/* Look: an exam paper. Indigo ink, warm paper, vermilion red pen; figures set in a serif face.
   Same visual system as the iOS app (ios/ITPassZH/SharedViews.swift). */
:root{
  --bg:#f4f2ec; --surface:#ffffff; --ink:#1a2233; --muted:#666c7a; --line:#e3dfd4;
  --accent:#1f4fa8; --good:#2c7a4b; --bad:#c8402b; --gold:#a9741a;
  --fill-a:#2c63cc; --fill-b:#1b4699; --hero-a:#17387f; --hero-b:#2f68d2;
  --shadow:0 4px 14px rgba(40,32,10,.06);
  --font-jp:"Hiragino Sans","Hiragino Kaku Gothic ProN","Noto Sans JP","Yu Gothic",sans-serif;
  --font-ui:"PingFang SC","Hiragino Sans GB","Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-num:ui-serif,"New York","Iowan Old Style",Georgia,"Times New Roman",serif;
  --r:18px;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0d111c; --surface:#181e2e; --ink:#e6eaf4; --muted:#9aa3b8; --line:#2a3247;
  --accent:#7aa5ff; --good:#5cc08a; --bad:#f27a63; --gold:#e3b25a;
  --fill-a:#3e74de; --fill-b:#2a57b8; --hero-a:#1a2f66; --hero-b:#2c52a6; --shadow:none; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0d111c; --surface:#181e2e; --ink:#e6eaf4; --muted:#9aa3b8; --line:#2a3247;
  --accent:#7aa5ff; --good:#5cc08a; --bad:#f27a63; --gold:#e3b25a;
  --fill-a:#3e74de; --fill-b:#2a57b8; --hero-a:#1a2f66; --hero-b:#2c52a6; --shadow:none; color-scheme:dark}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font-ui);font-size:15px;line-height:1.6;
  padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px));padding-block:14px 40px}
.wrap{max-width:600px;margin:0 auto;display:flex;flex-direction:column;gap:14px}
#view{display:flex;flex-direction:column;gap:14px;min-width:0}
button{font:inherit;color:inherit;cursor:pointer}
a{color:var(--accent)}
button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
h1,h2{font-family:var(--font-ui);text-wrap:balance;margin:0}
h1{font-size:22px;line-height:1.4}
h2{font-size:18px}
.muted{color:var(--muted)}
.hint{margin:0;font-size:13px}
.ic{width:1em;height:1em;flex:none;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}

/* header */
.top{display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap}
.brand{font-family:var(--font-jp);font-weight:700;font-size:19px;letter-spacing:.02em;cursor:pointer}
.brand small{display:block;font-family:var(--font-ui);font-weight:500;font-size:11px;color:var(--muted);letter-spacing:.04em}
.controls{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.toggle{font-size:13px;font-weight:600;padding:7px 12px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--accent)}
.toggle[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:var(--surface)}
footer a{color:var(--muted)}

/* surfaces */
.card{background:var(--surface);border:.5px solid var(--line);border-radius:var(--r);padding:16px;box-shadow:var(--shadow)}
.stack{display:flex;flex-direction:column;gap:10px}
.sec{padding:10px 4px 0}
.sec p{margin:2px 0 0;font-size:13px;color:var(--muted)}
.tile{flex:none;width:40px;height:40px;border-radius:12px;display:grid;place-items:center;font-size:18px;
  color:var(--c,var(--accent));background:color-mix(in srgb,var(--c,var(--accent)) 14%,transparent)}
.tile.sm{width:32px;height:32px;border-radius:10px;font-size:15px}
.gold{--c:var(--gold)} .good{--c:var(--good)} .bad{--c:var(--bad)} .brandc{--c:var(--accent)} .off{--c:var(--muted)}
.tile.year{display:flex;flex-direction:column;align-items:center;justify-content:center;line-height:1}
.tile.year small{font-size:9px;font-weight:600}
.tile.year b{font-family:var(--font-num);font-size:20px}
.tag{display:inline-block;font-size:11px;font-weight:600;padding:2px 9px;border-radius:999px;color:var(--c,var(--accent));background:color-mix(in srgb,var(--c,var(--accent)) 14%,transparent)}
.meter{display:block;height:5px;border-radius:3px;background:color-mix(in srgb,var(--ink) 9%,transparent);overflow:hidden}
.meter i{display:block;height:100%;border-radius:3px;background:var(--c,var(--accent));transition:width .2s}
.label{font-size:11px;font-weight:700;letter-spacing:.08em;color:var(--muted)}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:0;border-radius:14px;padding:13px 16px;font-weight:700;font-size:15px;text-decoration:none;
  color:#fff;background:linear-gradient(var(--fill-a),var(--fill-b))}
.btn.ghost{background:color-mix(in srgb,var(--accent) 12%,transparent);color:var(--accent)}
.btn.sm{padding:8px 12px;font-size:13px}
.btn:disabled{opacity:.4;cursor:not-allowed}
.btn:active:not(:disabled),.rowbtn:active:not(:disabled),.qt:active:not(:disabled),.cont:active{opacity:.75}
.row{display:flex;gap:8px;flex-wrap:wrap}
.row>.btn{flex:1 1 150px}
.nav>.btn{flex:1 1 80px;padding-inline:6px}
.link{border:0;background:none;padding:4px 0;color:var(--accent);font-size:14px;font-weight:600}
.field{flex:1 1 200px;min-width:0;padding:11px 12px;border:1px solid var(--line);border-radius:12px;background:var(--surface);color:var(--ink);font:inherit}

