Basic

HTML

HTML basic structure

<!DOCTYPE html>
<html>
<head>
 <title></title>
</head>
<body>
</body>
</html>

:root{
--(name of the var):(color, fontsize etc);
}
//-- two dash is mendatory

//when use
ex) font-size: var(--main-font-size);

position: absolute; it is fixed on the designated position

position: fixed; it is fixed on the designated position + it stays float in the position even if the page is being scrolled

position: relative; position relative to the previous element

default margin

if you don't want the default margin: margin: unset; or margin:0;