Update default thumbnail shadow style

[rapomon]

The file-preview shadow is horrible, I recommend a light shadow and hover.

Scope

This pull request includes a

• Bug fix
• New feature
• Translation

Changes

The following changes were made

Related Issues

If this is related to an existing ticket, include a link to it as well.

[kartik-v]

Thanks - could you submit a minified version of the CSS as well? You can use the following site to minify.

[rapomon]

Thanks. Done. El vie., 14 sept. 2018 a las 16:36, Kartik Visweswaran (< notifications@github.com>) escribió:

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Thanks - could you submit a minified version of the CSS as well - you can use the following site to minify <http://refresh-sf.com> — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1297 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFLfNxZWyl7uluFzUuCbgeMxw4LCjbJVks5ua772gaJpZM4Wo1lw> .