Filament

# Filament

## Philosophy

A reading system that strings a long story onto a single luminous wire. Set on a cool midnight ground, the prose rests on a warm vellum slip while the filament runs the spine of the page — gold behind you where you have read, ember at your place, cold ahead until you reach it and light it by reading. Following the story is the navigation.

### Values

- reading is following one lit wire; progress is the page's structure and its only chrome
- the prose is sovereign on a warm vellum slip; the apparatus stays in the margin
- three accents used like a scribe's marks — gold to light, ember to mark, slate to cite
- a cool reading night over a bright app window; light is the chrome

### Anti-Values

- defaulting to white or washing the ground pale — the cool night is the point
- a marginal gutter or facing columns that break the single line of reading
- a second loud accent, or flooding the page with embers
- card grids and bright SaaS chrome that compete with the body

### Visual Character

- The thread: a single luminous filament runs the spine of the page; every section is a node strung along it — gold where you have read, ember at your place, a cold hollow ring ahead — and following the story is the navigation.
- A cool midnight-indigo ground against which one warm wire and a vellum reading slip glow like a lit page held in the dark; structure comes from light, space, and a single hairline rule rather than borders.
- High-contrast literary serif display (Fraunces) over a calm reading serif (Source Serif 4), with Archivo folio labels set in wide uppercase, and a colour-pop or highlighter mark lighting one headline word.
- A rubricated ember drop-cap, superscript gloss markers, and a reading meter — a hairline track whose lit portion glows gold with an ember pip at your place — standing in for any stat row.

## Tokens

### Colors

| Name | Value |
|------|-------|
| bg | `#11121f` |
| bg_deep | `#0b0c16` |
| surface | `#1a1c2e` |
| vellum | `#f3ecdd` |
| ink | `#181a12` |
| text | `#ece9f3` |
| muted | `#9a9ab5` |
| border | `#2a2c44` |
| accent | `#e8a93c` |
| filament | `#e8a93c` |
| filament_hot | `#ffce78` |
| ember | `#e2492f` |
| cold | `#6f86b8` |
| on_accent | `#11121f` |
| success | `#5e9a6a` |
| warning | `#e8a93c` |
| error | `#e2492f` |
| info | `#6f86b8` |

### Typography

- **Heading Font**: Fraunces
- **Body Font**: Source Serif 4
- **Mono Font**: Archivo
- **Base Size**: 18px
- **Scale Ratio**: 1.2
- **Line Height**: 1.7
- **Letter Spacing**: -0.01em
- **Heading Weight**: 600
- **Heading Transform**: none
- **Google Fonts Url**: https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=Source+Serif+4:opsz,wght@8..60,400;8..60,500;8..60,600&family=Archivo:wght@400;500;600;700&display=swap

### Spacing

- **Base**: 8px
- **Scale**: [4,8,12,16,24,32,48,64,96]

### Radii

- **None**: 0
- **Md**: 16px
- **Lg**: 24px
- **Full**: 9999px

### Shadows

- **Sm**: 0 1px 0 rgba(0,0,0,.25)
- **Md**: 0 24px 60px rgba(0,0,0,.45)
- **Lg**: 0 30px 70px rgba(0,0,0,.5)

### Surfaces

- **Treatment**: cool midnight ground with a warm vellum reading slip and ink panels
- **Card Style**: raised ink panels and a glowing vellum reading slip, no borders; structure from light, the hairline rule, and space
- **Bg Pattern**: none

### Borders

- **Default Width**: 1px
- **Accent Width**: 3px
- **Style**: solid
- **Character**: hairline editorial rules and a 3px accent bar for notices and stats; never a frame border

### Motion

- **Duration**: 200ms
- **Easing**: cubic-bezier(0.2,0.8,0.2,1)
- **Philosophy**: settled by default and fully legible with no JavaScript; a quiet rise-in reveal added on top, respecting prefers-reduced-motion; the wire and nodes glow softly, nothing bounces

## Rules

### Composition

Organize the interface as a reading current: a masthead above, and the whole story strung onto a single luminous filament that runs the spine of the page. Sections are nodes on the wire — no marginal gutter, no facing columns. The prose rests on a warm vellum slip that is the brightest thing on screen; notes tie to the line from the margin and stay quieter than the body.

