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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-4);
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  line-height: 1.5;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

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

.btn svg {
  width: 16px;
  height: 16px;
}

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

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

.btn--secondary {
  background-color: var(--color-white);
  color: var(--color-gray-700);
  border-color: var(--color-gray-300);
}

.btn--secondary:hover:not(:disabled) {
  background-color: var(--color-gray-50);
  border-color: var(--color-gray-400);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-gray-600);
}

.btn--ghost:hover:not(:disabled) {
  background-color: var(--color-gray-100);
  color: var(--color-gray-900);
}

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

.btn--danger:hover:not(:disabled) {
  background-color: #dc2626;
}

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

.btn--success:hover:not(:disabled) {
  background-color: #16a34a;
}

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

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

.btn--icon {
  padding: var(--spacing-2);
}

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

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

.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
}

.card__header {
  padding: var(--spacing-4) var(--spacing-5);
  border-bottom: 1px solid var(--color-gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card__title {
  margin: 0;
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
}

.card__body {
  padding: var(--spacing-5);
}

.card__footer {
  padding: var(--spacing-4) var(--spacing-5);
  border-top: 1px solid var(--color-gray-200);
  background-color: var(--color-gray-50);
  border-radius: 0 0 var(--radius-xl) var(--radius-xl);
}

/* Card Variants */
.card--interactive {
  cursor: pointer;
  transition: all var(--transition-fast);
}

.card--interactive:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.card--highlight {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

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

.form-group {
  margin-bottom: var(--spacing-4);
}

.form-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
  margin-bottom: var(--spacing-2);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-700);
}

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

/* Tooltip icon */
.tooltip-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  font-size: 11px;
  font-weight: var(--font-weight-bold);
  color: var(--color-gray-400);
  background: var(--color-gray-100);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-full);
  cursor: help;
  transition: all var(--transition-fast);
}

.tooltip-icon:hover {
  color: var(--color-gray-600);
  background: var(--color-gray-200);
  border-color: var(--color-gray-400);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--spacing-2) var(--spacing-3);
  font-family: inherit;
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--color-gray-900);
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
}

.form-input:hover,
.form-select:hover,
.form-textarea:hover {
  border-color: var(--color-gray-400);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.form-input:disabled,
.form-select:disabled,
.form-textarea:disabled {
  background-color: var(--color-gray-100);
  cursor: not-allowed;
}

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

.form-input--error:focus,
.form-select--error:focus,
.form-textarea--error:focus {
  box-shadow: 0 0 0 3px var(--color-error-light);
}

.form-textarea {
  min-height: 100px;
  resize: vertical;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--spacing-3) center;
  padding-right: var(--spacing-10);
}

.form-hint {
  margin-top: var(--spacing-1);
  font-size: var(--font-size-sm);
  color: var(--color-gray-500);
}

.form-error {
  margin-top: var(--spacing-1);
  font-size: var(--font-size-sm);
  color: var(--color-error);
}

/* Input with addon */
.input-group {
  display: flex;
}

.input-group .form-input {
  border-radius: var(--radius-lg) 0 0 var(--radius-lg);
}

.input-group__addon {
  display: flex;
  align-items: center;
  padding: var(--spacing-2) var(--spacing-3);
  font-size: var(--font-size-sm);
  color: var(--color-gray-600);
  background-color: var(--color-gray-100);
  border: 1px solid var(--color-gray-300);
  border-left: none;
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

/* Inline form */
.form-inline {
  display: flex;
  align-items: flex-end;
  gap: var(--spacing-4);
}

.form-inline .form-group {
  margin-bottom: 0;
}

/* Checkbox & Radio */
.form-check {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  cursor: pointer;
}

.form-check input[type="checkbox"],
.form-check input[type="radio"] {
  width: 18px;
  height: 18px;
  margin: 0;
  cursor: pointer;
  accent-color: var(--color-primary);
}

