/**
 * Nucleora Component Styles
 * Base component library for CAD-style interface
 */

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-sans);
  font-size: var(--font-sm);
  font-weight: var(--font-medium);
  line-height: var(--leading-tight);
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  transition: var(--transition-colors), var(--transition-shadow);
  outline: none;
}

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

/* Button Sizes */
.btn-xs {
  padding: var(--space-1) var(--space-2);
  font-size: var(--font-xs);
  gap: var(--space-1);
}

.btn-sm {
  padding: var(--space-1-5) var(--space-2-5);
  font-size: var(--font-xs);
}

.btn-lg {
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-base);
}

.btn-xl {
  padding: var(--space-3-5) var(--space-5);
  font-size: var(--font-md);
}

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

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

.btn-primary:active {
  background-color: var(--nucleora-primary-active);
  border-color: var(--nucleora-primary-active);
}

/* Secondary Button */
.btn-secondary {
  background-color: var(--nucleora-bg-surface);
  color: var(--nucleora-text-primary);
  border-color: var(--nucleora-border-default);
}

.btn-secondary:hover {
  background-color: var(--nucleora-bg-hover);
  border-color: var(--nucleora-border-strong);
}

.btn-secondary:active {
  background-color: var(--nucleora-bg-active);
}

/* Ghost Button */
.btn-ghost {
  background-color: transparent;
  color: var(--nucleora-text-secondary);
  border-color: transparent;
}

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

.btn-ghost:active {
  background-color: var(--nucleora-bg-active);
}

/* Outline Button */
.btn-outline {
  background-color: transparent;
  color: var(--nucleora-primary);
  border-color: var(--nucleora-primary);
}

.btn-outline:hover {
  background-color: var(--nucleora-primary-muted);
}

.btn-outline:active {
  background-color: var(--nucleora-primary-subtle);
}

/* Danger Button */
.btn-danger {
  background-color: var(--nucleora-error);
  color: white;
  border-color: var(--nucleora-error);
}

.btn-danger:hover {
  background-color: #dc2626;
  border-color: #dc2626;
}

/* Success Button */
.btn-success {
  background-color: var(--nucleora-success);
  color: white;
  border-color: var(--nucleora-success);
}

.btn-success:hover {
  background-color: #16a34a;
  border-color: #16a34a;
}

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

.btn-icon.btn-xs {
  padding: var(--space-1);
}

.btn-icon.btn-sm {
  padding: var(--space-1-5);
}

.btn-icon.btn-lg {
  padding: var(--space-3);
}

/* Button Group */
.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:not(:last-child) {
  border-right-width: 0;
}

.btn-group .btn:hover,
.btn-group .btn:focus {
  z-index: 1;
}

/* ============================================
   INPUTS
   ============================================ */

.input {
  display: block;
  width: 100%;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-sans);
  font-size: var(--font-sm);
  line-height: var(--leading-normal);
  color: var(--nucleora-text-primary);
  background-color: var(--nucleora-bg-dark);
  border: 1px solid var(--nucleora-border-default);
  border-radius: var(--radius-md);
  transition: var(--transition-colors), var(--transition-shadow);
  outline: none;
}

.input::placeholder {
  color: var(--nucleora-text-muted);
}

.input:hover {
  border-color: var(--nucleora-border-strong);
}

.input:focus {
  border-color: var(--nucleora-primary);
  box-shadow: 0 0 0 3px var(--nucleora-primary-muted);
}

.input:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  background-color: var(--nucleora-bg-surface);
}

/* Input Sizes */
.input-xs {
  padding: var(--space-1) var(--space-2);
  font-size: var(--font-xs);
}

.input-sm {
  padding: var(--space-1-5) var(--space-2-5);
  font-size: var(--font-xs);
}

.input-lg {
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-base);
}

/* Input States */
.input-error {
  border-color: var(--nucleora-error);
}

.input-error:focus {
  box-shadow: 0 0 0 3px var(--nucleora-error-bg);
}

.input-success {
  border-color: var(--nucleora-success);
}

.input-success:focus {
  box-shadow: 0 0 0 3px var(--nucleora-success-bg);
}

/* Input with Icon */
.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.input-wrapper .input {
  padding-left: var(--space-9);
}

