:root {
  color-scheme: light;
  --bg: #f7f5ef;
  --surface: #fffdf8;
  --surface-strong: #ffffff;
  --ink: #24201a;
  --muted: #70695f;
  --line: #ded7cb;
  --teal: #147c74;
  --teal-soft: #d9f0ec;
  --coral: #c85c4a;
  --coral-soft: #f7ddd8;
  --gold: #a97912;
  --gold-soft: #f5e8c8;
  --blue: #315f9f;
  --blue-soft: #dfe9f7;
  --green: #317a43;
  --shadow: 0 18px 50px rgba(45, 36, 25, 0.1);
  --radius: 8px;
  --font: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --zh-font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", var(--font);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    linear-gradient(180deg, rgba(255, 253, 248, 0.96), rgba(247, 245, 239, 0.96)),
    repeating-linear-gradient(90deg, rgba(20, 124, 116, 0.035) 0 1px, transparent 1px 38px);
  color: var(--ink);
  font-family: var(--font);
}

button,
input,
select {
  font: inherit;
}

button,
select,
input {
  border-radius: var(--radius);
}

button {
  min-height: 40px;
  border: 1px solid var(--line);
  background: var(--surface-strong);
  color: var(--ink);
  cursor: pointer;
}

button:hover {
  border-color: rgba(20, 124, 116, 0.55);
  color: var(--teal);
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
.char-token:focus-visible {
  outline: 3px solid rgba(20, 124, 116, 0.22);
  outline-offset: 2px;
}

button:disabled {
  cursor: wait;
  opacity: 0.65;
}

.update-banner {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  border-bottom: 1px solid rgba(20, 124, 116, 0.24);
  background: #173e3a;
  color: #fff;
  padding: 10px 14px;
  text-align: center;
}

.update-banner .primary {
  min-height: 34px;
  border-color: #fff;
  background: #fff;
  color: #173e3a;
  padding: 0 12px;
}

label {
  display: block;
  margin: 14px 0 6px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

input,
select {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--line);
  background: var(--surface-strong);
  color: var(--ink);
  padding: 0 12px;
}

.primary {
  border-color: var(--teal);
  background: var(--teal);
  color: #fff;
  font-weight: 800;
}

.primary:hover {
  background: #0f6b64;
  color: #fff;
}

.wide {
  width: 100%;
  margin-top: 14px;
}

.hidden {
  display: none !important;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: 0.73rem;
  font-weight: 850;
  letter-spacing: 0;
  text-transform: uppercase;
}

.app-shell {
  min-height: 100vh;
  padding: 18px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  max-width: 1580px;
  margin: 0 auto 16px;
}

.brand-block h1,
.profile-dialog h1,
.section-heading h2,
.reader-toolbar h2 {
  margin: 0;
  letter-spacing: 0;
}

.brand-block h1 {
  font-size: clamp(1.5rem, 2.2vw, 2.15rem);
}

.topbar-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: wrap;
}

.nav-button {
  min-width: 72px;
  padding: 0 14px;
  font-weight: 850;
}

.nav-button.active {
  border-color: var(--teal);
  background: var(--teal-soft);
  color: var(--teal);
}

.profile-switch {
  display: grid;
  min-width: 174px;
  padding: 7px 12px;
  text-align: left;
}

.profile-switch span {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 750;
}

.profile-switch strong {
  overflow: hidden;
  max-width: 180px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  border: 1px solid rgba(49, 95, 159, 0.28);
  border-radius: 999px;
  background: var(--blue-soft);
  color: var(--blue);
  padding: 0 12px;
  font-size: 0.84rem;
  font-weight: 800;
}

.status-pill.soft {
  border-color: rgba(49, 122, 67, 0.24);
  background: #e4f1e7;
  color: var(--green);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(236px, 280px) minmax(520px, 1fr) minmax(300px, 380px);
  gap: 16px;
  max-width: 1580px;
  margin: 0 auto;
  align-items: start;
}

.side-panel,
.reader-panel,
.profile-dialog {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.94);
  box-shadow: var(--shadow);
}

.side-panel {
  display: grid;
  gap: 14px;
  padding: 14px;
  position: sticky;
  top: 16px;
}

