/* ==========================================================================
   Button Component - Wholesum Design System
   Unified button styles: primary, secondary, tertiary + modifiers.
   Version: 1.0 | Phase 2 of CSS Unification
   ========================================================================== */

/* ===== BASE BUTTON STYLES ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-family-base);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  padding: var(--spacing-2) var(--spacing-4);
  border: 1.5px solid transparent;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast),
              color var(--transition-fast), box-shadow var(--transition-fast),
              transform var(--transition-fast);
  white-space: nowrap;
  user-select: none;
  outline: none;
  background: none;
  color: inherit;
  text-decoration: none;
  line-height: 1;
  gap: var(--spacing-2);
}

.btn:focus-visible {
  box-shadow: var(--shadow-focus-ring);
}

/* ===== PRIMARY VARIANT ===== */
/* Solid colored background for main actions */
.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
  border-color: var(--color-primary);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
}

.btn-primary:active:not(:disabled) {
  background-color: var(--color-primary-active);
  border-color: var(--color-primary-active);
}

.btn-primary:disabled {
  background-color: var(--color-primary-disabled);
  border-color: var(--color-primary-disabled);
  color: var(--color-text-inverse);
  cursor: not-allowed;
  opacity: 0.7;
}

/* ===== PRIMARY DARK VARIANT ===== */
/* Dark background for strong secondary actions (e.g. Load More) */
.btn-dark {
  background-color: var(--color-secondary);
  color: var(--color-text-inverse);
  border-color: var(--color-secondary);
}

.btn-dark:hover:not(:disabled) {
  background-color: var(--color-secondary-hover);
  border-color: var(--color-secondary-hover);
}

.btn-dark:active:not(:disabled) {
  background-color: var(--color-secondary-active);
  border-color: var(--color-secondary-active);
}

/* ===== SECONDARY VARIANT ===== */
/* Outlined buttons for alternative actions */
.btn-secondary {
  background-color: var(--color-bg-primary);
  color: var(--color-gray-600);
  border-color: #e0e0e0;
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-bg-tertiary);
  border-color: #ccc;
  color: var(--color-text-primary);
}

.btn-secondary:active:not(:disabled) {
  background-color: var(--color-gray-200);
  border-color: var(--color-border-dark);
}

.btn-secondary:disabled {
  background-color: var(--color-bg-secondary);
  border-color: var(--color-border-light);
  color: var(--color-text-disabled);
  cursor: not-allowed;
}

/* ===== TERTIARY / GHOST VARIANT ===== */
/* Transparent background for subtle/icon actions */
.btn-tertiary {
  background-color: transparent;
  color: var(--color-gray-400);
  border-color: transparent;
  padding: var(--spacing-1);
}

.btn-tertiary:hover:not(:disabled) {
  background-color: var(--color-bg-tertiary);
  color: var(--color-gray-600);
}

.btn-tertiary:active:not(:disabled) {
  background-color: var(--color-gray-200);
  color: var(--color-text-primary);
}

.btn-tertiary:disabled {
  color: var(--color-text-disabled);
  cursor: not-allowed;
}

/* ===== SEMANTIC COLOR MODIFIERS ===== */
/* Apply these alongside .btn-primary for colored variants */

.btn-success {
  --_btn-bg: var(--color-success);
  --_btn-bg-hover: var(--color-success-hover);
  --_btn-light: var(--color-success-light);
  background-color: var(--_btn-bg);
  border-color: var(--_btn-bg);
  color: var(--color-text-inverse);
}
.btn-success:hover:not(:disabled) {
  background-color: var(--_btn-bg-hover);
  border-color: var(--_btn-bg-hover);
}

.btn-warning {
  --_btn-bg: var(--color-warning);
  --_btn-bg-hover: var(--color-warning-hover);
  --_btn-light: var(--color-warning-light);
  background-color: var(--_btn-bg);
  border-color: var(--_btn-bg);
  color: var(--color-text-inverse);
}
.btn-warning:hover:not(:disabled) {
  background-color: var(--_btn-bg-hover);
  border-color: var(--_btn-bg-hover);
}

.btn-danger {
  --_btn-bg: var(--color-error);
  --_btn-bg-hover: var(--color-error-hover);
  --_btn-light: var(--color-error-light);
  background-color: var(--_btn-bg);
  border-color: var(--_btn-bg);
  color: var(--color-text-inverse);
}
.btn-danger:hover:not(:disabled) {
  background-color: var(--_btn-bg-hover);
  border-color: var(--_btn-bg-hover);
}

.btn-info {
  --_btn-bg: var(--color-info);
  --_btn-bg-hover: var(--color-info-hover);
  --_btn-light: var(--color-info-light);
  background-color: var(--_btn-bg);
  border-color: var(--_btn-bg);
  color: var(--color-text-inverse);
}
.btn-info:hover:not(:disabled) {
  background-color: var(--_btn-bg-hover);
  border-color: var(--_btn-bg-hover);
}

/* ===== SIZE MODIFIERS ===== */

.btn-sm {
  padding: 6px 14px;
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: var(--spacing-4) var(--spacing-6);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
}

.btn-block {
  width: 100%;
}

/* ===== ICON BUTTON MODIFIERS ===== */

/* Button with icon + text */
.btn-icon {
  gap: var(--spacing-2);
}

.btn-icon svg {
  flex-shrink: 0;
}

/* Icon-only button (square/circle, no text) */
.btn-icon-only {
  padding: 0;
  border-radius: var(--radius-md);
  flex-shrink: 0;
}

.btn-icon-only.btn-xs {
  width: 20px;
  height: 20px;
}

.btn-icon-only.btn-sm {
  width: 32px;
  height: 32px;
  padding: 0;
}

.btn-icon-only.btn-md {
  width: 38px;
  height: 38px;
  padding: 0;
}

.btn-icon-only.btn-lg {
  width: 44px;
  height: 44px;
  padding: 0;
}

/* Round icon button (circle) */
.btn-round {
  border-radius: var(--radius-full);
}

/* ===== PILL SHAPE (explicit) ===== */
.btn-pill {
  border-radius: var(--radius-full);
}

/* ===== LOADING STATE ===== */

.btn-loading {
  position: relative;
  color: transparent !important;
  pointer-events: none;
}

.btn-loading::after {
  content: '';
  position: absolute;
  width: 1em;
  height: 1em;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: var(--radius-full);
  animation: btn-spin 600ms linear infinite;
}

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

/* ===== DISABLED STATE (all variants) ===== */
.btn:disabled,
.btn[disabled] {
  cursor: not-allowed;
}

/* ===== SPECIAL: Auth continue button ===== */
/* Full-width pill button that starts disabled and becomes active */
.btn-auth-continue {
  width: 100%;
  padding: 15px;
  border-radius: var(--radius-full);
  border: none;
  background: #d0d0d0;
  color: var(--color-text-inverse);
  font-size: 0.95rem;
  font-weight: var(--font-weight-semibold);
  font-family: var(--font-family-base);
  cursor: not-allowed;
  transition: background var(--transition-fast);
}

.btn-auth-continue.ready {
  background: var(--color-primary);
  cursor: pointer;
}

.btn-auth-continue.ready:hover {
  background: var(--color-primary-hover);
}