:root {
  --paper: #f3efe6;
  --paper-deep: #e9e1d2;
  --card: rgba(255, 253, 248, 0.86);
  --ink: #20201d;
  --muted: #77736b;
  --line: rgba(44, 42, 36, 0.13);
  --red: #b74332;
  --red-dark: #8f3025;
  --green: #52705b;
  --amber: #ad7a32;
  --shadow: 0 24px 80px rgba(61, 48, 30, 0.08);
  --han: "Songti SC", "STSong", "Noto Serif CJK SC", serif;
  --ui: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html { min-height: 100%; background: var(--paper); }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--ui);
  background:
    radial-gradient(circle at 82% 3%, rgba(183, 67, 50, 0.07), transparent 26rem),
    linear-gradient(rgba(255,255,255,.24), rgba(255,255,255,0)),
    var(--paper);
}

button { font: inherit; }
button:focus-visible { outline: 3px solid rgba(183,67,50,.25); outline-offset: 3px; }

.shell { width: min(1180px, calc(100% - 36px)); margin: 0 auto; min-height: 100vh; display: flex; flex-direction: column; }

.topbar {
  height: 92px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  border-bottom: 1px solid var(--line);
}

.brand { display: flex; gap: 12px; align-items: center; border: 0; background: none; padding: 0; color: var(--ink); text-align: left; cursor: pointer; width: fit-content; }
.brand-seal { width: 43px; height: 43px; display: grid; place-items: center; color: #fffaf2; background: var(--red); border-radius: 11px 5px 12px 6px; font: 26px/1 var(--han); transform: rotate(-1deg); box-shadow: inset 0 0 0 2px rgba(255,255,255,.22); }
.brand b { display: block; font: 700 19px/1.15 var(--han); letter-spacing: .02em; }
.brand small { display: block; color: var(--muted); margin-top: 3px; font-size: 11px; letter-spacing: .04em; }

nav { display: flex; gap: 6px; padding: 5px; border-radius: 13px; background: rgba(225, 218, 205, .52); }
.nav-item { border: 0; background: transparent; color: var(--muted); padding: 9px 17px; border-radius: 9px; cursor: pointer; font-size: 14px; }
.nav-item.active { background: #fffdf8; color: var(--ink); box-shadow: 0 2px 12px rgba(54,42,26,.06); }
.local-pill { justify-self: end; color: var(--muted); font-size: 12px; border: 1px solid var(--line); border-radius: 999px; padding: 7px 11px; }
.local-pill i { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: #69866f; margin-right: 6px; box-shadow: 0 0 0 3px rgba(105,134,111,.14); }

main { flex: 1; padding: 62px 0 56px; }
main:focus { outline: none; }
footer { min-height: 74px; border-top: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; color: var(--muted); font-size: 12px; }

.loading-state { min-height: 420px; display: grid; place-content: center; text-align: center; color: var(--muted); }
.ink-loader { font: 74px/1 var(--han); color: var(--red); animation: breathe 1.3s ease-in-out infinite alternate; }
@keyframes breathe { to { opacity: .3; transform: scale(.96); } }

.auth-screen .topbar nav, .auth-screen .local-pill, .auth-screen footer { visibility: hidden; }
.auth-screen main { display: grid; place-items: center; padding: 38px 0 70px; }
.login-view { width: min(420px, 100%); text-align: center; border: 1px solid var(--line); background: var(--card); border-radius: 30px 12px 30px 12px; padding: 38px; box-shadow: var(--shadow); }
.login-mark { width: 64px; height: 64px; display: grid; place-items: center; margin: 0 auto 22px; color: #fffaf2; background: var(--red); border-radius: 16px 7px 18px 8px; font: 38px/1 var(--han); }
.login-view h1 { font-size: 42px; margin: 9px 0 12px; }
.login-view > p { color: var(--muted); line-height: 1.55; margin-bottom: 25px; }
.login-form { display: grid; gap: 14px; text-align: left; }
.login-form label { display: grid; gap: 7px; color: var(--muted); font-size: 12px; }
.login-form input { width: 100%; border: 1px solid var(--line); border-radius: 12px 6px 12px 6px; background: rgba(255,255,255,.66); color: var(--ink); padding: 13px 14px; font: inherit; }
.login-form input:focus { outline: 3px solid rgba(183,67,50,.16); border-color: rgba(183,67,50,.42); }
.login-error { min-height: 17px; margin: -2px 0 0; color: var(--red-dark); font-size: 12px; }
.login-form button:disabled { opacity: .65; cursor: wait; }

