@font-face {
  font-family: "LXGW WenKai";
  src: url("/static/fonts/lxgw-wenkai.woff2") format("woff2");
  font-style: normal;
  font-weight: 400;
  font-display: block;
}
:root {
  color-scheme: light dark;
  --bg: #F5EDDD;
  --paper: #FFFDF7;
  --control: #FFFFFF;
  --line: #DDCFB8;
  --ink: #2C241B;
  --muted: #6E6253;
  --orange: #B23A2F;
  --danger: #8F2C23;
  --on-orange: #FFFFFF;
  --on-danger: #FFFFFF;
  --green: #23784A;
  --on-green: #FFFFFF;
  --amber: #E9A23B;
  --on-amber: #2C241B;
  --stamp-again: #975800;
  --gold: #F4B400;
  --hover: #F4EEE3;
  --active: #FBEEE9;
  --overlay: rgba(44, 36, 27, 0.35);
  --shadow: 0 12px 34px rgba(76, 55, 30, 0.12);
  --shadow-strong: 0 24px 60px rgba(0, 0, 0, 0.25);
  --toast-bg: #2C241B;
  --toast-ink: #FFFDF7;
  --focus: #B23A2F;
  --grid-line: #E6A39D;
  --grade-not-yet-bg: #FBE7C4;
  --grade-not-yet-border: #C98A1E;
  --grade-not-yet-ink: #7A4A00;
  --grade-not-yet-press: #F5D79F;
  --grade-got-it-bg: #D7EDDF;
  --grade-got-it-border: #23784A;
  --grade-got-it-ink: #1B5E3A;
  --grade-got-it-press: #C9E6D5;
  --slow-bg: #E4EEF7;
  --slow-border: #3B76AA;
  --slow-ink: #2A5F8F;
  --slow-press: #D5E5F2;
  --level-1-bg: #D6E6F2; --level-1-ink: #14100C;
  --level-2-bg: #A9CBE5; --level-2-ink: #14100C;
  --level-3-bg: #6FA6D3; --level-3-ink: #14100C;
  --level-4-bg: #3B76AA; --level-4-ink: #FFFDF7;
  --level-5-bg: #2A5F8F; --level-5-ink: #FFFDF7;
  --level-outline: #6E6253;
}
* { box-sizing: border-box; }
html { background: var(--bg); }
html, body { margin: 0; min-height: 100%; }
body {
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", "Noto Sans SC", Roboto, "PingFang SC", "Hiragino Sans GB", sans-serif;
}
button, input, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible, select:focus-visible,
textarea:focus-visible, a:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}
[hidden] { display: none !important; }
.app-top {
  display: flex; align-items: center; justify-content: space-between; gap: 14px;
  padding: 14px 22px; border-bottom: 1px solid var(--line);
  background: var(--paper); position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(8px);
}
.top-actions { display: flex; align-items: center; gap: 10px; }
.home { width: min(1000px, 100%); margin: 0 auto; padding: 34px 22px 70px; }
/* deck page */
.deck-view { min-height: calc(100vh - 60px); }
.deck-page { width: min(1000px, 100%); margin: 0 auto; padding: 22px 22px 70px; }
.deck-back { border: 0; background: transparent; color: var(--muted); padding: 4px 0; font-size: 14px; text-decoration: underline; }
.scope-hf-toggle {
  display: inline-flex; align-items: center; gap: 6px;
  border: 1px solid var(--muted); background: var(--control);
  border-radius: 999px; padding: 5px 10px; font-size: 12px;
  font-weight: 750; color: var(--muted); cursor: pointer;
}
.scope-hf-toggle input { width: 14px; height: 14px; margin: 0; }
.scope-hf-toggle.on { border-color: var(--orange); color: var(--ink); }
.deck-row {
  display: grid; grid-template-columns: 58px minmax(0,1fr) auto 42px;
  align-items: center; gap: 10px; padding: 10px 12px;
  background: var(--paper); border: 1px solid var(--line); border-radius: 16px;
}
.deck-drag-handle {
  width: 22px; height: 32px; padding: 0; border: 0; border-radius: 8px;
  background: transparent; color: var(--muted); font-size: 18px; line-height: 1;
  cursor: grab; touch-action: none; opacity: .6;
}
.deck-drag-handle:hover, .deck-drag-handle:focus-visible { color: var(--orange); opacity: 1; }
.deck-row.dragging { opacity: .3; }
.deck-row.drop-before { box-shadow: inset 0 3px 0 var(--orange); }
.deck-row.drop-after { box-shadow: inset 0 -3px 0 var(--orange); }
.deck-row-char { font: 38px/1 "LXGW WenKai", "KaiTi", "STKaiti", serif; color: var(--ink); text-align: center; }
.deck-row-info { min-width: 0; }
.deck-row-pinyin { font-weight: 700; font-size: 15px; }
.deck-row-example { color: var(--muted); font-size: 12.5px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.deck-row-arrow {
  width: 38px; height: 38px; border-radius: 999px; border: 1px solid var(--muted);
  background: var(--control); color: var(--muted); font-size: 24px; line-height: 1;
  display: grid; place-items: center; padding: 0;
}
.deck-row-arrow:hover { border-color: var(--orange); color: var(--orange); }
@media (max-width: 640px) {.deck-page { padding: 18px 16px 60px; }
