<svg>

This example shows that nested svg elements do not need the xmlns attribute.

html,
body,
svg {
  height: 100%;
}

<svg
  viewBox="0 0 300 100"
  xmlns="http://www.w3.org/2000/svg"
  stroke="red"
  fill="grey">
  <circle cx="50" cy="50" r="40" />
  <circle cx="150" cy="50" r="4" />

  <svg viewBox="0 0 10 10" x="200" width="100">
    <circle cx="5" cy="5" r="4" />
  </svg>
</svg>

In this example, the height and width attributes on the svg element are set using the dynamic viewport value 60vmin, equivalent to 60% of the viewport's width or height, whichever is smaller.

<div class="resizer">
  <iframe
    class="resized"
    srcdoc="

<svg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg' height='60vmin' width='60vmin'>
  <rect x='0' y='0' width='50%' height='50%' fill='tomato' opacity='0.75' />
  <rect x='25%' y='25%' width='50%' height='50%' fill='slategrey' opacity='0.75' />
  <rect x='50%' y='50%' width='50%' height='50%' fill='olive' opacity='0.75' />
  <rect x='0' y='0' width='100%' height='100%' stroke='cadetblue' stroke-width='0.5%' fill='none' />
</svg>

  "></iframe>
</div>

.resizer {
  display: flex;
  margin: 1rem;
  padding: 0;
  resize: both;
  overflow: hidden;
  border: 5px dotted red;
  height: 400px;
}
.resizer > .resized {
  flex-grow: 1;
  margin: 0;
  padding: 0;
  border: 0;
}

To change the iframe's dimensions try resizing the dotted red border from bottom right corner.

baseProfile Deprecated

The minimum SVG language profile that the document requires. Value type: <string> ; Default value: none; Animatable: no

height

The displayed height of the rectangular viewport. (Not the height of its coordinate system.) Value type: <length>|<percentage> ; Default value: auto; Animatable: yes

preserveAspectRatio

How the svg fragment must be deformed if it is displayed with a different aspect ratio. Value type: (none| xMinYMin| xMidYMin| xMaxYMin| xMinYMid| xMidYMid| xMaxYMid| xMinYMax| xMidYMax| xMaxYMax) (meet|slice)? ; Default value: xMidYMid meet; Animatable: yes

version Deprecated

Which version of SVG is used for the inner content of the element. Value type: <number> ; Default value: none; Animatable: no

viewBox

The SVG viewport coordinates for the current SVG fragment. Value type: <list-of-numbers> ; Default value: none; Animatable: yes

width

The displayed width of the rectangular viewport. (Not the width of its coordinate system.) Value type: <length>|<percentage> ; Default value: auto; Animatable: yes

x

The displayed x coordinate of the svg container. No effect on outermost svg elements. Value type: <length>|<percentage> ; Default value: 0; Animatable: yes

y

The displayed y coordinate of the svg container. No effect on outermost svg elements. Value type: <length>|<percentage> ; Default value: 0; Animatable: yes