/*
 * Buttons — the one primitive used everywhere.
 *
 * Variants compose on the base `.btn`:
 *   .btn.btn--primary   — the single affirmative action on a screen
 *   .btn.btn--secondary — neutral, alongside a primary
 *   .btn.btn--ghost     — no background, subtle hover
 *   .btn.btn--block     — full-width
 *   .btn.btn--sm        — small variant (default size is the standard)
 *
 * States: default, :hover, :focus-visible, :active, :disabled.
 */

@layer components {
  .btn {
    /* Default (secondary) — white surface, never changes on hover;
       only the border darkens. Text is a desaturated navy. */
    --btn-bg: var(--color-white);
    --btn-bg-hover: var(--color-white);
    --btn-fg: oklch(0.3405 0.0485 255.87);
    --btn-border: oklch(0.8935 0.0197 252.89);
    --btn-border-hover: oklch(0.7082 0.0377 258.86);
    --btn-ring: var(--color-primary);

    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    min-height: 2.5rem;
    padding: 0 1rem;
    border: 1px solid var(--btn-border);
    border-radius: 0.5rem;
    background: var(--btn-bg);
    color: var(--btn-fg);
    font: inherit;
    font-weight: 500;
    font-size: 0.875rem;
    line-height: 1;
    text-decoration: none;
    cursor: pointer;
    user-select: none;
    transition: background-color 120ms ease, border-color 120ms ease,
                box-shadow 120ms ease, transform 60ms ease;
  }

  .btn:hover {
    background: var(--btn-bg-hover);
    border-color: var(--btn-border-hover);
  }

  .btn:focus-visible {
    outline: none;
    box-shadow: 0 0 0 2px var(--color-white), 0 0 0 4px var(--btn-ring);
  }

  .btn:active {
    transform: translateY(0.5px);
  }

  .btn:disabled,
  .btn[aria-disabled="true"] {
    opacity: 0.55;
    cursor: not-allowed;
  }

  /* Variants --------------------------------------------------------- */

  .btn--primary {
    --btn-bg: var(--color-primary);
    --btn-bg-hover: var(--color-primary-hover);
    --btn-fg: var(--color-on-primary);
    --btn-border: var(--color-primary);
    --btn-border-hover: var(--color-primary-hover);
    --btn-ring: var(--color-primary);
  }

  .btn--secondary {
    /* Same as base .btn — listed for semantic intent. */
  }

  .btn--ghost {
    --btn-bg: transparent;
    --btn-bg-hover: var(--color-slate-100);
    --btn-border: transparent;
    --btn-border-hover: transparent;
  }

  /* Sizes ------------------------------------------------------------ */

  .btn--sm {
    min-height: 2rem;
    padding: 0 0.75rem;
    font-size: 0.8125rem;
  }

  /* Layout ----------------------------------------------------------- */

  .btn--block {
    display: flex;
    width: 100%;
  }
}