.eyebrow { color: var(--red); text-transform: uppercase; letter-spacing: .13em; font-size: 11px; font-weight: 700; }
h1, h2, h3, p { margin-top: 0; }
h1 { font: 600 clamp(38px, 5.6vw, 70px)/1.04 var(--han); letter-spacing: -.035em; margin-bottom: 18px; }
h2 { font: 600 30px/1.15 var(--han); letter-spacing: -.015em; }
h3 { font: 600 18px/1.25 var(--han); }
.lede { color: var(--muted); font-size: 17px; line-height: 1.6; max-width: 620px; }

.today-layout { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(310px, .8fr); gap: 52px; align-items: center; min-height: 490px; }
.today-copy { padding-left: 7%; }
.today-copy .eyebrow { margin-bottom: 18px; }
.today-copy h1 em { color: var(--red); font-style: normal; }
.microcopy { margin: 24px 0 0; color: var(--muted); font-size: 13px; display: flex; gap: 18px; flex-wrap: wrap; }
.microcopy span::before { content: "·"; color: var(--red); margin-right: 7px; }

.session-card { position: relative; overflow: hidden; border: 1px solid rgba(59,47,31,.11); background: var(--card); border-radius: 28px 12px 28px 12px; padding: 34px; box-shadow: var(--shadow); }
.session-card::after { content: "永"; position: absolute; right: -12px; bottom: -51px; font: 190px/1 var(--han); color: rgba(70,62,49,.035); pointer-events: none; }
.session-card-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 30px; }
.session-card-head strong { font: 600 21px/1 var(--han); }
.date-chip { color: var(--muted); font-size: 12px; }
.session-counts { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 16px; }
.count-box { border: 1px solid var(--line); border-radius: 15px 7px 15px 7px; padding: 18px; background: rgba(255,255,255,.45); }
.count-box b { display: block; font: 600 36px/1 var(--han); }
.count-box span { display: block; margin-top: 7px; color: var(--muted); font-size: 12px; }
.time-row { display: flex; gap: 10px; align-items: center; color: var(--muted); font-size: 13px; padding: 13px 2px 22px; }
.time-row svg { width: 17px; height: 17px; }
.primary-button, .secondary-button, .rating-button { border: 0; cursor: pointer; border-radius: 13px 6px 13px 6px; transition: transform .16s ease, box-shadow .16s ease, background .16s ease; }
.primary-button { width: 100%; padding: 16px 20px; background: var(--red); color: white; font-weight: 650; box-shadow: 0 10px 24px rgba(183,67,50,.18); }
.primary-button:hover { background: var(--red-dark); transform: translateY(-1px); }
.secondary-button { padding: 11px 15px; background: rgba(255,255,255,.6); border: 1px solid var(--line); color: var(--ink); }
.text-button { border: 0; padding: 6px; background: none; color: var(--muted); cursor: pointer; }
.text-button:hover { color: var(--red); }

.section-head { display: flex; justify-content: space-between; align-items: end; gap: 22px; margin-bottom: 30px; }
.section-head h1 { font-size: clamp(36px, 5vw, 56px); margin-bottom: 6px; }
.section-head p { color: var(--muted); margin-bottom: 0; }

.filter-row { display: flex; gap: 8px; flex-wrap: wrap; }
.filter-chip { cursor: pointer; border: 1px solid var(--line); background: transparent; color: var(--muted); padding: 9px 13px; border-radius: 999px; }
.filter-chip.active { background: var(--ink); color: white; }

