/**
 * Button primitives
 * Base button styles, variants, sizes, and icon buttons
 */
@layer ks-primitives {
  /* Base button structure; color variants below carry it too, so they work standalone. */
  .ks-button,
  .ks-button-primary,
  .ks-button-secondary,
  .ks-button-outline,
  .ks-button-outline-inverse,
  .ks-button-outline-fill,
  .ks-button-inverse,
  .ks-button-muted,
  .ks-button-ghost,
  .ks-button-danger,
  .ks-button-success,
  .ks-button-default,
  .ks-button-glass,
  .ks-button-white {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--ks-space-2);
    min-block-size: 2.75rem;
    padding-inline: var(--ks-space-5);
    padding-block: var(--ks-space-3);
    border: var(--ks-border-width) solid transparent;
    border-radius: var(--ks-radius-md);
    font-weight: var(--ks-font-weight-strong);
    text-decoration: none;
    transition:
      color var(--ks-duration-base) var(--ks-ease-standard),
      background-color var(--ks-duration-base) var(--ks-ease-standard),
      border-color var(--ks-duration-base) var(--ks-ease-standard),
      box-shadow var(--ks-duration-base) var(--ks-ease-standard),
      transform var(--ks-duration-fast) var(--ks-ease-emphasis);
  }

  .ks-button:focus-visible,
  .ks-button-primary:focus-visible,
  .ks-button-secondary:focus-visible,
  .ks-button-outline:focus-visible,
  .ks-button-outline-inverse:focus-visible,
  .ks-button-outline-fill:focus-visible,
  .ks-button-inverse:focus-visible,
  .ks-button-muted:focus-visible,
  .ks-button-ghost:focus-visible,
  .ks-button-danger:focus-visible,
  .ks-button-success:focus-visible,
  .ks-button-default:focus-visible,
  .ks-button-glass:focus-visible,
  .ks-button-white:focus-visible {
    outline: var(--ks-border-width-strong) solid var(--ks-color-primary-400);
    outline-offset: 0.125rem;
  }

  /* Size variants */
  .ks-button--sm {
    min-block-size: 2.25rem;
    padding-inline: var(--ks-space-4);
    padding-block: var(--ks-space-2);
    font-size: 0.875rem;
  }

  .ks-button--md {
    min-block-size: 2.5rem;
    padding-inline: var(--ks-space-4);
    padding-block: var(--ks-space-2);
    font-size: 0.875rem;
  }

  .ks-button--lg {
    min-block-size: 3rem;
    padding-inline: var(--ks-space-6);
    font-size: 1rem;
  }

  .ks-button--xl {
    min-block-size: 3.5rem;
    padding-inline: var(--ks-space-8);
    padding-block: var(--ks-space-4);
    font-size: 1.125rem;
  }

  /* Size aliases (single dash) */
  .ks-button-sm {
    min-block-size: 2rem;
    padding-inline: var(--ks-space-3);
    padding-block: var(--ks-space-1);
    font-size: 0.875rem;
  }

  .ks-button-lg {
    min-block-size: 3rem;
    padding-inline: var(--ks-space-6);
    font-size: 1rem;
  }

  .ks-button--full {
    inline-size: 100%;
  }

  .ks-button--pill {
    border-radius: var(--ks-radius-full);
  }

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

  /* Color variants */
  .ks-button-primary {
    background-color: var(--ks-color-primary-600);
    color: var(--ks-color-text-inverse);
  }

  .ks-button-primary:hover,
  .ks-button-primary:focus-visible {
    background-color: var(--ks-color-primary-700);
    box-shadow: var(--ks-shadow-md);
  }

  .ks-button-secondary {
    background-color: var(--ks-color-secondary-900);
    color: var(--ks-color-text-inverse);
  }

  .ks-button-secondary:hover,
  .ks-button-secondary:focus-visible {
    background-color: var(--ks-color-secondary-900);
    box-shadow: var(--ks-shadow-md);
  }

  .ks-button-outline {
    border-color: var(--ks-color-border-default);
    color: var(--ks-color-text-strong);
  }