#deckAddBtn { grid-column: 1 / -1; }
#deckBrowseBtn { grid-column: 1 / -1; }
#deckContinueBtn { grid-column: 1 / -1; }
.deck-row { grid-template-columns: 22px 52px minmax(0,1fr) auto 36px; gap: 8px; }
.deck-row-arrow { width: 34px; height: 34px; }}
/* modal */
.modal-overlay { z-index: 70; }
.modal-card {
  background: var(--paper); color: var(--ink); border-radius: 16px;
  box-shadow: var(--shadow-strong); padding: 22px;
  width: min(460px, 100%); max-height: min(90vh, 760px); overflow: auto;
}
.modal-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; }
.modal-head h2 { margin: 4px 0; }
.modal-x { border: 0; background: transparent; color: var(--muted); font-size: 30px; line-height: .9; padding: 0 4px; }
.modal-char { font: 64px/1 "LXGW WenKai", "KaiTi", "STKaiti", serif; margin: 6px 0 4px; }
.modal-actions { display: grid; gap: 8px; margin-top: 18px; }
.modal-action {
  display: flex; align-items: flex-start; gap: 12px; text-align: left;
  border: 1px solid var(--muted); background: var(--control); color: var(--ink);
  border-radius: 16px; padding: 11px 13px;
}
.modal-action:hover { border-color: var(--orange); }
.modal-action-icon { width: 28px; color: var(--orange); font-size: 19px; text-align: center; flex: none; }
.modal-action strong { display: block; font-size: 14px; }
.modal-action small { display: block; color: var(--muted); font-size: 12px; margin-top: 2px; line-height: 1.3; }
.modal-action.danger strong { color: var(--danger); }
.modal-action.danger .modal-action-icon { color: var(--danger); }
.confirm-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 18px; }
/* gate */
.overlay { position: fixed; inset: 0; background: var(--overlay); display: grid; place-items: center; z-index: 50; padding: 20px; }
.gate-card { background: var(--paper); border-radius: 16px; box-shadow: var(--shadow-strong); padding: 26px; width: min(380px,100%); text-align: center; }
.gate-card h2 { margin: 0 0 6px; }
.gate-card p { color: var(--muted); margin: 0 0 16px; }
.gate-question { font-size: 36px; font-weight: 900; letter-spacing: .02em; margin: 10px 0 16px; }
#gateForm { display: flex; gap: 8px; justify-content: center; }
#gateForm input { width: 96px; font-size: 22px; text-align: center; padding: 8px; border: 1px solid var(--muted); border-radius: 10px; }
.gate-card .ghost { margin-top: 12px; }
/* parent */
.parent { position: fixed; inset: 0; background: var(--bg); z-index: 30; overflow: auto; padding: 20px; }
.parent-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 18px; max-width: 1300px; margin: 0 auto 18px; }
.kicker { font-size: 11px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; color: var(--orange); }
.parent h1 { margin: 4px 0 0; font-size: clamp(24px,3vw,34px); }
.parent-layout { max-width: 1300px; margin: 0 auto; display: grid; grid-template-columns: 280px 1fr; gap: 18px; }
@media (max-width: 800px) {.parent-layout { grid-template-columns: 1fr; }}
.tree-panel, .parent-main { background: var(--paper); border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow); }
.tree-panel { padding: 14px; align-self: start; }
.small-btn { border: 1px solid var(--muted); background: var(--control); border-radius: 10px; padding: 6px 8px; font-size: 12px; font-weight: 650; }
.tree { display: grid; gap: 2px; }
.tree button { border: 0; background: transparent; text-align: left; padding: 7px 8px; border-radius: 10px; font-size: 14px; }
.tree button:hover { background: var(--hover); }
.tree button.active { background: var(--active); color: var(--orange); font-weight: 700; }
.tree-deck { display: flex; align-items: center; gap: 1px; border-radius: 10px; }
.tree-deck:hover { background: var(--hover); }
.tree-deck .tree-select { flex: 1; min-width: 0; padding-left: 2px; }
.tree-deck .tree-select:hover { background: transparent; }
.tree .tree-drag-handle {
  flex: none; width: 22px; height: 30px; padding: 0; border: 0; border-radius: 8px;
  background: transparent; color: var(--muted); font-size: 17px; line-height: 1;
  opacity: .55; cursor: grab; touch-action: none;
}
.tree .tree-drag-handle:hover { background: transparent; color: var(--orange); opacity: 1; }
.tree-drag-handle:focus-visible { color: var(--orange); opacity: 1; }
.tree-deck.dragging { opacity: .3; }
.tree-deck.drop-before { box-shadow: inset 0 2px 0 var(--orange); }
.tree-deck.drop-after { box-shadow: inset 0 -2px 0 var(--orange); }
