.labs-page, .lab-page { min-width: 0; }
.lab-back { margin-block: 0 14px; }
.labs-index-heading { max-width: 760px; margin: 8px 0 24px; }
.labs-index-heading .page-description { max-width: 62ch; margin-top: 8px; }
.lab-context { margin-top: 8px; color: var(--md-on-surface-variant); font-size: 14px; }
.lab-model-note { max-width: 80ch; margin-block: 14px 20px; padding: 12px 14px; border: 1px solid var(--md-outline-variant); border-radius: 8px; background: var(--md-surface-container-low); color: var(--md-on-surface-variant); font-size: 14px; line-height: 1.5; }

/* A numbered register suits a sequence of prescribed school experiments better than a card grid. */
.labs-index-grid { border-block: 1px solid var(--md-outline-variant); }
.lab-index-card { min-width: 0; border-bottom: 1px solid var(--md-outline-variant); transition: background-color 160ms ease; }
.lab-index-card:last-child { border-bottom: 0; }
.lab-index-card:hover, .lab-index-card:focus-within { background: var(--md-surface-container-low); }
.lab-card-link { min-height: 94px; display: grid; grid-template-columns: 116px minmax(0, 1fr) auto; align-items: center; gap: 16px; padding: 16px 12px; }
.lab-card-number { color: var(--md-primary); font-size: 14px; font-weight: 650; white-space: nowrap; }
.lab-card-copy { min-width: 0; }
.lab-card-copy h2 { font-size: 20px; line-height: 1.35; }
.lab-card-copy > p { max-width: 72ch; margin-top: 5px; color: var(--md-on-surface-variant); line-height: 1.45; }
.lab-card-action { color: var(--md-primary); font-weight: 600; white-space: nowrap; }

.lab-detail-heading { display: flex; align-items: end; justify-content: space-between; gap: 18px; padding-block: 7px 4px; }
.lab-detail-heading > div { min-width: 0; }
.lab-detail-heading .page-title { line-height: 1.15; text-wrap: balance; }
.lab-detail-heading .page-description { max-width: 68ch; margin-top: 9px; line-height: 1.55; }
.lab-lesson-link { flex: 0 0 auto; }
.lab-overview-grid, .lab-notes-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(260px, .9fr); gap: 14px; margin-block: 16px; }
.lab-panel { min-width: 0; padding: clamp(16px, 3vw, 22px); border: 1px solid var(--md-outline-variant); border-radius: 12px; background: var(--md-surface-container-low); }
.lab-panel h2 { font-size: 20px; line-height: 1.35; }
.lab-walkthrough :is(ol, p) { max-width: 72ch; line-height: 1.6; }
.lab-walkthrough > p { margin-top: 8px; }
.lab-walkthrough > a { margin-top: 12px; }
:is(#lab-walkthrough-title, #lab-stand-title) { scroll-margin-top: 72px; }
:is(#lab-walkthrough-title, #lab-stand-title):focus { outline: 3px solid var(--md-primary); outline-offset: 3px; }
.lab-purpose { display: grid; align-content: start; gap: 9px; background: var(--tone); color: var(--tone-ink); border-color: transparent; }
.lab-purpose > p:last-child, .lab-panel > p { line-height: 1.6; }
.lab-apparatus-list { display: grid; gap: 7px; margin: 12px 0 0; padding-inline-start: 20px; color: var(--md-on-surface-variant); }
.lab-apparatus-list li { padding-inline-start: 2px; line-height: 1.45; }
.lab-procedure { margin-block: 14px; }
.lab-section-heading { margin-bottom: 13px; }
.lab-section-heading h2 { font-size: 20px; }
.lab-section-heading > p { margin-top: 7px; color: var(--md-on-surface-variant); line-height: 1.5; }
.lab-procedure-steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0 24px; margin: 0; padding-inline-start: 1.5rem; }
.lab-procedure-steps li { min-width: 0; padding: 10px 0 10px 4px; border-top: 1px solid var(--md-outline-variant); line-height: 1.5; }
.lab-procedure-steps li::marker { color: var(--md-primary); font-weight: 700; font-variant-numeric: tabular-nums; }

