:root {
  --bg: #f3f6fa;
  --surface: #ffffff;
  --surface-soft: #f8fbff;
  --line: #d6dde6;
  --line-strong: #aeb9c7;
  --ink: #15202b;
  --muted: #5f6d7c;
  --accent: #1f5fa8;
  --accent-strong: #16497f;
  --accent-soft: #e7f0fb;
  --success: #1f7a46;
  --success-soft: #e8f6ee;
  --warning: #7b5a1d;
  --warning-soft: #f8f1df;
  --danger: #b5493c;
  --danger-soft: #fceceb;
  --shadow: 0 14px 34px rgba(21, 32, 43, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
}

button,
input,
select,
textarea {
  font: inherit;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--surface);
  color: var(--ink);
  padding: 0.7rem 1rem;
  z-index: 10;
}

.skip:focus {
  left: 1rem;
  top: 1rem;
}

.app-shell {
  min-height: 100vh;
  padding-bottom: 2rem;
}

.app-header,
.workspace,
.footer {
  width: min(1280px, calc(100vw - 2rem));
  margin-left: auto;
  margin-right: auto;
}

.app-header {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
  padding: 1.25rem 0 0.9rem;
}

.header-kicker,
.panel-kicker {
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.32rem;
}

.header-kicker-link {
  display: inline-flex;
  text-decoration: none;
}

.header-kicker-link:hover {
  color: var(--accent-strong);
}

.app-header h1,
.section-head h2,
.sticky-card h2 {
  margin: 0;
  font-size: clamp(1.55rem, 2.4vw, 2.1rem);
}

.project-meta,
.case-meta,
.chip-row {
  display: flex;
  gap: 0.45rem;
  flex-wrap: wrap;
  align-items: center;
}

.project-meta {
  margin-top: 0.45rem;
}

.status-badge,
.version-badge,
.chip {
  display: inline-flex;
  align-items: center;
  min-height: 1.55rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: var(--muted);
  padding: 0.2rem 0.55rem;
  font-size: 0.74rem;
  font-weight: 700;
  line-height: 1;
}

.version-badge {
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-weight: 600;
}

.status-prototype {
  border-color: #dcc58f;
  background: var(--warning-soft);
  color: var(--warning);
}

.safety-badge {
  border-color: #9ebee3;
  background: var(--accent-soft);
  color: var(--accent);
}

.source-synthetic {
  border-color: #dcc58f;
  background: var(--warning-soft);
  color: var(--warning);
}

.source-imported {
  border-color: #9ebee3;
  background: var(--accent-soft);
  color: var(--accent);
}

.source-template {
  border-color: #97cfab;
  background: var(--success-soft);
  color: var(--success);
}

.header-copy,
.muted {
  color: var(--muted);
}

.header-copy {
  margin: 0.45rem 0 0;
  max-width: 56rem;
  line-height: 1.5;
}

.header-actions,
.button-row {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
}

button,
.button {
  cursor: pointer;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  padding: 0.78rem 1rem;
  border-radius: 4px;
  transition: background 150ms ease, border-color 150ms ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
}

button:hover,
.button:hover {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
}

button.secondary,
.button.secondary {
  background: #fff;
  color: var(--accent);
}

button.secondary:hover,
.button.secondary:hover {
  background: var(--accent-soft);
}

button.ghost,
.button.ghost {
  background: transparent;
  color: var(--muted);
  border-color: var(--line);
}

button.ghost:hover,
.button.ghost:hover {
  background: #fff;
  border-color: var(--line-strong);
}

button:disabled {
  opacity: 0.6;
  cursor: default;
}

.workspace {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: start;
}

.main-pane,
.side-pane {
  display: grid;
  gap: 1rem;
}

.main-pane {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.ecg-card,
#quizPanel {
  grid-column: 1 / -1;
}

.ecg-card {
  order: -1;
}

#quizPanel {
  order: 0;
}

.session-card {
  order: 2;
}

.panel-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  box-shadow: var(--shadow);
  padding: 1rem;
}

.sticky-card {
  position: sticky;
  top: 1rem;
}

.status-card {
  position: static;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.section-head.compact {
  margin-bottom: 0.75rem;
}

.panel-title {
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.field {
  display: grid;
  gap: 0.35rem;
  margin-bottom: 0.8rem;
}