/* home: hero */
.hero{position:relative;overflow:hidden;display:flex;flex-direction:column;gap:16px;padding:18px;border-radius:24px;color:#fff;
  background:linear-gradient(135deg,var(--hero-a),var(--hero-b));box-shadow:0 8px 22px rgba(23,56,127,.26)}
.hero::before,.hero::after{content:"";position:absolute;border-radius:50%;background:#fff;pointer-events:none}
.hero::before{width:220px;height:220px;right:-70px;top:-90px;opacity:.07}
.hero::after{width:160px;height:160px;left:-60px;bottom:-70px;opacity:.05}
.hero>*{position:relative;z-index:1}
.herotop{display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:12px}
.herotop>span:last-child,.heroplan{opacity:.88}
.heroplan{border:0;background:none;color:#fff;font-size:12px;font-weight:600;padding:0;text-decoration:underline;text-underline-offset:3px}
.bubs{display:flex;gap:6px}
.bubs i{width:20px;height:20px;border-radius:50%;border:1px solid rgba(255,255,255,.55);display:grid;place-items:center;font-style:normal;font-size:10px;font-weight:700;color:rgba(255,255,255,.75)}
.bubs i.on{background:#fff;color:#1f4fa8;border-color:#fff}
.heromain{display:flex;align-items:center;gap:16px}
.heromain h1{font-size:20px;line-height:1.45}
.ringbox{position:relative;flex:none;width:88px;height:88px;display:grid;place-items:center}
.ringbox svg{position:absolute;inset:0;width:100%;height:100%}
.ring circle{fill:none;stroke-width:3;stroke-linecap:round}
.ring .t{stroke:color-mix(in srgb,currentColor 18%,transparent)}
.ring .v{stroke:var(--rc,currentColor)}
.ringbox div{text-align:center;line-height:1.1}
.ringbox b{display:block;font-family:var(--font-num);font-size:22px}
.ringbox span{font-size:11px;opacity:.8}
.herostats{display:grid;grid-template-columns:repeat(3,1fr);padding:10px 0;border-radius:14px;background:rgba(255,255,255,.12)}
.herostats div{text-align:center;line-height:1.25}
.herostats div+div{border-left:.5px solid rgba(255,255,255,.28)}
.herostats b{display:block;font-family:var(--font-num);font-size:20px;font-variant-numeric:tabular-nums}
.herostats span{font-size:11px;opacity:.8}
.cont{display:flex;align-items:center;justify-content:space-between;gap:10px;width:100%;text-align:left;border:0;border-radius:14px;padding:11px 16px;background:#fff;color:#1a408f;font-size:18px}
.cont b{display:block;font-size:16px;line-height:1.3}
.cont small{font-size:12px;opacity:.75}

/* home: rows and tiles */
.rowbtn{display:flex;align-items:center;gap:12px;width:100%;text-align:left;border:0;background:none;padding:14px}
.rowbtn:disabled{opacity:.45;cursor:not-allowed}
.rowbtn>.ic{color:var(--muted);opacity:.6;font-size:16px}
.rt{flex:1;min-width:0;display:flex;flex-direction:column;gap:3px;line-height:1.35}
.rt b{font-size:15px;font-family:var(--font-jp)}
.rt small{font-size:12px;color:var(--muted)}
.rt .meter{margin:2px 0}
.list{padding:0}
.list .rowbtn+.rowbtn{border-top:.5px solid var(--line)}
button.card{width:100%;font:inherit;color:inherit;background:var(--surface);border:.5px solid var(--line)}
.pill{flex:none;font-size:13px;font-weight:700;color:#fff;padding:6px 12px;border-radius:999px;background:linear-gradient(var(--fill-a),var(--fill-b))}
.quick{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.qt{display:flex;flex-direction:column;align-items:flex-start;gap:8px;text-align:left;padding:14px;line-height:1.35}
.qt:disabled{opacity:.45;cursor:not-allowed}
.qt b{display:block;font-size:15px}
.qt small{font-size:12px;color:var(--muted)}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{display:inline-flex;align-items:center;gap:5px;font-size:12px;font-weight:600;padding:4px 10px;border-radius:999px;color:var(--accent);background:color-mix(in srgb,var(--accent) 10%,transparent)}

