[CentOS] Buttons too big in Firefox for Linux

[Alice Wonder]

On 02/01/2017 06:44 AM, Jonathan Billings wrote:
> On Wed, Feb 01, 2017 at 02:32:53PM +0000, Gary Stainburn wrote:
>> A while back, after doing a yum update, a new version of Firefox was
>> installed and since then, the contents of my pages don't fit any
>> more because the buttons are now much bigger.
>>
>> I've done some searching and to be honest I've drowned in the results.  To
>> make matters worse, most of the results are OLD, referring to IE version 6
>> and Firefox version 30.
>>
>> This problem is only very recent (months).  The problem is only in Firefox for
>> Linux. Firefox for Android and Windows look fine, as does Chrome on
>> everything and I.E.
>>
>> Does anyone have any relevant / current suggestions on how to fix this?
>> Firefox on Linux is my main development platform so having it look different
>> to everything else is a real pain
>>
>> It doesn't seem to matter whether I use <input type=button> or <button
>> type=button>
>
> Any chance your browser is zoomed in?  Or maybe you've told firefox
> that your DPI is higher than it should be? (layout.css.devPixelsPerPx)
>

That's a good possibility, FireFox has an annoying habit of zooming if 
the ctrl button gets stuck even temporarily, and it isn't always obvious 
it has happened.