:root {
  --lab-page-bg: #f4f7fb;
  --lab-card: #ffffff;
  --lab-border: #d9e3ef;
  --lab-text: #112745;
  --lab-muted: #64758b;
  --lab-blue: #356be8;
  --lab-blue-dark: #2858c7;
  --lab-blue-soft: #edf3ff;
  --lab-green: #2f9b70;
  --lab-radius: 15px;
  --lab-shadow: 0 10px 28px rgba(26, 65, 112, .07);
}

.unified-lab {
  background: var(--lab-page-bg);
  color: var(--lab-text);
}

.unified-lab .app-header {
  position: relative;
  top: auto;
  z-index: 20;
  width: calc(100% - 72px);
  max-width: 1440px;
  height: auto;
  margin: 14px auto 0;
  border: 0;
  background: transparent;
  backdrop-filter: none;
}

.unified-lab .header-inner {
  width: 100%;
  max-width: none;
  min-height: 58px;
  height: auto;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.unified-lab .unified-brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 11px;
}

.unified-lab .unified-brand-icon {
  width: 38px;
  height: 38px;
  flex: 0 0 38px;
  display: grid;
  place-items: center;
  border-radius: 11px;
  color: #fff;
  background: linear-gradient(145deg, #3f7cf0, #2d60d7);
  box-shadow: 0 8px 18px rgba(53, 107, 232, .24);
}

.unified-lab .unified-brand-icon svg {
  width: 23px;
  height: 23px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.unified-lab .unified-brand-copy {
  min-width: 0;
}

.unified-lab .unified-brand .page-title,
.unified-lab .unified-brand h1 {
  margin: 0;
  color: var(--lab-text);
  font-size: 21px;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -.02em;
  white-space: nowrap;
}

.unified-lab .unified-brand-copy > span {
  display: block;
  margin-top: 2px;
  color: var(--lab-muted);
  font-size: 12px;
  line-height: 1.4;
}

.unified-lab .header-actions {
  min-width: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
}

.unified-lab .header-actions button {
  min-height: 38px;
  border-radius: 10px;
}

.unified-lab .header-actions .student-entry-button,
.unified-lab .header-actions .header-reset-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border-radius: 10px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.unified-lab .header-actions .student-entry-button {
  padding: 0 14px;
  border: 1px solid #aac6e7;
  background: #fff;
  color: var(--lab-blue-dark);
  white-space: nowrap;
}

.unified-lab .header-actions .header-reset-button {
  width: 40px;
  flex: 0 0 40px;
  padding: 0;
  border: 1px solid var(--lab-border);
  background: #fff;
  color: var(--lab-text);
  font-size: 20px;
  line-height: 1;
}

.unified-lab .header-actions .student-entry-button:hover,
.unified-lab .header-actions .header-reset-button:hover {
  transform: translateY(-1px);
  border-color: #7fa9d8;
  box-shadow: 0 6px 16px rgba(31, 78, 121, 0.1);
}

.unified-lab .header-actions .student-entry-button:focus-visible,
.unified-lab .header-actions .header-reset-button:focus-visible {
  outline: 3px solid rgba(35, 99, 203, 0.22);
  outline-offset: 2px;
}

.unified-lab .progress-wrap {
  position: relative;
  top: auto;
  z-index: 15;
  width: calc(100% - 72px);
  max-width: 1440px;
  margin: 8px auto 14px;
  border: 1px solid var(--lab-border);
  border-radius: var(--lab-radius);
  background: var(--lab-card);
  box-shadow: var(--lab-shadow);
  overflow: hidden;
}

.unified-lab .progress-rail,
.unified-lab .progress-track {
  width: 100%;
  max-width: none;
  margin: 0;
  padding: 12px 22px 11px;
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 0;
  overflow-x: visible;
}

.unified-lab .progress-step {
  min-width: 0;
  justify-content: center;
  gap: 8px;
  color: #5e6c80;
  font-size: 13px;
}

.unified-lab .progress-step::before {
  content: "";
  position: absolute;
  z-index: 0;
  top: 13px;
  left: calc(-50% + 23px);
  right: calc(50% + 23px);
  height: 1px;
  background: #d6e0ec;
}

.unified-lab .progress-step:first-child::before {
  display: none;
}

.unified-lab .progress-step::after {
  display: none;
}

.unified-lab .progress-step > * {
  position: relative;
  z-index: 1;
}

.unified-lab .step-number {
  width: 28px;
  height: 28px;
  flex: 0 0 28px;
  border-color: #cad6e4;
  background: #fff;
}