.form-check__label {
  font-size: var(--font-size-sm);
  color: var(--color-gray-700);
}

/* ==========================================================================
   Tables
   ========================================================================== */

.table-container {
  overflow-x: auto;
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

.table th,
.table td {
  padding: var(--spacing-3) var(--spacing-4);
  text-align: left;
  border-bottom: 1px solid var(--color-gray-200);
}

.table th {
  font-weight: var(--font-weight-semibold);
  color: var(--color-gray-600);
  background-color: var(--color-gray-50);
}

.table tbody tr:hover {
  background-color: var(--color-gray-50);
}

.table--striped tbody tr:nth-child(even) {
  background-color: var(--color-gray-50);
}

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

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

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

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

.badge--success {
  background-color: var(--color-success-light);
  color: #166534;
}

.badge--warning {
  background-color: var(--color-warning-light);
  color: #92400e;
}

.badge--error {
  background-color: var(--color-error-light);
  color: #dc2626;
}

/* ==========================================================================
   Progress Bar
   ========================================================================== */

.progress {
  height: 8px;
  background-color: var(--color-gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress__bar {
  height: 100%;
  background-color: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

.progress__bar--success {
  background-color: var(--color-success);
}

.progress__bar--warning {
  background-color: var(--color-warning);
}

.progress__bar--error {
  background-color: var(--color-error);
}

/* ==========================================================================
   Modal
   ========================================================================== */

.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: var(--z-modal-backdrop);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-4);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.modal-backdrop.open {
  opacity: 1;
  visibility: visible;
}

.modal {
  background-color: var(--color-white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  width: 100%;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transform: scale(0.95);
  transition: transform var(--transition-normal);
}

.modal-backdrop.open .modal {
  transform: scale(1);
}

.modal--lg {
  max-width: 700px;
}

.modal--xl {
  max-width: 900px;
}

.modal__header {
  padding: var(--spacing-4) var(--spacing-5);
  border-bottom: 1px solid var(--color-gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal__title {
  margin: 0;
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
}

.modal__close {
  padding: var(--spacing-1);
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-gray-400);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.modal__close:hover {
  background-color: var(--color-gray-100);
  color: var(--color-gray-600);
}

.modal__close svg {
  width: 20px;
  height: 20px;
}

.modal__body {
  padding: var(--spacing-5);
  overflow-y: auto;
  flex: 1;
}

.modal__footer {
  padding: var(--spacing-4) var(--spacing-5);
  border-top: 1px solid var(--color-gray-200);
  display: flex;
  justify-content: flex-end;
  gap: var(--spacing-3);
}

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

.toast-container {
  position: fixed;
  bottom: var(--spacing-6);
  right: var(--spacing-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.toast {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
  padding: var(--spacing-4);
  background-color: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  max-width: 400px;
  animation: slideIn var(--transition-normal) ease;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.toast__icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}

.toast__icon--success { color: var(--color-success); }
.toast__icon--error { color: var(--color-error); }
.toast__icon--warning { color: var(--color-warning); }
.toast__icon--info { color: var(--color-info); }

.toast__content {
  flex: 1;
}

.toast__title {
  font-weight: var(--font-weight-semibold);
  color: var(--color-gray-900);
  margin-bottom: var(--spacing-1);
}

.toast__message {
  font-size: var(--font-size-sm);
  color: var(--color-gray-600);
}

.toast__close {
  flex-shrink: 0;
  padding: var(--spacing-1);
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-gray-400);
}

.toast__close:hover {
  color: var(--color-gray-600);
}

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

.stat-card {
  padding: var(--spacing-5);
}

.stat-card__label {
  font-size: var(--font-size-sm);
  color: var(--color-gray-500);
  margin-bottom: var(--spacing-1);
}

.stat-card__value {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-gray-900);
}

.stat-card__change {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-1);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-2);
}

