:root {
  --bg: #f2f1ed;
  --surface: #fffefa;
  --surface-soft: #f8f7f2;
  --ink: #252724;
  --ink-soft: #68706c;
  --line: #d8d9d3;
  --line-strong: #bfc3bc;
  --seal: #a6382d;
  --seal-soft: #d9a19a;
  --seal-bg: #fbefed;
  --good: #347052;
  --good-bg: #e9f3ed;
  --amber: #9a641d;
  --amber-bg: #faf0df;
  --blue: #315f7b;
  --blue-bg: #eaf1f5;
  --shadow: 0 12px 32px rgba(37, 39, 36, 0.08);
  --serif: "Songti SC", STSong, SimSun, serif;
  --kai: "Kaiti SC", STKaiti, KaiTi, serif;
  --sans: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html { min-width: 320px; min-height: 100%; }

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

button, select, input, textarea { font: inherit; }
button, select { color: inherit; }
button { letter-spacing: 0; }

button:focus-visible,
select:focus-visible,
input:focus-visible,
textarea:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(49, 95, 123, 0.28);
  outline-offset: 2px;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 254, 250, 0.96);
  backdrop-filter: blur(14px);
}

.header-inner {
  width: min(1120px, calc(100% - 32px));
  min-height: 72px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
}

.home-link,
.icon-button {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  display: inline-grid;
  place-items: center;
  color: var(--seal);
  text-decoration: none;
  cursor: pointer;
}

.home-link:hover,
.icon-button:hover { border-color: var(--seal-soft); background: var(--seal-bg); }

.brand { min-width: 0; display: flex; align-items: center; gap: 11px; }
.brand-seal {
  width: 38px;
  height: 38px;
  flex: 0 0 38px;
  display: grid;
  place-items: center;
  border-radius: 7px;
  background: var(--seal);
  color: #fff;
  font: 700 21px/1 var(--kai);
  box-shadow: inset 0 2px 0 rgba(0, 0, 0, 0.12);
}
.brand-copy { min-width: 0; }
.brand-title {
  margin: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font: 600 20px/1.25 var(--kai);
}
.brand-subtitle { margin-top: 3px; color: var(--ink-soft); font-size: 12px; }

.header-actions { position: relative; }
.more-menu {
  position: absolute;
  top: 46px;
  right: 0;
  width: 176px;
  padding: 6px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.more-menu[hidden] { display: none; }
.menu-button {
  width: 100%;
  min-height: 38px;
  padding: 8px 10px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  text-align: left;
  cursor: pointer;
}
.menu-button:hover { background: var(--surface-soft); }
.menu-button.danger { color: var(--seal); }

.tab-band { border-bottom: 1px solid var(--line); background: var(--surface); }
.tabs {
  width: min(1120px, calc(100% - 32px));
  height: 49px;
  margin: 0 auto;
  display: flex;
  align-items: stretch;
  gap: 4px;
}
.tab-button {
  min-width: 74px;
  padding: 0 16px;
  border: 0;
  border-bottom: 3px solid transparent;
  background: transparent;
  color: var(--ink-soft);
  font-weight: 600;
  cursor: pointer;
}
.tab-button:hover { color: var(--ink); }
.tab-button.active { color: var(--seal); border-bottom-color: var(--seal); }

.page-main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 64px;
}

.loading,
.fatal-error {
  max-width: 680px;
  margin: 80px auto;
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  text-align: center;
  line-height: 1.8;
}
.fatal-error { color: var(--seal); }

.overview-lead {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(300px, 0.7fr);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.lead-copy { padding: 32px; }
.eyebrow { margin: 0 0 8px; color: var(--seal); font-size: 13px; font-weight: 700; }
.lead-title,
.view-title {
  margin: 0;
  font-family: var(--kai);
  font-weight: 600;
  letter-spacing: 0;
}
.lead-title { max-width: 620px; font-size: 30px; line-height: 1.35; }
.lead-text { max-width: 620px; margin: 12px 0 0; color: var(--ink-soft); line-height: 1.8; }
.lead-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }

