/* Workbench (lab) */
.page-lab header.lab-header {
  padding: 1.25rem 1.25rem 1.4rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
  text-align: center;
}

.page-lab .lab-header__intro {
  width: 100%;
  max-width: 48rem;
  margin: 0 auto;
}

.page-lab .lab-header__title {
  margin: 0 auto 0.5rem;
  max-width: 42rem;
  font-size: clamp(1.2rem, 2.4vw, 1.65rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.28;
  letter-spacing: -0.02em;
}

.page-lab .lab-header__subtitle {
  margin: 0 auto;
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.55;
  max-width: 42rem;
}

.page-lab .layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  max-width: 1400px;
  margin: 0 auto;
}

@media (min-width: 960px) {
  .page-lab .layout {
    grid-template-columns: 1fr 340px;
  }
}

.page-lab .panel {
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.25rem;
}

.page-lab .panel h2 {
  margin: 0 0 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.page-lab .regex-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.page-lab .regex-row label {
  font-size: 0.8rem;
  color: var(--muted);
}

.page-lab #pattern {
  flex: 1;
  min-width: 200px;
  font-family: var(--mono);
  font-size: 0.95rem;
  padding: 0.5rem 0.65rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
}

.page-lab #pattern:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-dim);
}

.page-lab .flags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.75rem;
  align-items: center;
}

.page-lab .flags span {
  font-size: 0.75rem;
  color: var(--muted);
  margin-right: 0.25rem;
}

.page-lab .flags label {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.8rem;
  cursor: pointer;
  user-select: none;
}

.page-lab textarea,
.page-lab input[type="text"] {
  width: 100%;
  font-family: var(--mono);
  font-size: 0.9rem;
  padding: 0.65rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  resize: vertical;
  min-height: 120px;
}

.page-lab textarea:focus,
.page-lab input[type="text"]:focus {
  outline: none;
  border-color: var(--accent);
}

.page-lab .tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  margin-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.page-lab .tabs button {
  background: transparent;
  border: 1px solid transparent;
  color: var(--muted);
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.85rem;
  font-family: inherit;
}

.page-lab .tabs button:hover {
  color: var(--text);
  background: var(--surface-hover);
}

.page-lab .tabs button.active {
  color: var(--accent);
  border-color: var(--border);
  background: var(--surface);
}

.page-lab .tab-panel {
  display: none;
}

.page-lab .tab-panel.active {
  display: block;
}

.page-lab .msg {
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}

.page-lab .msg.err {
  background: #f8514922;
  border: 1px solid #f8514966;
  color: #ff7b72;
}

.page-lab .msg.ok {
  background: #3fb95022;
  border: 1px solid #3fb95044;
  color: var(--ok);
}

.page-lab .highlight-box {
  font-family: var(--mono);
  font-size: 0.88rem;
  padding: 0.75rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  white-space: pre-wrap;
  word-break: break-word;
  min-height: 80px;
  max-height: 280px;
  overflow: auto;
}

.page-lab .highlight-box mark {
  background: var(--mark-bg);
  color: var(--text);
  padding: 0 2px;
  border-radius: 2px;
}

.page-lab table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
  margin-top: 0.5rem;
}

.page-lab th,
.page-lab td {
  border: 1px solid var(--border);
  padding: 0.35rem 0.5rem;
  text-align: left;
  vertical-align: top;
}

.page-lab th {
  background: var(--surface);
  color: var(--muted);
  font-weight: 600;
}

.page-lab .sidebar {
  background: var(--surface);
  border-left: 1px solid var(--border);
}

.page-lab .sidebar section {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
}

.page-lab .sidebar section.sidebar-note {
  padding: 1rem 1.25rem 1rem;
}

.page-lab .sidebar h3 {
  margin: 0 0 0.65rem;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* Notes + reference share one sidebar “card” vocabulary */
.page-lab .sidebar-note {
  margin: 0;
  padding: 1rem 1rem 1.05rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: inset 3px 0 0 var(--accent-dim);
}

.page-lab .sidebar-note h3 {
  margin-bottom: 0.6rem;
}

.page-lab .sidebar-note__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--muted);
}

