Css

Center a button inside a div

https://www.w3schools.com/howto/howto_css_center_button.asp

@media only screen and (min-width: 768px) {
    .container {
        position: relative;
    }
    .vertical-center {
        position: absolute;
        top: 40%;
    }
}

Pure-css

Putting a text element (ex: label) inside a pure-g directly makes it inherits a negative letter-spacing and makes the text mkhalat (overlap), it also happens if we don't set a pure-u class for a breakpoint (only tested with phones)

Wtforms SelectField with int values

Add coerce=int for god's sake!