:root {
  color-scheme: light;
  --paper: #f7f4ec;
  --paper-deep: #efe9dc;
  --ink: #22211f;
  --muted: #6c6a65;
  --dai: #375a5a;
  --dai-dark: #274646;
  --cinnabar: #b35a45;
  --bamboo: #708b72;
  --moon: #e8eef0;
  --apricot: #eedfcb;
  --line: rgba(55, 90, 90, 0.16);
  --shadow: 0 18px 46px rgba(55, 45, 31, 0.1);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--paper);
  color: var(--ink);
}

/* 儿童主线：听接龙 → 认生字 → 读故事 */
.is-welcome {
  padding-bottom: 0;
}

.is-welcome .site-header,
.is-welcome .bottom-nav {
  display: none;
}

.is-welcome #app {
  width: 100%;
  min-height: 100vh;
  margin: 0;
}

.welcome-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  text-align: center;
}

.welcome-kicker {
  margin: 0 0 16px;
  color: var(--cinnabar);
  font: 700 clamp(16px, 2.4vw, 22px)/1.2 "Songti SC", serif;
  letter-spacing: .24em;
}

.welcome-title {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: clamp(18px, 4vw, 52px);
  white-space: nowrap;
}

.welcome-title h1 {
  margin: 0;
  color: var(--ink);
  font: 700 clamp(30px, 7vw, 72px)/1.1 "Songti SC", serif;
  letter-spacing: .06em;
}

.welcome-subtitle {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(14px, 2.2vw, 18px);
  letter-spacing: .04em;
}

.welcome-copy > .btn {
  margin-top: 28px;
}

.child-home {
  width: min(1120px, 100%);
  margin: 0 auto;
}

.child-intro {
  max-width: 720px;
  margin: 18px auto 28px;
  text-align: center;
}

.child-intro-with-back {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
}

.child-intro-with-back > .btn {
  justify-self: start;
}

.child-intro h1 {
  margin: 8px 0 12px;
  font: 700 clamp(34px, 6vw, 58px)/1.15 "Songti SC", "STSong", serif;
  letter-spacing: .02em;
}

.child-intro > p:last-child {
  color: var(--muted);
  font-size: 17px;
}

.today-chain {
  padding: clamp(24px, 5vw, 48px);
  background: linear-gradient(145deg, rgba(255, 254, 249, .98), rgba(232, 238, 240, .86));
}

.today-chain-head,
.section-title-row,
.literacy-topbar,
.study-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.today-chain-head span:first-child {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.today-chain-head h2 {
  margin: 4px 0 0;
  font: 700 clamp(28px, 5vw, 42px)/1.2 "Songti SC", "STSong", serif;
}

.friendly-progress {
  padding: 7px 12px;
  color: var(--dai-dark);
  background: rgba(255, 255, 255, .72);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-weight: 700;
  white-space: nowrap;
}

.today-chain-preview {
  margin: 30px 0 22px;
  display: grid;
  justify-items: center;
  gap: 6px;
}

.today-chain-preview strong {
  font: 700 clamp(26px, 5vw, 38px)/1.2 "Songti SC", "STSong", serif;
  letter-spacing: .08em;
}

.today-chain-preview span {
  color: var(--bamboo);
  font-size: 22px;
}

.today-chain-note {
  color: var(--muted);
  text-align: center;
}

.today-chain .hero-actions {
  justify-content: center;
}

.curriculum-choice-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.curriculum-choice-card {
  min-height: 430px;
  padding: clamp(24px, 4vw, 40px);
  display: flex;
  flex-direction: column;
  background: linear-gradient(145deg, rgba(255, 254, 249, .98), rgba(232, 238, 240, .86));
}

.curriculum-choice-card.is-qianziwen {
  background: linear-gradient(145deg, rgba(255, 254, 249, .98), rgba(238, 223, 203, .78));
}

.curriculum-choice-card.is-duiyun {
  background: linear-gradient(145deg, rgba(255, 254, 249, .98), rgba(226, 238, 226, .82));
}

.duiyun-preview {
  align-items: stretch;
  text-align: center;
}

.duiyun-preview strong {
  letter-spacing: .02em;
}

.curriculum-choice-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.curriculum-choice-card h2 {
  min-height: 2.5em;
  margin: 18px 0;
  font: 700 clamp(28px, 4.2vw, 42px)/1.25 "Songti SC", "STSong", serif;
}

.curriculum-choice-card > p {
  margin: 18px 0 26px;
  color: var(--muted);
  line-height: 1.75;
}

.curriculum-choice-card > .btn {
  width: 100%;
  margin-top: auto;
}

.curriculum-choice-tools {
  margin-top: 12px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.curriculum-choice-tools > .btn,
.curriculum-jump > summary {
  min-height: 44px;
  display: grid;
  place-items: center;
}

.curriculum-jump {
  position: relative;
}

.curriculum-jump > summary {
  padding: 9px 14px;
  color: var(--dai-dark);
  background: rgba(255, 255, 255, .66);
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 800;
  list-style: none;
}

.curriculum-jump > summary::-webkit-details-marker {
  display: none;
}

.curriculum-jump[open] {
  grid-column: 1 / -1;
  padding: 12px;
  background: rgba(255, 255, 255, .66);
  border: 1px solid var(--line);
  border-radius: 16px;
}

.curriculum-jump[open] > summary {
  min-height: auto;
  padding: 0 0 10px;
  place-items: start;
  background: transparent;
  border: 0;
}

.curriculum-jump-row {
  display: grid;
  grid-template-columns: auto minmax(64px, 1fr) auto auto;
  align-items: center;
  gap: 7px;
}

.curriculum-jump-row input {
  width: 100%;
  min-height: 42px;
  padding: 8px;
  color: var(--ink);
  background: white;
  border: 1px solid var(--line);
  border-radius: 10px;
  font: 700 16px/1 system-ui, sans-serif;
  text-align: center;
}

.curriculum-jump > small {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  text-align: left;
}

.curriculum-choice-preview {
  min-height: 94px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  align-content: center;
  gap: 8px;
}

.curriculum-choice-preview strong {
  font: 700 clamp(19px, 2.5vw, 26px)/1.35 "Songti SC", "STSong", serif;
}

.curriculum-choice-preview span {
  color: var(--bamboo);
}

.learning-path {
  margin: 20px 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.learning-path > div {
  min-height: 132px;
  padding: 20px;
  display: grid;
  grid-template-columns: 36px 1fr;
  align-content: center;
  gap: 5px 12px;
  background: rgba(255, 253, 247, .7);
  border: 1px solid var(--line);
  border-radius: 20px;
}