### Hierarchy

Light carries the hierarchy: the lit (gold) wire behind your place, the ember node at your place, the cold (slate) wire ahead. Fraunces display sits over a Source Serif 4 reading body with Archivo folio labels. Emphasis comes from glow and position, not from many weights or many colours; exactly one ember marks your place and the one primary action.

### Density

Prose is spacious at an intimate measure (~42ch); utility regions and the marginalia can be moderately dense while staying visually lighter than the reading slip. Keep generous resting dark space between lit nodes.

### Signature

The thread — one luminous filament with three node states (lit gold / here ember / ahead cold), a wire whose gradient fades from gold to border at your place, a reading meter standing in for a stat row, a vellum reading slip with a rubricated ember drop-cap, and three accents used like a scribe's marks.

## Layout

### Grid

A single reading current rather than facing columns: the story is threaded onto one filament that runs the spine of the page, with sections as nodes. The dashboard turns the filament horizontal into a spine that shows your place across the issue. The masthead breathes above; the reading rail breathes as part of the page, never boxed into a pill.

### Breakpoints

Desktop shows the full thread and the vellum slip with its marginalia beside it; tablet keeps the slip with a narrower margin; mobile (~390px) becomes a single reading column with the hero headline shrinking via clamp() and the reading rail collapsing to an inline row.

### Whitespace

Generous outer space and paragraph spacing, padding above every title, intimate column measure, and dark resting space between lit nodes so the wire reads clearly.

### Breakpoints Map

- **Mobile**: 390px
- **Tablet**: 760px
- **Desktop**: 1080px
- **Wide**: 1440px

## Guidance

### Do

- Light only the part of the wire you have read; keep the page ahead cold until the reader reaches it
- Let the prose be sovereign on the vellum slip; keep notes in the margin tied to the line
- Use gold to light, ember to mark and act once, slate to cite — never a fourth accent
- Carry structure with light, space, and the hairline rule before any border
- Derive the hero from the filament mechanic — the wire itself, one CTA, the reading meter

### Don't

- Don't default to white or wash the ground pale — the cool night is the point
- Don't add a marginal gutter or facing columns that break the single line of reading
- Don't add a second loud accent or flood the page with embers
- Don't box the navigation into a pill bar or nest cards
- Don't widen the body so far the reading measure loses its intimacy

### Accessibility

High contrast throughout (parchment on midnight, ink on vellum); body text 18px; all form controls explicitly styled with a visible gold focus ring; motion respects prefers-reduced-motion and the page is fully legible with no JavaScript.

## Imagery Direction

### Pairs With

rubricator

### Summary

Ink-and-gilt manuscript illumination: a confident brush-and-reed-pen ink contour over a warm vellum ground, neutral grey wash for volume, hand-laid gilt-gold flecks and one or two rubricated red marks, in lamplit chiaroscuro — here applied to a single incandescent reading-lamp filament threading through the dark.

### Subjects

- a single incandescent lamp filament threading through the dark
- a reading lamp on a composing-room stone
- a bound issue or manuscript
- a quiet interior lit by one source
- a city or a coastline treated the same way

### Usage

Full-bleed hero behind a left-weighted overlay, and feature/illustration slots inside sections; never used for the thumbnail (the embodiment is the thumbnail source).

