:root {
  color-scheme: dark;
  --bg: #0c0f11;
  --surface: #12171b;
  --surface-2: #192026;
  --surface-3: #202a30;
  --line: #2b343b;
  --text: #eff4f2;
  --muted: #9ca8a3;
  --accent: #8bd6c7;
  --accent-strong: #42c2a9;
  --danger: #ff7d70;
  --warn: #e6bd67;
  --ok: #8bd47a;
  --shadow: 0 20px 70px rgba(0, 0, 0, 0.35);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100svh;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 0%, rgba(139, 214, 199, 0.14), transparent 28%),
    linear-gradient(135deg, #090b0d 0%, #11171a 48%, #090c0e 100%);
}

button,
input {
  font: inherit;
}

button {
  border-radius: 0;
}

.app-shell {
  max-width: 1480px;
  min-height: 100svh;
  margin: 0 auto;
  padding: 22px;
}

.topbar,
.section-head,
.play-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
}

.topbar {
  margin-bottom: 20px;
}

.section-head {
  align-items: center;
  margin-bottom: 18px;
}

.section-head.compact {
  margin-top: 18px;
}

.play-head {
  align-items: center;
  margin-bottom: 14px;
}

.eyebrow,
.case-label,
.section-label {
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(2rem, 4vw, 4rem);
  line-height: 0.95;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 0;
  max-width: 780px;
  font-size: clamp(1.25rem, 2.2vw, 1.8rem);
  line-height: 1.18;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 1rem;
  line-height: 1.25;
  letter-spacing: 0;
}

.muted-copy {
  color: var(--muted);
  margin-bottom: 0;
}

.screen {
  display: none;
}

.screen.active {
  display: block;
}

.main-nav,
.score-strip,
.case-score {
  display: flex;
  gap: 10px;
  white-space: nowrap;
}

.nav-button,
.score-strip span,
.case-score span {
  min-height: 42px;
  border: 1px solid var(--line);
  background: rgba(18, 23, 27, 0.72);
  color: var(--text);
}

.nav-button {
  padding: 0 14px;
  cursor: pointer;
}

.nav-button[aria-pressed="true"] {
  border-color: var(--accent);
  background: rgba(66, 194, 169, 0.16);
}

.score-strip span,
.case-score span {
  min-width: 92px;
  padding: 9px 12px;
  color: var(--muted);
  text-align: center;
}

.score-strip strong,
.case-score strong {
  color: var(--text);
  font-size: 1.1rem;
}

.profile-panel {
  display: grid;
  gap: 6px;
  min-width: 230px;
}

.profile-panel label {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
}

.profile-panel input {
  min-height: 42px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--text);
  padding: 0 12px;
}

.pack-grid,
.case-grid,
.tutorial-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.pack-card,
.case-card,
.tutorial-grid article,
.case-browser,
.stage-note,
.leaderboard-row,
.empty-state {
  border: 1px solid var(--line);
  background: rgba(18, 23, 27, 0.82);
  box-shadow: var(--shadow);
}

.pack-card,
.case-card,
.tutorial-grid article,
.stage-note,
.empty-state {
  padding: 16px;
}

.compact-empty {
  box-shadow: none;
  padding: 10px;
  color: var(--muted);
}

.pack-card {
  display: grid;
  gap: 12px;
  min-height: 220px;
  align-content: start;
  cursor: pointer;
}

.pack-card[data-selected="true"] {
  border-color: var(--accent);
}

.pack-card[data-locked="true"] {
  opacity: 0.78;
}

.pack-card p,
.case-card p,
.tutorial-grid p,
.stage-note p,
.leaderboard-row p {
  color: var(--muted);
  line-height: 1.45;
}

.pack-card-head {
  min-height: 70px;
}

.progress-bar {
  height: 8px;
  overflow: hidden;
  background: #07090a;
}

.progress-bar span {
  display: block;
  height: 100%;
  background: var(--accent);
}

.case-browser {
  margin-top: 16px;
  padding: 18px;
}

.case-card {
  display: grid;
  gap: 10px;
  min-height: 190px;
}

.case-card-footer {
  color: var(--accent);
  font-weight: 800;
}

.tutorial-grid article {
  min-height: 150px;
}

.leaderboard-list {
  display: grid;
  gap: 10px;
}

.leaderboard-row {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr) 120px;
  align-items: center;
  gap: 12px;
  padding: 14px;
}

.leaderboard-row[data-current="true"] {
  border-color: var(--accent);
  background: rgba(66, 194, 169, 0.11);
}