.tree-folder-drop.drop-into, .tree-top-drop.drop-into {
  background: var(--active); color: var(--orange);
  outline: 1px dashed var(--orange); outline-offset: -1px;
}
.drag-ghost {
  position: fixed; z-index: 200; pointer-events: none; opacity: .96;
  box-shadow: var(--shadow-strong); transform: rotate(.35deg);
}
.drag-ghost.tree-deck {
  background: var(--paper); border: 1px solid var(--orange); padding: 2px 4px;
}
.drag-ghost.deck-row { background: var(--paper); border-color: var(--orange); }
.drag-ghost button { pointer-events: none; }
body.is-dragging { user-select: none; -webkit-user-select: none; cursor: grabbing; }
.tree .folder-label { padding: 8px 4px 2px; color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: .08em; }
.tree .indent { padding-left: 16px; }
.data-note { margin-top: 18px; padding-top: 12px; border-top: 1px dashed var(--line); font-size: 11px; color: var(--muted); overflow-wrap: anywhere; }
.data-note code { display: block; margin-top: 4px; font-size: 10.5px; }
.parent-main { padding: 14px; min-width: 0; }
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin-bottom: 16px; }
.tabs button { border: 0; background: transparent; padding: 9px 12px; font-weight: 700; color: var(--muted); border-bottom: 2px solid transparent; }
.tabs button.active { color: var(--ink); border-bottom-color: var(--orange); }
.tab-panel { min-height: 300px; }
.toolbar { display: flex; justify-content: space-between; align-items: flex-end; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.toolbar-actions { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.group-toggle { display: flex; align-items: center; gap: 6px; color: var(--muted); font-size: 12.5px; white-space: nowrap; }
.group-toggle input { width: 16px; height: 16px; }
.group-section { border: 1px solid var(--line); border-radius: 16px; background: var(--paper); margin-bottom: 8px; overflow: hidden; }
.group-section > summary { cursor: pointer; padding: 9px 11px; font-weight: 750; background: var(--hover); user-select: none; }
.group-section > summary .count { color: var(--muted); font-weight: 400; font-size: 12.5px; margin-left: 5px; }
.group-section .group-body { padding: 0 10px; }
.group-section .group-section { margin: 8px 0; }
.group-section .group-section > summary { background: var(--hover); }
.scope-label { font-size: 19px; font-weight: 800; }
.teach-audio-banner {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  margin: 0 24px 12px; padding: 10px 12px;
  border: 1px solid var(--line); border-radius: 14px;
  background: var(--paper); color: var(--ink);
}
.teach-audio-text { flex: 1 1 260px; font-size: 13px; font-weight: 700; }
.scope-tools { display: flex; gap: 8px; margin-top: 4px; flex-wrap: wrap; }
.scope-tools button { border: 0; background: transparent; color: var(--muted); font-size: 12px; text-decoration: underline; padding: 2px 0; }
.scope-tools button.danger { color: var(--danger); }
.scope-tools .scope-play { border: 1px solid var(--orange); background: var(--orange); color: var(--on-orange); border-radius: 999px; padding: 6px 11px; font-weight: 750; text-decoration: none; }
.scope-tools .scope-play:hover { filter: brightness(.92); }
.scope-tools .scope-browse { border: 1px solid var(--muted); background: var(--control); border-radius: 999px; padding: 6px 11px; font-weight: 750; color: var(--ink); text-decoration: none; }
.scope-tools .scope-browse:hover { border-color: var(--orange); color: var(--orange); }
.hint { color: var(--muted); font-size: 13px; }
input[type=checkbox], input[type=radio] { accent-color: var(--orange); }
input[type=text], input[type=search], input[type=number], select, textarea {
  border: 1px solid var(--muted); border-radius: 10px; background: var(--control); padding: 9px 11px;
}
input[type=text], input[type=search] { min-width: 0; }
.btn { border: 1px solid var(--muted); background: var(--control); border-radius: 999px; padding: 9px 14px; font-weight: 700; }
.btn.primary { background: var(--orange); border-color: var(--orange); color: var(--on-orange); }
.btn.danger { background: var(--danger); border-color: var(--danger); color: var(--on-danger); }
.btn.primary:hover { filter: brightness(.92); }
.btn.ghost { background: transparent; }
.add-form { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; background: var(--hover); border: 1px solid var(--line); border-radius: 16px; padding: 12px; margin-bottom: 12px; }
