Custom Wisp theme CSS

SkillFiles & storage

Author a Wisp custom theme CSS file that uses documented tokens and import constraints. Use when the user wants a custom look, hide the paragraph lead bar, restyle chat Markdown, override colors, or import a stylesheet under Settings → Appearance.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the Custom Wisp theme CSS skill

What this skill tells your AI

The instructions your AI receives, as published by xuzhougeng/wisp-science in skills/custom-theme/SKILL.md and read by ahel’s review.

Wisp injects one user stylesheet after the built-in theme. Prefer CSS variables on :root. Do not invent Settings toggles for one-off look changes.

Workflow

  1. Ask what should change (lead bar, table size, accent, chat density, fonts).
  2. Write a .css file in the project, usually theme.css.
  3. Apply it:
    • Desktop: configure with action=set and values.custom_css set to the full stylesheet text. Empty string clears it.
    • Or tell the user to import the file under Settings → Appearance.
  4. Confirm the change is visible. If a rule did nothing, the selector is wrong; do not add !important unless a built-in rule requires it.

Constraints

The host sanitizes CSS before inject. These are stripped:

  • @import and @namespace
  • every url(...)
  • javascript:, expression(, behavior:, -moz-binding
  • </style and <script
  • NULs; payload longer than 64 KB is truncated

Do not rely on remote fonts, images, or other stylesheets. Name an installed font with configure ui_font_family / code_font_family instead.

Scope light/dark overrides with :root[data-theme="light"] and :root[data-theme="dark"]. System theme follows the OS, so also cover :root[data-theme="system"] when the user cares about both.

Tokens

Override these on :root. Leave unused tokens alone.

TokenDefault role
--bg-app, --bg-elev, --bg-sunken, --bg-input, --bg-panelSurfaces
--text, --text-muted, --text-faintInk
--border, --border-strongHairlines
--clay, --clay-strong, --clay-soft, --on-clayAccent (teal)
--ui-font-size, --code-font-sizeSet by Appearance sliders; do not hard-code px on chat body
--md-table-font-sizeMarkdown tables; default calc(var(--ui-font-size, 14px) - 1px)
--md-lead-bar-width, --md-lead-bar-padBold-at-start emphasis bar; 3px / 0.55em
--font-user-ui, --font-user-monoOptional family names; empty restores the stack
--radius, --radius-sm, --radius-xsCorners

Palette attributes (data-light-palette, data-dark-palette) already map onto the semantic tokens. Prefer --clay / --bg-app over palette internals (--lp-*, --dp-*) unless the user asked to restyle one palette only.

Common requests

Hide the lead bar (the vertical mark before a paragraph that starts with bold):

:root {
  --md-lead-bar-width: 0;
  --md-lead-bar-pad: 0;
}

Keep tables aligned with UI size, or pin a size:

:root { --md-table-font-size: calc(var(--ui-font-size, 14px) - 1px); }
:root { --md-table-font-size: 14px; }

Quiet chat chrome:

.msg.assistant .role { display: none; }
.msg.assistant .body.md { letter-spacing: 0; }

Do not restyle window controls, settings forms, or tool-approval cards unless the user asked. Keep contrast readable on both themes.

Apply via configure

{
  "action": "set",
  "values": {
    "custom_css": ":root { --md-lead-bar-width: 0; --md-lead-bar-pad: 0; }\n"
  }
}

After writing theme.css, read it and pass the exact file contents. Do not summarize or wrap the CSS in Markdown fences inside custom_css.

Signals

GitHub stars
1k
Forks
117
Last commit
Sep 2026
Advanced
Catalog kind
skill
Gateway key
custom-theme
Source
github.com/xuzhougeng/wisp-science