.character-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(108px, 1fr)); gap: 11px; }
.character-tile { min-height: 129px; position: relative; text-align: left; cursor: pointer; border: 1px solid var(--line); background: rgba(255,253,248,.58); border-radius: 15px 7px 15px 7px; padding: 14px; color: var(--ink); transition: transform .16s ease, background .16s ease; }
.character-tile:hover { transform: translateY(-2px); background: #fffdf8; }
.character-tile.learned { box-shadow: inset 0 3px 0 rgba(82,112,91,.65); }
.tile-order { position: absolute; right: 10px; top: 9px; color: #aaa398; font-size: 10px; }
.tile-char { display: block; font: 45px/1.1 var(--han); }
.tile-pinyin { display: block; color: var(--red); font-size: 12px; margin: 5px 0 3px; }
.tile-meaning { display: block; color: var(--muted); font-size: 11px; white-space: nowrap; text-overflow: ellipsis; overflow: hidden; }

.session-shell { max-width: 880px; margin: 0 auto; }
.session-progress { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 18px; margin-bottom: 34px; color: var(--muted); font-size: 12px; }
.progress-track { height: 4px; border-radius: 999px; background: rgba(69,61,49,.12); overflow: hidden; }
.progress-track i { display: block; height: 100%; background: var(--red); border-radius: inherit; transition: width .3s ease; }
.session-panel { min-height: 510px; border: 1px solid var(--line); background: var(--card); border-radius: 30px 12px 30px 12px; padding: 38px clamp(24px, 6vw, 58px); box-shadow: var(--shadow); }
.session-label { display: flex; align-items: center; justify-content: space-between; color: var(--muted); font-size: 12px; margin-bottom: 14px; }
.session-label span { color: var(--red); text-transform: uppercase; font-weight: 700; letter-spacing: .1em; }

.intro-layout { display: grid; grid-template-columns: minmax(250px, .9fr) minmax(250px, 1.1fr); gap: 44px; align-items: center; }
.writer-frame, .draw-frame { position: relative; aspect-ratio: 1; border: 1px solid var(--line); background-color: rgba(255,255,255,.58); border-radius: 19px 8px 19px 8px; overflow: hidden; background-image: linear-gradient(45deg, transparent 49.7%, rgba(69,61,49,.07) 49.8%, rgba(69,61,49,.07) 50.2%, transparent 50.3%), linear-gradient(-45deg, transparent 49.7%, rgba(69,61,49,.07) 49.8%, rgba(69,61,49,.07) 50.2%, transparent 50.3%); }
.writer-frame::before, .draw-frame::before { content: ""; position: absolute; inset: 50% 0 auto; border-top: 1px dashed rgba(69,61,49,.12); pointer-events: none; }
.writer-frame::after, .draw-frame::after { content: ""; position: absolute; inset: 0 auto 0 50%; border-left: 1px dashed rgba(69,61,49,.12); pointer-events: none; }
#writer-target { position: absolute; inset: 6%; z-index: 1; }
.writer-actions { display: flex; justify-content: center; gap: 8px; margin-top: 10px; }
.char-title { display: flex; gap: 18px; align-items: baseline; margin-bottom: 22px; }
.char-title b { font: 68px/1 var(--han); }
.char-title span { color: var(--red); font-size: 19px; }
.meaning-title { font: 600 28px/1.25 var(--han); margin-bottom: 19px; }
.detail-list { display: grid; gap: 10px; margin: 0 0 22px; }
.detail-row { display: grid; grid-template-columns: 112px 1fr; gap: 14px; border-top: 1px solid var(--line); padding-top: 10px; }
.detail-row dt { color: var(--muted); font-size: 12px; }
.detail-row dd { margin: 0; font-size: 14px; }
.component-pills { display: flex; gap: 7px; flex-wrap: wrap; }
.component-pill { display: inline-flex; gap: 6px; align-items: center; background: rgba(183,67,50,.07); color: var(--red-dark); border-radius: 999px; padding: 5px 9px; font-size: 12px; }
.component-pill b { font: 17px/1 var(--han); }
.mnemonic { padding: 14px 16px; border-left: 3px solid var(--red); background: rgba(183,67,50,.05); color: #514c44; font-size: 13px; line-height: 1.5; margin-bottom: 22px; }
.word-card { border-top: 1px solid var(--line); padding-top: 16px; margin-bottom: 24px; }
.word-hanzi { font: 600 25px/1 var(--han); }
.word-pinyin { color: var(--red); margin-left: 8px; }
.word-meaning { color: var(--muted); margin: 6px 0 0; font-size: 13px; }
.audio-button { border: 1px solid var(--line); background: transparent; border-radius: 999px; width: 34px; height: 34px; cursor: pointer; color: var(--red); margin-left: 8px; vertical-align: middle; }