.add-form input { width: 110px; }
.add-form input:nth-child(2) { width: 150px; }
.add-form input:nth-child(3) { width: 150px; }
.warn { color: var(--danger); background: var(--paper); border: 1px solid var(--danger); border-radius: 10px; padding: 8px 10px; font-size: 13px; margin-top: 8px; width: 100%; }
.card-list { display: grid; gap: 6px; }
.card-row { display: grid; grid-template-columns: 52px 110px 1fr auto; gap: 10px; align-items: center; border-bottom: 1px solid var(--line); padding: 9px 2px; }
.card-row:last-child { border-bottom: 0; }
.card-char { font: 32px/1 "LXGW WenKai", "KaiTi", "STKaiti", serif; }
.card-pinyin { font-weight: 650; }
.card-level { display: inline-block; margin-left: 3px; padding: 1px 6px; border: 1px solid transparent; border-radius: 999px; color: var(--muted); font-size: 10.5px; font-weight: 700; vertical-align: 1px; }
.card-example { color: var(--muted); font-size: 13px; }
.card-actions { display: flex; gap: 5px; flex-wrap: wrap; justify-content: flex-end; }
.card-actions button { border: 0; background: transparent; color: var(--muted); font-size: 12px; text-decoration: underline; padding: 3px; }
.card-actions button.danger { color: var(--danger); }
.empty { color: var(--muted); text-align: center; padding: 40px 10px; }
/* import */
.import-head { display: flex; justify-content: space-between; gap: 16px; align-items: flex-start; flex-wrap: wrap; }
.import-head h2 { margin: 0 0 4px; }
.import-head p { margin: 0; color: var(--muted); font-size: 14px; max-width: 66ch; }
#importTab textarea { width: 100%; min-height: 150px; margin: 14px 0; font-size: 20px; }
.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; margin: 10px 0; }
.row select { min-width: 180px; }
.field { font-weight: 700; font-size: 14px; }
.import-summary { color: var(--muted); font-size: 14px; min-height: 20px; }
.import-preview { display: grid; gap: 4px; max-height: 300px; overflow: auto; margin: 10px 0; }
.preview-row { display: grid; grid-template-columns: 44px 120px 1fr 130px; gap: 8px; align-items: center; border-bottom: 1px solid var(--line); padding: 5px 0; font-size: 13px; }
.preview-row .dupe { color: var(--danger); }
.preview-row .bad { color: var(--danger); }
.import-preview .head { color: var(--muted); font-weight: 700; font-size: 11px; text-transform: uppercase; letter-spacing: .05em; }
.level-meter { height: 8px; background: var(--line); border-radius: 999px; overflow: hidden; max-width: 300px; margin: 12px 0; }
.level-fill { height: 100%; width: 0; background: var(--ink); }
.help { margin-top: 18px; color: var(--muted); font-size: 13px; max-width: 70ch; }
/* search */
.search-view { min-height: calc(100vh - 60px); }
.search-page { width: min(900px, 100%); margin: 0 auto; padding: 22px 22px 70px; }
.search-page-head {
  display: flex; justify-content: space-between; align-items: flex-end;
  gap: 14px; flex-wrap: wrap; margin: 18px 0 16px;
}
.search-page-head h1 { margin: 0; font-size: clamp(28px, 4vw, 40px); }
.search-field {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 14px; border: 1px solid var(--muted); border-radius: 16px;
  background: var(--paper); box-shadow: var(--shadow);
}
.search-field:focus-within { border-color: var(--orange); }
.search-field > svg { color: var(--muted); flex: 0 0 auto; }
.search-field input {
  flex: 1 1 auto; min-width: 0; border: 0; padding: 8px 0;
  background: transparent; font-size: 18px;
}
.search-field input:focus { outline: none; }
.search-clear {
  border: 0; background: var(--hover); border-radius: 999px;
  padding: 5px 9px; color: var(--muted); font-size: 12px; font-weight: 700;
}
.search-status { margin: 12px 2px; }
.search-results { display: grid; gap: 8px; }
.search-result {
  display: grid; grid-template-columns: 58px minmax(0, 1fr) auto;
  align-items: center; gap: 12px; width: 100%;
  padding: 10px 12px; border: 1px solid var(--line); border-radius: 16px;
  background: var(--paper); color: inherit; text-align: left;
}
.search-result:hover { border-color: var(--orange); }
.search-result-char {
  font: 40px/1 "LXGW WenKai", "KaiTi", "STKaiti", serif;
  text-align: center;
}
.search-result-main { min-width: 0; display: flex; flex-direction: column; gap: 2px; }
.search-result-pinyin { font-weight: 750; }
.search-result-example {
