:root {
  --ink: #17211b;
  --muted: #65736c;
  --line: #d9dfda;
  --paper: #f6f4ef;
  --white: #ffffff;
  --green: #1f6b4b;
  --green-soft: #dcebe3;
  --blue: #244f7a;
  --blue-soft: #dfe8f3;
  --amber: #a86922;
  --amber-soft: #f3e3cf;
  --dark: #1f2a28;
  --shadow: 0 18px 42px rgba(24, 32, 27, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--paper);
  color: var(--ink);
}

button,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

[hidden] {
  display: none !important;
}

.shell {
  width: min(1440px, 100%);
  margin: 0 auto;
  padding: 28px;
}

.topbar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  padding: 8px 0 24px;
}

.eyebrow,
.tag,
.side-title {
  margin: 0 0 8px;
  color: var(--green);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 0;
  font-size: clamp(34px, 5vw, 64px);
  line-height: 1.02;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 10px;
  font-size: 25px;
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 15px;
  letter-spacing: 0;
}

.today-box,
.sidebar,
.workspace,
.side-card {
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.today-box {
  min-width: 180px;
  padding: 14px 16px;
}

.today-box span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.today-box strong {
  display: block;
  margin-top: 6px;
  color: var(--blue);
  font-size: 20px;
}

.layout {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr) 340px;
  gap: 18px;
  align-items: start;
}

.sidebar,
.rightbar {
  display: grid;
  gap: 12px;
}

.sidebar {
  padding: 12px;
}

.nav-item,
.stage,
#submitRound,
#resetExam,
#generateCase,
.quick-prompt,
.speak-button,
#markLearned,
#exportData,
.import-label,
#clearCases,
#saveGeneratedCase {
  min-height: 44px;
  border: 1px solid var(--line);
  background: #f8f9f7;
  color: var(--ink);
}

.nav-item {
  width: 100%;
  padding: 10px 12px;
  text-align: left;
}

.nav-item.active {
  background: var(--green-soft);
  border-color: #bdd5c7;
  color: var(--green);
  font-weight: 700;
}

.workspace {
  min-height: 720px;
  padding: 18px;
}

.stage-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 18px;
}

.stage.active {
  background: var(--blue);
  color: var(--white);
  border-color: var(--blue);
}

.module-head,
.coach-hero,
.exam-task {
  padding: 22px;
  border: 1px solid #c6d7d4;
  background: linear-gradient(135deg, var(--green-soft), var(--blue-soft));
}

.module-head p,
.coach-hero p,
.exam-task p {
  max-width: 760px;
  margin-bottom: 0;
  color: #3f4f46;
  line-height: 1.65;
}

.view {
  margin-top: 18px;
}

.dialogue-card {
  display: grid;
  gap: 12px;
  margin-bottom: 16px;
}

.message {
  padding: 16px;
  border: 1px solid var(--line);
  background: #fbfbf8;
}

.message span {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.message p {
  margin-bottom: 0;
  line-height: 1.6;
}

.incoming {
  border-left: 5px solid var(--amber);
}

.outgoing {
  border-left: 5px solid var(--green);
}

.learn-stack,
.rightbar,
.coach-view {
  display: grid;
  gap: 14px;
}

.learn-columns,
.exam-main,
.coach-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.coach-actions {
  grid-template-columns: 1fr 1fr 1.2fr;
}

.learn-section,
.exam-checklist,
.coach-panel,
.case-result {
  padding: 18px;
  border: 1px solid var(--line);
  background: #fffdf9;
}

.learn-section.warning {
  background: #fff7ea;
  border-color: #e2c49d;
}

.learn-section.usable {
  background: var(--green-soft);
  border-color: #bdd5c7;
}

.drill-card {
  background: #fbfbf8;
}

.pronunciation-card {
  background: #f7fbff;
  border-color: #c4d4e7;
}

.pronunciation-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.pronunciation-label {
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.pronunciation-text {
  margin-bottom: 8px;
  color: var(--blue);
  font-weight: 700;
  line-height: 1.55;
}