.lab-notebook { min-width: 0; margin-block: 18px; padding: clamp(16px, 3vw, 22px); border: 1px solid var(--md-outline-variant); border-radius: 12px; background: var(--md-surface-container-low); }
.lab-notebook .practice-model { margin: 16px 0; }
.lab-record-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 9px 14px; padding-block: 4px 10px; }
.lab-notebook-status { flex: 1 1 220px; color: var(--md-on-surface-variant); font-size: 14px; }
.lab-trial-list { display: grid; margin-top: 4px; }
.lab-trial-card { min-width: 0; padding-block: 16px; border-top: 1px solid var(--md-outline-variant); }
.lab-trial-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.lab-trial-heading h3, .lab-calc-title { font-size: 20px; }
.lab-recorded-mark { padding: 5px 10px; border-radius: 999px; background: var(--md-secondary-container); color: var(--md-on-secondary-container); font-size: 12px; font-weight: 600; }
.lab-readings { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 155px), 1fr)); gap: 1px; margin: 14px 0 19px; }
.lab-reading-row { min-width: 0; padding: 10px 12px; background: var(--md-surface-container); }
.lab-reading-row dt { color: var(--md-on-surface-variant); font-size: 14px; line-height: 1.35; }
.lab-reading-row dd { margin-top: 4px; font-size: 1rem; font-weight: 700; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.lab-calculation-form { display: grid; gap: 14px; margin-top: 10px; }
.lab-answer-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 245px), 1fr)); gap: 10px; }
.lab-answer-row { display: grid; gap: 6px; min-width: 0; color: var(--md-on-surface); font-weight: 550; }
.lab-answer-label { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 4px 10px; }
.lab-answer-label small { color: var(--md-on-surface-variant); font-weight: 500; }
.lab-answer-input { width: 100%; min-width: 0; min-height: 48px; padding: 9px 12px; border: 1px solid var(--md-outline); border-radius: 8px; background: var(--md-surface); color: var(--md-on-surface); font-variant-numeric: tabular-nums; }
.lab-answer-input:focus-visible { outline: 3px solid var(--md-primary); outline-offset: 2px; }
.lab-form-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 8px 12px; }
.lab-rounding-note { color: var(--md-on-surface-variant); font-size: 14px; }
.lab-check-result { margin-top: 2px; padding: 14px; border-radius: 8px; background: var(--md-surface-container); }
.lab-check-result h3 { font-size: 1rem; }
.lab-check-result > p { margin-top: 5px; color: var(--md-on-surface-variant); }
.lab-check-correct { background: var(--md-primary-container); color: var(--md-on-primary-container); }
.lab-check-review, .lab-check-incomplete { background: var(--md-surface-container-high); }
.lab-worked-results { display: grid; grid-template-columns: minmax(0, 1fr) minmax(130px, auto); gap: 8px 16px; align-items: center; margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--md-outline-variant); }
.lab-worked-results dt { color: var(--md-on-surface-variant); font-size: 14px; }
.lab-worked-results dd { display: flex; align-items: center; justify-content: end; gap: 7px; min-width: 0; text-align: end; font-weight: 650; font-variant-numeric: tabular-nums; }
.lab-worked-results .formula-ink { margin: 0; padding: 0; background: transparent; font-size: 14px; }
.lab-worked-value { white-space: nowrap; }
.lab-notes-grid { margin-top: 15px; }
.lab-fact { background: var(--tone); color: var(--tone-ink); border-color: transparent; }
.lab-fact p { margin-top: 8px; line-height: 1.6; }
.lab-error-note { background: var(--md-surface-container); }
.lab-page-footer { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; margin-top: 16px; }

@media (max-width: 720px) {
  .lab-detail-heading { align-items: start; flex-direction: column; }
  .lab-lesson-link { align-self: start; }
  .lab-overview-grid, .lab-notes-grid { grid-template-columns: minmax(0, 1fr); }
  .lab-procedure-steps { grid-template-columns: minmax(0, 1fr); }
  .lab-procedure-steps { gap: 0; }
  .lab-worked-results { grid-template-columns: minmax(0, 1fr); gap: 3px; }
  .lab-worked-results dd { justify-content: start; margin-bottom: 7px; text-align: start; }
}

@media (max-width: 460px) {
  .lab-card-link { grid-template-columns: minmax(0, 1fr) auto; gap: 7px 12px; padding: 14px 8px; }
  .lab-card-number { grid-column: 1 / -1; font-size: 12px; }
  .lab-card-action { grid-column: 2; grid-row: 2; font-size: 14px; }
  .lab-card-copy { grid-column: 1; grid-row: 2; }
  .lab-notebook { padding: 13px; }
  .lab-form-actions .practice-button { width: 100%; }
  .lab-rounding-note { width: 100%; }
  .lab-page-footer { flex-direction: column; align-items: stretch; }
  .lab-page-footer .practice-button { justify-content: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  .lab-index-card { transition: none; }
}