  color: var(--muted); font-size: 13px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.search-result-decks {
  color: var(--muted); font-size: 11.5px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.search-result-side { display: flex; align-items: center; gap: 8px; }
.search-result-arrow { color: var(--muted); font-size: 20px; line-height: 1; }
.search-empty {
  border: 1px dashed var(--line); border-radius: 16px;
  padding: 26px 16px; color: var(--muted); text-align: center;
}
@media (max-width: 560px) {.search-page { padding: 16px 14px 60px; }
.search-result { grid-template-columns: 48px minmax(0, 1fr) auto; gap: 9px; }
.search-result-char { font-size: 34px; }}
/* ---------------------------------------------------------- standard mode */
.study {
  position: fixed; inset: 0; z-index: 35; display: flex; flex-direction: column;
  background: var(--bg);
  color: var(--ink); overflow: hidden; overscroll-behavior: none;
  padding-top: env(safe-area-inset-top);
}
.study-top {
  display: grid; grid-template-columns: auto minmax(0,1fr) auto;
  align-items: center; gap: 14px; padding: 14px 20px 6px;
}
@media (max-width: 640px) {.study-top { gap: 8px; padding-left: 12px; padding-right: 12px; }}
.study :focus-visible { outline-color: var(--ink); }
.study-stage {
  position: relative; flex: 1; min-height: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: flex-start; gap: 10px;
  padding: 10px 20px calc(18px + env(safe-area-inset-bottom));
  touch-action: pan-x; overflow: hidden;
}
.study-card-wrap {
  --study-card-size: min(78vw, 44vh, 380px);
  display: flex; flex: 1; flex-direction: column; align-items: center; justify-content: center;
  gap: 8px; min-height: 0; width: 100%;
}
.card-strip-viewport {
  --strip-vertical-pad: 22px;
  --strip-meta-space: 42px;
  width: 100%; height: calc(var(--study-card-size) + var(--strip-vertical-pad) * 2 + var(--strip-meta-space));
  overflow-x: auto; overflow-y: hidden;
  scroll-snap-type: x mandatory;
  overscroll-behavior-x: contain; touch-action: pan-x;
  -webkit-overflow-scrolling: touch; scrollbar-width: none;
}
.card-strip-viewport::-webkit-scrollbar { display: none; }
.card-strip-viewport.grading { overflow-x: hidden; touch-action: none; }
.card-strip-track {
  display: flex; height: 100%;
  --strip-slide: calc(var(--study-card-size) + 40px);
  padding-inline: max(0px, calc((100% - var(--strip-slide)) / 2));
}
.strip-slide {
  flex: 0 0 var(--strip-slide); width: var(--strip-slide); height: 100%;
  display: grid; place-items: center;
  scroll-snap-align: center; scroll-snap-stop: always;
}
.study.browse-mode .strip-slide { scroll-snap-stop: normal; }
.study.browse-mode .card-strip-viewport { scroll-snap-type: x proximity; }
.strip-card {
  position: relative; width: var(--study-card-size); height: var(--study-card-size);
  perspective: 1000px; border-radius: 24px; box-shadow: var(--shadow);
  will-change: transform, opacity;
}
.strip-card-inner {
  position: absolute; inset: 0;
  transform-style: preserve-3d; -webkit-transform-style: preserve-3d;
  transition: transform 500ms ease;
}
.strip-card.flipped .strip-card-inner { transform: rotateY(180deg); }
.strip-face {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  padding: clamp(12px, 4vw, 18px);
  background: var(--paper); border: 1px solid var(--line); border-radius: 24px;
  backface-visibility: hidden; -webkit-backface-visibility: hidden;
  overflow: hidden;
}
.strip-front { gap: 0; }
.strip-back { transform: rotateY(180deg); gap: 7px; text-align: center; }
.strip-card.retry-card .strip-face { border-style: dashed; }
.strip-card.wrong-feedback { animation: card-wobble 650ms ease-in-out; }
.strip-card.wrong-feedback .strip-face { animation: wrong-border 750ms ease-out; }
.strip-card.correct-pop { animation: correct-pop 380ms ease-out; }
.strip-slide-card { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px; }
@media (prefers-reduced-motion: reduce) {.strip-card-inner { transition: none; }
.strip-card.correct-pop, .strip-card.wrong-feedback,
  .strip-card.wrong-feedback .strip-face { animation: none; }}
.tianzige {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  width: 72%; aspect-ratio: 1 / 1;
  border: 2px solid var(--orange); border-radius: 2px;
  pointer-events: none; z-index: 0;
}
.tianzige::before,
.tianzige::after {
  content: ""; position: absolute; pointer-events: none;
}
