Chalkhelm

A dark, precise and engineering-flavored dark-theme style for a crypto and web3 product website. Its look rests on 500-weight display type up to 96px, tight display tracking (-0.040em) and a sparing deep teal accent on a deep teal canvas. Apply it to a marketing site or the public pages of an app; the tokens and component specs carry the identity.

Build in this styleRead the build prompt

In the builder, open Gallery under the message and search for Chalkhelm.

What makes it

• 500-weight display type up to 96px
• tight display tracking (-0.040em)
• sans-serif headlines over a serif body
• short uppercase labels with open tracking
• small 6px corners on controls
• large 16px card corners
• no shadows; depth comes from surface tone steps
• one deep teal accent used sparingly

Colors

Precise, focused, nocturnal. A deep teal ground, 500-weight display type up to 96px and a sparing deep teal accent set the tone.

• canvas / text on band#012624
• surface#011d1c
• text#ffffff
• muted text#bbc7c6
• divider (decorative), never behind text#204543
• input border#377672
• accent / focus ring#007973
• primary action fill#cbfffc
• primary action label#222222
• link text#009890
• inverse band#edfffe

Every checked pair, measured again

Typefaces

uppercase only for short labels, with at least 0.05em tracking; no text below 12px; weights of 300 or lighter only at 24px and above; fonts are open Google Fonts chosen to match the observed letterforms

• InterHeadings
• Source Serif 4Body

Type scale

Corners and shadows

• cards: 16px
• small: 6px
• buttons: 6px

No shadows: depth comes from surfaces and lines.

Spacing and imagery

spacious density on a 4px base unit; container 1440px; section gap 68px; card padding 36px-48px; element gap 20px; radii cards 16px, small 6px, buttons 6px; no shadows

Photography, 3d renders, data graphics. Use placeholder or generated imagery only; partner marks are neutral placeholders in the muted text color. Photography is shown under a scrim wherever text overlaps it. Icons are outline style at 20-24px in the text or muted color.

Layout

1. top navigation: wordmark left, 4-6 text links, primary action right; collapses to a menu sheet under 768px
2. centered hero: headline, one-line lede and a primary plus secondary action, visual below
3. article or story cards with image, kicker, title and date
4. alternating two-column text-and-visual blocks
5. metrics band with three or four large figures and captions
6. feature grid of icon, title and two-line description cells (3-4 columns desktop, 1 column mobile)
7. footer with grouped link columns, legal line and social icons
8. content sits in a 1440px centered container with 24px side padding (16px on mobile)
9. sections are separated by 68px of vertical space on desktop, roughly half that on mobile

Patterns

• hero
• article or story cards with image, kicker, title and date
• alternating two-column text-and-visual blocks
• metrics band with three or four large figures and captions
• feature grid of icon, title and two-line description cells (3-4 columns desktop, 1 column mobile)

Components

• primary button: fill #cbfffc, label #222222; 6px radius; type 14px; uppercase with at least 0.05em tracking
• top navigation bar: colors: text #ffffff, muted text #bbc7c6; type 12px; uppercase with at least 0.05em tracking
• content card: colors: accent #007973, text #ffffff; 16px radius; type 36px; no shadow
• content card (variant 2): colors: surface #011d1c; 16px radius
• feature card: colors: text #ffffff; 16px radius
• icon button: transparent fill; 6px radius
• pill badge: colors: muted text #bbc7c6, inverse band #edfffe; uppercase with at least 0.05em tracking
• hero block: colors: text #ffffff
• metric block: colors: text #ffffff, inverse band #edfffe; type 13px; uppercase with at least 0.05em tracking
• top navigation bar (variant 2): 6px radius
• metric block (variant 2): colors: text #ffffff
• hero block (variant 2): colors: text #ffffff

Interactions and states

• hover reveals a 1px accent outline; code and terminal lines type in once on first view
• every interactive element shows a 2px #007973 focus ring with 2px offset
• primary action darkens or lightens by one step on hover and keeps its label color
• navigation collapses to a full-height menu sheet under 768px, trapping focus while open
• all motion is disabled under prefers-reduced-motion
• images show a surface-colored placeholder until loaded, with alt text if they fail
• forms: inline validation, disabled submit while sending, success message and retryable error
• mobile menu open and closed states
• hover, focus-visible, active and disabled states for every button style
• reduced-motion variant with no transitions beyond opacity

Guardrails

Experience

• Keep one primary action style (#cbfffc fill, #222222 label) and use it once per view; secondary actions stay outlined or text-only.
• Use the deep teal accent for small marks only (links, active states, icons), at most two or three times per screen.
• Use the 6px control radius consistently; do not mix in pill shapes.
• Limit headline sizes to the type scale; the 96px display size appears once per page, in the hero.
• Separate layers with surface tone and hairlines, not shadows.
• Keep gradients to backgrounds and decorative fields; they are never a button or text fill.
• Keep copy short and concrete: one idea per section, with a heading that states the benefit.

