X'inhuma pseudo-classes u liema huma l-komuni?

Question

Accepted Answer

A **pseudo-class** (kolon wieħed `:`) jagħżel elementi ibbażat fuq l-**istat** jew l-**pożizzjoni** tagħhom — xi ħaġa li ma tistax tiġi espressa b'klassi ordinarja, bħal "meta hemm hover" jew "l-ewwel tifel."

## State pseudo-classes (interazzjoni)

```css
a:hover    { color: blue; }      /* mouse is over it */
a:focus    { outline: 2px solid; } /* keyboard/tab focus — keep for accessibility! */
button:active   { transform: scale(0.98); } /* while being pressed */
button:disabled { opacity: 0.5; } /* disabled form controls */
input:checked   { } /* checked checkbox/radio */
input:focus-visible { } /* focus only when keyboard-navigating (not mouse) */
```

L-ordni għall-links hija importanti (LVHA): `:link`, `:visited`, `:hover`, `:active`.

## Structural pseudo-classes (pożizzjoni)

```css
li:first-child  { } /* first li among its siblings */
li:last-child   { } /* last one */
li:nth-child(2) { } /* the 2nd */
li:nth-child(odd)  { } /* 1st, 3rd, 5th... — zebra striping */
li:nth-child(3n)   { } /* every 3rd */
p:only-child    { } /* a p that's the sole child */
```

`:nth-child()` hija qawwija — `2n` (uniformi), `2n+1` (fard), `3n` (kull terz), eċċ.

## Form & modern pseudo-classes

```css
input:required  { }
input:invalid   { border-color: red; }
:is(h1, h2, h3) { }  /* matches any — shortens selector lists */
.card:has(img)  { }  /* the "parent selector": a card that CONTAINS an img */
:not(.active)   { }  /* everything except .active */
```

## Pseudo-class vs pseudo-element

Pseudo-classes jużaw **wieħed** kolon (`:hover`, *istat*); pseudo-elements jużaw **tnejn** (`::before`, *parti ġenerata*). Tħallitux bejniethom.

## Għaliex hija importanti

Pseudo-classes jippermettulek li tagħti stil għall-interazzjoni (hover/focus — essenzjali għal UI użabbli u aċċessibli) u struttura (striping, first/last) mingħajr markup addizzjonali jew JavaScript.

Dawk moderni (`:has`, `:is`, `:focus-visible`) isolvu problemi li qabel kellhom bżonn JS jew selettori ripetuti.