.learning-path > div > span {
  width: 36px;
  height: 36px;
  grid-row: span 2;
  display: grid;
  place-items: center;
  color: white;
  background: var(--bamboo);
  border-radius: 50%;
  font-weight: 800;
}

.learning-path strong { font-size: 17px; }
.learning-path small { color: var(--muted); }

.friendly-stats {
  margin: 18px 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.friendly-stats > div {
  padding: 20px;
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 10px;
  background: var(--moon);
  border-radius: 18px;
}

.friendly-stats strong {
  color: var(--dai-dark);
  font-size: 30px;
}

.parent-course {
  margin-top: 18px;
  padding: 20px;
}

.parent-course > summary,
.character-book-section > summary {
  cursor: pointer;
  color: var(--dai-dark);
  font-weight: 800;
}

.parent-course > p,
.parent-note {
  color: var(--muted);
  font-size: 13px;
}

.parent-course-content { margin-top: 18px; }
.parent-course-content > h2 { font-size: 20px; }

.parent-course-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.parent-course-columns > section {
  min-width: 0;
}

.parent-course-summary {
  min-height: 132px;
  padding: 20px;
  display: grid;
  align-content: center;
  justify-items: center;
  gap: 7px;
  text-align: center;
  background: var(--moon);
  border: 1px solid var(--line);
  border-radius: 18px;
}

.parent-course-summary > span,
.parent-course-summary > small {
  color: var(--muted);
}

.parent-course-summary > strong {
  color: var(--dai-dark);
  font-size: 30px;
}

.parent-course-columns .parent-chain-list {
  max-height: 520px;
  overflow: auto;
  padding-right: 4px;
}

.parent-chain-list {
  display: grid;
  gap: 8px;
}

.parent-chain-row {
  min-height: 62px;
  padding: 8px 10px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) 90px auto;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid var(--line);
}

.parent-chain-row > span,
.parent-chain-row small { color: var(--muted); }
.parent-chain-row .btn { min-height: 38px; padding: 7px 14px; }
.parent-chain-row.is-next { background: rgba(238, 223, 203, .45); }
.parent-actions { margin-top: 18px; }

.parent-voice-settings {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.parent-voice-settings h3 { margin-bottom: 6px; }
.parent-voice-settings p { color: var(--muted); font-size: 13px; }

.literacy-page,
.chain-study-page {
  width: min(900px, 100%);
  margin: 0 auto;
}

.literacy-topbar {
  min-height: 60px;
  margin-bottom: 14px;
}

.literacy-topbar > div {
  display: grid;
  gap: 3px;
  text-align: center;
}

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

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

.round-mode-chip {
  min-width: 78px;
  padding: 7px 11px;
  color: var(--dai-dark) !important;
  background: var(--moon);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-weight: 700;
  text-align: center;
}

.literacy-overview {
  padding: clamp(26px, 6vw, 54px);
}

.literacy-table-title {
  padding-top: 0;
}

.literacy-table-title > span {
  color: var(--muted);
  font-size: 12px;
}

.literacy-start-actions {
  justify-content: center;
  margin-top: 28px;
}

.literacy-start-actions .btn {
  min-width: 180px;
}

.character-card {
  position: relative;
  min-height: 620px;
  padding: clamp(28px, 6vw, 58px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.character-card.is-assessment {
  padding-bottom: 148px;
}

.literacy-speed-control {
  width: min(620px, 100%);
  margin: 22px auto 0;
  padding: 10px 12px 10px 16px;
  display: grid;
  grid-template-columns: minmax(120px, 1fr) minmax(210px, 1.2fr);
  align-items: center;
  gap: 14px;
  background: rgba(255, 253, 247, .94);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 10px 24px rgba(55, 90, 90, .08);
  text-align: left;
}

.literacy-speed-control.is-embedded {
  position: absolute;
  right: 24px;
  bottom: 24px;
  left: 24px;
  width: auto;
  margin: 0;
}

.literacy-speed-copy {
  display: grid;
  gap: 2px;
}

.literacy-speed-copy span {
  color: var(--muted);
  font-size: 11px;
}

.literacy-speed-options {
  padding: 3px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 3px;
  background: var(--paper-deep);
  border-radius: 999px;
}

.literacy-speed-options button {
  min-height: 38px;
  padding: 7px 12px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 800;
}

.literacy-speed-options button.is-selected {
  color: white;
  background: var(--dai);
  box-shadow: 0 5px 12px rgba(55, 90, 90, .2);
}

.character-card h1 {
  margin: 10px 0 0;
  font: 700 clamp(116px, 22vw, 190px)/1 "Songti SC", "STSong", serif;
  color: var(--ink);
}

.character-card h1.is-pop {
  animation: character-pop 420ms cubic-bezier(.2, .85, .3, 1.2) both;
}

.character-card.idiom-reading-card h1 {
  font-size: clamp(54px, 10vw, 92px);
  letter-spacing: .08em;
  white-space: nowrap;
}

@keyframes character-pop {
  0% { opacity: 0; transform: scale(.38); filter: blur(4px); }
  72% { opacity: 1; transform: scale(1.08); filter: blur(0); }
  100% { opacity: 1; transform: scale(1); filter: blur(0); }
}

.character-pinyin {
  margin: 0 0 8px;
  color: var(--cinnabar);
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
}

.character-group-plan {
  margin-top: 18px;
  padding: 12px 14px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  background: var(--moon);
  border-radius: 14px;
  font-size: 12px;
}

.character-group-plan strong {
  margin-right: 4px;
  color: var(--dai-dark);
}

.character-group-plan span {
  padding: 5px 9px;
  background: rgba(255, 255, 255, .72);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.round-sound-button {
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;
  background: var(--moon);
  border: 1px solid var(--line);
  border-radius: 50%;
  cursor: pointer;
  font-size: 22px;
}

.character-actions {
  width: min(600px, 100%);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.recognition-note {
  max-width: 540px;
  margin: 18px auto 0;
  color: var(--muted);
  font-size: 12px;
}

.auto-card-status {
  min-width: 180px;
  margin-top: 26px;
  padding: 12px 18px;
  color: var(--dai-dark);
  background: var(--moon);
  border-radius: 999px;
  font-weight: 800;
}

.character-card.is-assessment .auto-card-status {
  color: var(--dai-dark);
  background: var(--moon);
}

.recognition-listener {
  min-width: min(420px, 100%);
  padding: 15px 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.recognition-listener[data-recognition-state="starting"],
.recognition-listener[data-recognition-state="listening"],
.recognition-listener[data-recognition-state="heard"] {
  color: #214c58;
  background: #dcecef;
  box-shadow: 0 0 0 4px rgba(49, 94, 105, .1);
}