Accessibility

• Text, links, focus rings and input borders use only the verified pairs listed in contrast checks.
• Focus ring: 2px solid #007973 with 2px offset on every interactive element.
• Body text is 16px or larger at 1.5 line height; nothing is smaller than 12px.
• Decorative colors (dividers and supporting accents) never carry text or the only signal of state.
• Uppercase labels stay short, use at least 0.05em tracking and keep sentence-case text in the HTML source.
• Text over photos or gradients sits on a scrim that keeps it at 4.5:1 against the lightest area.
• Respect prefers-reduced-motion; no parallax or autoplay video without a pause control.
• Some observed colors were moved to the nearest passing shade of the same hue; use the palette values here, not lighter originals.

Security

• Validate every form with a shared zod schema on the client and again in the edge function; reject unknown fields.
• Rate-limit form endpoints per IP and add a honeypot field; store leads in a Supabase table with RLS allowing insert only for anonymous users and select only for staff.
• Set a strict Content-Security-Policy, self-host fonts and icons, and avoid third-party scripts beyond privacy-friendly analytics.
• Open external links with rel="noopener noreferrer" and never put secrets or API keys in client code.
• The marketing site shows no account data and never asks for credentials, seed phrases or keys; sign-in links go to the separate app domain.

Build prompt

The rules every style in the gallery assumes, then this style’s own ten sections, from goal to guardrails. A build in the style also gets its tokens as a file, so the colors and type above are exact.

Copy the rules and build prompt

### How to use these prompts
Paste an entry's build prompt into your coding agent as the first message. Each prompt names its own stack, tokens and acceptance criteria; the rules below apply to all of them and can be prepended once per project.

### Engineering baseline
- TypeScript strict mode, no `any`, small typed components, feature folders, and one source of truth for design tokens (CSS variables consumed by Tailwind).
- Validate every input with a shared zod schema on the client and again on the server or edge function. Never trust client-side checks alone.
- Show loading, empty and error states for every async view. Surface errors in plain language with a retry, and log details to the console in development only.
- Keep secrets out of the bundle. Only publishable keys (for example a Supabase anon key) belong in client code; service-role keys, API keys and webhooks live in server or edge-function environment variables.

### Data and auth baseline
- Enable Row Level Security on every table before inserting data. Default-deny, then add the narrowest policies the feature needs (for a lead form: insert-only for anonymous users, select for a staff role).
- Store roles in a separate table checked by a security-definer function, never in a user-editable profile field.
- Rate-limit public endpoints (forms, auth, AI calls) and add a honeypot field or captcha to anonymous forms.
- Take payments through a hosted checkout and verify webhooks by signature. Never handle raw card data.

### Accessibility and UX baseline
- Target WCAG 2.2 AA: 4.5:1 contrast for normal text and 3:1 for large text, input borders, focus rings and meaningful icons or chart lines. Every palette in this catalog lists its verified pairs; re-check with a contrast tool after any color change.
- Keep body text at 16px or larger with 1.5 line height, nothing below 12px, no light weights under 24px, and uppercase only for short labels.
- Give every interactive element a visible focus ring, full keyboard support, semantic landmarks, labeled form fields, and alt text on meaningful images.
- Respect `prefers-reduced-motion` for every animation. Give carousels and drag interactions keyboard and button alternatives, and never auto-advance them.
- Build mobile-first and test at 375px, 768px and 1280px.

### Content guardrails
- Use original copy, fictional sample data and placeholder or generated imagery. Do not reuse another product's name, logo, screenshots or marketing text.
- Partner and customer logo rows use neutral placeholder marks. Label demo testimonials and metrics as samples. Collect the minimum personal data a form needs.

