The line-height-step
CSS property sets the step unit for line box heights. When the property is set, line box heights are rounded up to the closest multiple of the unit.
Syntax
line-height-step: 18pt;
line-height-step: inherit;
line-height-step: initial;
line-height-step: revert;
line-height-step: revert-layer;
line-height-step: unset;
The line-height-step
property is specified as any one of the following:
Values
-
<length>
-
The specified <length>
is used in the calculation of the line box height step.
Setting step unit for line box height
In the following example, the height of line box in each paragraph is rounded up to the step unit. The line box in <h1>
does not fit into one step unit and thus occupies two, but it is still centered within the two step unit.
:root {
font-size: 12pt;
--my-grid: 18pt;
line-height-step: var(--my-grid);
}
h1 {
font-size: 20pt;
margin-top: calc(2 * var(--my-grid));
}
The result of these rules is shown below in the following screenshot:

Specifications
Browser compatibility
|
Desktop |
Mobile |
|
Chrome |
Edge |
Firefox |
Internet Explorer |
Opera |
Safari |
WebView Android |
Chrome Android |
Firefox for Android |
Opera Android |
Safari on IOS |
Samsung Internet |
line-height-step |
60 |
79 |
No |
No |
47 |
No |
No |
60 |
No |
No |
No |
No |