:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --panel: #ffffff;
  --ink: #182230;
  --muted: #667085;
  --line: #d7dde7;
  --soft-line: #ebeff5;
  --green: #19715f;
  --green-soft: #e2f1ed;
  --blue: #2d5f9a;
  --blue-soft: #e8f0fb;
  --amber: #8a5a00;
  --amber-soft: #fff3d8;
  --red: #9f2f38;
  --red-soft: #fde7e9;
  --shadow: 0 16px 40px rgba(24, 34, 48, .08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: linear-gradient(180deg, #edf5f1 0, #f4f6f8 260px), var(--bg);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", sans-serif;
}

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

button {
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 8px 11px;
  color: var(--ink);
  background: #fff;
  cursor: pointer;
}

button:hover, .nav a:hover, .entryCard:hover { border-color: #9eb2c8; }

input, select, textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  background: #fff;
}

input, select { min-height: 40px; padding: 8px 10px; }

textarea {
  resize: vertical;
  padding: 10px;
  line-height: 1.45;
}

label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.shell {
  width: min(1460px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 24px 0 44px;
}

.hero { padding: 8px 0 18px; }

.nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
  margin-bottom: 22px;
}

.nav a {
  color: var(--ink);
  text-decoration: none;
  background: rgba(255,255,255,.86);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 14px;
}

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

.eyebrow {
  margin-bottom: 8px;
  color: var(--green);
  font-size: 13px;
  font-weight: 850;
}

h1 {
  max-width: 920px;
  margin-bottom: 10px;
  font-size: clamp(36px, 5vw, 60px);
  line-height: .98;
  letter-spacing: 0;
}

.subtitle {
  max-width: 900px;
  margin-bottom: 0;
  color: #475467;
  font-size: 18px;
  line-height: 1.55;
}

.stats {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 10px;
  margin: 14px 0;
}

.stat,
.toolbar,
.entryCard,
.flowPanel,
.sidePanel,
.mainPanel,
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.stat {
  min-height: 76px;
  padding: 13px;
}

.stat strong {
  display: block;
  font-size: 25px;
  line-height: 1.05;
}

.stat span {
  display: block;
  margin-top: 5px;
  color: var(--muted);
  font-size: 12px;
}

.toolbar {
  display: grid;
  grid-template-columns: minmax(260px, 1fr) 120px 170px 150px 160px auto;
  gap: 10px;
  align-items: end;
  padding: 12px;
  box-shadow: var(--shadow);
}

.buttonGroup {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.buttonGroup.left { justify-content: flex-start; }

.entryGrid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 10px;
  margin: 14px 0;
}

.entryCard {
  min-height: 112px;
  padding: 13px;
  color: inherit;
  text-decoration: none;
}

.entryCard strong {
  display: block;
  margin-bottom: 8px;
  font-size: 15px;
}

.entryCard span {
  color: #475467;
  font-size: 13px;
  line-height: 1.45;
}

.flowPanel {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  align-items: center;
  margin-bottom: 14px;
  padding: 12px;
}

.flowArrow { display: none; }

.flowStep {
  min-height: 86px;
  border: 1px solid var(--soft-line);
  border-radius: 8px;
  background: #fbfcfe;
  padding: 12px;
}

.flowStep span {
  display: inline-grid;
  place-items: center;
  width: 24px;
  height: 24px;
  margin-bottom: 8px;
  border-radius: 50%;
  color: #fff;
  background: var(--green);
  font-size: 12px;
  font-weight: 800;
}

.flowStep strong,
.flowStep em {
  display: block;
  font-style: normal;
}

.flowStep em {
  margin-top: 4px;
  color: var(--muted);
  font-size: 12px;
}

.workspace {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
}

.sidePanel {
  position: sticky;
  top: 14px;
  max-height: calc(100vh - 28px);
  overflow: hidden;
}

.mainPanel { min-width: 0; }

.sectionHead {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 54px;
  padding: 13px 15px;
  border-bottom: 1px solid var(--line);
  background: #fbfcfe;
}

.sectionHead h2 {
  margin: 0;
  font-size: 17px;
}

.sectionHead span {
  color: var(--muted);
  font-size: 12px;
}

.verbList {
  display: grid;
  gap: 8px;
  max-height: calc(100vh - 84px);
  overflow: auto;
  padding: 12px;
}

.verbButton,
.scenarioCard,
.pathCard,
.reviewItem,
.practiceCardInner {
  border: 1px solid var(--soft-line);
  border-radius: 8px;
  background: #fff;
}

.verbButton {
  display: grid;
  gap: 6px;
  width: 100%;
  padding: 11px;
  text-align: left;
}

.verbButton.active {
  border-color: var(--green);
  box-shadow: 0 0 0 2px rgba(25, 113, 95, .13);
}

.verbTop {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.verbTop strong { font-size: 18px; }

.badge,
.tag,
.level,
.pill {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  border-radius: 999px;
  padding: 3px 8px;
  font-size: 12px;
  font-weight: 800;
}