/* question */
.qbar{display:flex;justify-content:space-between;align-items:center;gap:10px;font-size:13px;color:var(--muted)}
.qpos{text-align:right;font-weight:600;color:var(--ink)}
.timer{font-variant-numeric:tabular-nums;font-weight:700}
.timechip{display:inline-flex;align-items:center;gap:4px;margin-left:6px;font-size:12px;color:var(--muted);font-weight:600}
.prog{height:5px;border-radius:3px;background:color-mix(in srgb,var(--ink) 9%,transparent);overflow:hidden}
.prog i{display:block;height:100%;border-radius:3px;background:var(--accent);transition:width .2s}
.qtags{display:flex;gap:6px;flex-wrap:wrap}
.stem{font-family:var(--font-jp);font-weight:500;font-size:18px;line-height:1.9;white-space:pre-line;overflow-wrap:anywhere}
/* IPA figures are black on white: keep a white plate so they stay readable in dark mode */
.qimg{display:block;max-width:100%;height:auto;background:#fff;border-radius:8px;padding:6px;border:.5px solid var(--line)}
.qzhbox{margin:0;font-size:14px;color:var(--muted);padding:10px 12px;border-radius:10px;background:color-mix(in srgb,var(--ink) 4%,transparent)}
.src{font-size:12px;color:var(--muted)}
details summary{font-size:13px;font-weight:600;color:var(--accent);cursor:pointer}
.opts{display:flex;flex-direction:column;gap:10px}
.opt{--c:var(--line);position:relative;display:flex;gap:12px;align-items:flex-start;text-align:left;width:100%;border:1px solid var(--c);border-radius:14px;padding:12px;
  background:var(--surface);box-shadow:var(--shadow);font-family:var(--font-jp);font-size:16px;line-height:1.75}
.opt .bub{flex:none;width:30px;height:30px;border-radius:50%;display:grid;place-items:center;font-family:var(--font-ui);font-size:13px;font-weight:700;
  color:var(--muted);background:color-mix(in srgb,var(--ink) 6%,transparent)}
.opt>span:last-child{flex:1;min-width:0;padding-top:1px}
.opt:hover:not(:disabled):not(.picked){--c:color-mix(in srgb,var(--accent) 55%,var(--line))}
.opt.picked{--c:var(--accent)} .opt.right{--c:var(--good)} .opt.wrong{--c:var(--bad)}
.opt.picked,.opt.right,.opt.wrong{border-width:1.5px;box-shadow:none;background:color-mix(in srgb,var(--c) 9%,var(--surface))}
.opt.picked .bub,.opt.right .bub,.opt.wrong .bub{background:var(--c);color:#fff}
.opt.right::after,.opt.wrong::after{flex:none;width:22px;height:22px;margin-top:4px;border-radius:50%;display:grid;place-items:center;font:700 13px/1 var(--font-ui);color:#fff;background:var(--c)}
.opt.right::after{content:"✓"} .opt.wrong::after{content:"✕"}
.opt:disabled{cursor:default;color:inherit}
.optzh{display:block;font-family:var(--font-ui);font-size:13px;color:var(--muted);line-height:1.55;margin-top:3px}
.optzh[hidden]{display:none}
.verdict{--c:var(--muted);display:flex;align-items:center;gap:8px;font-weight:700;font-size:16px;color:var(--c);padding:10px 12px;border-radius:12px;background:color-mix(in srgb,var(--c) 12%,transparent)}
.verdict.ok,.vtext.ok{--c:var(--good)} .verdict.ng,.vtext.ng{--c:var(--bad)}
.vtext{--c:var(--ink);margin:0;font-weight:700;color:var(--c)}
.exp{display:flex;flex-direction:column;gap:10px}
.exp .tr{font-size:16px;line-height:1.8}
.exp hr{border:0;border-top:.5px solid var(--line);margin:2px 0;width:100%}
.trows{display:flex;flex-direction:column;gap:8px}
.trow{border-left:3px solid var(--gold);padding-left:9px;font-size:13px;line-height:1.4}
.trow b{display:block;font-family:var(--font-jp)}
.trow span{color:var(--muted)}
/* controls that stay above the bottom edge while the page scrolls */
.dock{position:sticky;bottom:0;z-index:5;margin:0 -16px;padding:10px 16px calc(10px + env(safe-area-inset-bottom,0px));
  background:color-mix(in srgb,var(--bg) 82%,transparent);-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);border-top:.5px solid var(--line)}
.dock[hidden]{display:none}
.dock .row+.row{margin-top:8px}