.field span {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--muted);
}

select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  color: var(--ink);
  padding: 0.68rem 0.75rem;
}

select:focus {
  outline: 2px solid var(--accent-soft);
  border-color: var(--accent);
}

input[type="range"] {
  accent-color: var(--accent);
}

.session-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}

.ecg-card {
  padding-bottom: 0.75rem;
}

.viewer-note {
  margin: -0.3rem 0 0.75rem;
  font-size: 0.86rem;
}

.viewer-controls {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  flex-wrap: wrap;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  padding: 0.65rem;
  margin-bottom: 0.75rem;
}

.lab-controls {
  display: grid;
  grid-template-columns: minmax(170px, 0.85fr) minmax(260px, 1.35fr) minmax(170px, 0.85fr) minmax(250px, 1.15fr);
  align-items: start;
  gap: 0.65rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  padding: 0.65rem;
  margin: -0.25rem 0 0.75rem;
}

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

.lab-group {
  display: grid;
  gap: 0.55rem;
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  padding: 0.6rem;
}

.lab-group-heading {
  display: grid;
  gap: 0.15rem;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.45rem;
}

.lab-group-heading h3 {
  margin: 0;
  color: var(--ink);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0;
}

.lab-group-heading p {
  margin: 0;
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.3;
}

.lab-group-p {
  border-top: 3px solid #2d8a57;
}

.lab-group-qrs {
  border-top: 3px solid #2f6fb2;
}

.lab-group-t {
  border-top: 3px solid #9b6f24;
}

.lab-group-window {
  border-top: 3px solid #6f7884;
}

.annotation-controls {
  display: grid;
  grid-template-columns: minmax(160px, 220px) auto minmax(240px, 1fr);
  align-items: end;
  gap: 0.65rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  padding: 0.65rem;
  margin: -0.25rem 0 0.75rem;
}

.annotation-controls[hidden] {
  display: none;
}

.annotation-status {
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  color: var(--muted);
  padding: 0.55rem 0.65rem;
  font-size: 0.78rem;
  line-height: 1.35;
}

.lab-controls .range-field {
  grid-template-columns: minmax(6.8rem, 0.9fr) minmax(110px, 1.35fr) 4.8rem;
  background: #fff;
}

.lab-status {
  grid-column: 1 / -1;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  color: var(--muted);
  padding: 0.55rem 0.65rem;
  font-size: 0.78rem;
  line-height: 1.35;
}

.analysis-report {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.45rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  padding: 0.55rem;
  font-size: 0.78rem;
}

.analysis-report .report-item {
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  padding: 0.45rem 0.5rem;
  min-width: 0;
}

.analysis-report .report-label {
  display: block;
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
}

.analysis-report .report-value {
  display: block;
  color: var(--ink);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}

.analysis-legend {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 0.85rem;
  align-items: center;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.35;
}

.analysis-legend span {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.legend-swatch,
.legend-line {
  display: inline-block;
  width: 1.4rem;
  height: 0.72rem;
  border-radius: 2px;
  border: 1px solid transparent;
}

.legend-p {
  background: rgba(31, 122, 70, 0.28);
  border-color: rgba(31, 122, 70, 0.55);
}

.legend-qrs {
  background: rgba(31, 95, 168, 0.32);
  border-color: rgba(31, 95, 168, 0.62);
}

.legend-t {
  background: rgba(123, 90, 29, 0.30);
  border-color: rgba(123, 90, 29, 0.58);
}

.legend-threshold {
  background: repeating-linear-gradient(
    to right,
    rgba(181, 73, 60, 0.75) 0,
    rgba(181, 73, 60, 0.75) 4px,
    transparent 4px,
    transparent 8px
  );
  border-color: rgba(181, 73, 60, 0.5);
}

.legend-line {
  height: 0;
  border-top: 2px solid rgba(31, 95, 168, 0.75);
}

.settings-row {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
  align-items: center;
  border-top: 1px solid var(--line);
  margin-top: 0.9rem;
  padding-top: 0.9rem;
}

.range-field {
  display: grid;
  grid-template-columns: auto minmax(150px, 220px) 3.4rem;
  align-items: center;
  gap: 0.55rem;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.compact-field {
  display: grid;
  grid-template-columns: auto 7.8rem;
  align-items: center;
  gap: 0.45rem;
  margin: 0;
}

.source-field {
  grid-template-columns: auto minmax(10rem, 13rem);
}

.lead-layout-field {
  grid-template-columns: auto minmax(10rem, 13rem);
}

.live-speed-field {
  grid-template-columns: auto minmax(5.4rem, 6rem);
}

.compact-field select {
  padding: 0.48rem 0.55rem;
}

.range-field strong {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
  white-space: nowrap;
}

.toggle input {
  width: auto;
}

.toggle input:checked + span {
  color: var(--accent);
}

.ecg-viewer-shell {
  position: relative;
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  max-height: 72vh;
}

