/*
 * Custom overrides for the Furo theme.
 *
 * Goal: give function-signature tokens clearly distinct colours, similar
 * to the style used in the pandas and NumPy documentation.
 *
 * Sphinx uses these CSS classes inside <em class="sig-param">:
 *   .n             – names (parameter name AND type annotation names share this!)
 *   .default_value – the default value (e.g. None, True, "hello")
 *   .o             – operators (=, *, **)
 *   .p             – punctuation (: , [ ] )
 *
 * Strategy:
 *   1. Set ALL .n inside .sig-param to the foreground colour → parameter names.
 *   2. Override: .n elements that follow a .p sibling are type annotations
 *      (the colon is always the first .p; brackets in complex types are also .p
 *      but they still come after the colon, so the cascade handles nesting too).
 *   3. Linked type annotations sit inside <a> elements after the colon .p.
 *   4. Return-type annotations live in .sig-return-annotation.
 */

/* Type-annotation colour — defined once here; auto-switches with Furo's
   dark-mode data attribute so no media query is needed. */
:root {
    --color-sig-type: #0969da;   /* GitHub blue, light mode */
}

[data-theme="dark"] {
    --color-sig-type: #58a6ff;   /* GitHub blue, dark mode  */
}

/* 1. Parameter names — standard body text so they are clearly distinct
      from the brand-coloured function name. */
.sig-param .n {
    color: var(--color-foreground-primary);
}

/* 2. Type annotation names (unlinked) — any .n that follows a .p sibling
      (i.e. comes after the colon, or inside brackets of a complex type). */
.sig-param > .p ~ .n {
    color: var(--color-sig-type);
}

/* 3. Type annotation names that hyperlink to their definition. */
.sig-param > .p ~ a .n {
    color: var(--color-sig-type);
}

/* 4. Return type annotation after the → arrow. */
.sig-return-annotation .n,
.sig-return-annotation a .n {
    color: var(--color-sig-type);
}

/* Default values — muted and italic so they read as "optional context"
   rather than the primary label. */
.sig-param .default_value {
    color: var(--color-foreground-secondary);
    font-style: italic;
}