.memory-scene {
  position: relative;
  min-height: 250px;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.1), rgba(49,95,123,0.08)),
    var(--blue-bg);
}
.memory-scene::before,
.memory-scene::after {
  content: "";
  position: absolute;
  left: -10%;
  right: -10%;
  bottom: -28px;
  height: 150px;
  border-radius: 50% 50% 0 0;
  background: rgba(49, 95, 123, 0.22);
  transform: rotate(-5deg);
}
.memory-scene::after {
  left: 16%;
  right: -18%;
  bottom: -64px;
  height: 190px;
  background: rgba(52, 112, 82, 0.18);
  transform: rotate(7deg);
}
.scene-copy {
  position: relative;
  z-index: 2;
  height: 100%;
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.scene-mark { font: 700 56px/1 var(--kai); color: var(--blue); }
.scene-caption { max-width: 230px; color: #3e565e; font: 18px/1.7 var(--serif); }

.primary-button,
.secondary-button,
.text-button,
.choice-button,
.rate-button {
  min-height: 42px;
  border-radius: 7px;
  padding: 9px 16px;
  font-weight: 600;
  cursor: pointer;
}
.primary-button { border: 1px solid var(--seal); background: var(--seal); color: #fff; }
.primary-button:hover { background: #8e2f26; }
.secondary-button { border: 1px solid var(--line-strong); background: var(--surface); color: var(--ink); }
.secondary-button:hover { border-color: var(--blue); color: var(--blue); }
.text-button { border: 0; background: transparent; color: var(--blue); padding-inline: 4px; }
.text-button:hover { color: var(--seal); }
.button-small { min-height: 34px; padding: 6px 11px; font-size: 13px; }
button:disabled { cursor: not-allowed; opacity: 0.56; }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 22px 0 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  overflow: hidden;
}
.stat { min-height: 104px; padding: 20px 24px; }
.stat + .stat { border-left: 1px solid var(--line); }
.stat-value { display: block; color: var(--ink); font: 600 27px/1.2 var(--serif); }
.stat-label { display: block; margin-top: 8px; color: var(--ink-soft); font-size: 13px; }
.stat-bar { height: 5px; margin-top: 14px; overflow: hidden; border-radius: 99px; background: #e7e7e1; }
.stat-bar > i { display: block; height: 100%; background: var(--good); }

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  margin: 0 0 12px;
}
.section-heading h2 { margin: 0; font-size: 20px; }
.section-heading p { margin: 0; color: var(--ink-soft); font-size: 13px; }

.lesson-catalog { border-top: 1px solid var(--line-strong); }
.lesson-group { border-bottom: 1px solid var(--line); background: transparent; }
.group-head {
  min-height: 58px;
  padding: 10px 4px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.group-title { font: 600 17px/1.5 var(--serif); }
.group-count { color: var(--ink-soft); font-size: 12px; white-space: nowrap; }
.piece-row {
  width: 100%;
  min-height: 58px;
  padding: 10px 12px 10px 28px;
  border: 0;
  border-top: 1px solid #e6e6e1;
  background: rgba(255, 254, 250, 0.6);
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 14px;
  text-align: left;
  cursor: pointer;
}
.piece-row:hover { background: var(--surface); }
.piece-title { min-width: 0; font-family: var(--serif); font-size: 16px; }
.piece-author { color: var(--ink-soft); font-size: 12px; }
.piece-meta { color: var(--ink-soft); font-size: 12px; white-space: nowrap; }

.status-chip,
.stage-chip,
.tiny-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 99px;
  white-space: nowrap;
}
.status-chip { min-height: 25px; padding: 3px 9px; font-size: 11px; }
.status-new { color: var(--ink-soft); background: var(--surface-soft); }
.status-learning { color: var(--blue); border-color: #b9ccd7; background: var(--blue-bg); }
.status-review { color: var(--amber); border-color: #e2c998; background: var(--amber-bg); }
.status-mastered { color: var(--good); border-color: #b8d2c1; background: var(--good-bg); }

