/* ========================================
   BUTTONS COMPONENT
   ======================================== */

/* ===== BUTTON BASE ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
  white-space: nowrap;
  user-select: none;
  position: relative;
  line-height: 1;
  font-family: var(--font-family-base);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ===== BUTTON PRIMARY ===== */
.btn-primary {
  background: var(--color-primary);
  color: white;
  border: none;
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

.btn-primary:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-primary-lighter);
}

/* ===== BUTTON SECONDARY ===== */
.btn-secondary {
  background: var(--color-surface-variant);
  color: var(--color-on-surface);
  border: 1px solid var(--color-outline);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--color-outline);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(21, 101, 192, 0.1);
}

/* ===== BUTTON OUTLINED ===== */
.btn-outlined {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outlined:hover:not(:disabled) {
  background: var(--color-primary-lighter);
  transform: translateY(-2px);
}

.btn-outlined:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-primary-lighter);
}

/* ===== BUTTON SUCCESS ===== */
.btn-success {
  background: var(--color-success);
  color: white;
  border: none;
}

.btn-success:hover:not(:disabled) {
  background: var(--color-success-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-success:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-success-lighter);
}

/* ===== BUTTON DANGER ===== */
.btn-danger {
  background: var(--color-error);
  color: white;
  border: none;
}

.btn-danger:hover:not(:disabled) {
  background: var(--color-error-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-danger:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-error-lighter);
}

/* ===== BUTTON WARNING ===== */
.btn-warning {
  background: var(--color-warning);
  color: white;
  border: none;
}

.btn-warning:hover:not(:disabled) {
  background: var(--color-warning-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ===== BUTTON SIZES ===== */
.btn-sm {
  padding: var(--space-sm) var(--space-md);
  font-size: var(--text-xs);
}

.btn-lg {
  padding: var(--space-lg) var(--space-2xl);
  font-size: var(--text-base);
}

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

/* ===== BUTTON STATES ===== */
.btn.loading::after {
  content: '';
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ===== ICON BUTTONS ===== */
.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.btn-icon .icon {
  width: 1.25rem;
  height: 1.25rem;
}

.btn-icon-sm {
  width: 36px;
  height: 36px;
}

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

/* ===== BUTTON GROUPS ===== */
.btn-group {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.btn-group-vertical {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.btn-group.full-width .btn,
.btn-group-vertical .btn {
  flex: 1;
}

/* ===== FAB (Floating Action Button) ===== */
.fab {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: fixed;
  bottom: var(--space-3xl);
  right: var(--space-3xl);
  background: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-xl);
  z-index: var(--z-fab);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.fab:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-2xl);
}

.fab:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-primary-lighter);
}

.fab .icon {
  width: 1.5rem;
  height: 1.5rem;
}

@media (max-width: 480px) {
  .fab {
    bottom: var(--space-2xl);
    right: var(--space-2xl);
    width: 48px;
    height: 48px;
  }

  .fab .icon {
    width: 1.25rem;
    height: 1.25rem;
  }
}

/* ===== LINK BUTTON ===== */
.btn-link {
  background: none;
  color: var(--color-primary);
  border: none;
  padding: 0;
  text-decoration: underline;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.btn-link:hover {
  color: var(--color-primary-dark);
}

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

/* ===== RESPONSIVE BUTTONS ===== */
@media (max-width: 480px) {
  .btn {
    font-size: var(--text-xs);
    padding: var(--space-md) var(--space-lg);
  }

  .btn-group {
    flex-direction: column;
  }

  .btn-group .btn {
    width: 100%;
  }

  .btn-lg {
    width: 100%;
  }
}