.recognition-listener[data-recognition-state="heard"] {
  font-size: 16px;
}

.recognition-signal {
  height: 20px;
  display: inline-flex;
  align-items: center;
  gap: 3px;
}

.recognition-signal i {
  width: 3px;
  height: 7px;
  background: currentColor;
  border-radius: 999px;
  opacity: .5;
}

.recognition-listener[data-recognition-state="listening"] .recognition-signal i,
.recognition-listener[data-recognition-state="heard"] .recognition-signal i {
  animation: recognition-signal 720ms ease-in-out 3 alternate;
}

.recognition-listener[data-recognition-state="heard"] .recognition-signal i {
  animation-duration: 280ms;
  animation-iteration-count: 2;
  opacity: 1;
}

.recognition-signal i:nth-child(2) { animation-delay: 110ms; }
.recognition-signal i:nth-child(3) { animation-delay: 220ms; }

@keyframes recognition-signal {
  from { height: 6px; }
  to { height: 20px; }
}

.last-recognition-message {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.recognition-feedback {
  width: min(600px, 100%);
  min-height: 54px;
  margin: 26px 0 0;
  padding: 16px 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #7a493f;
  background: #f5e4de;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 800;
}

.recognition-feedback.is-success {
  color: #274d32;
  background: #cfe2d0;
  box-shadow: 0 0 0 4px rgba(65, 116, 76, .1);
}

.recognition-feedback.is-heard {
  color: var(--dai-dark);
  background: var(--moon);
}

.character-book-section {
  margin-top: 18px;
  padding: 24px;
}

.character-book-section.compact { padding: 18px 22px; }
.character-book-section.compact .character-table { margin-top: 18px; }

.section-title-row h2 {
  margin: 3px 0 0;
  font: 700 24px/1.25 "Songti SC", serif;
}

.section-title-row > strong {
  color: var(--dai-dark);
  font-size: 22px;
}

.character-table {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  gap: 9px;
}

.character-table-groups {
  margin-top: 20px;
  display: grid;
  gap: 26px;
}

.character-table-group {
  padding: 18px;
  background: rgba(247, 244, 236, .44);
  border: 1px solid var(--line);
  border-radius: 20px;
}

.character-table-group + .character-table-group {
  position: relative;
  margin-top: 10px;
}

.character-table-group + .character-table-group::before {
  content: "";
  position: absolute;
  top: -19px;
  right: 8px;
  left: 8px;
  height: 2px;
  background: var(--dai);
  opacity: .42;
}

.character-table-group-heading {
  display: flex;
  align-items: center;
  gap: 10px;
}

.character-table-group-heading strong {
  padding: 6px 12px;
  color: white;
  background: var(--dai);
  border-radius: 999px;
  font-size: 13px;
}

.character-table-group-heading span {
  color: var(--muted);
  font-size: 13px;
}

.character-table-group-heading .btn {
  min-height: 38px;
  margin-left: auto;
  padding: 8px 15px;
}

.character-table-group .character-table {
  margin-top: 14px;
}

.character-table-item {
  min-height: 104px;
  padding: 10px 6px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 2px;
  background: rgba(247, 244, 236, .78);
  border: 1px solid var(--line);
  border-radius: 14px;
}

.character-table-item strong {
  font: 700 34px/1.1 "Songti SC", serif;
}

.character-table-item span,
.character-table-item small {
  color: var(--muted);
  font-size: 11px;
}

.character-table-item.is-known {
  background: #e5efe3;
  border-color: rgba(112, 139, 114, .35);
}

.character-table-item.is-practicing { background: #f3e6d6; }

.literacy-complete {
  padding: clamp(38px, 7vw, 72px);
  text-align: center;
}

.celebration-mark {
  width: 74px;
  height: 74px;
  margin: 0 auto 18px;
  display: grid;
  place-items: center;
  color: white;
  background: var(--bamboo);
  border-radius: 50%;
  font-size: 36px;
}

.celebration-mark.is-warning {
  background: var(--cinnabar);
}

.literacy-complete h1 {
  font: 700 clamp(34px, 6vw, 52px)/1.2 "Songti SC", serif;
}

.literacy-complete > p:not(.eyebrow) {
  max-width: 640px;
  margin: 14px auto 26px;
  color: var(--muted);
}

.assessment-result-grid {
  width: min(700px, 100%);
  margin: 26px auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  text-align: left;
}

.assessment-result-grid section {
  min-height: 150px;
  padding: 22px;
  background: #e5efe3;
  border: 1px solid rgba(112, 139, 114, .35);
  border-radius: 18px;
}

.assessment-result-grid section.needs-practice {
  background: #f3e6d6;
  border-color: rgba(179, 90, 69, .24);
}

.assessment-result-grid h2 {
  margin: 0 0 14px;
  font-size: 17px;
}

.assessment-result-grid p {
  margin: 0;
  font: 700 30px/1.8 "Songti SC", serif;
}

.idiom-result-grid p {
  font-size: 22px;
  line-height: 1.7;
}

.assessment-result-list {
  width: min(700px, 100%);
  margin: 24px auto;
  display: grid;
  gap: 10px;
  text-align: left;
}

.assessment-result-list section {
  display: grid;
  grid-template-columns: 120px 1fr;
  align-items: start;
  gap: 18px;
  padding: 14px 18px;
  background: #e5efe3;
  border-radius: 14px;
}

.assessment-result-list section.needs-practice {
  background: #f3e6d6;
}

.assessment-result-list h2,
.assessment-result-list p {
  margin: 0;
}

.assessment-result-list h2 {
  font-size: 16px;
  line-height: 1.8;
}

.assessment-result-list p {
  font: 700 26px/1.8 "Songti SC", serif;
}

.idiom-result-list p {
  font-size: 20px;
}

.study-header {
  margin: 10px 0 24px;
  display: grid;
  grid-template-columns: auto 1fr auto;
}

.study-header .eyebrow,
.study-header h1,
.study-header p { grid-column: 2; text-align: center; }
.study-header h1 { margin: 0; font: 700 clamp(34px, 6vw, 52px)/1.2 "Songti SC", serif; }
.study-header p { margin: 6px 0 0; color: var(--muted); }
.study-header > .btn:first-child { grid-row: 1 / span 4; align-self: start; }
.study-header > .btn:last-child { grid-column: 3; grid-row: 1 / span 4; align-self: center; }

.study-idiom-list { display: grid; gap: 12px; }

.study-idiom-card {
  padding: 22px;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr) auto;
  align-items: center;
  gap: 18px;
}

.study-order {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  color: var(--muted);
  background: var(--paper-deep);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 800;
}

