Welcome to HTMLcat: small, native web tricks worth remembering.

Each post-it pairs one useful platform feature with a small example and the inevitable caveats.
Next step: demos, lots of demos.

Some notes cover limited or experimental features. Check the support label, keep a fallback, and test with real browsers and assistive technology.

55

Detect input capabilities

JS

Hide scrollbars

CSS

Empty tags

CSS

Centering in CSS

CSS

clamp()

CSS

Smooth scrolling

CSS JS

Scroll margin

CSS

classList.toggle()

JS

Telephone and email links

HTML

Text selection highlight

CSS

The :has() relational selector

CSS

Styling list markers with ::marker

CSS

Localized prices with Intl.NumberFormat

JS

Disable a subtree with inert

HTML

The :target pseudo-class

CSS HTML

The translate global attribute

HTML

prefers-color-scheme

CSS

Container size queries

CSS

The dialog element

HTML JS

Better wrapping with text-wrap

CSS

Description list alignment

HTML CSS

Native form colors with accent-color

CSS

CSS Custom Highlight API

JS CSS

Detect hover across input types

CSS

Transparent colors with color-mix()

CSS

Scroll snap events

JS

Sort directories by size

Bash

light-dark()

CSS

contrast-color()

CSS

Scoped CSS with @scope

CSS

:where()

CSS

Scroll-driven animations

CSS

CSS carousels

CSS HTML

corner-shape

CSS

CSS custom functions

CSS

CSS Grid Lanes

CSS

Popover API

HTML

View Transitions API

JS CSS

Container style queries

CSS

Exclusive accordions with details name

HTML

Control dialogs with button commands

HTML

Searchable collapsed content with hidden=until-found

HTML

Sibling Index & Count

CSS

Find the 50 largest files

Bash

Find recently modified files

Bash

Find files larger than 100 MiB

Bash

Find empty directories

Bash

Typed attributes with attr()

CSS

Growing textareas with field-sizing

CSS

Entry transitions with @starting-style

CSS

Typographic alignment with text-box-trim

CSS

Conditional values with CSS if()

CSS

Light-dismiss dialogs with closedby

HTML

Animate height from 0 to auto

CSS

Calendar dates with Temporal.PlainDate

JS