---
version: "alpha"
name: "Filament"
description: "Agent-curated design language exported from Katagami as DESIGN.md."
colors:
  bg: "#11121f"
  bg_deep: "#0b0c16"
  surface: "#1a1c2e"
  vellum: "#f3ecdd"
  ink: "#181a12"
  text: "#ece9f3"
  muted: "#9a9ab5"
  border: "#2a2c44"
  accent: "#e8a93c"
  filament: "#e8a93c"
  filament_hot: "#ffce78"
  ember: "#e2492f"
  cold: "#6f86b8"
  on_accent: "#11121f"
  success: "#5e9a6a"
  warning: "#e8a93c"
  error: "#e2492f"
  info: "#6f86b8"
typography:
  headline-lg:
    fontFamily: "Fraunces"
    fontSize: "1.944rem"
    fontWeight: 700
    lineHeight: 1.1
    letterSpacing: "-0.01em"
  headline-md:
    fontFamily: "Fraunces"
    fontSize: "1.62rem"
    fontWeight: 600
    lineHeight: 1.15
    letterSpacing: "-0.01em"
  body-md:
    fontFamily: "Source Serif 4"
    fontSize: "18px"
    fontWeight: 400
    lineHeight: 1.7
    letterSpacing: "-0.01em"
  label-md:
    fontFamily: "Archivo"
    fontSize: "0.75rem"
    fontWeight: 600
    lineHeight: 1
    letterSpacing: "0.08em"
rounded:
  none: "0px"
  md: "16px"
  lg: "24px"
  full: "9999px"
spacing:
  base: "8px"
  xs: "4px"
  sm: "8px"
  md: "12px"
  lg: "16px"
  xl: "24px"
  2xl: "32px"
  3xl: "48px"
  4xl: "64px"
  step-8: "96px"
components:
  color-reference-bg:
    backgroundColor: "{colors.bg}"
  color-reference-bg_deep:
    backgroundColor: "{colors.bg_deep}"
  color-reference-surface:
    backgroundColor: "{colors.surface}"
  color-reference-vellum:
    backgroundColor: "{colors.vellum}"
  color-reference-ink:
    backgroundColor: "{colors.ink}"
  color-reference-text:
    backgroundColor: "{colors.text}"
  color-reference-muted:
    backgroundColor: "{colors.muted}"
  color-reference-border:
    backgroundColor: "{colors.border}"
  color-reference-accent:
    backgroundColor: "{colors.accent}"
  color-reference-filament:
    backgroundColor: "{colors.filament}"
  color-reference-filament_hot:
    backgroundColor: "{colors.filament_hot}"
  color-reference-ember:
    backgroundColor: "{colors.ember}"
  color-reference-cold:
    backgroundColor: "{colors.cold}"
  color-reference-on_accent:
    backgroundColor: "{colors.on_accent}"
  color-reference-success:
    backgroundColor: "{colors.success}"
  color-reference-warning:
    backgroundColor: "{colors.warning}"
  color-reference-error:
    backgroundColor: "{colors.error}"
  color-reference-info:
    backgroundColor: "{colors.info}"
  button-primary:
    backgroundColor: "{colors.accent}"
    textColor: "#000000"
    typography: "{typography.label-md}"
    rounded: "{rounded.md}"
    padding: "{spacing.md}"
  card-surface:
    backgroundColor: "{colors.surface}"
    textColor: "{colors.text}"
    rounded: "{rounded.md}"
    padding: "{spacing.md}"
  input-default:
    backgroundColor: "{colors.surface}"
    textColor: "{colors.text}"
    rounded: "{rounded.md}"
    height: "44px"
---

# Filament

## Overview

A reading system that strings a long story onto a single luminous wire. Set on a cool midnight ground, the prose rests on a warm vellum slip while the filament runs the spine of the page — gold behind you where you have read, ember at your place, cold ahead until you reach it and light it by reading. Following the story is the navigation.

### Values

- reading is following one lit wire; progress is the page's structure and its only chrome
- the prose is sovereign on a warm vellum slip; the apparatus stays in the margin
- three accents used like a scribe's marks — gold to light, ember to mark, slate to cite
- a cool reading night over a bright app window; light is the chrome

### Anti-Values

- defaulting to white or washing the ground pale — the cool night is the point
- a marginal gutter or facing columns that break the single line of reading
- a second loud accent, or flooding the page with embers
- card grids and bright SaaS chrome that compete with the body

### Visual Character

- The thread: a single luminous filament runs the spine of the page; every section is a node strung along it — gold where you have read, ember at your place, a cold hollow ring ahead — and following the story is the navigation.
- A cool midnight-indigo ground against which one warm wire and a vellum reading slip glow like a lit page held in the dark; structure comes from light, space, and a single hairline rule rather than borders.
- High-contrast literary serif display (Fraunces) over a calm reading serif (Source Serif 4), with Archivo folio labels set in wide uppercase, and a colour-pop or highlighter mark lighting one headline word.
- A rubricated ember drop-cap, superscript gloss markers, and a reading meter — a hairline track whose lit portion glows gold with an ember pip at your place — standing in for any stat row.

