Buttons Not Aligning with Custom CSS?

[npazo]

I have something weird going on. I have two buttons right next to each other. One of them (bottom) is using custom CSS class, and it's slightly to the left of the one above it. The custom CSS does nothing but change the colors.

If I remove the custom CSS class, the buttons are in vertical alignment.

Any thoughts?

.my-button {
    background-color: #83eede;
    color: #2e3440;
}