Half of css rules fails in Safari on OS X, not in other browsers [#2645982]

I built a site based on the Skeleton theme, but most of the css is not picked up in Safari under os x. This only happens in this specific browser and is tested on different mac devices. Safari version is 9.0.2. Safari on iPhone works as intended. Take a look at www.toegankelijkopreis.be to see te differences: text color, floats, text shadows, border radiuses, border colors, background colors and images, button styles, ... All gone under safari OS X. What could cause this?

Comments

Comment #1

7 January 2016 at 12:37

Denial created an issue. See original summary.

Comment #2

Denial CreditAttribution: Denial commented 7 January 2016 at 12:37

Title:

Half of css fails in Safari on OS X, not

» Half of css rules fails in Safari on OS X, not in other browsers

Comment #3

Denial CreditAttribution: Denial commented 19 January 2016 at 08:49

Turns out most of this issue is caused by selecting the "aggregate and compress css files" under admin/config/development/performance. Disabling it brought back all css styles.