Theming

FlowDrop uses a semantic-first design token system based on CSS custom properties with a --fd-* prefix.

Quick start

Override semantic tokens to customize FlowDrop:

:root {
  /* Change the primary color */
  --fd-primary: #8b5cf6;
  --fd-primary-hover: #7c3aed;

  /* Adjust border radius */
  --fd-radius-md: 0.5rem;
}

Token architecture

FlowDrop's token system has three tiers:

Tier	Prefix	Description
Internal Palette	`--_*`	Raw color values — not for direct use
Semantic Tokens	`--fd-*`	The public API — what you customize
Component Tokens	(varies)	Use semantic tokens in components

Key principle: Override --fd-* tokens. Components automatically use these tokens, so your theme cascades everywhere.

Semantic tokens reference

Surfaces

Token	Description
`--fd-background`	Main background color
`--fd-foreground`	Main text color
`--fd-muted`	Muted background (cards, inputs)
`--fd-muted-foreground`	Muted text
`--fd-card`	Card background
`--fd-card-foreground`	Card text color

Borders

Token	Description
`--fd-border`	Default border color
`--fd-border-muted`	Muted border
`--fd-border-strong`	Strong border
`--fd-ring`	Focus ring color

Primary and accent

Token	Description
`--fd-primary`	Primary action color
`--fd-primary-hover`	Primary hover state
`--fd-primary-foreground`	Text on primary
`--fd-primary-muted`	Light primary background
`--fd-accent`	Accent color
`--fd-accent-hover`	Accent hover

Status colors

Each status color has -hover, -foreground, and -muted variants:

--fd-success — Green
--fd-warning — Amber
--fd-error — Red
--fd-info — Blue

Spacing

Token	Value
`--fd-space-3xs`	4px
`--fd-space-2xs`	6px
`--fd-space-xs`	8px
`--fd-space-sm`	10px
`--fd-space-md`	12px
`--fd-space-lg`	14px
`--fd-space-xl`	16px
`--fd-space-2xl`	20px
`--fd-space-3xl`	24px

Border radius

Token	Value
`--fd-radius-sm`	4px
`--fd-radius-md`	6px
`--fd-radius-lg`	8px
`--fd-radius-xl`	12px
`--fd-radius-full`	Pill shape

Typography

Token	Value
`--fd-text-xs`	12px
`--fd-text-sm`	14px
`--fd-text-base`	16px
`--fd-text-lg`	18px
`--fd-text-xl`	20px

Layout

Token	Default
`--fd-sidebar-width`	320px
`--fd-navbar-height`	60px
`--fd-toolbar-height`	40px

Node layout

Node dimensions use a 10px grid for alignment with the editor snap grid:

Token	Default
`--fd-node-default-width`	290px
`--fd-node-header-height`	60px
`--fd-node-terminal-size`	80px
`--fd-node-square-size`	80px
`--fd-handle-size`	20px
`--fd-handle-visual-size`	12px

Theming examples

Purple theme

:root {
  --fd-primary: #8b5cf6;
  --fd-primary-hover: #7c3aed;
  --fd-primary-muted: #f5f3ff;
  --fd-accent: #8b5cf6;
  --fd-ring: #8b5cf6;
}

Rounded theme

:root {
  --fd-radius-sm: 0.5rem;
  --fd-radius-md: 0.75rem;
  --fd-radius-lg: 1rem;
  --fd-radius-xl: 1.5rem;
}

Compact spacing

:root {
  --fd-space-3xs: 0.125rem;
  --fd-space-xs: 0.25rem;
  --fd-space-md: 0.5rem;
  --fd-space-xl: 0.75rem;
}

Dark mode

FlowDrop supports dark mode. Enable it with:

<html data-theme="dark"></html>

Or via JavaScript:

document.documentElement.setAttribute('data-theme', 'dark');

Or use the built-in theme toggle:

import { toggleTheme, setTheme } from '@flowdrop/flowdrop/core';

toggleTheme(); // Cycles through light/dark/auto
setTheme('dark'); // Set explicitly

All semantic tokens have dark-mode equivalents that activate automatically.

Best practices

Use semantic tokens — Override --fd-primary instead of individual component colors
Keep it minimal — A few token overrides can transform the entire look
Test in context — Colors look different on light vs dark backgrounds
Consider accessibility — Ensure sufficient contrast ratios
Use the cascade — Semantic tokens update all components automatically

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