.practice-head { text-align: center; max-width: 590px; margin: 0 auto 26px; }
.practice-head h2 { margin: 8px 0 8px; }
.practice-head p { color: var(--muted); margin: 0; }
.practice-head .prompt-big { font: 600 34px/1.25 var(--han); color: var(--ink); margin: 12px 0 5px; }
.recognition-char { font: 140px/1 var(--han); margin: 24px 0 9px; }
.practice-grid { display: grid; grid-template-columns: minmax(270px, 390px) minmax(220px, 1fr); align-items: center; justify-content: center; gap: 38px; }
.canvas-wrap { position: relative; max-width: 390px; margin: 0 auto; }
#draw-canvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: 2; touch-action: none; cursor: crosshair; }
.ghost-char { position: absolute; inset: 0; display: grid; place-items: center; font: 250px/1 var(--han); color: rgba(40,40,35,.075); z-index: 1; pointer-events: none; }
.draw-tools { display: flex; justify-content: space-between; gap: 10px; margin-top: 11px; }
.draw-tools button { flex: 1; }
.answer-area { min-height: 250px; display: grid; place-content: center; text-align: center; }
.answer-placeholder { color: var(--muted); font-size: 14px; line-height: 1.6; }
.show-answer { width: auto; min-width: 180px; margin: 18px auto 0; }
.answer-char { font: 110px/1 var(--han); }
.answer-pinyin { color: var(--red); font-size: 19px; margin: 9px 0 5px; }
.answer-meaning { font: 600 19px/1.3 var(--han); }
.ratings { display: grid; grid-template-columns: repeat(3, 1fr); gap: 9px; margin-top: 20px; }
.rating-button { padding: 13px 8px; border: 1px solid var(--line); background: rgba(255,255,255,.58); color: var(--ink); }
.rating-button small { display: block; color: var(--muted); font-size: 10px; margin-top: 3px; }
.rating-button.again:hover { background: rgba(183,67,50,.1); border-color: rgba(183,67,50,.25); }
.rating-button.almost:hover { background: rgba(173,122,50,.12); border-color: rgba(173,122,50,.25); }
.rating-button.remember:hover { background: rgba(82,112,91,.11); border-color: rgba(82,112,91,.25); }

.complete-view { text-align: center; max-width: 520px; margin: 40px auto; }
.complete-mark { width: 90px; height: 90px; margin: 0 auto 24px; border-radius: 50% 45% 50% 42%; display: grid; place-items: center; background: rgba(82,112,91,.12); color: var(--green); font: 46px/1 var(--han); }
.complete-view p { color: var(--muted); line-height: 1.6; }
.complete-actions { display: flex; justify-content: center; gap: 9px; margin-top: 24px; }
.complete-actions .primary-button { width: auto; }

.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 34px; }
.stat-card { border: 1px solid var(--line); background: var(--card); border-radius: 17px 7px 17px 7px; padding: 22px; }
.stat-card span { display: block; color: var(--muted); font-size: 12px; margin-bottom: 14px; }
.stat-card b { font: 600 39px/1 var(--han); }
.stat-card small { color: var(--muted); margin-left: 5px; }
.stats-columns { display: grid; grid-template-columns: 1.1fr .9fr; gap: 18px; }
.panel { border: 1px solid var(--line); background: rgba(255,253,248,.55); border-radius: 20px 9px 20px 9px; padding: 25px; }
.panel h3 { margin-bottom: 20px; }
.progress-bar-row { margin-bottom: 18px; }
.progress-bar-copy { display: flex; justify-content: space-between; font-size: 13px; margin-bottom: 7px; }
.progress-bar-copy span { color: var(--muted); }
.wide-track { height: 9px; background: rgba(69,61,49,.09); border-radius: 999px; overflow: hidden; }
.wide-track i { height: 100%; display: block; background: var(--red); border-radius: inherit; min-width: 2px; }
.wide-track.green i { background: var(--green); }
.hard-list { list-style: none; padding: 0; margin: 0; }
.hard-list li { display: grid; grid-template-columns: 46px 1fr auto; align-items: center; gap: 11px; border-top: 1px solid var(--line); padding: 11px 0; }
.hard-list li:first-child { border-top: 0; padding-top: 0; }
.hard-char { font: 31px/1 var(--han); }
.hard-copy b, .hard-copy small { display: block; }
.hard-copy b { font-size: 13px; }
.hard-copy small { color: var(--muted); margin-top: 3px; }
.lapse-count { color: var(--red); font-size: 11px; }
.empty-note { color: var(--muted); font-size: 13px; line-height: 1.6; }