.lab-notebook { margin-block: 24px; padding: 0; border: 0; background: transparent; }
.lab-detail-heading { align-items: center; }
.lab-detail-heading .course-tabs { margin: 0; flex: 0 0 auto; }
.lab-detail-heading .page-title { font-size: clamp(34px, 3.75vw, 54px); }
.lab-notebook .lab-stand {
  display: grid;
  grid-template-columns: minmax(0, 2.1fr) minmax(280px, 1fr);
  align-items: stretch;
  gap: 20px;
  margin: 0;
}
.lab-stand .practice-model-figure {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-width: 0;
  padding: clamp(14px, 2vw, 28px);
  border: 0;
  border-radius: 28px;
  background: #f1eee7;
  color: #1a2230;
  box-shadow: var(--md-elevation-2);
}
.lab-stand .practice-model-canvas { background: #f1eee7; }
.lab-stand .practice-model-plot { width: min(100%, 640px); margin-inline: auto; }
.lab-instrument-header { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; font-size: 21px; }
.model-clock { font-variant-numeric: tabular-nums; font-weight: 700; }
.lab-instrument-header .model-clock { font-size: clamp(18px, 2vw, 28px); white-space: nowrap; }
.lab-stand .practice-measurements {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 125px), 1fr));
  padding-top: 12px;
  gap: 9px 16px;
  border-top: 1px solid #c3c5c1;
}
.lab-stand .practice-measurements > div { padding: 3px 0; background: transparent; border: 0; }
.lab-stand .practice-measurements dt { color: #545d66; }
.lab-stand .practice-measurements dd { color: #1a2230; font-size: clamp(16px, 2vw, 29px); line-height: 1.2; margin-top: 3px; }
.lab-stand .practice-measurements > div:last-child dd { color: #2549ad; }
.lab-stand-settings {
  min-width: 0;
  display: flex;
  flex-direction: column;
  padding: clamp(16px, 2vw, 28px);
  border-radius: 28px;
  background: var(--md-surface-container);
  box-shadow: var(--md-elevation-2);
}
.lab-stand-settings h2 { font-size: 25px; line-height: 1.3; }
.lab-stand-settings .practice-controls { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; padding-block: 16px 14px; }
.lab-stand-settings .practice-control {
  padding: 9px 10px 1px;
  border: 1px solid var(--md-outline);
  border-radius: 14px;
  background: var(--md-surface-low);
}
.lab-stand-settings .control-caption { flex-direction: column; align-items: start; gap: 3px; color: var(--muted); line-height: 1.28; }
.lab-stand-settings .control-reading { color: var(--ink); font-size: 20px; }
.lab-stand-settings .practice-control input { height: 44px; min-width: 0; }
.lab-stand-settings .model-actions { padding-top: 12px; border-top: 1px solid var(--line); margin-top: auto; }
.lab-stand-settings .model-actions .practice-button { flex: 1 1 auto; }
.lab-stand-settings > .practice-button { width: 100%; margin-top: 10px; }
.lab-stand-settings > .practice-button:disabled { background: var(--md-surface-low); color: var(--muted); opacity: 1; border-color: var(--line); }
.lab-stand .scene-grip::before { background: #f8f6f1; border-color: #2549ad; box-shadow: 0 0 0 2px #f1eee7; }
.lab-stand .scene-grip:active::before { background: #2549ad; }
.lab-series-title { margin-block: 27px 10px; font-size: 24px; }
.lab-notebook-status:empty { display: none; }
.lab-panel { border-radius: 20px; }

@media (max-width: 810px) {
  .lab-notebook .lab-stand { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .lab-stand .practice-model-figure, .lab-stand-settings { border-radius: 24px; }
}
@media (max-width: 460px) {
  .lab-detail-heading { align-items: start; }
  .lab-detail-heading .course-tabs { display: none; }
  .lab-instrument-header { font-size: 16px; }
  .lab-stand .practice-measurements { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .lab-stand-settings .practice-control { padding-inline: 8px; }
}