.tianzige::before {
  left: 0; right: 0; top: 50%; border-top: 1px dashed var(--grid-line);
}
.tianzige::after {
  top: 0; bottom: 0; left: 50%; border-left: 1px dashed var(--grid-line);
}
.study-char {
  font-family: "LXGW WenKai", "KaiTi", "STKaiti", serif;
  font-size: clamp(64px, calc(var(--study-card-size) * 0.68), 220px);
  line-height: 1; color: var(--ink);
  position: relative; z-index: 1;
}
.study-back-kicker {
  color: var(--muted); font-size: 10px; font-weight: 800;
  letter-spacing: .1em; text-transform: uppercase;
}
.study-back-pinyin {
  font-size: clamp(20px, calc(var(--study-card-size) * 0.09), 34px);
  font-weight: 800; line-height: 1.15; overflow-wrap: anywhere;
}
.study-back-meaning {
  font-size: clamp(18px, calc(var(--study-card-size) * 0.075), 30px);
  font-weight: 700; line-height: 1.25; overflow-wrap: anywhere;
}
.study:not(.hands-free-mode) .strip-card { cursor: pointer; }
.study-speak-btn {
  border: 1px solid var(--line); background: var(--control); color: var(--muted);
  border-radius: 999px; padding: 5px 11px; min-height: 32px;
  font-size: 13px; font-weight: 750;
}
.study-speak-btn:disabled { opacity: .55; }
.study-level-badge {
  display: inline-flex; align-items: center; justify-content: center;
  height: 20px; padding: 0 8px; border: 1px solid transparent;
  border-radius: 999px; font-size: 11px; font-weight: 800; line-height: 1;
  white-space: nowrap;
}
.study-level-badge.level-0 { background: transparent; border-color: var(--level-outline); color: var(--muted); }
.study-level-badge.level-1 { background: var(--level-1-bg); border-color: var(--level-1-ink); color: var(--level-1-ink); }
.study-level-badge.level-2 { background: var(--level-2-bg); border-color: var(--level-2-ink); color: var(--level-2-ink); }
.study-level-badge.level-3 { background: var(--level-3-bg); border-color: var(--level-3-ink); color: var(--level-3-ink); }
.study-level-badge.level-4 { background: var(--level-4-bg); border-color: var(--level-4-ink); color: var(--level-4-ink); }
.study-level-badge.level-5 { background: var(--level-5-bg); border-color: var(--level-5-ink); color: var(--level-5-ink); }
.study-level-badge.pop { animation: level-badge-pop 320ms ease-out; }
@keyframes level-badge-pop {
  0% { transform: scale(.7); }
  45% { transform: scale(1.35); }
  100% { transform: scale(1); }
}
.level-burst {
  position: fixed; left: 0; top: 0; width: 72px; height: 72px;
  transform: translate(-50%, -50%) scale(.3); opacity: 0;
  color: var(--gold); pointer-events: none; z-index: 60;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, .2));
}
.level-burst svg { display: block; width: 100%; height: 100%; }
.level-burst.show { animation: level-burst 560ms ease-out; }
@keyframes level-burst {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(.3) rotate(-12deg); }
  28% { opacity: 1; transform: translate(-50%, -50%) scale(1.15) rotate(0deg); }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(1.9) rotate(12deg); }
}
.correct-star {
  position: fixed; left: 0; top: 0; width: 112px; height: 112px;
  transform: translate(-50%, -50%) scale(0); opacity: 0;
  color: var(--gold); pointer-events: none; z-index: 55;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, .18));
}
.correct-star svg { display: block; width: 100%; height: 100%; }
@keyframes slot-land {
  0% { transform: scale(1); }
  45% { transform: scale(1.6); }
  100% { transform: scale(1); }
}
/* Correct answer: a brief card pop before it exits. */
.correct-pop { animation: correct-pop 380ms ease-out; }
@keyframes correct-pop {
  0% { scale: 1; }
  40% { scale: 1.1; }
  100% { scale: 1; }
}
/* Wrong answer: wobble + amber outline flash. */
.wrong-feedback { animation: card-wobble 650ms ease-in-out; }
@keyframes card-wobble {
  0% { rotate: 0deg; }
  15% { rotate: -7deg; }
  30% { rotate: 6deg; }
  45% { rotate: -4deg; }
  60% { rotate: 2deg; }
  75%, 100% { rotate: 0deg; }
}
@keyframes wrong-border {
  0%, 100% { border-color: var(--line); }
  20%, 60% { border-color: var(--amber); }
}
@media (prefers-reduced-motion: reduce) {.study-level-badge.pop { animation: none; }
.level-burst { display: none; }
.correct-pop { animation: none; }
.strip-card.correct-pop,
  .strip-card.wrong-feedback,
  .strip-card.wrong-feedback .strip-face { animation: none; }}
.study-arrow {
  display: none; position: absolute; top: calc(50% - 74px); transform: translateY(-50%);
