Defines the space outside the element, on the left side.

默认属性 margin-left: 0;

Removes any margin on the left.

margin-left: 50px;

You can use pixel values.

margin-left: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

margin-left: 30%;

You can use percentage values.
The percentage is based on the width of the container.

margin-left: auto;

The auto keyword will give the left side a share of the remaining space.

When combined with margin-right: auto, it will center the element, if a fixed width is defined.