  .ks-button-outline:hover,
  .ks-button-outline:focus-visible {
    border-color: var(--ks-color-primary-600);
    color: var(--ks-color-primary-700);
  }

  :where(.dark) .ks-button-outline {
    background: var(--ks-color-gray-800);
    border-color: var(--ks-color-gray-600);
    color: var(--ks-color-gray-300);
  }

  :where(.dark) .ks-button-outline:hover {
    background: var(--ks-color-gray-700);
  }

  /* Inverse buttons for dark surfaces */
  .ks-button-inverse {
    background-color: var(--ks-color-surface-card);
    color: var(--ks-color-text-strong);
    border-color: var(--ks-color-surface-card);
  }

  .ks-button-inverse:hover,
  .ks-button-inverse:focus-visible {
    background-color: var(--ks-color-surface-section);
    border-color: var(--ks-color-surface-section);
  }

  .ks-button-outline-inverse {
    background-color: transparent;
    border-color: var(--ks-color-overlay-inverse-medium);
    color: var(--ks-color-text-inverse);
  }

  .ks-button-outline-inverse:hover,
  .ks-button-outline-inverse:focus-visible {
    background-color: var(--ks-color-surface-card);
    border-color: var(--ks-color-surface-card);
    color: var(--ks-color-text-strong);
  }

  /* Muted button */
  .ks-button-muted {
    background-color: var(--ks-color-gray-200);
    color: var(--ks-color-text-muted);
  }

  .ks-button-muted:hover,
  .ks-button-muted:focus-visible {
    background-color: var(--ks-color-gray-300);
  }

  :where(.dark) .ks-button-muted {
    background-color: var(--ks-color-gray-700);
    color: var(--ks-color-gray-300);
  }

  :where(.dark) .ks-button-muted:hover,
  :where(.dark) .ks-button-muted:focus-visible {
    background-color: var(--ks-color-gray-600);
  }

  /* Outline fill button */
  .ks-button-outline-fill {
    background-color: transparent;
    border-color: var(--ks-color-primary-600);
    border-width: var(--ks-border-width-strong);
    color: var(--ks-color-primary-700);
  }

  .ks-button-outline-fill:hover,
  .ks-button-outline-fill:focus-visible {
    background-color: var(--ks-color-primary-600);
    border-color: var(--ks-color-primary-600);
    color: var(--ks-color-text-inverse);
    box-shadow: var(--ks-shadow-md);
  }

  /* Animated fill buttons */
  .btn-outline-fill {
    position: relative;
    overflow: hidden;
    z-index: 0;
    transition: color 0.3s var(--ks-ease-standard);
  }

  .btn-outline-fill::before {
    content: '';
    position: absolute;
    inset: 3px;
    background: var(--color-primary-600);
    border-radius: 0.25rem;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s var(--ks-ease-standard);
    z-index: -1;
  }

  .btn-outline-fill:hover::before,
  .btn-outline-fill:focus-visible::before {
    transform: scaleX(1);
  }

  .btn-outline-fill:hover,
  .btn-outline-fill:focus-visible {
    color: white;
  }

  .btn-outline-fill:hover svg,
  .btn-outline-fill:focus-visible svg {
    color: white;
  }

  .btn-primary-sweep {
    position: relative;
    overflow: hidden;
    z-index: 0;
  }

  .btn-primary-sweep::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--color-primary-700);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s var(--ks-ease-standard);
    z-index: -1;
  }

  .btn-primary-sweep:hover::before,
  .btn-primary-sweep:focus-visible::before {
    transform: scaleX(1);
  }

  /* Ghost button */
  .ks-button-ghost {
    color: var(--ks-color-text-strong);
  }

  .ks-button-ghost:hover,
  .ks-button-ghost:focus-visible {
    background-color: var(--ks-color-surface-section);
  }

  /* Danger button */
  .ks-button-danger {
    background-color: var(--ks-color-tertiary-700);
    color: var(--ks-color-text-inverse);
  }

  .ks-button-danger:hover,
  .ks-button-danger:focus-visible {
    background-color: var(--ks-color-tertiary-800);
    box-shadow: var(--ks-shadow-md);
  }