.study-idiom-copy h2 {
  margin: 0;
  font: 700 30px/1.2 "Songti SC", serif;
  letter-spacing: .06em;
}

.study-idiom-copy .pinyin { margin: 6px 0 2px; }
.study-idiom-copy small { color: var(--muted); }
.study-idiom-copy > p:last-child { margin-bottom: 0; }
.study-idiom-actions { display: grid; gap: 8px; }

@media (max-width: 700px) {
  .curriculum-choice-grid,
  .parent-course-columns { grid-template-columns: 1fr; }
  .curriculum-choice-card { min-height: 390px; }
  .learning-path { grid-template-columns: 1fr; }
  .learning-path > div { min-height: 92px; }
  .today-chain-head,
  .section-title-row { align-items: flex-start; }
  .parent-chain-row { grid-template-columns: 30px 1fr auto; }
  .parent-chain-row small { display: none; }
  .character-card { min-height: 560px; padding-inline: 18px; }
  .character-card.is-assessment { padding-bottom: 154px; }
  .character-card.idiom-reading-card h1 { font-size: clamp(38px, 12vw, 58px); }
  .literacy-speed-control { grid-template-columns: 1fr; gap: 8px; text-align: center; }
  .literacy-speed-control.is-embedded { right: 12px; bottom: 14px; left: 12px; }
  .character-actions .btn { flex: 1 1 100%; }
  .literacy-topbar { gap: 6px; }
  .literacy-topbar-actions { flex-wrap: wrap; }
  .literacy-topbar .btn { min-height: 38px; padding: 7px 10px; font-size: 12px; }
  .round-mode-chip { min-width: 68px; padding-inline: 8px; }
  .assessment-result-grid { grid-template-columns: 1fr; }
  .assessment-result-list section { grid-template-columns: 1fr; gap: 4px; }
  .study-header { grid-template-columns: 1fr; text-align: center; }
  .study-header > *,
  .study-header .eyebrow,
  .study-header h1,
  .study-header p,
  .study-header > .btn:last-child { grid-column: 1; grid-row: auto; }
  .study-header > .btn:first-child { grid-row: auto; justify-self: start; }
  .study-header > .btn:last-child { justify-self: center; }
  .study-idiom-card { grid-template-columns: 34px 1fr; }
  .study-idiom-actions { grid-column: 2; grid-template-columns: 1fr 1fr; }
  .study-idiom-actions .btn { padding-inline: 10px; }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background:
    radial-gradient(circle at 10% 8%, rgba(238, 223, 203, 0.72), transparent 28rem),
    radial-gradient(circle at 92% 26%, rgba(232, 238, 240, 0.8), transparent 24rem),
    var(--paper);
  padding-bottom: 92px;
}

button,
input {
  font: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(179, 90, 69, 0.45);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: -80px;
  z-index: 100;
  background: var(--ink);
  color: white;
  padding: 12px 18px;
  border-radius: 10px;
}

.skip-link:focus {
  top: 16px;
}

.paper-grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.22;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='72' height='72' viewBox='0 0 72 72'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.55' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.08'/%3E%3C/svg%3E");
}

.site-header {
  width: min(1120px, calc(100% - 32px));
  min-height: 86px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
  color: var(--ink);
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
}

.brand-mark {
  width: 45px;
  height: 45px;
  display: grid;
  place-items: center;
  color: white;
  background: var(--cinnabar);
  border-radius: 14px 14px 14px 5px;
  font: 700 23px/1 "Songti SC", "STSong", serif;
  box-shadow: 0 8px 22px rgba(179, 90, 69, 0.24);
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 18px;
  letter-spacing: 0.08em;
}

.brand small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.header-status {
  max-width: 48%;
  color: var(--muted);
  font-size: 13px;
  text-align: right;
}

#app {
  width: min(1120px, calc(100% - 32px));
  margin: 8px auto 40px;
}

.page {
  animation: page-in 260ms ease both;
}

@keyframes page-in {
  from { opacity: 0; transform: translateY(7px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--cinnabar);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.14em;
}

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

h1 {
  margin-bottom: 14px;
  font: 700 clamp(34px, 5vw, 62px)/1.15 "Songti SC", "STSong", serif;
  letter-spacing: 0.03em;
}

h2 {
  font: 700 clamp(25px, 3vw, 36px)/1.25 "Songti SC", "STSong", serif;
}

h3 {
  font-size: 18px;
}

.lead {
  color: #484640;
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.8;
}

.card {
  background: rgba(255, 253, 247, 0.88);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.chain-library {
  width: min(960px, 100%);
  margin: 0 auto;
}

.library-intro {
  max-width: 760px;
  margin: 22px auto 30px;
  text-align: center;
}

.library-intro h1 {
  margin-bottom: 12px;
}

.chain-choice {
  padding: clamp(24px, 5vw, 46px);
}

.chain-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.curriculum-overview {
  margin-bottom: 16px;
  padding: 24px 28px;
}

.curriculum-overview > div:first-child {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}

.curriculum-overview > div:first-child span,
.curriculum-overview p {
  color: var(--muted);
}

.curriculum-overview > div:first-child strong {
  font: 700 27px/1 "Songti SC", serif;
  color: var(--dai-dark);
}

.curriculum-overview p {
  margin: 10px 0 0;
  font-size: 13px;
}

.curriculum-progress {
  height: 9px;
  margin-top: 14px;
  overflow: hidden;
  background: var(--paper-deep);
  border-radius: 999px;
}

.curriculum-progress span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--bamboo), var(--dai));
  border-radius: inherit;
}

.review-banner {
  margin: 0 0 18px;
  padding: 14px 18px;
  display: flex;
  align-items: center;
  gap: 12px;
  color: #714336;
  background: rgba(238, 223, 203, .68);
  border: 1px solid rgba(179, 90, 69, .18);
  border-radius: 16px;
  font-size: 13px;
}

.review-banner strong {
  flex: 0 0 auto;
}

.volume-tabs {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 18px;
}

.volume-tab {
  min-height: 66px;
  padding: 10px 8px;
  display: grid;
  place-items: center;
  gap: 3px;
  color: var(--muted);
  background: rgba(255, 253, 247, .74);
  border: 1px solid var(--line);
  border-radius: 15px;
  cursor: pointer;
}

.volume-tab span {
  font-size: 12px;
}

.volume-tab strong {
  color: var(--dai-dark);
}

.volume-tab.is-selected {
  color: white;
  background: var(--dai);
  border-color: var(--dai);
  box-shadow: 0 10px 24px rgba(55, 90, 90, .2);
}

.volume-tab.is-selected strong {
  color: white;
}

.volume-tab.has-next:not(.is-selected) {
  border-color: rgba(179, 90, 69, .5);
}

