Css Validation Errors?

Store Builder Questions
1

design/themes/basic/css/grid.less 




<br />
.input-block-level {<br />
  display: block;<br />
  width: 100%;<br />
  min-height: ;<br />
  -webkit-box-sizing: border-box;<br />
  -moz-box-sizing: border-box;<br />
  box-sizing: border-box;<br />
}<br />
<br />
<br />

```<br />
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why is [color=#000000]min-height: ; nothing?[/color]<br />
<br />
<br />
<br />
[color=#000000]this comes from responsive...[/color]<br />
<br />
<br />
// Block level inputs<br />
.input-block-level {<br />
  display: block;<br />
  width: 100%;<br />
  min-height: @inputHeight; // Make inputs at least the height of their button counterpart (base line-height + padding + border)<br />
  .box-sizing(border-box); // Makes inputs behave like true block-level elements<br />
}<br />
<br />
<br />
from  design/themes/basic/css/lib/bootstrap/less/mixins.less<br />
<br />
seems its missing default values ? <br />
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https://github.com/twbs/bootstrap/blob/master/less/variables.less