Things that might come in handy one day1

- dummy link : <a href = "#">

- to make a full viewport : height: 100vh 

but 1) only the portion of the picture will be shown (looks too zoomed in)

but 2) if there's margin up on the top it's because of the <h1>~<h6> element's margin that we have on html file

- position : absolute is the only way to make sth vertically & horizontally centered

- background-image: linear-gradient(rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0.8)), url("something.jpg"); covers up the image with color, linear gradient() needs two specification. used for gradients but if darkening is the purpose, than just write the same two color inside the bracket.

- inline block (think of it as a mix of block element and inline element) : similar to inline block but can have padding and margin. So the difference is that it doesn't force line break but can attribute padding & margin.

- <a></a> is an inline element

- hover

means) when the cursor is over sth

position in the editor) write after sth:link & sth:visited (if there is/are one). 

- active state : when sth is clicked

- transition: background-color 0.2s, border 0.2s, color 0,2s; it makes a gradual transition within background of the button. More than one property can be included