.volume-content {
  display: grid;
  gap: 18px;
}

.volume-heading {
  padding: 20px 4px 2px;
}

.volume-heading h2 {
  margin-bottom: 0;
  font-size: clamp(25px, 3.5vw, 39px);
}

.section-block {
  padding: clamp(20px, 3vw, 30px);
  background: rgba(255, 253, 247, .78);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
}

.section-block > header {
  margin-bottom: 14px;
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.section-block > header span {
  color: var(--cinnabar);
  font-size: 12px;
  font-weight: 700;
}

.section-block > header h2 {
  margin: 0;
  font-size: clamp(22px, 3vw, 30px);
}

.curriculum-chain-list {
  display: grid;
  gap: 9px;
}

.curriculum-chain {
  min-height: 92px;
  padding: 14px 16px;
  display: grid;
  grid-template-columns: minmax(210px, .8fr) minmax(300px, 1.2fr) minmax(150px, auto);
  align-items: center;
  gap: 18px;
  background: rgba(247, 244, 236, .72);
  border: 1px solid transparent;
  border-radius: 18px;
}

.curriculum-chain.is-next {
  background: rgba(232, 238, 240, .88);
  border-color: rgba(55, 90, 90, .32);
}

.curriculum-chain.is-learned {
  background: rgba(228, 236, 228, .72);
}

.curriculum-chain.is-locked {
  opacity: .6;
}

.curriculum-chain-main {
  display: flex;
  align-items: center;
  gap: 12px;
}

.chain-sequence {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  color: var(--muted);
  background: white;
  border-radius: 50%;
  font-size: 11px;
  font-weight: 700;
}

.curriculum-chain h3 {
  margin: 0 0 3px;
  font: 700 21px/1.3 "Songti SC", serif;
}

.curriculum-chain p,
.curriculum-chain small {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
}

.chain-mini-preview {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--bamboo);
  white-space: nowrap;
}

.chain-mini-preview strong {
  color: var(--ink);
  font: 600 16px/1.3 "Songti SC", serif;
}

.curriculum-chain-action {
  display: grid;
  justify-items: end;
  gap: 5px;
}

.curriculum-chain-action .btn {
  min-height: 42px;
  padding: 9px 15px;
  font-size: 13px;
}

.chain-list .chain-choice {
  padding: clamp(20px, 3vw, 30px);
}

.chain-choice.is-next {
  border-color: rgba(55, 90, 90, .46);
  box-shadow: 0 20px 50px rgba(55, 90, 90, .16);
}

.chain-choice.is-learned {
  background: rgba(239, 245, 239, .88);
}

.chain-choice.is-locked {
  opacity: .62;
  box-shadow: none;
}

.chain-list .chain-preview {
  margin: 22px 0 14px;
}

.chain-list .preview-card {
  min-height: 104px;
}

.chain-list .preview-card strong {
  font-size: clamp(17px, 2vw, 23px);
}

.learned-note {
  align-self: center;
  color: var(--bamboo);
  font-size: 12px;
  font-weight: 700;
}

.learned-badge {
  display: inline-flex;
  margin-bottom: 12px;
  padding: 6px 12px;
  color: #38553d;
  background: #dfeadd;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 800;
}

.chain-choice-head,
.flashcard-topbar,
.flashcard-footnote,
.home-secondary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.chain-choice-head h2 {
  margin: 0;
}

.chain-preview {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  margin: 30px 0;
}

.preview-card {
  min-height: 138px;
  padding: 18px 12px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 12px;
  text-align: center;
  color: var(--dai-dark);
  background: linear-gradient(145deg, #fffdf7, #f1eee4);
  border: 1px solid var(--line);
  border-radius: 20px;
}

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

.preview-card strong {
  font: 700 clamp(20px, 3vw, 30px)/1.25 "Songti SC", "STSong", serif;
  letter-spacing: 0.05em;
}

.preview-arrow {
  color: var(--bamboo);
  font-size: 24px;
}

.play-setup {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  padding: 24px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.play-setup.is-single {
  grid-template-columns: 1fr;
}

.setup-group {
  display: grid;
  gap: 10px;
}

.setup-label {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.segmented-control {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.segmented-control button {
  min-height: 40px;
  padding: 8px 14px;
  color: var(--dai-dark);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  font-weight: 700;
}

.segmented-control button.is-selected {
  color: white;
  background: var(--dai);
  border-color: var(--dai);
}

.chain-choice-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.btn-large {
  min-height: 56px;
  padding-inline: 28px;
}

.voice-disclosure {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.home-secondary {
  margin-top: 18px;
  padding: 18px 4px;
}

.home-secondary > div:first-child {
  display: grid;
  gap: 5px;
}

.home-secondary span {
  color: var(--muted);
  font-size: 13px;
}

.flashcard-player {
  width: min(900px, 100%);
  margin: 0 auto;
  animation: none;
}

.flashcard-topbar {
  min-height: 60px;
  margin-bottom: 14px;
}

.chain-position-controls {
  margin: -2px 0 14px;
  padding: 9px 12px 9px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  background: rgba(255, 253, 247, .72);
  border: 1px solid var(--line);
  border-radius: 14px;
  font-size: 12px;
}

.chain-position-controls > div {
  display: flex;
  gap: 8px;
}

.chain-position-controls .btn {
  min-height: 38px;
  padding: 7px 12px;
  color: var(--cinnabar);
  background: rgba(179, 90, 69, .08);
}

.chain-position-controls .btn:disabled {
  color: var(--muted);
  background: rgba(91, 83, 72, .05);
}

.flashcard-topbar > div {
  display: grid;
  gap: 3px;
  text-align: center;
}

.flashcard-topbar > div span {
  color: var(--muted);
  font-size: 12px;
}

.flashcard-stage {
  position: relative;
  min-height: 570px;
  padding: clamp(28px, 6vw, 62px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  text-align: center;
  animation: flash-card-in 420ms cubic-bezier(.2,.8,.2,1) both;
}

.flashcard-stage::before,
.flashcard-stage::after {
  content: "";
  position: absolute;
  width: 210px;
  height: 210px;
  border: 1px solid rgba(112, 139, 114, 0.12);
  border-radius: 50%;
  pointer-events: none;
}

.flashcard-stage::before { left: -100px; top: -100px; }
.flashcard-stage::after { right: -110px; bottom: -110px; }

@keyframes flash-card-in {
  from { opacity: 0; transform: translateX(22px) scale(.985); }
  to { opacity: 1; transform: translateX(0) scale(1); }
}

