Foundations

The design system

Every value the concept renders comes from tailwind.config.js. There is no raw hex and no one-off pixel value in the markup, so the whole surface re-themes from one file — the same file this would use in the Rails app.

Values are sampled from searchapi.io rather than invented. The point of the concept is that it could ship into the existing product on a Tuesday, not that it looks like somebody else's product.

Named by role, not by hue. ink-500 is secondary text; calling it gray-500 would leave the next person guessing which grey to use where.

Ink — text, borders, surfaces

• ink-900headings, code fg
• ink-700body copy
• ink-500secondary
• ink-400placeholder
• ink-200borders
• ink-100chips, hover
• ink-50furniture

Brand — one accent, used sparingly

• brand-600primary action
• brand-700hover, keys
• brand-800the logo
• brand-200borders
• brand-50tint

Semantic — status only

• 200 OK · ok-700 on ok-50
• 400 · danger-700 on danger-50
• deprecated · warn-700

Each pairing is checked against its own tint rather than against white, because that is where it actually appears. Status is never colour alone — every state in the concept carries a word as well.

Two themes, one set of names

Every token above is a CSS variable with a light value and a dark value; nothing in the markup says which. The swatches on this page are the current theme — switch it with the button in the header, or under Prototype for the three-way choice. Dark keeps the brand hue and inverts the neutral ramp, so ink-900 is always "the most text-like" and ink-50 always "the most page-like". Two things flip with it: the primary button becomes dark-on-pale-indigo (it says text-surface, not text-white), and the code card sits a step lighter than the page with a hairline edge, because in a dark UI the raised thing is the lighter one. The default is the OS setting, remembered once changed.

Every text node on the rendered page was swept against its effective background in both themes; the lowest text pairing is 4.5 or better in each. The sweep is what caught text-white on the pale dark-theme brand — 2.6:1 — before it shipped.

A scale, not a bag of sizes. Anything that does not fit one of these steps is a design question, not a CSS question. The current docs set section headings at 18px/600, close enough to body text that a section boundary is hard to see while scrolling — h2 here is 22px with a rule under it.

In the Rails app each of these is a ViewComponent holding its own utilities. Static HTML has no component layer, so the patterns that repeat are named once in src/css/application.css — thirty-one classes — rather than pasted at every call site. Everything below is the real class, not a copy of it: change the class and this page changes with the product.

Ten of the thirty-one are not shown here because they carry behaviour rather than appearance — how a focus ring composes on a control made of parts, a scrollbar that only appears on hover, the colour inversion a selected search row needs, the console's docked position. They are documented in the stylesheet, beside the rule.

One 16×16 grid, one 1.5 stroke, round caps and joins, currentColor, one render size. Before the set existed they were drawn where they were needed: five stroke widths, three grids and six sizes across twenty-one inline SVGs — which nobody reads as a bug, only as the drawing being slightly off everywhere. A shape that scales while its stroke does not gets optically lighter, so a second size would need a second weight; one size instead. play is the exception: a solid triangle, because its weight is area and an outlined play glyph on a filled button reads as a different control.

The sheet below is rendered from src/js/icons.js — the same module the app draws from — so it cannot drift from what ships.

Tailwind's 4px scale, unchanged — inventing a spacing scale is a way of making a codebase harder to join. Two radius tokens only: rounded-ctl (8px, their chip radius, shared by every control so buttons and inputs always agree) and rounded-card (12px).

• Visible focus on every interactive element, defined once in @layer base so nothing can opt out.
• The response tree is buttons and aria-expanded, so it is keyboard-operable and announced — a JSON viewer built from divs is a wall to a screen reader.
• Status uses role="status", so a result that arrives 600ms later is announced rather than silently appearing.
• Text with colour in every state; contrast checked on the tint each pairing actually sits on.
• prefers-reduced-motion respected globally.

Concept by Umanga Shrestha · back to the interactive docs