  width: 46px; height: 46px; border-radius: 999px; border: 1px solid var(--muted);
  background: var(--control); color: var(--muted); font-size: 28px; line-height: 1;
  place-items: center; z-index: 2;
}
.study.browse-mode .study-arrow { top: calc(50% - 56px); }
.study-arrow.prev { left: 10px; }
.study-arrow.next { right: 10px; }
.study-arrow:disabled { opacity: .3; cursor: default; }
@media (hover: hover) and (pointer: fine) {.study-arrow { display: grid; }}
@media (max-width: 640px) {.study-arrow { display: none; }}
.study-done {
  position: relative; flex: 1; min-height: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
  gap: 12px; padding: 24px 24px calc(24px + env(safe-area-inset-bottom));
}
.study-done h2 { margin: 0; font-size: clamp(34px, 7vh, 58px); }
.study-done .kicker { color: var(--muted); }
@keyframes ladder-star-pop {
  0% { transform: scale(1); }
  50% { transform: scale(1.5); }
  100% { transform: scale(1); }
}
@media (max-width: 640px) {.study-done { gap: 8px; padding: 16px 12px calc(16px + env(safe-area-inset-bottom)); }
.study-done h2 { font-size: clamp(30px, 7vh, 46px); }}
@media (max-height: 700px) {.study-done { gap: 6px; padding-top: 10px; }}
@media (max-height: 620px) {.study-card-wrap { --study-card-size: min(78vw, 38vh, 340px); }
.study-stage { gap: 8px; }}
.toast { position: fixed; left: 50%; bottom: calc(22px + env(safe-area-inset-bottom, 0px)); transform: translateX(-50%); background: var(--toast-bg); color: var(--toast-ink); padding: 10px 16px; border-radius: 999px; font-size: 14px; opacity: 0; visibility: hidden; transition: opacity .2s, visibility .2s; z-index: 80; max-width: 90vw; pointer-events: none; }
.toast.show { opacity: 1; visibility: visible; }
.toast:empty { display: none; }
.toast.error { background: var(--ink); color: var(--paper); }
/* ------------------------------------------------------------ hands-free */
.study-card-wrap { position: relative; }
.hf-status {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  color: var(--muted); font-size: clamp(18px, 3vh, 24px); font-weight: 750;
}
.hf-checking {
  display: flex; flex-direction: column; align-items: center; gap: 12px;
  color: var(--muted); font-size: 17px; font-weight: 700;
}
.hf-spinner {
  width: 42px; height: 42px; border-radius: 999px;
  border: 3px solid var(--line); border-top-color: var(--orange);
  animation: hf-spin 800ms linear infinite;
}
@keyframes hf-spin { to { transform: rotate(360deg); } }
.hf-feedback {
  width: min(100%, 360px); display: flex; flex-direction: column;
  align-items: center; gap: 6px; padding: 18px;
}
.hf-feedback-icon { font-size: 44px; line-height: 1; }
.hf-feedback-title { font-size: clamp(24px, 4vh, 34px); font-weight: 850; }
.hf-feedback-sub { color: var(--muted); font-size: 17px; font-weight: 700; }
.hf-heard { color: var(--muted); font-size: 13px; min-height: 18px; }
.hf-replay {
  pointer-events: auto; border: 0; background: transparent; color: var(--muted);
  font-size: 12px; font-weight: 700; padding: 3px 5px; text-decoration: underline;
  text-underline-offset: 2px;
}
.hf-replay:active, .hf-replay.playing { color: var(--ink); }
.hf-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 8px; }
.study.hands-free-mode .card-strip-viewport { visibility: hidden; touch-action: none; --strip-meta-space: 0px; }
.study.hands-free-mode.hf-listening .card-strip-viewport { visibility: visible; }
.study.hands-free-mode.hf-listening #handsFreePanel { display: none; }
.study.hands-free-mode.hf-listening .strip-card {
  animation: hf-listen-pulse 1.4s ease-in-out infinite;
  box-shadow: 0 0 0 6px color-mix(in srgb, var(--orange) 30%, transparent), var(--shadow);
}
@keyframes hf-listen-pulse {
  0%, 100% { outline: 2px solid transparent; outline-offset: 4px; }
  50% { outline: 2px solid color-mix(in srgb, var(--orange) 45%, transparent); outline-offset: 10px; }
}
.study.hands-free-mode .study-stage { touch-action: none; }
.hf-teach-text {
  position: absolute; left: 50%; bottom: 2px; transform: translateX(-50%);
  z-index: 7; max-width: 82%; padding: 5px 10px; border-radius: 10px;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  color: var(--muted); font-size: 14px; font-weight: 700; text-align: center;
  pointer-events: none;
}
.study.hands-free-mode.hf-teach .card-strip-viewport { visibility: visible; }