### Style preset baseline
- Treat the entry's palette, type scale, radii, spacing and shadows as the complete token set. Do not introduce new colors; derive hover and pressed states by moving one step lighter or darker within the same hue, then re-check contrast.
- Colors marked decorative (dividers, supporting accents) never sit behind text and never carry meaning on their own.
- Fonts are open Google Fonts chosen to match the observed letterforms. Self-host them with `font-display: swap` and keep to the listed weights.
- Keep the signature moves listed for the entry, and keep everything else quiet so they stay recognizable.
- One primary action style per view. Secondary actions are outlined or text-only, and links are distinguishable by more than color (underline or weight).

### Goal
Build a responsive dark-theme marketing site for a fictional crypto and web3 product in the "Chalkhelm" style: dark, precise and engineering-flavored, with 500-weight display type up to 96px, tight display tracking (-0.040em), sans-serif headlines over a serif body. Use invented copy and placeholder imagery throughout.

### Stack
Astro, TypeScript, Tailwind CSS, React islands with Radix primitives (tabs, accordion, dialog), Lucide icons, zod, Supabase (form submissions only). Design tokens live as CSS variables and are mapped into the Tailwind theme.

### Pages & layout
Home page sections, in order:
- top navigation: wordmark left, 4-6 text links, primary action right; collapses to a menu sheet under 768px
- centered hero: headline, one-line lede and a primary plus secondary action, visual below
- article or story cards with image, kicker, title and date
- alternating two-column text-and-visual blocks
- metrics band with three or four large figures and captions
- feature grid of icon, title and two-line description cells (3-4 columns desktop, 1 column mobile)
- footer with grouped link columns, legal line and social icons
- content sits in a 1440px centered container with 24px side padding (16px on mobile)
- sections are separated by 68px of vertical space on desktop, roughly half that on mobile
Also build a simple contact page with a lead form and a 404 page in the same style. Test at 375px, 768px and 1280px.

### Design system
```css
:root {
  --color-canvas: #012624;
  --color-surface: #011d1c;
  --color-text: #ffffff;
  --color-muted-text: #bbc7c6;
  --color-divider: #204543;
  --color-input-border: #377672;
  --color-accent: #007973;
  --color-primary-action-fill: #cbfffc;
  --color-primary-action-label: #222222;
  --color-link-text: #009890;
  --color-inverse-band: #edfffe;
  --text-12: 12px;
  --text-16: 16px;
  --text-24: 24px;
  --text-36: 36px;
  --text-61: 61px;
  --text-96: 96px;
  --radius-cards: 16px;
  --radius-small: 6px;
  --radius-buttons: 6px;
  --space-unit: 4px;
  --container: 1440px;
}
```
Display Inter, body Source Serif 4 (Google Fonts, self-hosted, font-display: swap).
Type scale (size/weight/line-height tracking): 12px/400/1.4 0.150em, 16px/400/1.4, 24px/400/1.3 -0.020em, 36px/500/1.0, 61px/500/1.0 -0.040em, 96px/500/1.0 -0.040em.
Spacing: spacious density on a 4px base unit; container 1440px; section gap 68px; card padding 36px-48px; element gap 20px; radii cards 16px, small 6px, buttons 6px; no shadows.
Signature moves: 500-weight display type up to 96px; tight display tracking (-0.040em); sans-serif headlines over a serif body; short uppercase labels with open tracking; small 6px corners on controls; large 16px card corners; no shadows; depth comes from surface tone steps; one deep teal accent used sparingly.

### Components & interactions
- **primary button**: fill #cbfffc, label #222222; 6px radius; type 14px; uppercase with at least 0.05em tracking
- **top navigation bar**: colors: text #ffffff, muted text #bbc7c6; type 12px; uppercase with at least 0.05em tracking
- **content card**: colors: accent #007973, text #ffffff; 16px radius; type 36px; no shadow
- **content card (variant 2)**: colors: surface #011d1c; 16px radius
- **feature card**: colors: text #ffffff; 16px radius
- **icon button**: transparent fill; 6px radius
- **pill badge**: colors: muted text #bbc7c6, inverse band #edfffe; uppercase with at least 0.05em tracking
- **hero block**: colors: text #ffffff
- **metric block**: colors: text #ffffff, inverse band #edfffe; type 13px; uppercase with at least 0.05em tracking
- **top navigation bar (variant 2)**: 6px radius
- **metric block (variant 2)**: colors: text #ffffff
- **hero block (variant 2)**: colors: text #ffffff
- hover reveals a 1px accent outline; code and terminal lines type in once on first view
- every interactive element shows a 2px #007973 focus ring with 2px offset
- primary action darkens or lightens by one step on hover and keeps its label color
- navigation collapses to a full-height menu sheet under 768px, trapping focus while open
- all motion is disabled under prefers-reduced-motion

