Welcome to HTMLcat: a small collection of useful snippets and references for HTML, CSS, and JavaScript. The focus is on simple, native features that are easy to forget and nice to rediscover.

This site also uses new and experimental browser features for study purposes, so a few details may look different across browsers.

Device type in js

🍬 Post-it JS

Apply Opacity to CSS Variables with color-mix()

🍬 Post-it CSS

Empty tags

🍬 Post-it CSS

Dialog

🍬 Post-it HTML

Using ::marker in CSS

🍬 Post-it CSS

Device type in js

🍬 Post-it JS

Scroll margin

🍬 Post-it CSS

classList toggle

🍬 Post-it JS

Tel and mail links

🍬 Post-it HTML

Text selection/highlight

🍬 Post-it CSS

CSS Parent Selector :has

🍬 Post-it CSS

Using ::marker in CSS

🍬 Post-it CSS

Clamp

🍬 Post-it CSS

Ignoring User Interactions with inert

🍬 Post-it HTML

View Transitions API

🍬 Post-it JS CSS

The translate global attribute

🍬 Post-it HTML

Prefers color scheme

🍬 Post-it CSS

Container queries

🍬 Post-it CSS

Scroll margin

🍬 Post-it CSS

Text wrap

🍬 Post-it CSS

Centering in CSS

🍬 Post-it CSS

Customizing native form control colors

🍬 Post-it CSS

Fine-Grained Highlighting with the CSS Custom Highlight API

🍬 Post-it JS CSS

Sort directories by weight

🍬 Post-it Bash

Apply Opacity to CSS Variables with color-mix()

🍬 Post-it CSS

Listen to scroll snap transitions with new events

🍬 Post-it JS

Smooth scrolling

🍬 Post-it CSS JS

light-dark()

🍬 Post-it CSS

contrast-color()

🍬 Post-it CSS

Detect hover capability across all input types

🍬 Post-it CSS

:where()

🍬 Post-it CSS

Scroll-driven animations

🍬 Post-it CSS

CSS Carousels

🍬 Post-it CSS HTML

corner-shape

🍬 Post-it CSS

CSS custom functions

🍬 Post-it CSS

Grid Lanes

🍬 Post-it CSS

Popover API

🍬 Post-it HTML

View Transitions API

🍬 Post-it JS CSS

Container style queries

🍬 Post-it CSS