Vellum
demos
HTML, CSS and a little JavaScript, laid out by Vellum and painted by Minecraft.
Settings
Vanilla-styled form controls
Layout
Flexbox and grid
Animation
Keyframes and transitions
Templates
Todos, a counter, live data
Map
Tiles and a canvas
Inventory
Real slots:
/vellum demo chest
HUD
A title card:
/vellum demo hud