/* ============================================================
   BUTTON — primary / secondary / ghost / danger
   Sizes: sm / md (default) / lg
   States: default / hover / active / focus / disabled / loading
   ============================================================ */

.btn {
  /* layout */
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  /* box */
  height: 36px;
  padding: 0 var(--space-4);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  /* typography */
  font-family: inherit;
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: 0;
  /* visual */
  transition: background var(--transition-fast),
              border-color var(--transition-fast),
              color var(--transition-fast);
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
}

.btn:disabled,
.btn[aria-disabled="true"] {
  cursor: not-allowed;
  opacity: 0.5;
}

.btn__icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  stroke-width: 1.75;
}

/* ---------- VARIANTS ---------- */
.btn--primary {
  background: var(--color-primary);
  color: var(--text-on-primary);
  border-color: var(--color-primary);
}
.btn--primary:hover:not(:disabled),
a.btn--primary:hover {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: var(--text-on-primary);  /* keep text white when global a:hover would override */
}
.btn--primary:active:not(:disabled) {
  background: var(--color-primary-active);
  border-color: var(--color-primary-active);
  color: var(--text-on-primary);
}

.btn--secondary {
  background: var(--bg-surface);
  color: var(--text-primary);
  border-color: var(--border-strong);
}
.btn--secondary:hover:not(:disabled),
a.btn--secondary:hover {
  background: var(--bg-subtle);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: transparent;
}
.btn--ghost:hover:not(:disabled),
a.btn--ghost:hover {
  background: var(--bg-subtle);
  color: var(--text-primary);
}

.btn--danger {
  background: var(--color-danger);
  color: var(--text-on-primary);
  border-color: var(--color-danger);
}
.btn--danger:hover:not(:disabled),
a.btn--danger:hover {
  background: var(--color-danger-hover);
  border-color: var(--color-danger-hover);
  color: var(--text-on-primary);
}

/* ---------- SIZES ---------- */
.btn--sm {
  height: 28px;
  padding: 0 var(--space-3);
  font-size: var(--text-xs);
  border-radius: var(--radius-sm);
}
.btn--sm .btn__icon { width: 14px; height: 14px; }

.btn--lg {
  height: 44px;
  padding: 0 var(--space-5);
  font-size: var(--text-base);
}
.btn--lg .btn__icon { width: 18px; height: 18px; }

/* ---------- DESTRUCTIVE (admin red) ---------- */
.btn--destructive {
  background: var(--admin-accent);
  color: var(--text-on-primary);
  border-color: var(--admin-accent);
}
.btn--destructive:hover:not(:disabled),
a.btn--destructive:hover {
  background: color-mix(in srgb, var(--admin-accent) 85%, black);
  border-color: color-mix(in srgb, var(--admin-accent) 85%, black);
  color: var(--text-on-primary);
}