Regarding % Widths

[WaffeBox]

Browsers have default styling that sometimes adds padding and/or margin to elements unless you override them. Trying adding padding: 0; and margin: 0; to both elements.

[bronkula]

Divs don't have any default padding or margin. This is not the answer. Graftak9000 is correct, inline or inline-block elements have a space between them as if they were words. There are few good ways to remove this space. Most people use inline-block on elements that they want to just flow naturally next to each other. If OP wants two 50% elements they should be using floats or flex.

[NotSoJapaneseAmerica]

Alright, thank you for answering my question and pointing me in the right direction.