.input-wrapper .input-icon {
  position: absolute;
  left: var(--space-3);
  color: var(--nucleora-text-tertiary);
  pointer-events: none;
}

.input-wrapper .input-icon-right {
  left: auto;
  right: var(--space-3);
}

.input-wrapper .input:has(~ .input-icon-right) {
  padding-right: var(--space-9);
}

/* Textarea */
.textarea {
  min-height: 80px;
  resize: vertical;
}

/* Select */
.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='%2371717a' 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(--space-3) center;
  padding-right: var(--space-9);
}

/* Checkbox & Radio */
.checkbox,
.radio {
  appearance: none;
  width: 16px;
  height: 16px;
  background-color: var(--nucleora-bg-dark);
  border: 1px solid var(--nucleora-border-default);
  cursor: pointer;
  transition: var(--transition-colors);
  flex-shrink: 0;
}

.checkbox {
  border-radius: var(--radius-sm);
}

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

.checkbox:hover,
.radio:hover {
  border-color: var(--nucleora-border-strong);
}

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

.checkbox:checked {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
}

.radio:checked {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='8' height='8' viewBox='0 0 8 8'%3E%3Ccircle cx='4' cy='4' r='4' fill='white'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
}

/* Toggle Switch */
.toggle {
  appearance: none;
  width: 36px;
  height: 20px;
  background-color: var(--nucleora-bg-hover);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition-colors);
  position: relative;
}

.toggle::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  background-color: white;
  border-radius: var(--radius-full);
  transition: var(--transition-transform);
}

.toggle:checked {
  background-color: var(--nucleora-primary);
}

.toggle:checked::before {
  transform: translateX(16px);
}

/* ============================================
   CARDS
   ============================================ */

.card {
  background-color: var(--nucleora-bg-elevated);
  border: 1px solid var(--nucleora-border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--nucleora-border-subtle);
}

.card-header-title {
  font-size: var(--font-sm);
  font-weight: var(--font-semibold);
  color: var(--nucleora-text-primary);
}

.card-body {
  padding: var(--space-4);
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-top: 1px solid var(--nucleora-border-subtle);
  background-color: var(--nucleora-bg-surface);
}

/* Card Variants */
.card-interactive {
  cursor: pointer;
  transition: var(--transition-colors), var(--transition-shadow);
}

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

.card-compact .card-header,
.card-compact .card-body,
.card-compact .card-footer {
  padding: var(--space-2) var(--space-3);
}

/* ============================================
   BADGES
   ============================================ */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-0-5) var(--space-2);
  font-size: var(--font-xs);
  font-weight: var(--font-medium);
  line-height: var(--leading-normal);
  border-radius: var(--radius-full);
  white-space: nowrap;
}

/* Badge Variants */
.badge-default {
  background-color: var(--nucleora-bg-hover);
  color: var(--nucleora-text-secondary);
}

.badge-primary {
  background-color: var(--nucleora-primary-muted);
  color: var(--nucleora-primary-hover);
}

.badge-success {
  background-color: var(--nucleora-success-bg);
  color: var(--nucleora-success);
}

.badge-warning {
  background-color: var(--nucleora-warning-bg);
  color: var(--nucleora-warning);
}

.badge-error {
  background-color: var(--nucleora-error-bg);
  color: var(--nucleora-error);
}

.badge-info {
  background-color: var(--nucleora-info-bg);
  color: var(--nucleora-info);
}

/* Badge with dot */
.badge-dot::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background-color: currentColor;
}

/* Badge Sizes */
.badge-sm {
  padding: var(--space-0-5) var(--space-1-5);
  font-size: var(--font-2xs);
}

.badge-lg {
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-sm);
}

/* DNA Base Badges */
.badge-base-a {
  background-color: rgba(34, 197, 94, 0.15);
  color: var(--nucleora-base-a);
}

.badge-base-t {
  background-color: rgba(239, 68, 68, 0.15);
  color: var(--nucleora-base-t);
}

.badge-base-g {
  background-color: rgba(245, 158, 11, 0.15);
  color: var(--nucleora-base-g);
}

.badge-base-c {
  background-color: rgba(59, 130, 246, 0.15);
  color: var(--nucleora-base-c);
}

.badge-base-u {
  background-color: rgba(168, 85, 247, 0.15);
  color: var(--nucleora-base-u);
}