## Colors

Use the YAML color tokens as the normative palette. The prose below names the roles agents should preserve when generating UI.

| Token | Value |
|-------|-------|
| bg | `#11121f` |
| bg_deep | `#0b0c16` |
| surface | `#1a1c2e` |
| vellum | `#f3ecdd` |
| ink | `#181a12` |
| text | `#ece9f3` |
| muted | `#9a9ab5` |
| border | `#2a2c44` |
| accent | `#e8a93c` |
| filament | `#e8a93c` |
| filament_hot | `#ffce78` |
| ember | `#e2492f` |
| cold | `#6f86b8` |
| on_accent | `#11121f` |
| success | `#5e9a6a` |
| warning | `#e8a93c` |
| error | `#e2492f` |
| info | `#6f86b8` |

## Typography

- **Headline-Lg**: Fraunces, 1.944rem, weight 700, line-height 1.1.
- **Headline-Md**: Fraunces, 1.62rem, weight 600, line-height 1.15.
- **Body-Md**: Source Serif 4, 18px, weight 400, line-height 1.7.
- **Label-Md**: Archivo, 0.75rem, weight 600, line-height 1.

## Layout

### Spacing Tokens

- **Base**: `8px`
- **Xs**: `4px`
- **Sm**: `8px`
- **Md**: `12px`
- **Lg**: `16px`
- **Xl**: `24px`
- **2xl**: `32px`
- **3xl**: `48px`
- **4xl**: `64px`
- **Step-8**: `96px`

### Grid

A single reading current rather than facing columns: the story is threaded onto one filament that runs the spine of the page, with sections as nodes. The dashboard turns the filament horizontal into a spine that shows your place across the issue. The masthead breathes above; the reading rail breathes as part of the page, never boxed into a pill.

### Breakpoints

Desktop shows the full thread and the vellum slip with its marginalia beside it; tablet keeps the slip with a narrower margin; mobile (~390px) becomes a single reading column with the hero headline shrinking via clamp() and the reading rail collapsing to an inline row.

### Whitespace

Generous outer space and paragraph spacing, padding above every title, intimate column measure, and dark resting space between lit nodes so the wire reads clearly.

### Breakpoints Map

- **Mobile**: 390px
- **Tablet**: 760px
- **Desktop**: 1080px
- **Wide**: 1440px

## Elevation & Depth

### Shadows

- **Sm**: 0 1px 0 rgba(0,0,0,.25)
- **Md**: 0 24px 60px rgba(0,0,0,.45)
- **Lg**: 0 30px 70px rgba(0,0,0,.5)

## Shapes

### Rounded

- **None**: `0px`
- **Md**: `16px`
- **Lg**: `24px`
- **Full**: `9999px`

### Surfaces

- **Treatment**: cool midnight ground with a warm vellum reading slip and ink panels
- **Card Style**: raised ink panels and a glowing vellum reading slip, no borders; structure from light, the hairline rule, and space
- **Bg Pattern**: none

### Borders

- **Default Width**: 1px
- **Accent Width**: 3px
- **Style**: solid
- **Character**: hairline editorial rules and a 3px accent bar for notices and stats; never a frame border

## Components

### Composition

Organize the interface as a reading current: a masthead above, and the whole story strung onto a single luminous filament that runs the spine of the page. Sections are nodes on the wire — no marginal gutter, no facing columns. The prose rests on a warm vellum slip that is the brightest thing on screen; notes tie to the line from the margin and stay quieter than the body.