.pronunciation-note {
  margin-bottom: 0;
  color: #3f4f46;
  line-height: 1.65;
}

.pronunciation-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.speak-button {
  background: var(--blue);
  color: var(--white);
  border-color: var(--blue);
  font-weight: 700;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.section-title span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--blue);
  color: var(--white);
  font-size: 12px;
  font-weight: 700;
}

.section-title h3 {
  margin: 0;
}

ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

li {
  display: grid;
  grid-template-columns: minmax(120px, 190px) 1fr;
  gap: 10px;
  line-height: 1.6;
}

li strong {
  color: var(--blue);
}

.side-card {
  padding: 18px;
}

.side-card.dark {
  background: var(--dark);
  border-color: var(--dark);
  color: var(--white);
}

.side-card.dark .tag,
.side-card.dark label {
  color: #b7d8c7;
}

.side-card p,
.learn-section p,
.exam-checklist p,
.case-result p {
  line-height: 1.65;
}

.exam-progress {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
}

.exam-progress span {
  color: #dcebe3;
  font-size: 13px;
  font-weight: 700;
}

#resetExam {
  min-height: 34px;
  padding: 6px 10px;
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.18);
  color: #dcebe3;
}

.exam-chat {
  display: grid;
  gap: 10px;
  max-height: 300px;
  overflow: auto;
  padding-right: 4px;
}

.chat-line {
  margin: 0;
  padding: 12px;
  background: rgba(255, 255, 255, 0.08);
  line-height: 1.55;
}

.chat-line.bot {
  border-left: 4px solid #f3c36a;
}

.chat-line.user {
  margin-left: 20px;
  background: rgba(183, 216, 199, 0.14);
  border-left: 4px solid #b7d8c7;
}

label {
  display: block;
  margin: 12px 0 8px;
  font-size: 13px;
  font-weight: 700;
}

textarea {
  width: 100%;
  resize: vertical;
  border: 1px solid #6f7d78;
  padding: 10px;
  line-height: 1.45;
}

#submitRound,
#generateCase,
#saveGeneratedCase,
#markLearned {
  width: 100%;
  margin-top: 10px;
  background: #f3c36a;
  color: #251b0a;
  font-weight: 700;
}

#markLearned:disabled {
  cursor: default;
  background: var(--green-soft);
  color: var(--green);
}

.progress-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-top: 14px;
}

.progress-grid div {
  padding: 10px;
  border: 1px solid var(--line);
  background: #fbfbf8;
}

.progress-grid span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.progress-grid strong {
  display: block;
  margin-top: 4px;
  color: var(--blue);
  font-size: 20px;
}

.quick-prompt {
  background: var(--blue-soft);
  color: var(--blue);
  font-weight: 700;
}

.coach-panel textarea {
  min-height: 180px;
}

.case-result {
  background: var(--blue-soft);
  border-color: #c4d4e7;
}

.feedback {
  color: #dcebe3;
  line-height: 1.7;
  word-break: break-word;
}

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

.saved-list article {
  padding: 10px;
  border: 1px solid var(--line);
  background: #fbfbf8;
}

.saved-list strong,
.saved-list span {
  display: block;
}

.saved-list span {
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
}

#clearCases {
  width: 100%;
  margin-top: 12px;
}

.data-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 12px;
}

#exportData,
.import-label {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 13px;
  font-weight: 700;
}

@media (max-width: 1120px) {
  .layout {
    grid-template-columns: 160px minmax(0, 1fr);
  }

  .rightbar {
    grid-column: 1 / -1;
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 760px) {
  .shell {
    padding: 18px;
  }

  .topbar,
  .layout,
  .rightbar,
  .learn-columns,
  .exam-main,
  .coach-actions,
  .pronunciation-grid,
  .pronunciation-actions,
  .progress-grid,
  .data-actions {
    grid-template-columns: 1fr;
  }

  .topbar {
    align-items: stretch;
  }

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

  .stage-row {
    grid-template-columns: 1fr;
  }

  .nav-item {
    text-align: center;
  }

  li {
    grid-template-columns: 1fr;
    gap: 2px;
  }
}