/* ============================================
   TABLES
   ============================================ */

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

.table th,
.table td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 1px solid var(--nucleora-border-subtle);
}

.table th {
  font-weight: var(--font-semibold);
  color: var(--nucleora-text-secondary);
  background-color: var(--nucleora-bg-surface);
  white-space: nowrap;
}

.table td {
  color: var(--nucleora-text-primary);
}

/* Striped Table */
.table-striped tbody tr:nth-child(odd) {
  background-color: var(--nucleora-bg-dark);
}

/* Hover Table */
.table-hover tbody tr {
  transition: var(--transition-colors);
}

.table-hover tbody tr:hover {
  background-color: var(--nucleora-bg-hover);
}

/* Compact Table */
.table-compact th,
.table-compact td {
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-xs);
}

/* Bordered Table */
.table-bordered th,
.table-bordered td {
  border: 1px solid var(--nucleora-border-subtle);
}

/* Fixed Layout */
.table-fixed {
  table-layout: fixed;
}

/* Sortable Headers */
.table th.sortable {
  cursor: pointer;
  user-select: none;
}

.table th.sortable:hover {
  color: var(--nucleora-text-primary);
}

.table th.sortable::after {
  content: '';
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: var(--space-2);
  vertical-align: middle;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 4px solid currentColor;
  opacity: 0.3;
}

.table th.sort-asc::after {
  border-top: none;
  border-bottom: 4px solid currentColor;
  opacity: 1;
}

.table th.sort-desc::after {
  opacity: 1;
}

/* ============================================
   TABS
   ============================================ */

.tabs {
  display: flex;
  border-bottom: 1px solid var(--nucleora-border-subtle);
}

.tab {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-sm);
  font-weight: var(--font-medium);
  color: var(--nucleora-text-tertiary);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: var(--transition-colors);
  margin-bottom: -1px;
}

.tab:hover {
  color: var(--nucleora-text-secondary);
}

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

.tab-content {
  display: none;
  padding: var(--space-4);
}

.tab-content.active {
  display: block;
}

/* Pill Tabs */
.tabs-pills {
  border-bottom: none;
  gap: var(--space-1);
  background-color: var(--nucleora-bg-dark);
  padding: var(--space-1);
  border-radius: var(--radius-md);
}

.tabs-pills .tab {
  border-bottom: none;
  border-radius: var(--radius-sm);
  margin-bottom: 0;
}

.tabs-pills .tab.active {
  background-color: var(--nucleora-bg-surface);
  color: var(--nucleora-text-primary);
}

/* ============================================
   TOOLTIPS
   ============================================ */

[data-tooltip] {
  position: relative;
}

[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-1-5) var(--space-2-5);
  font-size: var(--font-xs);
  font-weight: var(--font-normal);
  color: var(--nucleora-text-primary);
  background-color: var(--nucleora-bg-overlay);
  border: 1px solid var(--nucleora-border-default);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: var(--transition-opacity);
  z-index: var(--z-tooltip);
}

[data-tooltip]:hover::after {
  opacity: 1;
  visibility: visible;
}

/* ============================================
   DROPDOWNS
   ============================================ */

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

.dropdown-menu {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  min-width: 180px;
  padding: var(--space-1);
  background-color: var(--nucleora-bg-elevated);
  border: 1px solid var(--nucleora-border-default);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-dropdown);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: var(--transition-opacity), var(--transition-transform);
  z-index: var(--z-dropdown);
}

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

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-sm);
  color: var(--nucleora-text-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition-colors);
}

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

.dropdown-item.active {
  background-color: var(--nucleora-primary-muted);
  color: var(--nucleora-primary);
}

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

/* ============================================
   MODALS
   ============================================ */

.modal-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-opacity);
  z-index: var(--z-modal);
}

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

.modal {
  width: 100%;
  max-width: 480px;
  max-height: 90vh;
  background-color: var(--nucleora-bg-elevated);
  border: 1px solid var(--nucleora-border-default);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-modal);
  display: flex;
  flex-direction: column;
  transform: scale(0.95);
  transition: var(--transition-transform);
}

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

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4);
  border-bottom: 1px solid var(--nucleora-border-subtle);
}

