Lessons · HTML and CSS · a CSS rule
A CSS rule
A rule is a selector, then braces holding property: value pairs. Rules that match the same element all apply; they add up rather than replace each other.
Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.
What it is for
Every stylesheet is a list of these. Reading one as 'which elements, then what changes' is the whole grammar.
How to think about it
Selector first: who does this touch? Then each declaration: what changes, to what. End every declaration with a semicolon so the next one is not swallowed.
Worked example
<p class="note">Careful.</p>Something to style: a paragraph with a class.
p { color: rgb(200, 0, 0); }Selector p, one declaration: every paragraph's text goes red..note { font-weight: bold; }A second rule matches the same paragraph; both apply. It is red and bold.Your turn
Make every heading green.
h1 { : green; }Write a page and watch it render
The trap
A missing semicolon between declarations. The browser reads the next property as part of the previous value and drops both, without an error.
Practise a CSS rule on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.