Custom Styling Form Inputs With Modern CSS Features . The length units described in the CSS Values and Units module specification. Alternatively, you can also use the size attribute to define the width of the . In fact, there isn’t any simple HTML or CSS way to make them do that. It’s entirely possible to build custom checkboxes, radio buttons, and toggle switches these days, while staying semantic and accessible. Instead of changing the font-size, we only need to change the scale to .75 which means 75% of the original size. From a display perspective, one character is equivalent to 1 em (actually that’s the definition of the em CSS unit). Le pseudo-élément::placeholder représente le texte de substitution pour un élément ou