#ecgCanvas {
  display: block;
  width: 100%;
  height: auto;
  background: #fff;
}

.annotation-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.ecg-viewer-shell.annotating #ecgCanvas {
  cursor: crosshair;
}

.annotation-marker {
  position: absolute;
  top: var(--marker-y);
  left: var(--marker-x);
  transform: translate(-50%, -100%);
  color: var(--marker-color);
  font-size: 10px;
  font-weight: 800;
  line-height: 1;
  text-shadow: 0 1px 0 #fff;
}

.annotation-marker::after {
  content: "";
  display: block;
  width: 2px;
  height: 44px;
  margin: 2px auto 0;
  background: currentColor;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.72);
}

.lab-dom-overlay {
  position: absolute;
  inset: 0;
  display: none;
  pointer-events: none;
  z-index: 1;
}

.ecg-viewer-shell.lab-dom-active .lab-dom-overlay {
  display: block;
}

.lab-dom-band {
  position: absolute;
  top: var(--lab-top, 24%);
  height: var(--lab-height, 10%);
  border: 2px solid currentColor;
  border-radius: 3px;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 0.25rem;
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--ink);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.72) inset;
}

.lab-dom-band span {
  display: none;
  border: 1px solid rgba(174, 185, 199, 0.8);
  background: rgba(255, 255, 255, 0.88);
  border-radius: 3px;
  padding: 0.1rem 0.3rem;
}

.lab-dom-p {
  left: var(--lab-p-left, 38%);
  width: var(--lab-p-width, 4%);
  background: rgba(31, 122, 70, var(--lab-opacity, 0.24));
  color: #1f7a46;
}

.lab-dom-qrs {
  left: var(--lab-qrs-left, 48%);
  width: var(--lab-qrs-width, 4%);
  background: rgba(31, 95, 168, var(--lab-opacity, 0.26));
  color: #1f5fa8;
}

.lab-dom-t {
  left: var(--lab-t-left, 58%);
  width: var(--lab-t-width, 8%);
  background: rgba(123, 90, 29, var(--lab-opacity, 0.24));
  color: #7b5a1d;
}

.lab-dom-line {
  position: absolute;
  left: 2.5%;
  right: 2.5%;
  border-top: 2px dashed rgba(181, 73, 60, 0.78);
}

.lab-dom-line.top {
  top: var(--lab-threshold-top, 32%);
}

.lab-dom-line.bottom {
  top: var(--lab-threshold-bottom, 42%);
}

#magnifierCanvas {
  position: absolute;
  left: 0;
  top: 0;
  display: none;
  width: 420px;
  height: 300px;
  border: 2px solid var(--accent);
  border-radius: 6px;
  background: #fff;
  box-shadow: var(--shadow);
  pointer-events: none;
  z-index: 2;
}

.ecg-viewer-shell.magnifier-active {
  cursor: crosshair;
}

.ecg-viewer-shell.magnifier-active #magnifierCanvas.is-visible {
  display: block;
}

.explorer-controls {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  padding: 0.65rem;
  margin-bottom: 0.75rem;
}

.explorer-search {
  grid-template-columns: auto minmax(12rem, 20rem);
}

.explorer-search input {
  padding: 0.48rem 0.55rem;
}

.explorer-list {
  display: grid;
  gap: 0.45rem;
  max-height: 18rem;
  overflow: auto;
  padding-right: 0.15rem;
}

.explorer-item {
  display: grid;
  grid-template-columns: minmax(7rem, 9rem) 1fr auto;
  gap: 0.7rem;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  padding: 0.55rem 0.65rem;
}

.explorer-item.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.explorer-record {
  font-weight: 800;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.explorer-meta {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 0.8rem;
}

.explorer-meta span {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface-soft);
  padding: 0.16rem 0.42rem;
}

.explorer-item button {
  min-height: 2.2rem;
  padding: 0.45rem 0.7rem;
}

.teaching-box,
.feedback {
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  padding: 0.85rem;
  margin-bottom: 0.85rem;
  line-height: 1.5;
}

.feedback.correct {
  border-color: #97cfab;
  background: var(--success-soft);
}

.feedback.incorrect {
  border-color: #dda39d;
  background: var(--danger-soft);
}

.options-list {
  display: grid;
  gap: 0.55rem;
}

.options-list.numpad-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  align-items: stretch;
}

.option-button {
  width: 100%;
  justify-content: flex-start;
  text-align: left;
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
  min-height: 3.2rem;
}

.options-list.numpad-grid .option-button {
  min-height: 4.6rem;
  align-items: flex-start;
  line-height: 1.25;
  padding: 0.7rem;
}

