Opacity
The opacity property sets the opacity level for an element. The opacity level describes the transparency level, where 1 is not transparent at all, .5 is 50% visible, and 0 is completely transparent.
Set the opacity of an element using .opacity-{value} utilities.
Example
<div class="opacity-100">...</div>
<div class="opacity-75">...</div>
<div class="opacity-50">...</div>
<div class="opacity-25">...</div>
opacity-100
opacity-75
opacity-50
opacity-25