.view-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 20px;
}
.view-head-main { min-width: 0; }
.view-kicker { margin: 0 0 5px; color: var(--seal); font-size: 12px; font-weight: 700; }
.view-title { font-size: 28px; line-height: 1.35; }
.view-byline { margin: 7px 0 0; color: var(--ink-soft); font-size: 13px; }
.view-tools { display: flex; align-items: center; gap: 8px; }

.piece-select,
.review-select {
  min-height: 40px;
  max-width: 340px;
  padding: 7px 34px 7px 11px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--surface);
}

.stepper {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-bottom: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
}
.step-button {
  min-height: 50px;
  padding: 8px;
  border: 0;
  border-right: 1px solid var(--line);
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
}
.step-button:last-child { border-right: 0; }
.step-button.active { background: var(--seal-bg); color: var(--seal); font-weight: 700; }
.step-button.complete { color: var(--good); }
.step-number { display: inline-grid; place-items: center; width: 21px; height: 21px; margin-right: 5px; border: 1px solid currentColor; border-radius: 50%; font-size: 11px; }

.guide-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(260px, 0.7fr);
  gap: 24px;
}
.guide-primary,
.guide-aside,
.practice-surface,
.review-surface,
.empty-state {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}
.guide-primary { padding: 30px; }
.guide-aside { padding: 24px; background: var(--blue-bg); border-color: #c8d7df; }
.guide-label { margin: 0 0 8px; color: var(--seal); font-size: 12px; font-weight: 700; }
.guide-primary h3,
.guide-aside h3,
.practice-surface h3,
.review-surface h3 { margin: 0; font-size: 19px; }
.guide-primary p,
.guide-aside p { margin: 12px 0 0; line-height: 1.9; }
.guide-facts { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 26px; border-top: 1px solid var(--line); }
.guide-fact { padding: 18px 14px 0 0; }
.guide-fact strong { display: block; font-size: 18px; }
.guide-fact span { display: block; margin-top: 4px; color: var(--ink-soft); font-size: 12px; }
.guide-action { margin-top: 26px; }

.reader-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 22px;
  align-items: start;
}
.reading-paper {
  min-height: 500px;
  padding: 34px clamp(24px, 5%, 52px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.reading-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 26px; }
.reading-mode { color: var(--ink-soft); font-size: 12px; }
.classical-text {
  margin: 0;
  color: #262825;
  font: 19px/2.15 var(--serif);
  white-space: pre-wrap;
  word-break: break-word;
}
.vocab-mark {
  display: inline;
  padding: 1px 2px;
  border: 0;
  border-bottom: 2px solid var(--seal-soft);
  background: transparent;
  color: inherit;
  font: inherit;
  line-height: inherit;
  cursor: pointer;
}
.vocab-mark:hover,
.vocab-mark.active { background: var(--seal-bg); color: var(--seal); border-bottom-color: var(--seal); }

.note-panel {
  position: sticky;
  top: 146px;
  min-height: 210px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}
.note-empty { color: var(--ink-soft); font-size: 13px; line-height: 1.8; }
.note-word { margin: 0; color: var(--seal); font: 600 28px/1.3 var(--kai); }
.note-explanation { margin: 14px 0 0; line-height: 1.8; }
.note-context { margin: 18px 0 0; padding-top: 16px; border-top: 1px solid var(--line); color: var(--ink-soft); font: 14px/1.8 var(--serif); }
.note-nav { display: flex; gap: 8px; margin-top: 18px; }
.note-close { display: none; }