.page-lab .sidebar-note__list li {
  margin: 0;
  padding: 0;
}

.page-lab .sidebar-note__label {
  display: block;
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 0.25rem;
}

.page-lab .sidebar-note__list code {
  font-family: var(--mono);
  font-size: 0.88em;
  color: var(--text);
  background: rgba(110, 118, 129, 0.15);
  padding: 0.12em 0.38em;
  border-radius: 4px;
}

/* Quick reference accordion */
.page-lab .ref {
  padding-top: 0;
}

.page-lab .ref h3 {
  margin-bottom: 0.45rem;
}

.page-lab .ref-intro {
  margin: 0 0 0.85rem;
  font-size: 0.75rem;
  line-height: 1.45;
  color: var(--muted);
}

.page-lab .ref-item {
  margin-bottom: 0.4rem;
  font-size: 0.8rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  overflow: hidden;
}

.page-lab .ref-item:last-child {
  margin-bottom: 0;
}

.page-lab .ref-item summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.65rem;
  color: var(--text);
  font-weight: 500;
  user-select: none;
  transition: background 0.12s ease;
}

.page-lab .ref-item summary::-webkit-details-marker {
  display: none;
}

.page-lab .ref-item summary::before {
  content: "";
  flex-shrink: 0;
  width: 0.5rem;
  height: 0.5rem;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: rotate(-45deg);
  margin-top: -0.15rem;
  opacity: 0.75;
  transition: transform 0.15s ease, border-color 0.12s ease;
}

.page-lab .ref-item[open] summary::before {
  transform: rotate(45deg);
  margin-top: 0.1rem;
}

.page-lab .ref-item summary:hover {
  background: rgba(110, 118, 129, 0.12);
}

.page-lab .ref-item summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-radius: 4px;
}

.page-lab .ref-item summary:hover::before {
  border-color: var(--accent);
  opacity: 1;
}

.page-lab .ref-item__title {
  flex: 1;
}

.page-lab .ref-item__body {
  padding: 0 0.65rem 0.6rem 1.75rem;
  line-height: 1.5;
  color: var(--muted);
  border-top: 1px solid var(--border);
  background: rgba(26, 34, 48, 0.45);
}

.page-lab .ref-item code {
  font-family: var(--mono);
  color: var(--text);
  font-size: 0.9em;
  background: rgba(110, 118, 129, 0.12);
  padding: 0.1em 0.32em;
  border-radius: 4px;
}

.page-lab .ref-item__link {
  display: inline-block;
  margin-top: 0.45rem;
  font-size: 0.92em;
}

.page-lab .btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.page-lab button.primary {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.85rem;
}

.page-lab button.primary:hover {
  filter: brightness(1.1);
}

.page-lab button.ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.8rem;
}

.page-lab button.ghost:hover {
  background: var(--surface-hover);
}

.page-lab #unit-tests-table input {
  min-height: auto;
  font-size: 0.8rem;
}

.page-lab .stat {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0.25rem 0;
}

.page-lab .footer-note {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.5;
  padding: 1rem 1.25rem 1.25rem;
  border-top: 1px solid var(--border);
}

.page-lab .footer-note + .site-footer {
  border-top: none;
  padding-top: 0;
}

.page-lab select {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.35rem 0.5rem;
  border-radius: 6px;
  font-size: 0.85rem;
}

.page-lab .tool-grid {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: 1fr;
}

@media (min-width: 600px) {
  .page-lab .tool-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.page-lab .small {
  font-size: 0.78rem;
  color: var(--muted);
}

.page-lab .code-lang-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.75rem 1rem;
  margin-bottom: 0.75rem;
}

.page-lab .code-lang-toolbar label {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.8rem;
  color: var(--muted);
}

.page-lab .code-lang-toolbar select,
.page-lab .code-lang-toolbar input[type="search"] {
  min-width: 10rem;
  max-width: min(100%, 28rem);
}

.page-lab #code-lang {
  min-width: 14rem;
}

/* Code generation panel (always visible) */
.page-lab #panel-codegen {
  border-top: 1px solid var(--accent);
  background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%);
}