<p dir="auto">I noticed that if you use customizer, this block of css is compiled to the end of bootstrap.css instead of normally around line 2800:</p>
<p dir="auto">.fade {<br>
opacity: 0;<br>
-webkit-transition: opacity 0.15s linear;<br>
transition: opacity 0.15s linear;<br>
}<br>
.fade.in {<br>
opacity: 1;<br>
}<br>
.collapse {<br>
display: none;<br>
}<br>
.collapse.in {<br>
display: block;<br>
}<br>
.collapsing {<br>
position: relative;<br>
height: 0;<br>
overflow: hidden;<br>
-webkit-transition: height 0.35s ease;<br>
transition: height 0.35s ease;<br>
}</p>
<p dir="auto">This causes issues such as modals with fade to have a completely black background (as ,fade.in is after .modal-backdrop.in)</p>
<p dir="auto">I am not sure if this is an issue with other css blocks as well but so far I haven't noticed any other effects except for this one.</p>
<p dir="auto">Hi!</p>
<p dir="auto">I just generated a customized version and the modal background is totally black (I also generated a version without any change to be sure it wasn't me that caused that):</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/7c884cd09470c8345f0304ad6c0a9768a9b9ad1b1cf415c28d5eb6df1beb82ab/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f353238373238352f313030393333382f66653335323434612d306233362d313165332d393531332d3962363637663362646665652e706e67"><img src="https://camo.githubusercontent.com/7c884cd09470c8345f0304ad6c0a9768a9b9ad1b1cf415c28d5eb6df1beb82ab/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f353238373238352f313030393333382f66653335323434612d306233362d313165332d393531332d3962363637663362646665652e706e67" alt="image" data-canonical-src="https://f.cloud.github.com/assets/5287285/1009338/fe35244a-0b36-11e3-9513-9b667f3bdfee.png" style="max-width: 100%;"></a></p>
<p dir="auto">The download link on the home page does have transparency:</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/c35f738d5bc9c495c9e5c3e792a7c2a713e064f7ba536da495ecd6830f696e96/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f353238373238352f313030393335332f33396635313138342d306233372d313165332d383231622d3263396365363830626339352e706e67"><img src="https://camo.githubusercontent.com/c35f738d5bc9c495c9e5c3e792a7c2a713e064f7ba536da495ecd6830f696e96/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f353238373238352f313030393335332f33396635313138342d306233372d313165332d383231622d3263396365363830626339352e706e67" alt="image" data-canonical-src="https://f.cloud.github.com/assets/5287285/1009353/39f51184-0b37-11e3-821b-2c9ce680bc95.png" style="max-width: 100%;"></a></p>