Missing form elements

[pghqdev]

What to build

Native HTML form elements that are currently excluded from or untouched by the form styling in base/elements.css get styled to match Hikari's token system. Every field follows the same design language — accent focus ring, surface border radius.

Elements in scope:

• input[type="range"] — slider
• input[type="file"] — file upload button
• <meter> — gauge display
• <progress> — progress bar (determinate and indeterminate)
• <output> — computed result display
• <datalist> — suggestion popup (styled where the browser supports appearance: base-select or similar)

Acceptance criteria

• input[type="range"] styled as a track+thumb slider matching Hikari tokens
• input[type="file"] styled with a consistent button appearance
• <meter> renders a bar using the accent or tone-respecting colors
• <progress> renders determinate and indeterminate states
• <output> styled as a small monospaced or muted value display
• <datalist> suggestion popup inherits page tokens where supported
• All styles in @layer hikari, no !important
• Author CSS overrides win
• Kitchen-sink demo shows each element
• rules/hikari-rules.md updated with examples

Blocked by

None — can start immediately.