.level { color: var(--blue); background: var(--blue-soft); }
.tag { color: var(--green); background: var(--green-soft); }
.pill { color: #475467; background: #f2f4f7; }
.badge { color: var(--amber); background: var(--amber-soft); }

.verbButton p {
  margin: 0;
  color: #475467;
  font-size: 13px;
  line-height: 1.38;
}

.detailBody,
.panelBody,
.trainer,
.scenarioDetail,
.practiceCard,
.reviewQueue {
  padding: 14px;
}

.verbHero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(260px, .9fr);
  gap: 12px;
  margin-bottom: 12px;
}

.explainBox,
.chunkGroup,
.patternCard,
.sceneLink,
.mistakeBox,
.trainerOutput,
.practiceCardInner {
  border: 1px solid var(--soft-line);
  border-radius: 8px;
  background: #fff;
  padding: 12px;
}

.explainBox h3,
.chunkGroup h3,
.patternCard h3,
.sceneLink h3,
.mistakeBox h3 {
  margin: 0 0 8px;
  font-size: 15px;
}

.explainBox p,
.chunkGroup p,
.patternCard p,
.sceneLink p,
.mistakeBox p {
  margin: 0;
  color: #475467;
  line-height: 1.5;
}

.chipGrid,
.chunkGrid,
.patternGrid,
.sceneMiniGrid,
.tagRow {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.chunkGrid button,
.chipGrid button,
.tagRow button {
  min-height: 30px;
  border-radius: 999px;
  padding: 5px 9px;
  font-size: 13px;
}

.sectionStack {
  display: grid;
  gap: 12px;
}

.splitGrid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  margin-top: 14px;
}

.panel { overflow: hidden; }

.chunkRows {
  display: grid;
  gap: 10px;
}

.chunkGroup {
  display: grid;
  gap: 10px;
}

.sentenceList {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.sentenceList li {
  border-left: 3px solid var(--green);
  background: #fbfcfe;
  padding: 8px 10px;
  color: #344054;
}

.trainer {
  display: grid;
  gap: 12px;
}

.trainerOutput {
  display: grid;
  gap: 10px;
  min-height: 90px;
}

.outputLine {
  display: grid;
  gap: 4px;
  border-left: 3px solid var(--blue);
  background: #fbfcfe;
  padding: 8px 10px;
}

.outputLine strong {
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
}

.scenarioGrid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  padding: 12px;
}

.scenarioCard {
  padding: 12px;
  text-align: left;
}

.scenarioCard.active {
  border-color: var(--green);
  box-shadow: 0 0 0 2px rgba(25, 113, 95, .13);
}

.scenarioCard h3,
.pathCard h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.scenarioCard p,
.pathCard p {
  margin: 0 0 10px;
  color: #475467;
  font-size: 13px;
  line-height: 1.45;
}

.scenarioDetail {
  border-top: 1px solid var(--line);
}

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

.detailGrid .explainBox {
  min-height: 120px;
}

.pathList {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  padding: 12px;
}

.pathCard {
  padding: 12px;
}

.practiceCardInner {
  display: grid;
  gap: 12px;
}

.practicePrompt {
  margin: 0;
  font-size: 18px;
  line-height: 1.45;
}

.answerBox {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfe;
  padding: 10px;
  color: #344054;
}

.reviewQueue {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.reviewItem {
  display: grid;
  gap: 8px;
  padding: 12px;
}

.reviewItem p { margin: 0; color: #475467; }

.empty {
  padding: 18px;
  color: var(--muted);
  text-align: center;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 10;
  max-width: 360px;
  border: 1px solid rgba(25, 113, 95, .28);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
  padding: 10px 12px;
  color: var(--ink);
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

mark {
  background: #fff0b3;
  color: inherit;
  padding: 0 2px;
  border-radius: 3px;
}

@media (max-width: 1180px) {
  .stats,
  .entryGrid { grid-template-columns: repeat(3, minmax(0, 1fr)); }

  .toolbar { grid-template-columns: repeat(3, minmax(0, 1fr)); }

  .workspace { grid-template-columns: 320px minmax(0, 1fr); }

  .scenarioGrid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  .shell { width: min(100% - 24px, 760px); padding-top: 16px; }

  .nav { justify-content: flex-start; }

  .toolbar,
  .workspace,
  .splitGrid,
  .verbHero,
  .detailGrid,
  .flowPanel {
    grid-template-columns: 1fr;
  }

  .sidePanel {
    position: static;
    max-height: none;
  }

  .verbList { max-height: 360px; }

  .scenarioGrid,
  .pathList,
  .reviewQueue {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .stats,
  .entryGrid {
    grid-template-columns: 1fr 1fr;
  }

  h1 { font-size: 36px; }

  .subtitle { font-size: 16px; }

  .sectionHead {
    align-items: flex-start;
    flex-direction: column;
  }
}