.flashcard-number {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .12em;
}

.flashcard-stage .current-idiom {
  margin-top: 32px;
}

.chain-game-stage {
  min-height: 570px;
  justify-content: flex-start;
}

.single-idiom-stage {
  justify-content: center;
  animation: none;
}

.single-idiom-card {
  width: min(680px, 100%);
  min-height: 330px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.single-idiom-progress {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.single-idiom-card .current-idiom {
  margin: 24px 0 10px;
  white-space: nowrap;
}

.single-idiom-card .current-idiom.is-duiyun-text {
  max-width: 100%;
  white-space: normal;
  word-break: keep-all;
  overflow-wrap: normal;
  text-wrap: balance;
  letter-spacing: .04em;
  line-height: 1.28;
}

.duiyun-line {
  position: relative;
  display: block;
  width: max-content;
  max-width: 100%;
  margin-inline: auto;
}

.duiyun-line-text {
  display: block;
}

.duiyun-punctuation {
  position: absolute;
  top: 0;
  left: 100%;
  letter-spacing: 0;
}

.single-idiom-card .current-idiom.is-duiyun-text.is-long {
  font-size: clamp(42px, 7vw, 68px);
}

.single-idiom-card .current-idiom.is-duiyun-text.is-very-long {
  font-size: clamp(38px, 6vw, 60px);
}

.single-idiom-card .pinyin {
  margin: 0;
  min-height: 1.3em;
}

.single-idiom-card .pinyin.is-empty {
  visibility: hidden;
}

.chain-waterfall {
  width: min(680px, 100%);
  margin: auto;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.chain-step {
  position: relative;
  min-height: 62px;
  padding: 10px 16px;
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) 76px;
  align-items: center;
  gap: 14px;
  color: var(--dai-dark);
  background: rgba(247, 244, 236, .72);
  border: 1px solid var(--line);
  border-radius: 18px;
  text-align: left;
}

.chain-step.is-current {
  min-height: 190px;
  padding-block: 30px;
  color: var(--ink);
  background: linear-gradient(145deg, #fffef9, #eef3f1);
  border-color: rgba(55, 90, 90, .34);
  box-shadow: 0 16px 34px rgba(55, 90, 90, .12);
  animation: chain-step-in 420ms cubic-bezier(.18,.85,.24,1) both;
}

@keyframes chain-step-in {
  from { opacity: 0; transform: translateY(-14px) scale(.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.chain-step.is-anchor {
  min-height: 48px;
  padding-block: 7px;
  opacity: .58;
  border-style: dashed;
}

.chain-step-number {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  color: var(--muted);
  background: var(--paper-deep);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 700;
}

.chain-step-copy strong {
  font: 700 clamp(18px, 2.8vw, 24px)/1.3 "Songti SC", "STSong", serif;
  letter-spacing: .03em;
  white-space: nowrap;
}

.chain-step-copy {
  min-width: 0;
}

.chain-step-copy .current-idiom {
  margin: 0 0 5px;
  font-size: clamp(54px, 9vw, 84px);
  line-height: 1.08;
  letter-spacing: .05em;
  white-space: nowrap;
}

.chain-step-copy .pinyin {
  margin: 0;
}

.chain-step .sound-wave {
  width: 76px;
  margin: 0;
}

.chain-step-done {
  width: 27px;
  height: 27px;
  display: grid;
  place-items: center;
  justify-self: center;
  color: white;
  background: var(--bamboo);
  border-radius: 50%;
}

.chain-connector {
  min-height: 34px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 2px;
  color: var(--bamboo);
}

.chain-connector span {
  font-size: 21px;
  line-height: 1;
}

.chain-connector.is-near-sound {
  color: var(--cinnabar);
}


.flashcard-status {
  min-height: 24px;
  color: var(--muted);
}

.flashcard-controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.round-complete-panel {
  width: min(600px, 100%);
  margin-top: 12px;
  padding: 22px;
  background: var(--moon);
  border-radius: 20px;
}

.round-complete-panel > strong {
  display: block;
  margin-bottom: 8px;
  font: 700 22px/1.3 "Songti SC", serif;
}

.round-complete-panel p {
  color: var(--muted);
}

.round-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-top: 14px;
}

.round-card {
  min-height: 66px;
  padding: 12px 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  background: rgba(255, 253, 247, .72);
  border: 1px solid var(--line);
  border-radius: 16px;
}

.round-card span {
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--paper-deep);
  font-size: 11px;
}

.round-card.is-current {
  color: var(--dai-dark);
  background: var(--moon);
  border-color: rgba(55, 90, 90, .34);
}

.round-card.is-complete {
  color: var(--bamboo);
}

.round-card.is-complete span::after {
  content: "✓";
}

.round-card.is-complete span {
  font-size: 0;
}

.round-card.is-complete span::after {
  font-size: 13px;
}

.flashcard-footnote {
  padding: 14px 4px 0;
  color: var(--muted);
  font-size: 12px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.65fr;
  gap: 20px;
}

.hero-card {
  min-height: 430px;
  padding: clamp(28px, 5vw, 58px);
  position: relative;
  overflow: hidden;
}

.hero-card::after {
  content: "竹";
  position: absolute;
  right: -22px;
  bottom: -58px;
  color: rgba(112, 139, 114, 0.08);
  font: 700 230px/1 "Songti SC", serif;
  pointer-events: none;
}

.hero-actions,
.action-row,
.control-row,
.detail-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.hero-actions {
  margin-top: 30px;
}

.btn {
  min-height: 48px;
  padding: 12px 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:disabled {
  cursor: not-allowed;
  opacity: .56;
  transform: none;
}

.btn-primary {
  background: var(--dai);
  color: white;
  box-shadow: 0 10px 24px rgba(55, 90, 90, 0.24);
}

.btn-primary:hover {
  background: var(--dai-dark);
}

.btn-secondary {
  background: var(--apricot);
  color: var(--ink);
  border-color: rgba(179, 90, 69, 0.1);
}

.btn-quiet {
  background: transparent;
  color: var(--dai-dark);
  border-color: var(--line);
}

.btn-danger-quiet {
  background: transparent;
  color: #8f4334;
  border-color: rgba(179, 90, 69, 0.2);
}

.side-stack {
  display: grid;
  gap: 20px;
}

.mini-card {
  padding: 25px;
}

.mini-card p:last-child {
  margin-bottom: 0;
}

.metric {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
}

.metric:last-child {
  border-bottom: 0;
}

.metric strong {
  font: 700 27px/1 "Songti SC", serif;
  color: var(--dai);
}

.status-chip,
.culture-tag,
.transition-chip {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 5px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
}

