I have 3 issues:
I can see a part of the parent white background bottom (& right side sometimes) under its child that have a 100% width & height (see green arrow on my screenshot)
The child width is set to 100% but when i inspect it is larger than the parent (see the red arrow on the screenshot)
My line-height is
line-height:30px;
and myfont-size:30px;
but there is a different spacing on top and bottom of the text (see the blues arrows on my screenshot). This prevent me from centering correctly vertically my text
Note: My browser zoom is on 100%
Fiddle: https://jsfiddle.net/gr85n2es/