.memorize-layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 22px; }
.chunk-list { border-top: 1px solid var(--line); }
.chunk-button {
  width: 100%;
  min-height: 48px;
  padding: 9px 10px;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  text-align: left;
  cursor: pointer;
}
.chunk-button:hover { background: var(--surface); }
.chunk-button.active { background: var(--blue-bg); color: var(--blue); font-weight: 700; }
.tiny-chip { min-width: 23px; height: 21px; padding: 2px 6px; color: var(--ink-soft); font-size: 10px; }
.practice-surface { min-height: 430px; padding: 28px; }
.mode-control {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 20px;
  border: 1px solid var(--line);
  border-radius: 7px;
  overflow: hidden;
}
.mode-button { min-height: 42px; padding: 6px; border: 0; border-right: 1px solid var(--line); background: var(--surface); cursor: pointer; font-size: 12px; }
.mode-button:last-child { border-right: 0; }
.mode-button.active { color: var(--seal); background: var(--seal-bg); font-weight: 700; }
.chunk-stage {
  min-height: 210px;
  margin: 28px 0 18px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--surface-soft);
  display: grid;
  place-items: center;
  text-align: center;
}
.chunk-text { margin: 0; font: 20px/2.1 var(--serif); white-space: pre-wrap; }
.masked-char { color: var(--line-strong); }
.memory-blank { display: inline-block; min-width: 2em; margin: 0 2px; border-bottom: 1px solid var(--line-strong); color: transparent; }
.hidden-prompt { color: var(--ink-soft); font-size: 14px; line-height: 1.8; }
.rate-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 9px; }
.rate-button { border: 1px solid var(--line); background: var(--surface); }
.rate-button.good { color: var(--good); border-color: #aac9b5; }
.rate-button.hint { color: var(--amber); border-color: #ddc38f; }
.rate-button.bad { color: var(--seal); border-color: var(--seal-soft); }
.practice-footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 18px; }

.quiz-wrap,
.review-wrap { max-width: 760px; margin: 0 auto; }
.quiz-progress,
.round-progress { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; color: var(--ink-soft); font-size: 12px; }
.progress-track { height: 7px; flex: 1; border-radius: 99px; background: #e4e5e0; overflow: hidden; }
.progress-track > i { display: block; height: 100%; background: var(--blue); transition: width 0.2s ease; }
.practice-surface.quiz,
.review-surface { min-height: 430px; padding: 30px; }
.question-label { color: var(--blue); font-size: 12px; font-weight: 700; }
.question-prompt { margin: 14px 0 0; font: 600 22px/1.65 var(--serif); }
.question-context { margin: 18px 0 0; padding: 16px; border-left: 3px solid var(--seal-soft); background: var(--surface-soft); font: 16px/1.9 var(--serif); }
.choices { display: grid; gap: 9px; margin-top: 24px; }
.choice-button { border: 1px solid var(--line); background: var(--surface); text-align: left; font-weight: 400; line-height: 1.6; }
.choice-button:hover { border-color: var(--blue); }
.choice-button.selected.correct { border-color: var(--good); background: var(--good-bg); color: var(--good); }
.choice-button.selected.wrong { border-color: var(--seal); background: var(--seal-bg); color: var(--seal); }
.answer-form { display: flex; gap: 9px; margin-top: 24px; }
.answer-input { min-width: 0; flex: 1; height: 44px; padding: 8px 12px; border: 1px solid var(--line-strong); border-radius: 7px; background: #fff; }
.feedback { margin-top: 22px; padding: 16px; border-radius: 7px; line-height: 1.75; }
.feedback.correct { background: var(--good-bg); color: var(--good); }
.feedback.wrong { background: var(--seal-bg); color: #7d2b24; }
.feedback strong { display: block; margin-bottom: 3px; }
.feedback-answer { margin-bottom: 3px; font-weight: 600; }
.question-actions { display: flex; justify-content: flex-end; gap: 9px; margin-top: 20px; }

