Styling Overview

c15t's theming system gives you multiple levels of control, but most customization should stay inside the pre-built components.

Start with the lowest-power tool that solves the problem:

1. Pre-built component APIs — provider options and component props such as layout, direction, primaryButton, legalLinks, and theme.consentActions
2. Design tokens — global colors, typography, spacing, radius, shadows, and motion
3. Slots — targeted styling for specific parts such as the banner card, footer, or title
4. CSS variables or className-level overrides — when you need to integrate with external CSS systems
5. Compound components — when you must rearrange markup while still using c15t primitives
6. noStyle — when you want c15t structure but you need to own all visual styling
7. Headless — when you want fully custom markup and behavior

Keep styling and escalation as separate decisions:

• If you are still using the stock banner, dialog, or widget, stay with props, tokens, and slots.
• Escalate to compound components, noStyle, or headless only when the structure or behavior itself must change.

Styling Approaches

Quick Start

import {
  type Theme,
  ConsentManagerProvider,
  ConsentBanner,
  ConsentDialog,
} from '@c15t/nextjs';

const theme = {
  colors: {
    primary: '#6366f1',
    primaryHover: '#4f46e5',
  },
  radius: {
    md: '0.75rem',
    lg: '1rem',
  },
  slots: {
    consentBannerTitle: 'text-xl font-semibold',
    buttonPrimary: 'rounded-full',
  },
} satisfies Theme;

export function ConsentManager({ children }) {
  return (
    <ConsentManagerProvider
      options={{
        mode: 'hosted',
        backendURL: '/api/c15t',
        theme,
      }}
    >
      <ConsentBanner />
      <ConsentDialog />
      {children}
    </ConsentManagerProvider>
  );
}

Styling Inside Pre-Built Components

Start here before you consider compound components or headless mode.

1. Provider and component configuration

Use the stock APIs first:

• layout, direction, and primaryButton for banner action arrangement
• legalLinks for link visibility
• hideBranding and showTrigger for dialog and widget behavior
• theme.consentActions for stock banner and dialog button treatment
• i18n on ConsentManagerProvider for copy changes

<ConsentBanner
  layout={['customize', ['reject', 'accept']]}
  primaryButton="accept"
/>;

2. Design tokens

Set global values for colors, typography, spacing, radius, shadows, and motion:

options={{ theme: { colors: { primary: '#6366f1' } } }}

Use tokens first when the change is semantic:

• Banner card background -> theme.colors.surface
• Banner footer background -> theme.colors.surfaceHover
• Shared copy color -> theme.colors.text and theme.colors.textMuted
• Primary-filled surfaces such as stock branding tags and filled actions -> theme.colors.primary with theme.colors.textOnPrimary as the matching foreground override

options={{
  theme: {
    colors: {
      surface: '#ffffff',
      surfaceHover: '#f6f3ee',
    },
  },
}}

If you set theme.colors.primary but omit theme.colors.textOnPrimary, c15t derives a readable foreground automatically. Add textOnPrimary only when you need to force a specific branded foreground color.

3. Component slots

Target specific component parts via the slots object:

options={{
  theme: {
    slots: {
      consentBannerCard: 'rounded-[28px] shadow-xl',
      consentBannerFooter: 'border-t border-black/10',
      consentBannerTitle: 'tracking-tight',
    },
  },
}}

Use slots when the component part is right but the local styling needs adjustment.

4. CSS variables and className-level overrides

Override --c15t-* custom properties in your stylesheet or attach classes through slots when your app styling is driven externally.

Reach for this after tokens and slots, not before.

options={{
  theme: {
    slots: {
      consentBannerFooter: 'bg-[var(--banner-footer)]',
    },
  },
}}

Escalating Beyond Pre-Built Components

Only move up this ladder when the lower rung cannot satisfy the request.

5. Compound components

Use compound components when you need to rearrange existing c15t primitives:

<ConsentBanner.Root>
  <ConsentBanner.Card>
    <ConsentBanner.Header>
      <ConsentBanner.Title />
      <ConsentBanner.Description />
    </ConsentBanner.Header>
    <ConsentBanner.Footer>
      <ConsentBanner.CustomizeButton />
      <ConsentBanner.FooterSubGroup>
        <ConsentBanner.RejectButton />
        <ConsentBanner.AcceptButton />
      </ConsentBanner.FooterSubGroup>
    </ConsentBanner.Footer>
  </ConsentBanner.Card>
</ConsentBanner.Root>;

6. noStyle

Use noStyle only when the c15t structure is still correct but you want to replace all visual defaults:

<ConsentBanner noStyle />;

7. Headless

Go headless only when you are replacing both markup and behavior. For that path, continue to Headless Mode.

Common Styling Tasks

Change the banner footer background

options={{
  theme: {
    colors: {
      surfaceHover: '#f6f3ee',
    },
  },
}}

Use theme.colors.surfaceHover before trying raw CSS.

Change the banner card background

options={{
  theme: {
    colors: {
      surface: '#fffdf8',
    },
  },
}}

Use theme.colors.surface before overriding banner CSS variables directly.

Tweak the banner card, footer, or title styling without changing markup

options={{
  theme: {
    slots: {
      consentBannerCard: 'rounded-[28px] shadow-xl',
      consentBannerFooter: 'border-t border-black/10 px-6',
      consentBannerTitle: 'text-xl tracking-tight',
    },
  },
}}

Change stock consent action button styles semantically

options={{
  theme: {
    consentActions: {
      default: { mode: 'stroke' },
      accept: { variant: 'primary', mode: 'stroke' },
      customize: { variant: 'neutral', mode: 'ghost' },
    },
  },
}}

Use theme.consentActions when you want to change the stock banner/dialog button treatment without rewriting the component layout. Policy packs still control action arrangement and primary-action hints. The theme controls whether those actions render as stroke, filled, ghost, or lighter.

Change banner copy without replacing the component

options={{
  i18n: {
    locale: 'en',
    messages: {
      en: {
        cookieBanner: {
          title: 'We value your privacy',
          description: 'We use cookies to improve the site and measure performance.',
        },
        common: {
          acceptAll: 'Accept all',
          rejectAll: 'Reject all',
          customize: 'Manage preferences',
        },
      },
    },
  },
}}

Enable dark mode safely

options={{
  colorScheme: 'system',
  theme: {
    colors: { surface: '#ffffff', text: '#1f2937' },
    dark: { surface: '#111827', text: '#f9fafb' },
  },
}}

API Reference