/**
 * Modern UI Components
 * Includes: Buttons, Cards, Dropdowns, Modals, Forms, Toast Notifications
 */

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font-sans);
  font-weight: var(--font-weight-medium);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-tight);
  border-radius: var(--radius-lg);
  border: 1px solid transparent;
  padding: var(--space-2) var(--space-4);
  cursor: pointer;
  transition: all var(--transition-base);
  white-space: nowrap;
  user-select: none;
  text-decoration: none;
}

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

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Button Variants */
.btn-primary {
  background-color: var(--color-primary-600);
  color: var(--color-white);
  border-color: var(--color-primary-600);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-700);
  border-color: var(--color-primary-700);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  border-color: var(--border-primary);
}

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

.btn-success {
  background-color: var(--color-success-600);
  color: var(--color-white);
  border-color: var(--color-success-600);
}

.btn-success:hover:not(:disabled) {
  background-color: var(--color-success-700);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-danger {
  background-color: var(--color-error-600);
  color: var(--color-white);
  border-color: var(--color-error-600);
}

.btn-danger:hover:not(:disabled) {
  background-color: var(--color-error-700);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.btn-ghost:hover:not(:disabled) {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

/* Button Sizes */
.btn-sm {
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: var(--space-3) var(--space-6);
  font-size: var(--font-size-base);
}

.btn-icon {
  padding: var(--space-2);
  aspect-ratio: 1;
}

/* ============================================
   Cards
   ============================================ */

.card {
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: all var(--transition-base);
}

.card-hover:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-secondary);
}

.card-header {
  padding: var(--space-6);
  border-bottom: 1px solid var(--border-primary);
}

.card-body {
  padding: var(--space-6);
}

.card-footer {
  padding: var(--space-6);
  border-top: 1px solid var(--border-primary);
  background-color: var(--bg-secondary);
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.card-description {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

/* ============================================
   Dropdowns
   ============================================ */

.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-trigger {
  cursor: pointer;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  z-index: var(--z-dropdown);
  min-width: 12rem;
  margin-top: var(--space-2);
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--space-2);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px) scale(0.95);
  transition: all var(--transition-fast);
}

.dropdown-menu.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
  color: var(--text-primary);
  text-align: left;
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.dropdown-item:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.dropdown-divider {
  height: 1px;
  margin: var(--space-2) 0;
  background-color: var(--border-primary);
}

/* ============================================
   Modals
   ============================================ */

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal-backdrop);
  background-color: var(--bg-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.modal-overlay.show {
  opacity: 1;
  visibility: visible;
}

.modal {
  position: relative;
  z-index: var(--z-modal);
  width: 100%;
  max-width: 32rem;
  max-height: 90vh;
  background-color: var(--bg-elevated);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-2xl);
  transform: scale(0.95) translateY(20px);
  transition: all var(--transition-base);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.modal-overlay.show .modal {
  transform: scale(1) translateY(0);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-6);
  border-bottom: 1px solid var(--border-primary);
}

.modal-title {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
}

.modal-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  padding: 0;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.modal-close:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.modal-body {
  flex: 1;
  padding: var(--space-6);
  overflow-y: auto;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-3);
  padding: var(--space-6);
  border-top: 1px solid var(--border-primary);
  background-color: var(--bg-secondary);
}

/* ============================================
   Forms
   ============================================ */

.form-group {
  margin-bottom: var(--space-6);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
}

.form-label-required::after {
  content: " *";
  color: var(--color-error-500);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--text-primary);
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-tertiary);
}

.form-textarea {
  resize: vertical;
  min-height: 6rem;
}

.form-error {
  margin-top: var(--space-2);
  font-size: var(--font-size-xs);
  color: var(--color-error-600);
}

.form-hint {
  margin-top: var(--space-2);
  font-size: var(--font-size-xs);
  color: var(--text-tertiary);
}

.form-input.error,
.form-textarea.error,
.form-select.error {
  border-color: var(--color-error-500);
}

.form-input.error:focus,
.form-textarea.error:focus,
.form-select.error:focus {
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

/* Checkbox and Radio */
.form-checkbox,
.form-radio {
  width: 1rem;
  height: 1rem;
  color: var(--color-primary-600);
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.form-radio {
  border-radius: var(--radius-full);
}