.stat-card__change--positive {
  color: var(--color-success);
}

.stat-card__change--negative {
  color: var(--color-error);
}

/* ==========================================================================
   Empty State
   ========================================================================== */

.empty-state {
  text-align: center;
  padding: var(--spacing-12) var(--spacing-6);
}

.empty-state__icon {
  width: 64px;
  height: 64px;
  color: var(--color-gray-300);
  margin-bottom: var(--spacing-4);
}

.empty-state__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-gray-900);
  margin-bottom: var(--spacing-2);
}

.empty-state__description {
  color: var(--color-gray-500);
  margin-bottom: var(--spacing-6);
}

/* ==========================================================================
   File Upload / Drop Zone
   ========================================================================== */

.dropzone {
  border: 2px dashed var(--color-gray-300);
  border-radius: var(--radius-xl);
  padding: var(--spacing-8);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.dropzone:hover {
  border-color: var(--color-primary);
  background-color: var(--color-primary-light);
}

.dropzone.dragover {
  border-color: var(--color-primary);
  background-color: var(--color-primary-light);
}

.dropzone__icon {
  width: 48px;
  height: 48px;
  color: var(--color-gray-400);
  margin-bottom: var(--spacing-4);
}

.dropzone__text {
  color: var(--color-gray-600);
  margin-bottom: var(--spacing-2);
}

.dropzone__hint {
  font-size: var(--font-size-sm);
  color: var(--color-gray-400);
}

/* ==========================================================================
   Cost Breakdown
   ========================================================================== */

.cost-breakdown {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.cost-breakdown__row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-2) 0;
}

.cost-breakdown__label {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  color: var(--color-gray-600);
}

.cost-breakdown__dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
}

.cost-breakdown__value {
  font-weight: var(--font-weight-medium);
  font-family: var(--font-family-mono);
}

.cost-breakdown__divider {
  border-top: 1px solid var(--color-gray-200);
  margin: var(--spacing-2) 0;
}

.cost-breakdown__total {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
}

.cost-breakdown__total .cost-breakdown__value {
  font-size: var(--font-size-xl);
  color: var(--color-primary);
}

.cost-breakdown__row--indent {
  padding-left: var(--spacing-6);
  font-size: var(--font-size-sm);
}

.cost-breakdown__row--indent .cost-breakdown__dot {
  width: 8px;
  height: 8px;
}

.cost-breakdown__profit {
  font-weight: var(--font-weight-semibold);
}

.cost-breakdown__profit--positive .cost-breakdown__value {
  color: var(--color-success);
}

.cost-breakdown__profit--negative .cost-breakdown__value {
  color: var(--color-error);
}

/* ==========================================================================
   Color Swatch
   ========================================================================== */

.color-swatch {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-white);
  box-shadow: 0 0 0 1px var(--color-gray-200);
}

.color-swatch--lg {
  width: 32px;
  height: 32px;
}

/* ==========================================================================
   Alert
   ========================================================================== */

.alert {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
  padding: var(--spacing-4);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-sm);
}

.alert__icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}

.alert--info {
  background-color: var(--color-info-light);
  color: var(--color-primary);
}

.alert--success {
  background-color: var(--color-success-light);
  color: #166534;
}

.alert--warning {
  background-color: var(--color-warning-light);
  color: #92400e;
}

.alert--error {
  background-color: var(--color-error-light);
  color: #dc2626;
}

/* ==========================================================================
   Tabs (within card/section)
   ========================================================================== */

.tabs {
  display: flex;
  gap: var(--spacing-1);
  border-bottom: 1px solid var(--color-gray-200);
  margin-bottom: var(--spacing-4);
}

.tab {
  padding: var(--spacing-2) var(--spacing-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-500);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tab:hover {
  color: var(--color-gray-700);
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

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

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid var(--color-gray-200);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.spinner--sm {
  width: 16px;
  height: 16px;
  border-width: 2px;
}

.spinner--lg {
  width: 40px;
  height: 40px;
  border-width: 4px;
}