### Hierarchy

Light carries the hierarchy: the lit (gold) wire behind your place, the ember node at your place, the cold (slate) wire ahead. Fraunces display sits over a Source Serif 4 reading body with Archivo folio labels. Emphasis comes from glow and position, not from many weights or many colours; exactly one ember marks your place and the one primary action.

### Density

Prose is spacious at an intimate measure (~42ch); utility regions and the marginalia can be moderately dense while staying visually lighter than the reading slip. Keep generous resting dark space between lit nodes.

### Signature

The thread — one luminous filament with three node states (lit gold / here ember / ahead cold), a wire whose gradient fades from gold to border at your place, a reading meter standing in for a stat row, a vellum reading slip with a rubricated ember drop-cap, and three accents used like a scribe's marks.

## shadcn/ui Usage

When the target app uses shadcn/ui, copy DESIGN.md with shadcn instead of the plain DESIGN.md. It contains the same Katagami design-language source plus the shadcn/ui primitives, imports, theme variables, component recipes, and preview-shot guidance.

DESIGN.md with shadcn: `/language/en-019efd7d-6f97-7d12-af94-59afbc7b5d11/DESIGN.with-shadcn.md`.

The shadcn page also exposes optional machine-readable files for automation, but the human-facing handoff is DESIGN.md with shadcn.

Install recommended primitives with `npx shadcn@latest add button card input textarea select dialog sheet tabs badge separator checkbox switch slider tooltip dropdown-menu table`.

Use these primitives in shadcn apps:
- button
- card
- input
- textarea
- select
- dialog
- sheet
- tabs
- badge
- separator
- checkbox
- switch
- slider
- tooltip
- dropdown-menu
- table

Implementation rule for agents: import shadcn primitives from `@/components/ui/*`, apply the generated CSS variables first, then compose the language-specific recipes from the companion MD. Katagami remains the source of truth; shadcn names are the implementation surface.

## Do's and Don'ts

- Do Light only the part of the wire you have read; keep the page ahead cold until the reader reaches it
- Do Let the prose be sovereign on the vellum slip; keep notes in the margin tied to the line
- Do Use gold to light, ember to mark and act once, slate to cite — never a fourth accent
- Do Carry structure with light, space, and the hairline rule before any border
- Do Derive the hero from the filament mechanic — the wire itself, one CTA, the reading meter
- Don't Don't default to white or wash the ground pale — the cool night is the point
- Don't Don't add a marginal gutter or facing columns that break the single line of reading
- Don't Don't add a second loud accent or flood the page with embers
- Don't Don't box the navigation into a pill bar or nest cards
- Don't Don't widen the body so far the reading measure loses its intimacy

### Accessibility

High contrast throughout (parchment on midnight, ink on vellum); body text 18px; all form controls explicitly styled with a visible gold focus ring; motion respects prefers-reduced-motion and the page is fully legible with no JavaScript.

## Imagery Direction

### Pairs With

rubricator

### Summary

Ink-and-gilt manuscript illumination: a confident brush-and-reed-pen ink contour over a warm vellum ground, neutral grey wash for volume, hand-laid gilt-gold flecks and one or two rubricated red marks, in lamplit chiaroscuro — here applied to a single incandescent reading-lamp filament threading through the dark.

### Subjects

- a single incandescent lamp filament threading through the dark
- a reading lamp on a composing-room stone
- a bound issue or manuscript
- a quiet interior lit by one source
- a city or a coastline treated the same way