.lab-stand-status { margin-block: 8px 16px; min-block-size: 3em; color: var(--md-on-surface-variant); line-height: 1.45; }
.lab-assembly-tools, .lab-parts, .lab-dock, .lab-ports { display: grid; gap: 8px; min-width: 0; }
.lab-build-help { font-size: 14px; line-height: 1.45; color: var(--md-on-surface-variant); }
.lab-assembly-tools > .practice-button { justify-self: start; }
.lab-parameter-title { margin-top: 18px; }
.lab-parts, .lab-dock, .lab-ports { grid-template-columns: repeat(auto-fit, minmax(min(100%, 115px), 1fr)); }
.lab-placement { display: grid; gap: 12px; margin-block: 8px 16px; }
.lab-parts { padding-block-start: 10px; border-block-start: 1px solid #c3c5c1; }
.lab-stand .practice-button:is(.lab-part, .lab-target, .lab-port) {
  min-block-size: 44px;
  padding: 7px 10px;
  white-space: normal;
  line-height: 1.25;
  touch-action: none;
  user-select: none;
}
.lab-part, .lab-port { cursor: grab; }
.lab-part[aria-pressed="true"] { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.lab-stand .lab-target, .lab-stand .lab-port, .lab-stand .lab-part {
  background: #f8f6f1;
  color: #1a2230;
  border: 1px solid #7b8792;
  border-radius: 10px;
}
.lab-stand .lab-target { border-style: dashed; }
.lab-stand .practice-button:is(.lab-target, .lab-port, .lab-part):is([aria-pressed="true"], .lab-dragging) {
  background: #d9e5ff;
  color: #163577;
  border-color: #2549ad;
  border-style: solid;
}
.lab-stand .lab-dragging { cursor: grabbing; outline: 2px solid #2549ad; outline-offset: 2px; }
.lab-stand .practice-button:focus-visible { outline: 3px solid var(--md-primary); outline-offset: 3px; }
.lab-stand .practice-model-figure .practice-button:focus-visible { outline-color: #2549ad; }
.lab-travel { grid-column: 1 / -1; }
.lab-stand .lab-load-grip { z-index: 2; }
.lab-circuit { min-width: 0; margin-block: 10px 16px; }
.lab-circuit-board { position: relative; container-type: inline-size; }
.lab-circuit-drawing { width: 100%; display: block; overflow: visible; }
.lab-circuit-drawing text { text-anchor: middle; font-size: 19px; font-weight: 700; fill: #1a2230; }
.lab-circuit-drawing .lab-terminal-label { font-size: 16px; }
.lab-component-shape { stroke: #1a2230; fill: none; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.lab-terminal-mark { fill: #f1eee7; stroke: #2549ad; stroke-width: 3; }
.lab-junction { fill: #2549ad; }
.lab-wire-bridge, .lab-wire, .lab-wire-current { fill: none; stroke-linejoin: round; stroke-linecap: round; }
.lab-wire-bridge { stroke: #f1eee7; stroke-width: 9; }
.lab-wire { stroke: #496077; stroke-width: 4; }
.lab-wire-current { stroke: #2549ad; stroke-width: 5; }
.lab-flowing .lab-wire-current { stroke-dasharray: 7 13; animation: lab-flow 900ms linear infinite; }
@keyframes lab-flow { to { stroke-dashoffset: -40; } }
@media (prefers-reduced-motion: reduce) {
  .lab-flowing .lab-wire-current { animation: none; stroke-dasharray: none; }
}
.lab-ports { margin-bottom: 10px; }
.lab-port strong { min-width: 1em; font-size: 18px; }
@container (min-width: 280px) {
  .lab-ports { position: absolute; inset: 0; display: block; pointer-events: none; margin: 0; }
  .lab-stand .practice-button.lab-port {
    position: absolute; inset: auto; left: var(--port-x); top: var(--port-y);
    translate: -50% -50%; width: 44px; height: 44px; padding: 0; border: 0; border-radius: 50%;
    background: transparent; box-shadow: none; pointer-events: auto;
  }
  .lab-ports .lab-port :is(span, strong) { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .lab-stand .practice-button.lab-port:is(:hover, [aria-pressed="true"], .lab-dragging) { background: rgb(37 73 173 / 18%); }
}
.lab-wires { padding: 0; list-style: none; font-size: 14px; }
.lab-wires:empty { display: none; }
.lab-wires li { display: flex; align-items: center; justify-content: space-between; gap: 6px; border-top: 1px solid var(--md-outline-variant); }
.lab-wires .practice-button { min-height: 44px; flex: none; }
.lab-heater-water {
  display: flex; position: relative; align-items: center; gap: 16px; width: max-content; margin: 4px auto 0;
  border: 2px solid #496077; border-top: 0; border-radius: 0 0 14px 14px; padding: 7px 14px;
  background: color-mix(in srgb, #d9e5ff, #edaa83 calc(100% * var(--heater-rise, 0))); font-weight: 650;
}
.lab-water-level { position: relative; display: block; width: 12px; height: 44px; border: 2px solid #496077; border-radius: 6px; background: #f8f6f1; }
.lab-water-level::after {
  content: ""; position: absolute; inset-inline: 1px; bottom: 1px; height: calc(4px + 31px * var(--heater-rise, 0));
  border-radius: 4px; background: #a7472f;
}