.form-checkbox:checked,
.form-radio:checked {
  background-color: var(--color-primary-600);
  border-color: var(--color-primary-600);
}

/* ============================================
   Toast Notifications
   ============================================ */

.toast-container {
  position: fixed;
  z-index: var(--z-toast);
  top: var(--space-4);
  right: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 24rem;
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4);
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  pointer-events: auto;
  transform: translateX(calc(100% + var(--space-4)));
  opacity: 0;
  transition: all var(--transition-base);
}

.toast.show {
  transform: translateX(0);
  opacity: 1;
}

.toast-icon {
  flex-shrink: 0;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
}

.toast-success .toast-icon {
  background-color: var(--color-success-100);
  color: var(--color-success-700);
}

.toast-error .toast-icon {
  background-color: var(--color-error-100);
  color: var(--color-error-700);
}

.toast-warning .toast-icon {
  background-color: var(--color-warning-100);
  color: var(--color-warning-700);
}

.toast-info .toast-icon {
  background-color: var(--color-info-100);
  color: var(--color-info-700);
}

.toast-content {
  flex: 1;
  min-width: 0;
}

.toast-title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}

.toast-message {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  line-height: var(--line-height-normal);
}

.toast-close {
  flex-shrink: 0;
  width: 1.25rem;
  height: 1.25rem;
  padding: 0;
  color: var(--text-tertiary);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.toast-close:hover {
  color: var(--text-primary);
  background-color: var(--bg-tertiary);
}

/* ============================================
   Badges
   ============================================ */

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-1) var(--space-2);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.badge-primary {
  background-color: var(--color-primary-100);
  color: var(--color-primary-700);
}

.badge-success {
  background-color: var(--color-success-100);
  color: var(--color-success-700);
}

.badge-warning {
  background-color: var(--color-warning-100);
  color: var(--color-warning-700);
}

.badge-error {
  background-color: var(--color-error-100);
  color: var(--color-error-700);
}

.badge-secondary {
  background-color: var(--color-gray-100);
  color: var(--color-gray-700);
}

[data-theme="dark"] .badge-primary {
  background-color: var(--color-primary-900);
  color: var(--color-primary-200);
}

[data-theme="dark"] .badge-success {
  background-color: var(--color-success-900);
  color: var(--color-success-200);
}

[data-theme="dark"] .badge-warning {
  background-color: var(--color-warning-900);
  color: var(--color-warning-200);
}

[data-theme="dark"] .badge-error {
  background-color: var(--color-error-900);
  color: var(--color-error-200);
}

/* ============================================
   Avatar
   ============================================ */

.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background-color: var(--color-primary-600);
  color: var(--color-white);
  font-weight: var(--font-weight-medium);
  overflow: hidden;
}

.avatar-sm {
  width: 2rem;
  height: 2rem;
  font-size: var(--font-size-xs);
}

.avatar-md {
  width: 2.5rem;
  height: 2.5rem;
  font-size: var(--font-size-sm);
}

.avatar-lg {
  width: 3rem;
  height: 3rem;
  font-size: var(--font-size-base);
}

.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ============================================
   Loading Spinner
   ============================================ */

.spinner {
  display: inline-block;
  width: 1.5rem;
  height: 1.5rem;
  border: 2px solid var(--border-primary);
  border-top-color: var(--color-primary-600);
  border-radius: var(--radius-full);
  animation: spin 0.6s linear infinite;
}

.spinner-sm {
  width: 1rem;
  height: 1rem;
  border-width: 1.5px;
}

.spinner-lg {
  width: 2rem;
  height: 2rem;
  border-width: 3px;
}

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

/* ============================================
   Skeleton Loader
   ============================================ */

.skeleton {
  background: linear-gradient(
    90deg,
    var(--bg-tertiary) 0%,
    var(--bg-secondary) 50%,
    var(--bg-tertiary) 100%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

.skeleton-text {
  height: 1rem;
  margin-bottom: var(--space-2);
}

.skeleton-title {
  height: 1.5rem;
  margin-bottom: var(--space-3);
}

.skeleton-avatar {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-full);
}

@keyframes skeleton-loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}