  /* Success button */
  .ks-button-success {
    background-color: var(--ks-color-secondary-600);
    color: var(--ks-color-text-inverse);
  }

  .ks-button-success:hover,
  .ks-button-success:focus-visible {
    background-color: var(--ks-color-secondary-700);
    box-shadow: var(--ks-shadow-md);
  }

  /* Icon button */
  .ks-button-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    inline-size: 2.5rem;
    block-size: 2.5rem;
    padding: 0;
    border: var(--ks-border-width) solid transparent;
    border-radius: var(--ks-radius-md);
    background-color: transparent;
    color: var(--ks-color-text-muted);
    transition:
      color var(--ks-duration-base) var(--ks-ease-standard),
      background-color var(--ks-duration-base) var(--ks-ease-standard),
      border-color var(--ks-duration-base) var(--ks-ease-standard);
  }

  .ks-button-icon:hover,
  .ks-button-icon:focus-visible {
    background-color: var(--ks-color-surface-section);
    color: var(--ks-color-text-strong);
  }

  .ks-button-icon-primary {
    background-color: var(--ks-color-primary-600);
    color: var(--ks-color-text-inverse);
  }

  .ks-button-icon-primary:hover,
  .ks-button-icon-primary:focus-visible {
    background-color: var(--ks-color-primary-700);
    color: var(--ks-color-text-inverse);
  }

  /* Icon pill */
  .ks-icon-pill {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    inline-size: 2.5rem;
    block-size: 2.5rem;
    border-radius: var(--ks-radius-full);
    background-color: var(--ks-color-surface-section);
    color: var(--ks-color-text-muted);
    transition:
      color var(--ks-duration-base) var(--ks-ease-standard),
      background-color var(--ks-duration-base) var(--ks-ease-standard);
  }

  a.ks-icon-pill:hover,
  a.ks-icon-pill:focus-visible,
  button.ks-icon-pill:hover,
  button.ks-icon-pill:focus-visible {
    background-color: var(--ks-color-border-subtle);
    color: var(--ks-color-text-strong);
  }

  .ks-icon-pill--outline {
    background-color: transparent;
    border: 1px solid var(--ks-color-border-default);
  }

  a.ks-icon-pill--outline:hover,
  a.ks-icon-pill--outline:focus-visible,
  button.ks-icon-pill--outline:hover,
  button.ks-icon-pill--outline:focus-visible {
    background-color: var(--ks-color-primary-600);
    border-color: var(--ks-color-primary-600);
    color: var(--ks-color-text-inverse);
  }

  /* Frosted-glass icon pill: translucent white circle, dark glyph, green on hover. */
  .ks-icon-pill--frosted {
    background-color: color-mix(in srgb, white 90%, transparent);
    color: var(--ks-color-text-strong);
  }

  a.ks-icon-pill--frosted:hover,
  a.ks-icon-pill--frosted:focus-visible,
  button.ks-icon-pill--frosted:hover,
  button.ks-icon-pill--frosted:focus-visible {
    background-color: var(--ks-color-primary-600);
    color: var(--ks-color-text-inverse);
  }

  /* Additional button variants */
  .ks-btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--ks-space-2); padding: var(--ks-space-2) var(--ks-space-4); border-radius: var(--ks-radius-md); font-weight: var(--ks-font-weight-strong); cursor: pointer; }
  .ks-button-default { background-color: var(--ks-color-surface-section); color: var(--ks-color-text-default); border: 1px solid var(--ks-color-border-default); }
  .ks-button-default:hover { background-color: var(--ks-color-surface-page); border-color: var(--ks-color-border-strong); }
  .ks-button-disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }
  :where(.dark) .ks-button-disabled {
    background: var(--ks-color-gray-700);
    color: var(--ks-color-gray-400);
  }
  .ks-button-glass { background-color: var(--ks-color-overlay-inverse-faint); color: var(--ks-color-text-inverse); backdrop-filter: blur(8px); border: var(--ks-border-width-strong) solid var(--ks-color-overlay-inverse-light); }
  .ks-button-glass:hover { background-color: var(--ks-color-overlay-inverse); }
  .ks-button-white { background-color: var(--ks-color-surface-page); color: var(--ks-color-text-strong); }
  .ks-button-white:hover { background-color: var(--ks-color-surface-section); }