.modal-title {
  font-size: var(--font-md);
  font-weight: var(--font-semibold);
}

.modal-close {
  padding: var(--space-1);
  color: var(--nucleora-text-tertiary);
  background: none;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition-colors);
}

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

.modal-body {
  padding: var(--space-4);
  overflow-y: auto;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-2);
  padding: var(--space-4);
  border-top: 1px solid var(--nucleora-border-subtle);
}

/* Modal Sizes */
.modal-sm {
  max-width: 360px;
}

.modal-lg {
  max-width: 640px;
}

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

.modal-full {
  max-width: calc(100vw - 40px);
  max-height: calc(100vh - 40px);
}

/* ============================================
   PROGRESS INDICATORS
   ============================================ */

.progress {
  height: 4px;
  background-color: var(--nucleora-bg-hover);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background-color: var(--nucleora-primary);
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
}

.progress-bar-success {
  background-color: var(--nucleora-success);
}

.progress-bar-warning {
  background-color: var(--nucleora-warning);
}

.progress-bar-error {
  background-color: var(--nucleora-error);
}

/* Spinner */
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--nucleora-bg-hover);
  border-top-color: var(--nucleora-primary);
  border-radius: var(--radius-full);
  animation: spin 0.8s linear infinite;
}

.spinner-sm {
  width: 14px;
  height: 14px;
  border-width: 1.5px;
}

.spinner-lg {
  width: 32px;
  height: 32px;
  border-width: 3px;
}

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

/* ============================================
   ALERTS / NOTICES
   ============================================ */

.alert {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  border: 1px solid;
}

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

.alert-content {
  flex: 1;
}

.alert-title {
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-1);
}

.alert-message {
  font-size: var(--font-sm);
  color: inherit;
  opacity: 0.9;
}

.alert-info {
  background-color: var(--nucleora-info-bg);
  border-color: var(--nucleora-info-border);
  color: var(--nucleora-info);
}

.alert-success {
  background-color: var(--nucleora-success-bg);
  border-color: var(--nucleora-success-border);
  color: var(--nucleora-success);
}

.alert-warning {
  background-color: var(--nucleora-warning-bg);
  border-color: var(--nucleora-warning-border);
  color: var(--nucleora-warning);
}

.alert-error {
  background-color: var(--nucleora-error-bg);
  border-color: var(--nucleora-error-border);
  color: var(--nucleora-error);
}

/* ============================================
   TOASTS
   ============================================ */

.toast-container {
  position: fixed;
  bottom: var(--space-4);
  right: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  z-index: var(--z-toast);
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  min-width: 280px;
  max-width: 400px;
  background-color: var(--nucleora-bg-overlay);
  border: 1px solid var(--nucleora-border-default);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  animation: slideIn var(--duration-moderate) var(--ease-out);
}

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

/* ============================================
   LABELS & FORM GROUPS
   ============================================ */

.label {
  display: block;
  font-size: var(--font-xs);
  font-weight: var(--font-medium);
  color: var(--nucleora-text-secondary);
  margin-bottom: var(--space-1-5);
}

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

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

.form-hint {
  font-size: var(--font-xs);
  color: var(--nucleora-text-tertiary);
  margin-top: var(--space-1);
}

.form-error {
  font-size: var(--font-xs);
  color: var(--nucleora-error);
  margin-top: var(--space-1);
}

/* ============================================
   AVATARS
   ============================================ */

.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background-color: var(--nucleora-primary-muted);
  color: var(--nucleora-primary);
  font-weight: var(--font-semibold);
  font-size: var(--font-sm);
  overflow: hidden;
}

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

.avatar-xs {
  width: 20px;
  height: 20px;
  font-size: var(--font-2xs);
}

.avatar-sm {
  width: 24px;
  height: 24px;
  font-size: var(--font-xs);
}

.avatar-lg {
  width: 40px;
  height: 40px;
  font-size: var(--font-base);
}

.avatar-xl {
  width: 56px;
  height: 56px;
  font-size: var(--font-lg);
}

/* Avatar Group */
.avatar-group {
  display: flex;
}

.avatar-group .avatar {
  border: 2px solid var(--nucleora-bg-base);
  margin-left: -8px;
}