/* answer sheet */
.sheetgrid{display:grid;grid-template-columns:repeat(10,minmax(0,1fr));gap:5px}
.sheetgrid button{position:relative;height:36px;padding:0;border:.5px solid var(--line);border-radius:8px;background:var(--surface);font-size:12px;font-variant-numeric:tabular-nums}
.sheetgrid .ans,.key.ans{border-color:transparent;color:#fff;font-weight:700;background:linear-gradient(var(--fill-a),var(--fill-b))}
.sheetgrid .flag::after,.key.flag::after{content:"";position:absolute;top:-3px;right:-3px;width:9px;height:9px;border-radius:50%;background:var(--bad);border:1.5px solid var(--bg)}
.sheetgrid .cur{outline:2px solid var(--ink);outline-offset:1px}
.key{position:relative;display:inline-block;width:14px;height:14px;border:.5px solid var(--line);border-radius:4px;background:var(--surface);vertical-align:-2px;margin-right:4px}

/* result */
.score{position:relative}
.scorerow{display:flex;align-items:center;gap:18px}
.ringbox.lg{width:116px;height:116px;color:var(--ink)}
.ringbox.lg b{font-size:30px;font-variant-numeric:tabular-nums}
.cnt{display:block;font-size:20px;font-variant-numeric:tabular-nums}
.stamp{position:absolute;top:14px;right:14px;width:66px;height:66px;border-radius:50%;display:grid;place-items:center;text-align:center;
  font:800 15px/1.2 var(--font-num);color:var(--bad);border:2.5px solid var(--bad);outline:1px solid var(--bad);outline-offset:-6px;transform:rotate(-12deg);opacity:.85}
.frow{display:flex;align-items:center;gap:10px}
.frow>div{flex:1;min-width:0;display:flex;flex-direction:column;gap:5px}
.frow .fh{display:flex;align-items:baseline;gap:8px;font-size:13px}
.frow .fh b:first-child{flex:1;font-family:var(--font-jp)}
.frow .fh span{font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}
.frow .fh .pct{font-family:var(--font-num);font-size:15px;min-width:44px;text-align:right;font-variant-numeric:tabular-nums}
.frow .fh .pct.low{color:var(--bad)}
.frow .meter{height:6px}
.wq{display:flex;flex-direction:column;gap:10px}
.wq .ja{font-family:var(--font-jp);white-space:pre-line;line-height:1.75;overflow-wrap:anywhere}
.wq .ansline{display:flex;gap:8px;align-items:flex-start;margin:0;font-size:14px}
.wq .ansline .ic{margin-top:4px;font-size:15px}
.wq .zhbox{margin:0;font-size:13.5px;color:var(--muted);padding:10px 12px;border-radius:10px;background:color-mix(in srgb,var(--ink) 4%,transparent)}

/* glossary */
.gl{display:flex;flex-direction:column}
.gl>div{display:flex;flex-direction:column;gap:1px;padding:10px 0;border-top:.5px solid var(--line);font-size:13px;line-height:1.45;overflow-wrap:anywhere}
.gl>div:first-child{border-top:0}
.gl b{font-family:var(--font-jp);font-size:15px}
.gl .en{color:var(--accent)}
.gl .zh{color:var(--muted)}

/* unlock */
.hero.center{align-items:center;text-align:center;gap:8px;padding:26px 16px}
.hero.center .seal{width:52px;height:52px;border-radius:50%;display:grid;place-items:center;font-size:26px;background:rgba(255,255,255,.2)}
.hero.center p{margin:0;font-size:13px;opacity:.88}
.feat{display:flex;align-items:center;gap:12px}
.feat b{display:block;font-size:15px;line-height:1.35}
.feat small{font-size:12px;color:var(--muted)}

@media (prefers-reduced-motion:no-preference){.card,.hero,.opt{animation:in .18s ease-out}@keyframes in{from{transform:translateY(4px);opacity:.6}to{transform:none;opacity:1}}}
@media (max-width:420px){.stem{font-size:17px}.heromain h1{font-size:18px}}