.status-chip {
  color: var(--dai-dark);
  background: var(--moon);
}

.culture-tag {
  color: #8d4032;
  background: #f3dfd7;
}

.transition-chip {
  color: #4a644c;
  background: #e4ece4;
}

.player-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 20px;
}

.player-card {
  min-height: 590px;
  padding: clamp(22px, 4vw, 46px);
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.player-kicker {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  color: var(--muted);
  font-size: 14px;
}

.neighbor {
  color: #aaa59b;
  font: 500 clamp(18px, 2.5vw, 25px)/1.4 "Songti SC", serif;
  min-height: 35px;
}

.current-idiom {
  margin: 20px 0 8px;
  font: 700 clamp(48px, 10vw, 92px)/1.15 "Songti SC", "STSong", serif;
  letter-spacing: 0.08em;
}

.pinyin {
  color: var(--dai);
  font-size: clamp(16px, 2.2vw, 21px);
  letter-spacing: 0.08em;
}

.sound-wave {
  height: 38px;
  margin: 28px auto 18px;
  display: flex;
  gap: 5px;
  align-items: center;
  justify-content: center;
}

.sound-wave span {
  width: 4px;
  height: 8px;
  background: var(--bamboo);
  border-radius: 999px;
  opacity: 0.38;
}

.sound-wave.is-speaking span {
  animation: wave 1s ease-in-out infinite;
}

.sound-wave span:nth-child(2) { animation-delay: 0.12s; }
.sound-wave span:nth-child(3) { animation-delay: 0.24s; }
.sound-wave span:nth-child(4) { animation-delay: 0.36s; }
.sound-wave span:nth-child(5) { animation-delay: 0.48s; }

@keyframes wave {
  0%, 100% { height: 8px; opacity: 0.35; }
  50% { height: 34px; opacity: 0.9; }
}

.control-row {
  justify-content: center;
  margin-top: 12px;
}

.icon-btn {
  width: 52px;
  height: 52px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: white;
  color: var(--dai-dark);
  cursor: pointer;
  font-size: 20px;
}

.play-btn {
  width: 68px;
  height: 68px;
  background: var(--dai);
  color: white;
  border-color: transparent;
  box-shadow: 0 12px 26px rgba(55, 90, 90, 0.26);
}

.node-panel {
  padding: 24px;
}

.node-panel h2 {
  font-size: 22px;
}

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

.node-button {
  aspect-ratio: 1;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.7);
  color: var(--muted);
  cursor: pointer;
  font-weight: 700;
}

.node-button.is-current {
  background: var(--cinnabar);
  color: white;
  border-color: var(--cinnabar);
}

.node-button.is-seen:not(.is-current)::after {
  content: "·";
  display: block;
  color: var(--bamboo);
  line-height: 0;
  font-size: 22px;
}

.speech-note {
  margin-top: 18px;
  padding: 14px;
  border-radius: 14px;
  background: var(--moon);
  color: #4d595b;
  font-size: 13px;
  line-height: 1.6;
}

.detail-layout {
  display: grid;
  grid-template-columns: 1fr 0.68fr;
  gap: 20px;
}

.detail-main,
.detail-side,
.resume-main,
.resume-side {
  padding: clamp(24px, 4vw, 42px);
}

.learning-record-page {
  display: grid;
  gap: 20px;
}

.learning-record-header {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
  text-align: center;
}

.learning-record-header > :last-child {
  justify-self: end;
}

.learning-record-header h1 {
  margin: 2px 0 0;
  font-size: clamp(30px, 5vw, 48px);
}

.review-track-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.review-track-card,
.literacy-record-card {
  padding: clamp(22px, 3vw, 32px);
}

.review-track-heading {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  gap: 14px;
}

.review-track-heading h2,
.literacy-record-card h2 {
  margin: 4px 0 0;
  font: 700 25px/1.35 "Songti SC", serif;
}

.review-track-heading > strong {
  color: var(--dai-dark);
  white-space: nowrap;
  font-size: 13px;
}

.review-track-card > p,
.literacy-record-card > p {
  color: var(--muted);
  line-height: 1.7;
}

.review-progress {
  height: 8px;
  margin: 18px 0;
  overflow: hidden;
  background: var(--paper-deep);
  border-radius: 999px;
}

.review-progress span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--bamboo), var(--dai));
  border-radius: inherit;
}

.literacy-record-card {
  display: grid;
  grid-template-columns: minmax(220px, .75fr) minmax(260px, 1.25fr) auto;
  align-items: center;
  gap: 24px;
}

.detail-title {
  margin-bottom: 4px;
  font-size: clamp(42px, 8vw, 72px);
}

.detail-section {
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.detail-section:first-of-type {
  margin-top: 25px;
}

.detail-section p {
  font-size: 17px;
  line-height: 1.8;
}

.source-quote {
  padding: 22px;
  color: var(--dai-dark);
  background: var(--moon);
  border-left: 4px solid var(--bamboo);
  border-radius: 6px 16px 16px 6px;
  font: 600 18px/1.8 "Songti SC", serif;
}

.source-status {
  display: block;
  margin-bottom: 8px;
  color: var(--bamboo);
  font: 700 13px/1.4 system-ui, sans-serif;
}

.history-story-panel {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}

.history-story-status {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.history-story-status span {
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--moon);
  color: var(--dai-dark);
  font-size: 12px;
  font-weight: 700;
}

.history-story-status span:last-child {
  background: #e5eee1;
  color: #31564e;
}

.history-story-intro {
  margin: 0;
  color: var(--ink);
  font: 700 18px/1.65 "Songti SC", serif;
}

.history-story-block {
  padding-top: 15px;
  border-top: 1px solid var(--line);
}

.history-story-block p {
  margin: 8px 0 0;
  font-size: 16px;
  line-height: 1.85;
}

.history-story-block .history-story-label {
  margin: 0;
  color: var(--cinnabar);
  font-size: 14px;
  font-weight: 800;
}

.history-story-block small {
  display: block;
  margin-top: 10px;
  color: var(--muted);
}

.history-source-link {
  width: fit-content;
  color: var(--dai-dark);
  font-size: 13px;
  font-weight: 700;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

.story-pending {
  margin-top: 18px;
  padding: 20px;
  border-radius: 16px;
  background: var(--moon);
  color: #4d595b;
}

.story-pending p {
  margin: 8px 0 0;
  line-height: 1.7;
}

.blocked-card {
  padding: 20px;
  background: #f1eee6;
  border: 1px dashed #b7b0a1;
  border-radius: 18px;
  color: #625f58;
}

.challenge-card {
  width: min(780px, 100%);
  min-height: 580px;
  margin: 0 auto;
  padding: clamp(28px, 5vw, 56px);
  text-align: center;
}