.unified-lab .progress-step.current {
  color: var(--lab-blue);
}

.unified-lab .progress-step.current .step-number {
  border-color: var(--lab-blue);
  background: var(--lab-blue);
}

.unified-lab main {
  width: calc(100% - 72px);
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 0 64px;
}

.unified-lab main > section {
  scroll-margin-top: 18px;
  margin: 0 0 14px;
  padding: 17px 20px;
  border: 1px solid var(--lab-border);
  border-radius: var(--lab-radius);
  background: var(--lab-card);
  box-shadow: var(--lab-shadow);
}

.unified-lab main > #student {
  padding-top: 14px;
  padding-bottom: 14px;
}

.unified-lab main > #principle {
  padding: 0;
  overflow: hidden;
}

.unified-lab main > #principle.section {
  padding: 17px 20px;
}

.unified-lab main > #simulation,
.unified-lab main > #records,
.unified-lab main > #tasks,
.unified-lab main > #report {
  padding: 18px 20px 20px;
}

.unified-lab .section-head {
  margin-bottom: 13px;
}

.unified-lab .section-head h2 {
  color: var(--lab-text);
  font-size: 20px;
  font-weight: 900;
}

.unified-lab .section-head p {
  color: var(--lab-muted);
  font-size: 13px;
}

.unified-lab .record-summary,
.unified-lab #studentSummary.status-line {
  min-height: 32px;
  margin-top: 0;
  padding: 7px 11px;
  border-radius: 9px;
  color: #8b650d;
  background: #fff8e8;
  font-size: 12px;
}

.unified-lab .principle-band {
  box-shadow: none;
}

.unified-lab #principle.principle-band {
  border: 0;
  border-radius: 0;
  background: #fff;
  box-shadow: none;
}

.unified-lab #principle.principle-band .principle-main {
  background: #fff;
}

.unified-lab .principle-intro {
  grid-template-columns: minmax(310px, .9fr) minmax(0, 1.35fr);
}

.unified-lab .main-equation {
  justify-content: center;
  gap: 9px;
  overflow: visible;
  white-space: nowrap;
  font-size: clamp(20px, 2vw, 29px);
}

.unified-lab .simulation-grid,
.unified-lab .lab-grid,
.unified-lab .live-metrics,
.unified-lab .table-frame,
.unified-lab .table-wrap,
.unified-lab .report-document,
.unified-lab .report-sheet {
  box-shadow: none;
}

.unified-lab .simulation-grid,
.unified-lab .lab-grid {
  border-radius: 13px;
}

.unified-lab .apparatus-panel,
.unified-lab .controls-panel,
.unified-lab .control-rail {
  border-color: var(--lab-border);
}

.unified-lab .lab-method-panel {
  padding: 0;
  overflow: hidden;
}

.lab-method-head {
  min-height: 65px;
  padding: 13px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  border-bottom: 1px solid var(--lab-border);
}

.lab-method-heading {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 12px;
}

.lab-method-kicker {
  flex: 0 0 auto;
  padding: 5px 9px;
  border-radius: 8px;
  color: #325fae;
  background: var(--lab-blue-soft);
  font-size: 11px;
  font-weight: 800;
}

.lab-method-heading h2 {
  margin: 0;
  color: var(--lab-text);
  font-size: 19px;
}

.lab-method-heading p {
  margin: 2px 0 0;
  color: var(--lab-muted);
  font-size: 12px;
}

.lab-guide-start {
  flex: 0 0 auto;
  color: #2e58ae;
  border-color: #b9cce8;
  background: #fff;
}

.lab-method-grid {
  display: grid;
  grid-template-columns: 1.08fr .92fr;
  min-width: 0;
}

.lab-method-column {
  min-width: 0;
  padding: 17px 20px 19px;
}

.lab-method-column + .lab-method-column {
  border-left: 1px solid var(--lab-border);
  background: #fbfcfe;
}

.lab-method-column h3 {
  margin: 0 0 12px;
  color: var(--lab-text);
  font-size: 15px;
}

.lab-device-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 7px;
}

.lab-device-card {
  min-width: 0;
  min-height: 64px;
  padding: 9px 10px;
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 8px;
  border: 1px solid #e1e8f1;
  border-radius: 9px;
  background: #fff;
  transition: border-color .2s ease, background .2s ease, transform .2s ease;
}

.lab-device-index,
.lab-step-index {
  width: 27px;
  height: 27px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #315fba;
  background: var(--lab-blue-soft);
  font-size: 11px;
  font-weight: 900;
}