### Data & state
Content comes from typed local collections: Feature{icon, title, body}, Post{slug, title, kicker, excerpt, coverUrl, publishedAt}, Metric{value, label}, Lead{email, name?, message?, createdAt}. The lead form posts to a Supabase edge function. Handle these states:
- images show a surface-colored placeholder until loaded, with alt text if they fail
- forms: inline validation, disabled submit while sending, success message and retryable error
- mobile menu open and closed states
- hover, focus-visible, active and disabled states for every button style
- reduced-motion variant with no transitions beyond opacity

### Accessibility
- Text, links, focus rings and input borders use only the verified pairs listed in contrast checks.
- Focus ring: 2px solid #007973 with 2px offset on every interactive element.
- Body text is 16px or larger at 1.5 line height; nothing is smaller than 12px.
- Decorative colors (dividers and supporting accents) never carry text or the only signal of state.
- Uppercase labels stay short, use at least 0.05em tracking and keep sentence-case text in the HTML source.
- Text over photos or gradients sits on a scrim that keeps it at 4.5:1 against the lightest area.
- Respect prefers-reduced-motion; no parallax or autoplay video without a pause control.
- Some observed colors were moved to the nearest passing shade of the same hue; use the palette values here, not lighter originals.
Verified contrast: body text on canvas #ffffff on #012624 = 16.1:1; body text on surface #ffffff on #011d1c = 17.59:1; muted text on canvas #bbc7c6 on #012624 = 9.28:1; muted text on surface #bbc7c6 on #011d1c = 10.13:1; primary action label on fill #222222 on #cbfffc = 14.58:1; link text on canvas #009890 on #012624 = 4.52:1; focus ring on canvas #007973 on #012624 = 3.05:1; focus ring on surface #007973 on #011d1c = 3.34:1; input border on canvas #377672 on #012624 = 3.07:1; accent icons and active marks on canvas #007973 on #012624 = 3.05:1; text on inverse band #012624 on #edfffe = 15.6:1.

### Security
- Validate every form with a shared zod schema on the client and again in the edge function; reject unknown fields.
- Rate-limit form endpoints per IP and add a honeypot field; store leads in a Supabase table with RLS allowing insert only for anonymous users and select only for staff.
- Set a strict Content-Security-Policy, self-host fonts and icons, and avoid third-party scripts beyond privacy-friendly analytics.
- Open external links with rel="noopener noreferrer" and never put secrets or API keys in client code.
- The marketing site shows no account data and never asks for credentials, seed phrases or keys; sign-in links go to the separate app domain.

### Performance & SEO
- Static generation for every content page; ship no JavaScript to sections that do not need it.
- Images in AVIF/WebP with explicit width and height, lazy-loaded below the fold; preload the hero image and the display font only.
- One h1 per page, descriptive titles and meta descriptions, Open Graph tags with a generated preview image, and a sitemap.
- Target Lighthouse 95+ for performance, accessibility, best practices and SEO.

### Guardrails
- Keep one primary action style (#cbfffc fill, #222222 label) and use it once per view; secondary actions stay outlined or text-only.
- Use the deep teal accent for small marks only (links, active states, icons), at most two or three times per screen.
- Use the 6px control radius consistently; do not mix in pill shapes.
- Limit headline sizes to the type scale; the 96px display size appears once per page, in the hero.
- Separate layers with surface tone and hairlines, not shadows.
- Keep gradients to backgrounds and decorative fields; they are never a button or text fill.
- Keep copy short and concrete: one idea per section, with a heading that states the benefit.
Acceptance criteria:
- Every color in the build comes from the tokens above and every text pair matches a verified contrast pair.
- The page works with keyboard only, shows a visible focus ring everywhere and passes an automated axe check with no violations.
- No real brand names, logos, product screenshots or copied marketing text appear anywhere.
- Layout holds at 375px with no horizontal scrolling.

Open the builderThe whole gallery