### Usage

Full-bleed hero behind a left-weighted overlay, and feature/illustration slots inside sections; never used for the thumbnail (the embodiment is the thumbnail source).

```json
{
  "$schema": "https://ui.shadcn.com/schema/registry-item.json",
  "name": "filament",
  "type": "registry:theme",
  "title": "Filament shadcn Theme",
  "cssVars": {
    "theme": {},
    "light": {
      "background": "#11121f",
      "foreground": "#ece9f3",
      "card": "#1a1c2e",
      "card-foreground": "#ece9f3",
      "popover": "#1a1c2e",
      "popover-foreground": "#ece9f3",
      "primary": "#ece9f3",
      "primary-foreground": "#111111",
      "secondary": "#f4f4f5",
      "secondary-foreground": "#111111",
      "muted": "#9a9ab5",
      "muted-foreground": "#ece9f3",
      "accent": "#e8a93c",
      "accent-foreground": "#ffffff",
      "destructive": "#e2492f",
      "border": "#2a2c44",
      "input": "#2a2c44",
      "ring": "#e8a93c",
      "chart-1": "#ece9f3",
      "chart-2": "#f4f4f5",
      "chart-3": "#e8a93c",
      "chart-4": "#5e9a6a",
      "chart-5": "#e8a93c",
      "sidebar": "#1a1c2e",
      "sidebar-foreground": "#ece9f3",
      "sidebar-primary": "#ece9f3",
      "sidebar-primary-foreground": "#111111",
      "sidebar-accent": "#6f86b8",
      "sidebar-accent-foreground": "#ffffff",
      "sidebar-border": "#2a2c44",
      "sidebar-ring": "#e8a93c",
      "radius": "16px"
    },
    "dark": {
      "background": "#0f1115",
      "foreground": "#f8fafc",
      "card": "#181b22",
      "card-foreground": "#f8fafc",
      "popover": "#181b22",
      "popover-foreground": "#f8fafc",
      "primary": "#ece9f3",
      "primary-foreground": "#111111",
      "secondary": "#252a33",
      "secondary-foreground": "#f8fafc",
      "muted": "#252a33",
      "muted-foreground": "#a1a1aa",
      "accent": "#e8a93c",
      "accent-foreground": "#ffffff",
      "destructive": "#e2492f",
      "border": "#303642",
      "input": "#303642",
      "ring": "#e8a93c",
      "chart-1": "#ece9f3",
      "chart-2": "#f4f4f5",
      "chart-3": "#e8a93c",
      "chart-4": "#5e9a6a",
      "chart-5": "#e8a93c",
      "sidebar": "#181b22",
      "sidebar-foreground": "#f8fafc",
      "sidebar-primary": "#ece9f3",
      "sidebar-primary-foreground": "#111111",
      "sidebar-accent": "#e8a93c",
      "sidebar-accent-foreground": "#ffffff",
      "sidebar-border": "#303642",
      "sidebar-ring": "#e8a93c",
      "radius": "16px"
    }
  },
  "meta": {
    "source": "katagami",
    "languageId": "en-019efd7d-6f97-7d12-af94-59afbc7b5d11",
    "slug": "filament",
    "componentManifest": [
      "button",
      "card",
      "input",
      "textarea",
      "select",
      "dialog",
      "sheet",
      "tabs",
      "badge",
      "separator",
      "checkbox",
      "switch",
      "slider",
      "tooltip",
      "dropdown-menu",
      "table"
    ],
    "installCommand": "npx shadcn@latest add button card input textarea select dialog sheet tabs badge separator checkbox switch slider tooltip dropdown-menu table",
    "nativeTokenNames": {
      "colors": [
        "accent",
        "bg",
        "bg_deep",
        "border",
        "cold",
        "ember",
        "error",
        "filament",
        "filament_hot",
        "info",
        "ink",
        "muted",
        "on_accent",
        "success",
        "surface",
        "text",
        "vellum",
        "warning"
      ],
      "typography": [
        "base_size",
        "body_font",
        "google_fonts_url",
        "heading_font",
        "heading_transform",
        "heading_weight",
        "letter_spacing",
        "line_height",
        "mono_font",
        "scale_ratio"
      ],
      "spacing": [
        "base",
        "scale"
      ],
      "radii": [
        "full",
        "lg",
        "md",
        "none"
      ],
      "shadows": [
        "lg",
        "md",
        "sm"
      ],
      "surfaces": [
        "bg_pattern",
        "card_style",
        "treatment"
      ],
      "borders": [
        "accent_width",
        "character",
        "default_width",
        "style"
      ],
      "motion": [
        "duration",
        "easing",
        "philosophy"
      ]
    }
  }
}
```