.lab-device-card strong,
.lab-step-card strong {
  display: block;
  color: #213c62;
  font-size: 12px;
}

.lab-device-card p,
.lab-step-card p {
  margin: 2px 0 0;
  color: var(--lab-muted);
  font-size: 11px;
  line-height: 1.55;
}

.lab-method-notes {
  margin-top: 9px;
  padding: 9px 11px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  border-radius: 9px;
  background: #eef4ff;
}

.lab-method-note strong {
  display: block;
  color: #2f57a3;
  font-size: 11px;
}

.lab-method-note span {
  display: block;
  margin-top: 2px;
  color: #5e6f86;
  font-size: 10px;
  line-height: 1.5;
}

.lab-step-list {
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 7px;
  list-style: none;
}

.lab-step-card {
  min-width: 0;
  min-height: 65px;
  padding: 9px 10px;
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 8px;
  border: 1px solid #e1e8f1;
  border-radius: 9px;
  background: #fff;
  transition: border-color .2s ease, background .2s ease, transform .2s ease;
}

.lab-method-footnote {
  margin: 10px 0 0;
  padding: 8px 10px;
  border-left: 3px solid var(--lab-green);
  border-radius: 0 8px 8px 0;
  color: #4f657c;
  background: #eff8f4;
  font-size: 11px;
  line-height: 1.55;
}

.lab-device-card.guide-active,
.lab-step-card.guide-active,
.lab-method-note.guide-active {
  border-color: #6f9af0;
  background: #edf4ff;
  transform: translateY(-2px);
  box-shadow: 0 7px 16px rgba(53, 107, 232, .12);
}

.lab-guide-target {
  outline: 3px solid rgba(53, 107, 232, .34);
  outline-offset: 4px;
  animation: labGuideTargetPulse 1.8s ease-in-out infinite;
  transition: outline-color .2s ease;
}

.lab-guide-focus {
  outline: 4px solid rgba(255, 174, 0, .92);
  outline-offset: 5px;
  border-radius: 10px;
  animation: labGuideFocusPulse 1.15s ease-in-out infinite;
}

svg .lab-guide-focus {
  outline: none;
  filter: drop-shadow(0 0 4px #fff) drop-shadow(0 0 9px rgba(255, 158, 0, .95));
}

@keyframes labGuideTargetPulse {
  0%, 100% { outline-color: rgba(53, 107, 232, .28); }
  50% { outline-color: rgba(53, 107, 232, .7); }
}

@keyframes labGuideFocusPulse {
  0%, 100% { outline-color: rgba(255, 174, 0, .68); }
  50% { outline-color: rgba(255, 174, 0, 1); }
}

.lab-guide-player {
  position: fixed;
  z-index: 90;
  left: 50%;
  bottom: 18px;
  width: min(820px, calc(100vw - 32px));
  transform: translateX(-50%);
  border: 1px solid #b9cce8;
  border-radius: 15px;
  color: var(--lab-text);
  background: rgba(255, 255, 255, .97);
  box-shadow: 0 22px 60px rgba(17, 45, 83, .2);
  backdrop-filter: blur(12px);
  overflow: hidden;
}

.lab-guide-player[hidden] {
  display: none;
}

.lab-guide-open #platformSyncStatus {
  bottom: 192px !important;
}

.lab-guide-progress {
  height: 4px;
  background: #e4ebf5;
}

.lab-guide-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--lab-blue);
  transition: width .25s ease;
}

.lab-guide-body {
  padding: 13px 16px 12px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: center;
}

.lab-guide-meta {
  display: flex;
  align-items: center;
  gap: 8px;
}

.lab-guide-count,
.lab-guide-mode {
  color: var(--lab-blue);
  font-size: 11px;
  font-weight: 900;
}

.lab-guide-mode {
  padding: 2px 7px;
  border-radius: 999px;
  color: #8a5100;
  background: #fff1c9;
}

.lab-guide-title {
  margin: 2px 0 3px;
  color: var(--lab-text);
  font-size: 16px;
}

.lab-guide-copy {
  margin: 0;
  color: var(--lab-muted);
  font-size: 12px;
  line-height: 1.55;
}

.lab-guide-actions {
  display: flex;
  align-items: center;
  gap: 7px;
}

.lab-guide-actions button {
  min-height: 34px;
  padding: 6px 10px;
  border: 1px solid #c5d4e6;
  border-radius: 9px;
  color: #2b4d7c;
  background: #fff;
  font-weight: 800;
}