.avatar-group .avatar:first-child {
  margin-left: 0;
}

/* ============================================
   DIVIDERS
   ============================================ */

.divider {
  height: 1px;
  background-color: var(--nucleora-border-subtle);
  margin: var(--space-4) 0;
}

.divider-vertical {
  width: 1px;
  height: auto;
  align-self: stretch;
  margin: 0 var(--space-4);
}

.divider-text {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--nucleora-text-tertiary);
  font-size: var(--font-xs);
}

.divider-text::before,
.divider-text::after {
  content: '';
  flex: 1;
  height: 1px;
  background-color: var(--nucleora-border-subtle);
}

/* ============================================
   SKELETON LOADERS
   ============================================ */

.skeleton {
  background: linear-gradient(
    90deg,
    var(--nucleora-bg-surface) 25%,
    var(--nucleora-bg-hover) 50%,
    var(--nucleora-bg-surface) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-md);
}

.skeleton-text {
  height: 1em;
  margin-bottom: 0.5em;
}

.skeleton-circle {
  border-radius: var(--radius-full);
}

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

/* ============================================
   CODE & MONOSPACE
   ============================================ */

.code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: var(--space-0-5) var(--space-1-5);
  background-color: var(--nucleora-bg-surface);
  border-radius: var(--radius-sm);
}

.code-block {
  display: block;
  padding: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--font-sm);
  line-height: var(--leading-relaxed);
  background-color: var(--nucleora-bg-dark);
  border: 1px solid var(--nucleora-border-subtle);
  border-radius: var(--radius-lg);
  overflow-x: auto;
}

/* DNA Sequence Display */
.sequence {
  font-family: var(--font-mono);
  font-size: var(--font-sm);
  letter-spacing: 0.05em;
  line-height: var(--leading-loose);
}

.sequence .base-a { color: var(--nucleora-base-a); }
.sequence .base-t { color: var(--nucleora-base-t); }
.sequence .base-g { color: var(--nucleora-base-g); }
.sequence .base-c { color: var(--nucleora-base-c); }
.sequence .base-u { color: var(--nucleora-base-u); }

/* ==========================================================================
   Virtual List / DOM Optimization Styles
   ========================================================================== */

/* Virtual list container */
.vlist-container {
  position: relative;
  overflow-y: auto;
  overflow-x: hidden;
  will-change: scroll-position;
  contain: strict;
}

.vlist-content {
  position: relative;
  width: 100%;
}

.vlist-content > * {
  box-sizing: border-box;
}

/* Optimized table rendering */
.optimized-table {
  table-layout: fixed;
  will-change: contents;
}

.optimized-table tbody {
  contain: layout style;
}

/* Paint containment for frequently updated elements */
.paint-contain {
  contain: paint;
}

.layout-contain {
  contain: layout;
}

.strict-contain {
  contain: strict;
}

/* GPU-accelerated transforms for animations */
.gpu-accelerate {
  transform: translateZ(0);
  backface-visibility: hidden;
  perspective: 1000px;
}

/* Reduce motion for accessibility */
@media (prefers-reduced-motion: reduce) {
  .vlist-content > *,
  .activity-feed-item,
  .search-result-item {
    transition: none !important;
    animation: none !important;
  }
}

/* Activity feed animations */
.activity-feed-item {
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.activity-feed-item.entering {
  opacity: 0;
  transform: translateY(-10px);
}

.activity-feed-item.entered {
  opacity: 1;
  transform: translateY(0);
}

/* Search results optimization */
.search-results-virtual {
  position: relative;
  overflow-y: auto;
  will-change: scroll-position;
}

.search-result-item {
  transition: background-color 0.15s ease;
}

/* Skeleton loading for chunked table rendering */
.table-loading-skeleton {
  height: 40px;
  background: linear-gradient(
    90deg,
    var(--nucleora-bg-subtle) 25%,
    var(--nucleora-bg-surface) 50%,
    var(--nucleora-bg-subtle) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s infinite;
}

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

/* Scroll performance hints */
.scroll-optimized {
  -webkit-overflow-scrolling: touch;
  scroll-behavior: auto;
  overscroll-behavior: contain;
}

/* Content visibility for off-screen elements */
@supports (content-visibility: auto) {
  .lazy-render {
    content-visibility: auto;
    contain-intrinsic-size: auto 200px;
  }
}