.connection-head { display: flex; align-items: center; gap: 22px; margin-bottom: 30px; }
.connection-char { font: 72px/1 var(--han); width: 94px; height: 94px; display: grid; place-items: center; border: 1px solid var(--line); border-radius: 19px 8px 19px 8px; background: var(--card); }
.connection-head h1 { font-size: 40px; margin-bottom: 4px; }
.connection-head p { color: var(--muted); margin: 0; }
.connection-layout { display: grid; grid-template-columns: .85fr 1.15fr; gap: 18px; }
.component-stack { display: flex; gap: 9px; flex-wrap: wrap; }
.component-card { min-width: 98px; border: 1px solid var(--line); padding: 15px; border-radius: 14px 6px 14px 6px; background: rgba(255,255,255,.45); }
.component-card b { display: block; font: 35px/1 var(--han); }
.component-card span { color: var(--muted); font-size: 11px; }
.related-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(108px, 1fr)); gap: 8px; }
.related-card { border: 1px solid var(--line); border-radius: 12px 5px 12px 5px; padding: 12px; background: rgba(255,255,255,.4); }
.related-card b { font: 30px/1 var(--han); }
.related-card span { color: var(--red); font-size: 11px; margin-left: 5px; }
.related-card small { display: block; color: var(--muted); margin-top: 5px; }

#toast { position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 16px); opacity: 0; pointer-events: none; background: var(--ink); color: white; padding: 10px 15px; border-radius: 9px; font-size: 12px; transition: .2s ease; z-index: 20; }
#toast.show { opacity: 1; transform: translate(-50%, 0); }
.error-card { max-width: 560px; margin: 50px auto; border: 1px solid rgba(183,67,50,.25); background: rgba(255,255,255,.6); border-radius: 18px; padding: 28px; }
.error-card code { display: block; margin-top: 12px; color: var(--red-dark); white-space: pre-wrap; }

@media (max-width: 800px) {
  .shell { width: min(100% - 24px, 680px); }
  .topbar { height: auto; min-height: 82px; grid-template-columns: 1fr auto; }
  .topbar nav { position: fixed; z-index: 10; bottom: 10px; left: 50%; transform: translateX(-50%); box-shadow: 0 8px 30px rgba(50,42,30,.18); background: rgba(239,233,222,.94); backdrop-filter: blur(15px); }
  .local-pill { display: none; }
  main { padding: 38px 0 95px; }
  footer { display: none; }
  .today-layout, .intro-layout, .practice-grid, .stats-columns, .connection-layout { grid-template-columns: 1fr; }
  .today-copy { padding: 0; }
  .session-card { padding: 25px; }
  .writer-frame { max-width: 340px; width: 100%; margin: auto; }
  .session-panel { padding: 25px 18px; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .section-head { display: block; }
  .filter-row { margin-top: 18px; }
}

@media (max-width: 460px) {
  .brand small { display: none; }
  .nav-item { padding: 9px 12px; }
  .today-copy h1 { font-size: 43px; }
  .session-counts { grid-template-columns: 1fr 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .stat-card { padding: 17px; }
  .ratings { grid-template-columns: 1fr; }
  .recognition-char { font-size: 108px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; transition-duration: .01ms !important; }
}