.lab-guide-actions .lab-guide-toggle {
  color: #fff;
  border-color: var(--lab-blue);
  background: var(--lab-blue);
}

.lab-guide-actions button:disabled {
  opacity: .42;
}

.lab-guide-paused .lab-guide-target,
.lab-guide-paused .lab-guide-focus {
  animation-play-state: paused !important;
}

@media (prefers-reduced-motion: reduce) {
  .lab-guide-target,
  .lab-guide-focus {
    animation: none;
  }
}

@media (max-width: 960px) {
  .unified-lab .app-header,
  .unified-lab .progress-wrap,
  .unified-lab main {
    width: calc(100% - 32px);
  }

  .unified-lab .header-inner {
    min-height: 58px;
    flex-direction: row;
  }

  .unified-lab .header-actions {
    width: auto;
  }

  .unified-lab .progress-rail,
  .unified-lab .progress-track {
    display: flex;
    overflow-x: auto;
  }

  .unified-lab .progress-step {
    min-width: 130px;
  }

  .lab-method-grid {
    grid-template-columns: 1fr;
  }

  .lab-method-column + .lab-method-column {
    border-top: 1px solid var(--lab-border);
    border-left: 0;
  }

  .unified-lab .principle-intro {
    grid-template-columns: 1fr;
  }

  .unified-lab .main-equation {
    justify-content: flex-start;
    overflow-x: auto;
  }
}

@media (max-width: 680px) {
  .unified-lab {
    font-size: 14px;
  }

  .unified-lab .app-header,
  .unified-lab .progress-wrap,
  .unified-lab main {
    width: calc(100% - 16px);
  }

  .unified-lab .app-header {
    margin-top: 8px;
  }

  .unified-lab .header-inner {
    min-height: 52px;
    align-items: center;
    padding: 0;
  }

  .unified-lab .unified-brand-icon {
    width: 34px;
    height: 34px;
    flex-basis: 34px;
  }

  .unified-lab .unified-brand .page-title,
  .unified-lab .unified-brand h1 {
    max-width: 190px;
    overflow: hidden;
    font-size: 17px;
    text-overflow: ellipsis;
  }

  .unified-lab .unified-brand-copy > span {
    display: none;
  }

  .unified-lab .progress-wrap {
    margin-top: 6px;
    margin-bottom: 9px;
  }

  .unified-lab .progress-rail,
  .unified-lab .progress-track {
    padding: 10px 11px 9px;
  }

  .unified-lab .progress-step {
    min-width: 116px;
  }

  .unified-lab main {
    padding: 0 0 40px;
  }

  .unified-lab main > section,
  .unified-lab main > #simulation,
  .unified-lab main > #records,
  .unified-lab main > #tasks,
  .unified-lab main > #report {
    margin-bottom: 9px;
    padding: 15px 12px;
    border-radius: 13px;
  }

  .unified-lab main > #principle,
  .unified-lab main > #method {
    padding: 0;
  }

  .unified-lab main > #principle.section {
    padding: 15px 12px;
  }

  .unified-lab .section-head {
    gap: 9px;
  }

  .unified-lab .section-head h2 {
    font-size: 18px;
  }

  .lab-method-head {
    padding: 12px;
    align-items: flex-start;
    flex-direction: column;
    gap: 9px;
  }

  .lab-method-heading {
    align-items: flex-start;
  }

  .lab-method-heading > div {
    min-width: 0;
  }

  .lab-guide-start {
    width: 100%;
  }

  .lab-method-column {
    padding: 14px 12px 16px;
  }

  .lab-device-grid,
  .lab-step-list,
  .lab-method-notes {
    grid-template-columns: 1fr;
  }

  .lab-device-card,
  .lab-step-card {
    min-height: 58px;
  }

  .lab-guide-player {
    bottom: 8px;
    width: calc(100vw - 16px);
  }

  .lab-guide-open #platformSyncStatus {
    bottom: 176px !important;
  }

  .lab-guide-body {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .lab-guide-actions {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
  }

  .lab-guide-actions button {
    padding-left: 6px;
    padding-right: 6px;
    font-size: 12px;
  }
}

@media (max-width: 760px) {
  .unified-lab .header-actions .student-entry-button {
    min-height: 36px;
    padding: 0 10px;
    font-size: 12px;
  }

  .unified-lab .header-actions .header-reset-button {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .lab-device-card,
  .lab-step-card,
  .lab-guide-progress span {
    transition: none;
  }
}

@media print {
  .unified-lab .lab-method-panel,
  .lab-guide-player {
    display: none !important;
  }
}