CSS customisation hooks for ggpaintr apps

Every raw-Shiny entry point (ptr_app(), ptr_app_grid(), ptr_ui(), ptr_shared_panel()) accepts a css = argument: a character vector of paths to .css files. Each path's parent directory is registered as a Shiny resource under a hash-derived prefix, and one <link> tag is emitted per file. User stylesheets are linked after ggpaintr's bundled stylesheet, so rules at equal specificity win.

Details

The bundled stylesheet exposes its theme as CSS custom properties under the .ptr-app selector. Override any subset of these in a user-supplied stylesheet to retheme without touching individual rules.

Tokens

--ptr-bg

App background. Default #fafbfc.

--ptr-surface

Card / sidebar background. Default #ffffff.

--ptr-border

Standard border colour. Default #e7e9ee.

--ptr-ink

Body text colour. Default #1f2530.

--ptr-muted

Muted / secondary text. Default #6b7280.

--ptr-accent

Primary accent (action button bg). Default #c1372c.

--ptr-accent-strong

Hover / active accent. Default #9a2b22.

--ptr-accent-weak

Faint accent tint. Default rgba(193,55,44,0.13).

--ptr-accent-line

Accent border. Default rgba(193,55,44,0.22).

--ptr-radius

Large radius (cards, sidebar). Default 10px.

--ptr-radius-sm

Small radius (buttons, controls). Default 7px.

--ptr-shadow

Card shadow. Default two-layer drop.

--ptr-shadow-lg

Floating-window shadow. Default two-layer drop.

--ptr-font

UI font stack. Default system-ui stack.

--ptr-mono

Mono font stack. Default system mono stack.

Specificity

Some rules use a doubly-scoped selector (e.g. .ptr-app .btn.action-button). To override these, match or exceed that specificity in your stylesheet (either with the same selector, or with !important).