.reader-panel {
  min-width: 0;
  padding: 18px;
}

.panel-section {
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
}

.panel-section:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.section-heading,
.reader-toolbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.section-heading h2 {
  font-size: 1.05rem;
}

.with-action {
  align-items: center;
}

.with-action select {
  width: 118px;
  min-height: 36px;
  padding: 0 8px;
  font-size: 0.86rem;
}

.level-card {
  display: grid;
  gap: 10px;
  border: 1px solid rgba(20, 124, 116, 0.18);
  border-radius: var(--radius);
  background: var(--teal-soft);
  padding: 12px;
}

.level-card strong {
  display: block;
  font-size: 1.03rem;
}

.level-card p {
  margin: 4px 0 0;
  color: #315c57;
  font-size: 0.88rem;
  line-height: 1.45;
}

.level-meter {
  display: grid;
  gap: 5px;
}

.meter-track {
  overflow: hidden;
  height: 8px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
}

.meter-fill {
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--coral), var(--gold), var(--teal));
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.stat {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  padding: 10px;
}

.stat span {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 760;
}

.stat strong {
  display: block;
  margin-top: 3px;
  font-size: 1.16rem;
}

.reader-toolbar {
  align-items: center;
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
}

.reader-toolbar h2 {
  font-family: var(--zh-font);
  font-size: clamp(1.25rem, 2vw, 1.78rem);
}

.article-text {
  display: grid;
  gap: 18px;
  margin: 20px 0;
  font-family: var(--zh-font);
}

.article-paragraph {
  margin: 0;
  color: #1f1a16;
  font-size: clamp(1.32rem, 1.9vw, 1.72rem);
  line-height: 2.08;
  text-indent: 2em;
}

.char-token {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.32em;
  min-height: 1.62em;
  margin: 0 1px 4px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: inherit;
  padding: 0 2px;
  font: inherit;
  line-height: 1.25;
  vertical-align: baseline;
  touch-action: manipulation;
}

.char-token:hover {
  background: rgba(20, 124, 116, 0.1);
  color: inherit;
}

.char-token.marked {
  background: var(--gold-soft);
  box-shadow: inset 0 -3px 0 var(--gold);
}

.punct-token {
  display: inline;
  color: #4c453d;
}

.comprehension-box {
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.question-list {
  display: grid;
  gap: 12px;
  margin-top: 12px;
}

.question-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  padding: 12px;
}

.question-card h3 {
  margin: 0 0 10px;
  font-size: 0.98rem;
  line-height: 1.45;
}

.option-grid {
  display: grid;
  gap: 8px;
}

.option-label {
  display: grid;
  grid-template-columns: 22px 1fr;
  gap: 8px;
  align-items: start;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfaf6;
  padding: 9px;
  color: var(--ink);
  font-size: 0.92rem;
  line-height: 1.35;
}

.option-label input {
  width: 18px;
  min-height: 18px;
  margin: 1px 0 0;
}

.option-label.correct {
  border-color: rgba(49, 122, 67, 0.45);
  background: #e8f3eb;
}

.option-label.wrong {
  border-color: rgba(200, 92, 74, 0.5);
  background: #f9e8e4;
}

.selected-vocab,
.vocab-card,
.progress-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
}

.selected-vocab {
  padding: 12px;
}

.empty-state {
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.55;
}

.vocab-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
}

.vocab-term {
  font-family: var(--zh-font);
  font-size: 1.35rem;
  font-weight: 850;
}

.vocab-pinyin {
  color: var(--coral);
  font-size: 0.9rem;
  font-weight: 780;
}

.vocab-text {
  margin: 7px 0;
  color: var(--ink);
  font-size: 0.92rem;
  line-height: 1.52;
}

.vocab-text.en {
  color: var(--blue);
}

.vocab-example {
  border-left: 3px solid var(--teal);
  margin: 9px 0 0;
  padding-left: 9px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.45;
}

.vocab-list {
  display: grid;
  gap: 10px;
  max-height: 48vh;
  overflow: auto;
  padding-right: 2px;
}

.vocab-card {
  padding: 11px;
}

.status-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 6px;
  margin-top: 10px;
}