.review-intro { display: grid; grid-template-columns: minmax(0, 1fr) 250px; gap: 24px; }
.review-surface p { line-height: 1.8; color: var(--ink-soft); }
.round-guide { padding: 24px; border: 1px solid #d7c59c; border-radius: 8px; background: var(--amber-bg); }
.round-guide strong { display: block; color: var(--amber); font-size: 28px; }
.round-guide span { display: block; margin-top: 6px; color: #71552f; line-height: 1.7; }
.review-start-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 22px; }
.recall-mask { margin-top: 22px; padding: 28px; border: 1px solid var(--line); border-radius: 7px; background: var(--surface-soft); font: 19px/2.05 var(--serif); text-align: center; }
.recall-answer { margin-top: 14px; padding: 16px; border-left: 3px solid var(--good); background: var(--good-bg); font: 16px/1.9 var(--serif); }
.review-rate-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 9px; margin-top: 20px; }

.summary-grid { display: grid; grid-template-columns: repeat(3, 1fr); margin: 24px 0; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.summary-item { padding: 18px; text-align: center; }
.summary-item + .summary-item { border-left: 1px solid var(--line); }
.summary-item strong { display: block; font-size: 24px; }
.summary-item span { display: block; margin-top: 5px; color: var(--ink-soft); font-size: 12px; }

.empty-state { padding: 42px 28px; text-align: center; }
.empty-state h3 { margin: 0; font-size: 20px; }
.empty-state p { margin: 10px auto 20px; max-width: 520px; color: var(--ink-soft); line-height: 1.8; }

.fulltext-controls { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 18px; }
.control-group { display: flex; align-items: center; gap: 8px; }
.toggle-label { display: flex; align-items: center; gap: 8px; color: var(--ink-soft); font-size: 13px; }
.toggle-label input { width: 17px; height: 17px; accent-color: var(--seal); }
.guide-details { margin-top: 20px; border-top: 1px solid var(--line); }
.guide-details details { border-bottom: 1px solid var(--line); }
.guide-details summary { padding: 14px 0; cursor: pointer; font-weight: 600; }
.guide-details p { margin: 0 0 15px; color: var(--ink-soft); line-height: 1.8; }

.modal {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(27, 31, 29, 0.48);
}
.modal.show { display: flex; }
.dialog { width: min(420px, 100%); max-height: calc(100vh - 40px); overflow: auto; padding: 24px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); box-shadow: 0 24px 60px rgba(0,0,0,0.22); }
.dlg-title { margin: 0 0 10px; font: 600 20px/1.4 var(--kai); }
.dlg-body { color: var(--ink-soft); font-size: 13px; line-height: 1.75; }
.dlg-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 18px; }
.progress-textarea { width: 100%; height: 180px; margin-top: 12px; padding: 10px; border: 1px solid var(--line); border-radius: 7px; resize: vertical; font: 11px/1.5 ui-monospace, Menlo, Consolas, monospace; }
.note { min-height: 18px; margin-top: 10px; color: var(--ink-soft); font-size: 12px; line-height: 1.6; }
.note.ok { color: var(--good); }
.note.err { color: var(--seal); }

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  z-index: 100;
  max-width: calc(100% - 32px);
  padding: 10px 16px;
  border-radius: 7px;
  background: #252724;
  color: #fff;
  font-size: 13px;
  transform: translate(-50%, 20px);
  opacity: 0;
  pointer-events: none;
  transition: 0.18s ease;
}
.toast.show { transform: translate(-50%, 0); opacity: 1; }

