Add hover effect to the AUTO refresh UI in the preview (#1732)
Add hover effect to the AUTO refresh UI in the preview (#1732)

* Add hover effect to the AUTO refresh UI in the preview.

Color changes to dark grey when we hover over AUTO refresh button.

* Change in rgba value

Changed rgba value to rgba(0,0,0,.6)

mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org,humphd/thimble.mozilla.org,mozilla/thimble.mozilla.org,humphd/thimble.mozilla.org,humphd/thimble.mozilla.org,humphd/thimble.mozilla.org