.status-row button {
  min-height: 34px;
  padding: 0 6px;
  font-size: 0.78rem;
  font-weight: 800;
  white-space: nowrap;
}

.status-row button.active[data-status="new"] {
  border-color: var(--coral);
  background: var(--coral-soft);
  color: #843428;
}

.status-row button.active[data-status="learning"] {
  border-color: var(--gold);
  background: var(--gold-soft);
  color: #73510b;
}

.status-row button.active[data-status="mastered"] {
  border-color: var(--green);
  background: #e4f1e7;
  color: var(--green);
}

.progress-panel {
  display: grid;
  gap: 10px;
}

.progress-card {
  padding: 12px;
}

.progress-card strong {
  display: block;
  margin-bottom: 4px;
}

.progress-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.45;
}

.history-list {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.history-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfaf6;
  padding: 9px;
}

.history-item span {
  color: var(--muted);
  font-size: 0.78rem;
}

.history-item strong {
  display: block;
  margin-top: 2px;
  font-size: 0.9rem;
}

.mistake-book-view {
  max-width: 1280px;
  margin: 0 auto;
}

.mistake-book-hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.94);
  box-shadow: var(--shadow);
  padding: 18px;
}

.mistake-book-hero h2 {
  margin: 0;
  font-size: clamp(1.35rem, 2vw, 1.9rem);
}

.mistake-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: wrap;
}

.mistake-actions select {
  width: 128px;
}

.mistake-stats {
  margin: 14px 0;
}

.mistake-book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}

.mistake-book-grid .vocab-card {
  min-height: 224px;
}

.profile-gate {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  background: rgba(36, 32, 26, 0.36);
  padding: 18px;
}

.profile-dialog {
  width: min(780px, 100%);
  padding: 22px;
}

.profile-dialog h1 {
  font-size: 1.8rem;
}

.profile-copy {
  margin: 8px 0 18px;
  color: var(--muted);
  line-height: 1.55;
}

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

.profile-card {
  min-height: 116px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  padding: 14px;
  text-align: left;
}

.profile-card strong {
  display: block;
  margin-bottom: 6px;
  font-size: 1.06rem;
}

.profile-card span {
  display: block;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.45;
}

.profile-card.student {
  border-color: rgba(20, 124, 116, 0.36);
}

.profile-card.tester {
  border-color: rgba(49, 95, 159, 0.36);
}

.profile-form {
  display: grid;
  grid-template-columns: 1fr 160px 132px;
  gap: 10px;
  align-items: end;
  border-top: 1px solid var(--line);
  margin-top: 18px;
  padding-top: 16px;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 30;
  max-width: min(360px, calc(100vw - 36px));
  border: 1px solid rgba(20, 124, 116, 0.26);
  border-radius: var(--radius);
  background: #173e3a;
  color: #fff;
  padding: 11px 14px;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 160ms ease, transform 160ms ease;
  pointer-events: none;
}

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

@media (max-width: 1180px) {
  .workspace {
    grid-template-columns: 250px minmax(0, 1fr);
  }

  .study-panel {
    grid-column: 1 / -1;
    position: static;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .vocab-list {
    max-height: 360px;
  }
}

@media (max-width: 860px) {
  .app-shell {
    padding: 10px;
  }

  .topbar {
    align-items: stretch;
    flex-direction: column;
  }

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

  .side-panel,
  .study-panel {
    position: static;
    grid-template-columns: 1fr;
  }

  .reader-toolbar,
  .section-heading {
    align-items: stretch;
    flex-direction: column;
  }

  .profile-list,
  .profile-form {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .topbar-actions,
  .stat-grid,
  .status-row {
    grid-template-columns: 1fr;
  }

  .topbar-actions {
    display: grid;
  }

  .profile-switch,
  .nav-button,
  .status-pill {
    width: 100%;
  }

  .mistake-book-hero,
  .mistake-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .mistake-actions select,
  .mistake-actions button {
    width: 100%;
  }

  .article-paragraph {
    font-size: 1.22rem;
    line-height: 2.12;
  }

  .reader-panel,
  .side-panel,
  .study-panel,
  .profile-dialog {
    padding: 12px;
  }
}