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

@media (max-width: 900px) {
  .overview-lead { grid-template-columns: 1fr; }
  .memory-scene { min-height: 180px; }
  .scene-copy { min-height: 180px; }
  .guide-layout,
  .reader-grid,
  .review-intro { grid-template-columns: 1fr; }
  .reader-grid { gap: 0; }
  .note-panel {
    position: fixed;
    inset: auto 0 0 0;
    z-index: 60;
    min-height: 0;
    max-height: 55vh;
    overflow: auto;
    padding: 22px 20px calc(22px + env(safe-area-inset-bottom));
    border-radius: 8px 8px 0 0;
    box-shadow: 0 -18px 50px rgba(0,0,0,0.18);
    transform: translateY(105%);
    transition: transform 0.2s ease;
  }
  .note-panel.open { transform: translateY(0); }
  .note-close { display: grid; position: absolute; top: 12px; right: 12px; width: 32px; height: 32px; place-items: center; border: 0; background: transparent; font-size: 22px; cursor: pointer; }
  .memorize-layout { grid-template-columns: 1fr; }
  .chunk-list { display: flex; overflow-x: auto; border: 1px solid var(--line); border-radius: 7px; }
  .chunk-button { width: auto; min-width: 92px; border-right: 1px solid var(--line); border-bottom: 0; }
}

@media (max-width: 640px) {
  .header-inner,
  .tabs,
  .page-main { width: min(100% - 24px, 1120px); }
  .header-inner { min-height: 64px; gap: 9px; }
  .brand-seal { width: 34px; height: 34px; flex-basis: 34px; font-size: 19px; }
  .brand-title { font-size: 17px; }
  .brand-subtitle { display: none; }
  .home-link,
  .icon-button { width: 36px; height: 36px; }
  .tabs { height: 46px; }
  .tab-button { min-width: 0; flex: 1; padding: 0 6px; font-size: 13px; }
  .page-main { padding-top: 18px; padding-bottom: 48px; }
  .lead-copy { padding: 24px 20px; }
  .lead-title { font-size: 25px; }
  .memory-scene { min-height: 150px; }
  .scene-copy { min-height: 150px; padding: 22px; }
  .scene-mark { font-size: 42px; }
  .scene-caption { font-size: 16px; }
  .stats-grid { grid-template-columns: 1fr; }
  .stat { min-height: 82px; display: grid; grid-template-columns: auto 1fr; column-gap: 12px; align-items: center; }
  .stat + .stat { border-left: 0; border-top: 1px solid var(--line); }
  .stat-value { font-size: 23px; }
  .stat-label { margin: 0; }
  .stat-bar { grid-column: 1 / -1; width: 100%; margin-top: 8px; }
  .section-heading { align-items: flex-start; flex-direction: column; gap: 4px; }
  .piece-row { grid-template-columns: minmax(0, 1fr) auto; gap: 8px; padding-left: 14px; }
  .piece-meta { display: none; }
  .view-head { flex-direction: column; gap: 12px; }
  .view-title { font-size: 24px; }
  .view-tools,
  .piece-select { width: 100%; max-width: none; }
  .stepper { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .step-button { min-height: 56px; padding: 6px 3px; font-size: 11px; }
  .step-number { display: grid; margin: 0 auto 3px; }
  .guide-primary,
  .guide-aside,
  .practice-surface,
  .practice-surface.quiz,
  .review-surface { padding: 22px 18px; }
  .guide-facts { grid-template-columns: 1fr; }
  .guide-fact { padding-top: 14px; }
  .reading-paper { min-height: 420px; padding: 25px 20px; }
  .classical-text { font-size: 18px; line-height: 2.05; }
  .mode-control { grid-template-columns: repeat(2, 1fr); }
  .mode-button:nth-child(2) { border-right: 0; }
  .mode-button:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .chunk-stage { min-height: 220px; margin-top: 20px; padding: 20px 14px; }
  .chunk-text { font-size: 18px; }
  .rate-row,
  .review-rate-row { grid-template-columns: 1fr; }
  .practice-footer { align-items: stretch; flex-direction: column-reverse; }
  .practice-footer .primary-button { width: 100%; }
  .question-prompt { font-size: 20px; }
  .answer-form { flex-direction: column; }
  .summary-grid { grid-template-columns: 1fr; }
  .summary-item + .summary-item { border-left: 0; border-top: 1px solid var(--line); }
  .fulltext-controls { align-items: stretch; flex-direction: column; }
  .control-group { justify-content: space-between; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; }
}