.challenge-prompt {
  margin: 35px 0 14px;
  font: 700 clamp(46px, 9vw, 80px)/1.2 "Songti SC", serif;
}

.challenge-arrow {
  color: var(--bamboo);
  font-size: 34px;
}

.hint-card,
.reveal-card {
  margin: 24px auto;
  padding: 20px;
  border-radius: 18px;
  max-width: 520px;
}

.hint-card {
  background: var(--apricot);
}

.reveal-card {
  background: var(--moon);
}

.hint-char {
  font: 700 42px/1 "Songti SC", serif;
  color: var(--cinnabar);
}

.session-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 28px 0;
}

.summary-box {
  padding: 18px 10px;
  border-radius: 16px;
  background: var(--paper);
}

.summary-box strong,
.summary-box span {
  display: block;
}

.summary-box strong {
  color: var(--dai);
  font: 700 30px/1.1 "Songti SC", serif;
}

.summary-box span {
  margin-top: 5px;
  color: var(--muted);
  font-size: 12px;
}

.weak-list {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin: 18px 0 28px;
}

.weak-item {
  padding: 9px 13px;
  border-radius: 999px;
  background: var(--apricot);
  color: #604b3c;
}

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

.state-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.dev-box {
  margin-top: 22px;
  padding: 18px;
  background: #f1eee6;
  border-radius: 16px;
}

.date-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.date-row input {
  min-height: 44px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: white;
}

.bottom-nav {
  position: fixed;
  z-index: 50;
  left: 50%;
  bottom: 14px;
  transform: translateX(-50%);
  width: min(650px, calc(100% - 28px));
  min-height: 64px;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  padding: 7px;
  background: rgba(255, 253, 247, 0.9);
  backdrop-filter: blur(18px);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: 0 14px 40px rgba(37, 41, 36, 0.16);
}

.bottom-nav button {
  min-height: 50px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 2px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 16px;
  cursor: pointer;
  font-size: 11px;
}

.bottom-nav button span {
  font-size: 19px;
}

.bottom-nav button.is-active {
  color: white;
  background: var(--dai);
}

.toast {
  position: fixed;
  z-index: 80;
  left: 50%;
  bottom: 92px;
  transform: translate(-50%, 20px);
  max-width: min(460px, calc(100% - 32px));
  padding: 11px 16px;
  color: white;
  background: rgba(34, 33, 31, 0.92);
  border-radius: 999px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease, transform 180ms ease;
  font-size: 14px;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

.error-card {
  max-width: 720px;
  margin: 80px auto;
  padding: 34px;
}

@media (max-width: 820px) {
  .hero-grid,
  .player-shell,
  .detail-layout {
    grid-template-columns: 1fr;
  }

  .review-track-grid {
    grid-template-columns: 1fr;
  }

  .literacy-record-card {
    grid-template-columns: 1fr;
  }

  .hero-card {
    min-height: 390px;
  }

  .player-card {
    min-height: 530px;
  }

  .node-panel {
    order: 2;
  }

  .play-setup {
    grid-template-columns: 1fr;
  }

  .chain-list {
    grid-template-columns: 1fr;
  }

  .volume-tabs {
    display: flex;
    overflow-x: auto;
    padding-bottom: 5px;
  }

  .volume-tab {
    min-width: 104px;
  }

  .curriculum-chain {
    grid-template-columns: 1fr auto;
  }

  .chain-mini-preview {
    grid-column: 1 / -1;
    grid-row: 2;
    justify-content: flex-start;
    padding-left: 56px;
  }
}

@media (max-width: 520px) {
  .site-header,
  #app {
    width: min(100% - 22px, 1120px);
  }

  .site-header {
    min-height: 76px;
  }

  .learning-record-header {
    grid-template-columns: 1fr;
    justify-items: start;
    text-align: left;
  }

  .learning-record-header > :last-child {
    display: none;
  }

  .brand small,
  .header-status {
    display: none;
  }

  .hero-card,
  .mini-card,
  .player-card,
  .node-panel,
  .detail-main,
  .detail-side,
  .resume-main,
  .resume-side,
  .challenge-card {
    border-radius: 22px;
  }

  .hero-actions .btn,
  .detail-actions .btn,
  .challenge-card .action-row .btn {
    flex: 1 1 100%;
  }

  .current-idiom {
    letter-spacing: 0.04em;
  }

  .session-summary {
    grid-template-columns: 1fr;
  }

  .chain-choice {
    padding: 22px 16px;
  }

  .curriculum-overview {
    padding: 20px;
  }

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

  .section-block {
    padding: 18px 12px;
  }

  .curriculum-chain {
    grid-template-columns: 1fr;
    gap: 11px;
  }

  .chain-mini-preview {
    grid-column: auto;
    grid-row: auto;
    padding-left: 0;
    justify-content: center;
    gap: 5px;
  }

  .chain-mini-preview strong {
    font-size: 14px;
  }

  .curriculum-chain-action {
    justify-items: stretch;
  }

  .curriculum-chain-action .btn {
    width: 100%;
  }

  .chain-preview {
    gap: 6px;
  }

  .preview-card {
    min-height: 112px;
    padding-inline: 5px;
  }

  .preview-card strong {
    font-size: 17px;
  }

  .preview-arrow {
    font-size: 16px;
  }

  .chain-choice-actions .btn,
  .home-secondary .btn,
  .round-complete-panel .btn {
    flex: 1 1 100%;
  }

  .home-secondary,
  .flashcard-footnote {
    align-items: flex-start;
    flex-direction: column;
  }

  .flashcard-topbar {
    align-items: center;
    gap: 8px;
  }

  .flashcard-topbar .btn {
    min-height: 40px;
    padding: 8px 11px;
    font-size: 12px;
  }

  .chain-position-controls {
    align-items: stretch;
    flex-direction: column;
    text-align: center;
  }

  .chain-position-controls > div .btn {
    flex: 1;
  }

  .flashcard-stage {
    min-height: 510px;
    padding-inline: 18px;
  }

  .single-idiom-card {
    min-height: 300px;
  }

  .chain-step {
    grid-template-columns: 38px minmax(0, 1fr) 38px;
    gap: 9px;
    padding-inline: 12px;
  }

  .chain-step-number {
    width: 34px;
    height: 34px;
  }

  .chain-step.is-current {
    min-height: 174px;
  }

  .chain-step-copy .current-idiom {
    font-size: clamp(42px, 13vw, 58px);
  }

  .chain-step .sound-wave {
    width: 38px;
    gap: 3px;
  }

  .chain-step .sound-wave span {
    width: 3px;
  }

  .round-strip {
    grid-template-columns: 1fr;
  }
}