.options-list.numpad-grid .option-button span:last-child {
  overflow-wrap: anywhere;
}

.options-list.numpad-grid .option-button[data-key="7"] {
  grid-column: 1;
  grid-row: 1;
}

.options-list.numpad-grid .option-button[data-key="8"] {
  grid-column: 2;
  grid-row: 1;
}

.options-list.numpad-grid .option-button[data-key="9"] {
  grid-column: 3;
  grid-row: 1;
}

.options-list.numpad-grid .option-button[data-key="4"] {
  grid-column: 1;
  grid-row: 2;
}

.options-list.numpad-grid .option-button[data-key="5"] {
  grid-column: 2;
  grid-row: 2;
}

.options-list.numpad-grid .option-button[data-key="6"] {
  grid-column: 3;
  grid-row: 2;
}

.options-list.numpad-grid .option-button[data-key="1"] {
  grid-column: 1;
  grid-row: 3;
}

.options-list.numpad-grid .option-button[data-key="2"] {
  grid-column: 2;
  grid-row: 3;
}

.options-list.numpad-grid .option-button[data-key="3"] {
  grid-column: 3;
  grid-row: 3;
}

.option-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 1.7rem;
  width: 1.7rem;
  height: 1.7rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  color: var(--accent);
  font-weight: 700;
}

.options-list.numpad-grid .option-number {
  margin-bottom: 0.25rem;
}

.option-button.pending {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.option-button:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.option-button.selected.correct {
  background: var(--success-soft);
  border-color: var(--success);
}

.option-button.selected.incorrect {
  background: var(--danger-soft);
  border-color: var(--danger);
}

.quiz-actions {
  margin-top: 0.85rem;
}

.mini-stats {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  justify-content: flex-end;
  max-width: 15rem;
}

.mini-stats span {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--muted);
  padding: 0.18rem 0.48rem;
  font-size: 0.74rem;
  font-weight: 700;
}

.mini-stats strong {
  color: var(--ink);
}

.compact-note {
  margin: -0.3rem 0 0;
  font-size: 0.86rem;
}

.side-section {
  border-top: 1px solid var(--line);
  margin-top: 1rem;
  padding-top: 1rem;
}

details summary {
  cursor: pointer;
  color: var(--accent);
  font-weight: 700;
}

.dataset-summary {
  margin-top: 0.75rem;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.45;
}

.category-list {
  display: grid;
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.category-item {
  display: grid;
  grid-template-columns: 4.2rem 1fr auto;
  gap: 0.55rem;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface-soft);
  padding: 0.52rem 0.6rem;
  font-size: 0.85rem;
}

.category-item code {
  color: var(--accent);
  font-weight: 700;
}

.category-item strong {
  font-variant-numeric: tabular-nums;
}

dialog {
  border: 1px solid var(--line);
  border-radius: 6px;
  box-shadow: var(--shadow);
  color: var(--ink);
  max-width: 680px;
}

.citation-box {
  border-top: 1px solid var(--line);
  margin-top: 1rem;
  padding-top: 1rem;
  line-height: 1.5;
}

.about-meta {
  display: grid;
  gap: 0.45rem;
  margin: 1rem 0;
  color: var(--muted);
  font-size: 0.86rem;
}

.about-meta div {
  display: flex;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.about-meta dt {
  font-weight: 700;
  color: var(--ink);
}

.about-meta dd {
  margin: 0;
}

.citation-box h3 {
  margin: 0 0 0.5rem;
}

.citation-box p {
  margin: 0.5rem 0;
}

.citation-box a {
  color: var(--accent);
  font-weight: 700;
}

dialog::backdrop {
  background: rgba(16, 25, 34, 0.4);
}

.icon-button {
  min-width: 2.4rem;
  padding-left: 0.75rem;
  padding-right: 0.75rem;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 0.9rem;
  padding: 1rem 0 2rem;
}

@media (max-width: 1180px) {
  .lab-controls {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 980px) {
  .workspace,
  .main-pane,
  .session-grid {
    grid-template-columns: 1fr;
  }

  .sticky-card {
    position: static;
  }
}

@media (max-width: 680px) {
  .app-header {
    display: grid;
  }

  button,
  .button {
    width: 100%;
  }

  .options-list.numpad-grid .option-button {
    width: 100%;
    min-height: 4.2rem;
    padding: 0.6rem;
    font-size: 0.9rem;
  }

  .section-head {
    display: grid;
  }

  .range-field {
    grid-template-columns: 1fr;
    width: 100%;
  }

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