG solution using nested elements. The only CSS we are using is just to ensure the SVG occupies the full size of the page.

It works by making the top and bottom rectangles extend outside the viewBox by an extra 1000 pixels. To make sure they are visible, we set overflow="visible". 1000 is an arbitrary value. If you want to support screens > 2400 pixels high, then you could choose a larger value.

The inner SVG gets centred vertically using a combination of a y offset and a transform that shifts it up by 200px. This is equivalent to the common top: 50%; transform: translate(0,-50%)" trick to vertically centre CSS block elements.

body {
    background-color: #dad9c7;
    padding: 0;
    margin: 0;
}

#mysvg {
    position: absolute;
    display: block;
    width: 100%;
    height: 100%;
}

Responsive SVG sizing

Answers (2)

Related Questions