  /* Icon button variants */
  .ks-icon-button { display: inline-flex; align-items: center; justify-content: center; padding: var(--ks-space-2); border-radius: var(--ks-radius-md); background: transparent; color: var(--ks-color-text-muted); cursor: pointer; }
  .ks-icon-button:hover { background-color: var(--ks-color-surface-section); color: var(--ks-color-text-strong); }
  .ks-icon-button--sm { padding: var(--ks-space-1); }
  .ks-icon-button--danger { color: var(--ks-color-danger-500); }
  .ks-icon-button--danger:hover { background-color: var(--ks-color-danger-50); }
  :where(.dark) .ks-icon-button {
    background: var(--ks-color-gray-800);
    color: var(--ks-color-gray-300);
  }
  :where(.dark) .ks-icon-button:hover {
    background: var(--ks-color-gray-700);
    color: var(--ks-color-primary-400);
  }

  /* Icon disc - circular icon container */
  .ks-icon-disc { display: inline-flex; align-items: center; justify-content: center; width: 3rem; height: 3rem; border-radius: var(--ks-radius-full); background-color: var(--ks-color-surface-section); color: var(--ks-color-text-muted); }
  .ks-icon-disc--sm { width: 2rem; height: 2rem; }
  .ks-icon-disc--lg { width: 4rem; height: 4rem; }
  .ks-icon-disc--primary, .ks-icon-disc-primary { background-color: var(--ks-color-primary-100); color: var(--ks-color-primary-700); }
  .ks-icon-disc--secondary { background-color: var(--ks-color-secondary-100); color: var(--ks-color-secondary-700); }
  .ks-icon-disc--success { background-color: var(--ks-color-success-100); color: var(--ks-color-success-700); }
  .ks-icon-disc--info { background-color: var(--ks-color-info-100); color: var(--ks-color-info-700); }
  .ks-icon-disc--inverse { background-color: var(--ks-color-overlay-inverse); color: var(--ks-color-text-inverse); }
  :where(.dark) .ks-icon-disc--sm { background: var(--ks-color-gray-600); }
  :where(.dark) .ks-icon-disc--secondary { background: color-mix(in srgb, var(--ks-color-secondary-900) 40%, transparent); }
  :where(.dark) .ks-icon-disc--success { background: var(--ks-color-success-900); color: var(--ks-color-success-400); }
  .ks-icon-disc--float {
    position: absolute;
    top: var(--ks-space-4);
    inset-inline-start: var(--ks-space-4);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    background-color: var(--ks-color-primary-100);
    color: var(--ks-color-primary-600);
  }

  :where(.dark) .ks-icon-disc--float {
    background-color: var(--ks-color-primary-900);
    color: var(--ks-color-primary-400);
  }

  /* Icon circle variants */
  .ks-icon-circle-accent { display: inline-flex; align-items: center; justify-content: center; width: 2.5rem; height: 2.5rem; border-radius: var(--ks-radius-full); background-color: var(--ks-color-accent-100); color: var(--ks-color-accent-700); }
  .ks-icon-circle-muted { display: inline-flex; align-items: center; justify-content: center; width: 2.5rem; height: 2.5rem; border-radius: var(--ks-radius-full); background-color: var(--ks-color-surface-section); color: var(--ks-color-text-muted); }
  .ks-icon-circle-secondary { display: inline-flex; align-items: center; justify-content: center; width: 2.5rem; height: 2.5rem; border-radius: var(--ks-radius-full); background-color: var(--ks-color-secondary-100); color: var(--ks-color-secondary-700); }

  /* Icon tile */
  .ks-icon-tile-primary { display: inline-flex; align-items: center; justify-content: center; padding: var(--ks-space-3); border-radius: var(--ks-radius-md); background-color: var(--ks-color-primary-100); color: var(--ks-color-primary-700); }

  /* Icon size xxl */
  .ks-icon-xxl { width: 4rem; height: 4rem; }
}