.leaderboard-row > strong {
  color: var(--accent);
  font-size: 1.4rem;
}

.leaderboard-row span {
  text-align: right;
  font-weight: 900;
}

.stage-note {
  margin-top: 14px;
}

.study-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(310px, 380px);
  gap: 18px;
  align-items: start;
}

.viewer-panel,
.control-panel {
  border: 1px solid var(--line);
  background: rgba(18, 23, 27, 0.82);
  box-shadow: var(--shadow);
}

.viewer-panel {
  min-width: 0;
}

.viewer-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 18px;
  border-bottom: 1px solid var(--line);
}

.image-stage {
  position: relative;
  display: grid;
  place-items: center;
  overflow: hidden;
  background: #050607;
  cursor: crosshair;
}

#cxr-canvas {
  display: block;
  width: auto;
  height: auto;
  max-width: 100%;
  max-height: min(76svh, 860px);
  user-select: none;
  touch-action: none;
}

.control-panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
  padding: 18px;
}

.panel-section {
  padding-bottom: 18px;
}

.mark-tools[hidden] {
  display: none;
}

.tool-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 8px;
}

.tool-row button[aria-pressed="true"] {
  border-color: var(--accent);
  background: rgba(66, 194, 169, 0.16);
}

.mark-list {
  display: grid;
  gap: 6px;
  margin-top: 10px;
}

.mark-chip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  min-height: 34px;
  border: 1px solid var(--line);
  background: rgba(5, 6, 7, 0.32);
  color: var(--muted);
  padding: 6px 8px;
  font-size: 0.86rem;
}

.mark-chip strong {
  color: var(--text);
}

.choice-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}

.choice {
  width: 100%;
  min-height: 42px;
  padding: 9px 11px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--text);
  text-align: left;
  cursor: pointer;
  transition: border-color 140ms ease, background 140ms ease, transform 140ms ease;
}

.choice:hover {
  border-color: rgba(139, 214, 199, 0.7);
  transform: translateY(-1px);
}

.choice[aria-pressed="true"] {
  border-color: var(--accent);
  background: rgba(66, 194, 169, 0.18);
}

.choice:disabled {
  cursor: default;
  opacity: 0.9;
  transform: none;
}

.choice[data-truth="present"] {
  border-color: rgba(139, 212, 122, 0.72);
}

.choice[data-truth="extra"] {
  border-color: rgba(255, 125, 112, 0.72);
  background: rgba(255, 125, 112, 0.08);
}

.feedback-section {
  flex: 1;
}

.feedback,
.rationale {
  border: 1px solid var(--line);
  background: rgba(5, 6, 7, 0.38);
  padding: 12px;
  line-height: 1.45;
}

.feedback {
  min-height: 78px;
  color: var(--muted);
}

.feedback.good {
  color: var(--ok);
  border-color: rgba(139, 212, 122, 0.45);
}

.feedback.mixed {
  color: var(--warn);
  border-color: rgba(230, 189, 103, 0.45);
}

.feedback.bad {
  color: var(--danger);
  border-color: rgba(255, 125, 112, 0.45);
}

.rationale {
  margin-top: 10px;
  color: #d3ddd8;
  font-size: 0.94rem;
}

.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.primary-button,
.secondary-button,
.ghost-button {
  min-height: 44px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 140ms ease, opacity 140ms ease, background 140ms ease;
}

.compact-button {
  min-height: 40px;
  padding: 0 14px;
}

.primary-button {
  background: var(--accent);
  color: #06110f;
  font-weight: 900;
}

.secondary-button,
.ghost-button {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
}

.primary-button:hover:not(:disabled),
.secondary-button:hover:not(:disabled),
.ghost-button:hover:not(:disabled) {
  transform: translateY(-1px);
}

button:disabled {
  cursor: default;
  opacity: 0.55;
}

@media (max-width: 1080px) {
  .topbar,
  .section-head,
  .play-head {
    align-items: stretch;
    flex-direction: column;
  }

  .main-nav,
  .score-strip,
  .case-score {
    width: 100%;
  }

  .main-nav > *,
  .score-strip > *,
  .case-score > * {
    flex: 1;
  }

  .pack-grid,
  .case-grid,
  .tutorial-grid,
  .study-layout {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 560px) {
  .app-shell {
    padding: 12px;
  }

  .main-nav,
  .score-strip,
  .case-score,
  .actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .choice-grid {
    grid-template-columns: 1fr;
  }

  .leaderboard-row {
    grid-template-columns: 42px minmax(0, 1fr);
  }

  .leaderboard-row span {
    grid-column: 2;
    text-align: left;
  }
}