.study.hands-free-mode.hf-teach .card-strip-viewport { touch-action: none; }
.study.hands-free-mode.hf-teach #handsFreePanel { display: none; }
@media (prefers-reduced-motion: reduce) {.hf-spinner { animation: none; }
.study.hands-free-mode.hf-listening .strip-card { animation: none; }}
/* --------------------------------------------------------------- history */
.history-toolbar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.history-toolbar label { display: inline-flex; align-items: center; gap: 5px; color: var(--muted); font-size: 12px; font-weight: 700; }
.history-toolbar input[type=date] { padding: 6px 8px; }
.history-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 8px; margin-bottom: 14px; }
.history-stat { padding: 10px 12px; border: 1px solid var(--line); border-radius: 12px; background: var(--paper); }
.history-stat strong { display: block; font-size: 20px; line-height: 1.1; }
.history-stat span { color: var(--muted); font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: .04em; }
.history-list { display: grid; gap: 8px; }
.history-run { display: grid; grid-template-columns: minmax(0,1fr) auto auto; gap: 10px; align-items: center; padding: 11px 12px; border: 1px solid var(--line); border-radius: 14px; background: var(--paper); cursor: pointer; text-align: left; color: inherit; }
.history-run:hover { border-color: var(--orange); }
.history-run-main { min-width: 0; }
.history-run-title { font-weight: 800; font-size: 14px; }
.history-run-meta { color: var(--muted); font-size: 12px; margin-top: 3px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.history-run-counts { color: var(--muted); font-size: 12px; white-space: nowrap; }
.history-run-badges { display: flex; gap: 5px; align-items: center; justify-content: flex-end; flex-wrap: wrap; }
.history-badge { border-radius: 999px; padding: 3px 7px; font-size: 10px; font-weight: 800; white-space: nowrap; border: 1px solid var(--line); color: var(--muted); }
.history-badge.review { border-color: var(--amber); color: var(--amber); }
.history-badge.reviewed { border-color: var(--green); color: var(--green); }
.history-detail-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 8px; }
.history-detail-title { flex: 1 1 220px; font-weight: 800; }
.history-items { display: grid; gap: 10px; }
.history-item { border: 1px solid var(--line); border-radius: 14px; background: var(--paper); padding: 12px; }
.history-item.review { border-color: var(--amber); }
.history-item-head { display: flex; align-items: flex-start; gap: 10px; flex-wrap: wrap; }
.history-item-char { font-family: "LXGW WenKai", "KaiTi", serif; font-size: 34px; line-height: 1; }
.history-item-info { flex: 1 1 200px; min-width: 0; }
.history-item-pinyin { color: var(--muted); font-size: 12px; }
.history-item-example { font-size: 13px; margin-top: 2px; }
.history-item-verdicts { display: flex; gap: 6px; flex-wrap: wrap; margin: 10px 0; font-size: 12px; color: var(--muted); }
.history-take { border-top: 1px solid var(--line); padding-top: 8px; margin-top: 8px; display: grid; gap: 5px; }
.history-take audio { width: 100%; max-width: 420px; height: 34px; }
.history-take-meta { color: var(--muted); font-size: 12px; overflow-wrap: anywhere; }
.history-actions { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 9px; }
.history-actions .btn { padding: 6px 9px; font-size: 12px; }
.history-actions .btn.active { background: var(--orange); border-color: var(--orange); color: var(--on-orange); }
.history-empty-line { color: var(--muted); font-size: 13px; }
@media (max-width: 640px) {.history-run { grid-template-columns: minmax(0,1fr) auto; }
.history-run-badges { grid-column: 1 / -1; justify-content: flex-start; }
.history-run-counts { grid-column: 2; grid-row: 1; }}

.field-counter-group { display: inline-flex; align-items: center; gap: 4px; }
.smart-name-info { width: 20px; height: 20px; margin: 0; }
.smart-name-info svg { width: 16px; height: 16px; }


.smart-name-text {
  display: inline;
  padding: 0;
  font-size: 22px;
  font-weight: 800;
  line-height: 1.25;
  color: var(--ink);
}


.smart-name-static {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  vertical-align: middle;
}
.smart-name-static[hidden] { display: none; }
.smart-name-info { width: 22px; height: 22px; margin: 0 0 0 2px; align-self: center; }
.smart-name-info svg { width: 17px; height: 17px; }