Selector points to the HTML element you want to style<|>Declaration block contains one or more declarations separated by semicolons<|>Each declaration includes a CSS property name and a value, separated by a colon<|>Multiple CSS declarations are separated with semicolons, and declaration blocks are surrounded by curly braces
em - Relative to the font-size of the element (2em means 2 times the size of the current font)<|>rem - Relative to font-size of the root element<|>% - Relative to the parent element
letter-spacing: sets the horizontal spacing behavior between text characters<|>word-spacing: property sets the length of space between words and between tags.
Apply a style rule to a particular element only when it lies inside a particular element. E.g., the style rule will apply to <a> element only when its parent is <li>
The child combinator (>) is placed between two CSS selectors. It matches only those elements matched by the second selector that are the direct children of elements matched by the first. Descendent elements further down the hierarchy don't match.