/* ==========================================================================
   BUTTONS.CSS — Button Component System
   CRM + HRMS Platform | Infusion Business Intelligence
   ==========================================================================
   Variants:  --primary | --secondary | --danger | --ghost | --icon
   Sizes:     --sm | (default) | --lg
   States:    hover | focus | active | disabled | --loading
   ========================================================================== */

/* ------------------------------------------------------------------
   1. Base button
   ------------------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 10px var(--space-2);
  font-family: var(--font-base);
  font-size: var(--text-base);
  font-weight: 500;
  line-height: 1;
  white-space: nowrap;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn:focus-visible {
  outline: 2px solid var(--company-primary);
  outline-offset: 2px;
}

/* ------------------------------------------------------------------
   2. Primary — solid company brand color
   ------------------------------------------------------------------ */
.btn--primary {
  background: var(--company-primary);
  color: var(--text-inverse);
  border-color: var(--company-primary);
}

.btn--primary:hover {
  background: var(--company-secondary);
  border-color: var(--company-secondary);
}

.btn--primary:active {
  transform: scale(0.98);
}

/* ------------------------------------------------------------------
   3. Secondary — outlined, transparent bg
   ------------------------------------------------------------------ */
.btn--secondary {
  background: transparent;
  color: var(--company-primary);
  border-color: var(--company-primary);
}

.btn--secondary:hover {
  background: var(--company-primary);
  color: var(--text-inverse);
}

.btn--secondary:active {
  transform: scale(0.98);
}

/* ------------------------------------------------------------------
   4. Danger — destructive actions
   ------------------------------------------------------------------ */
.btn--danger {
  background: var(--danger);
  color: var(--text-inverse);
  border-color: var(--danger);
}

.btn--danger:hover {
  background: #DC2626;
  border-color: #DC2626;
}

.btn--danger:active {
  transform: scale(0.98);
}

.btn--danger:focus-visible {
  outline-color: var(--danger);
}

/* ------------------------------------------------------------------
   5. Ghost — transparent, minimal emphasis
   ------------------------------------------------------------------ */
.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: transparent;
}

.btn--ghost:hover {
  background: var(--content-bg);
  color: var(--text-primary);
}

.btn--ghost:active {
  transform: scale(0.98);
}

/* ------------------------------------------------------------------
   6. Icon — square button for icon-only actions
   ------------------------------------------------------------------ */
.btn--icon {
  width: 40px;
  height: 40px;
  padding: 0;
  background: transparent;
  color: var(--text-secondary);
  border-color: transparent;
  flex-shrink: 0;
}

.btn--icon:hover {
  background: var(--content-bg);
  color: var(--text-primary);
}

/* ------------------------------------------------------------------
   7. Size modifiers
   ------------------------------------------------------------------ */
.btn--sm {
  padding: 6px var(--space-1);
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
}

.btn--sm.btn--icon {
  width: 32px;
  height: 32px;
}

.btn--lg {
  padding: 14px var(--space-3);
  font-size: var(--text-md);
  border-radius: var(--radius-md);
}

.btn--lg.btn--icon {
  width: 48px;
  height: 48px;
}

/* ------------------------------------------------------------------
   8. Disabled state
   ------------------------------------------------------------------ */
.btn:disabled,
.btn[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ------------------------------------------------------------------
   9. Loading state — spinner + disable clicks
   ------------------------------------------------------------------ */
.btn--loading {
  color: transparent !important;
  pointer-events: none;
  position: relative;
}

.btn--loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 18px;
  height: 18px;
  margin: -9px 0 0 -9px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: var(--radius-full);
  animation: btn-spin 0.6s linear infinite;
}

/* Restore visible color on the pseudo-element for each variant */
.btn--primary.btn--loading::after {
  border-color: var(--text-inverse);
  border-right-color: transparent;
}

.btn--secondary.btn--loading::after {
  border-color: var(--company-primary);
  border-right-color: transparent;
}

.btn--danger.btn--loading::after {
  border-color: var(--text-inverse);
  border-right-color: transparent;
}

.btn--ghost.btn--loading::after {
  border-color: var(--text-secondary);
  border-right-color: transparent;
}

@keyframes btn-spin {
  to { transform: rotate(360deg); }
}

/* ------------------------------------------------------------------
   10. Button text / loader pattern (SKILL 05 pattern)
       <span class="btn-text">Save</span>
       <span class="btn-loader hidden">Saving...</span>
   ------------------------------------------------------------------ */
.btn-text,
.btn-loader {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}

/* ------------------------------------------------------------------
   11. Button group — adjacent buttons with shared border
   ------------------------------------------------------------------ */
.btn-group {
  display: inline-flex;
}

.btn-group .btn {
  border-radius: 0;
}

.btn-group .btn:first-child {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.btn-group .btn:last-child {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.btn-group .btn + .btn {
  margin-left: -1px;
}