/* QR card quiz + plan. Builds on site.css tokens. Layout: one 640px column, card-coloured head, 3D keys, no borders. */
:root{--deck:#0F3B2E;--hot:#b8550f;--hotbg:#fdf0e3}
body{min-height:100%}
.app{max-width:640px;margin:0 auto;padding:0 18px calc(28px + env(safe-area-inset-bottom,0px))}
.top{display:flex;align-items:center;justify-content:space-between;gap:12px;height:64px}
.top img{height:34px;width:auto}
.top .code{font-family:var(--sans);font-size:13px;color:var(--muted);font-variation-settings:"wdth" 90}.top .code b{color:var(--deck)}
.lnk{font-family:var(--sans);font-weight:600;font-size:14px;color:var(--ink-soft);cursor:pointer;padding:10px 4px;min-height:44px;text-decoration:underline;text-underline-offset:3px;text-decoration-color:var(--mist-2)}
.label{font-family:var(--sans);font-weight:600;font-size:13px;color:var(--verm);font-variation-settings:"wdth" 90}
/* card head = the physical card */
.cardhead{border-radius:22px;overflow:hidden;background:#fff;box-shadow:var(--e2);margin-top:6px}
.cardhead .band{background:var(--deck);color:#fff;display:flex;align-items:center;gap:10px;padding:14px 16px;font-family:var(--sans);font-weight:600}
.cardhead .pill{font-size:12px;letter-spacing:.08em;text-transform:uppercase;background:rgba(255,255,255,.12);border-radius:999px;padding:6px 12px}
.cardhead .code{margin-left:auto;font-size:13px;opacity:.85}
.cardhead .solves{background:#fff;color:var(--deck);border-radius:12px;padding:7px 12px;font-size:14px;font-variant-numeric:tabular-nums}
.cardhead .cbody{padding:20px 20px 22px}
.cardhead h1{font-size:clamp(34px,8vw,48px);color:var(--deck)}
.cardhead .lede{margin-top:12px;color:var(--ink-soft);font-size:17px}
.kpis{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:16px}
.kpis div{background:var(--mist);border-radius:16px;padding:14px 12px}
.kpis b{display:block;font-family:var(--display);font-weight:400;font-size:30px;line-height:1}
.kpis span{display:block;font-family:var(--sans);font-size:12px;color:var(--muted);margin-top:6px}
.modes{margin-top:22px;display:grid;gap:12px}
.row3{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.row3 .btn{padding-left:8px;padding-right:8px}
.pace{display:flex;align-items:center;gap:10px;justify-content:center;font-family:var(--sans);font-size:14px;color:var(--ink-soft);background:var(--mist);border-radius:999px;padding:10px 16px;min-height:44px;cursor:pointer;justify-self:center}
.pace input{width:18px;height:18px;accent-color:var(--verm)}
.plancta{display:grid;grid-template-columns:1fr auto;gap:2px 12px;align-items:center;margin-top:18px;padding:16px 18px;border-radius:18px;background:var(--mist);transition:transform .2s var(--ease-out),background .2s}
.plancta:hover{background:var(--mist-2);transform:translateY(-1px)}
.plancta b{font-family:var(--sans);font-weight:700;font-size:16px}.plancta span{grid-column:1;font-family:var(--sans);font-size:13px;color:var(--muted)}
.plancta i{grid-row:1 / span 2;grid-column:2;font-style:normal;font-size:22px;color:var(--verm)}
/* question */
.session{padding-top:4px;scroll-margin-top:80px}
.qbar{height:6px;border-radius:6px;background:var(--mist);overflow:hidden}.qbar i{display:block;height:100%;background:var(--deck);transition:width .4s var(--ease-out)}
.qmeta{display:flex;align-items:center;gap:10px;margin:14px 0 6px;font-family:var(--sans);font-size:13px;color:var(--muted);flex-wrap:wrap}
.tags{display:flex;gap:6px;flex-wrap:wrap}
.tg{background:var(--mist);border-radius:999px;padding:5px 10px;font-weight:600;color:var(--ink-soft)}
.tg.hot{background:var(--hotbg);color:var(--hot)}.tg.code{background:var(--deck);color:#fff}.tg.again{background:var(--nobg);color:var(--verm)}
.clock{margin-left:auto;font-weight:700;color:var(--ink)}.clock.low{color:var(--verm)}
.stem{font-size:20px;line-height:1.5;margin:10px 0 18px}
.opts{display:grid;gap:10px}
.opt{display:flex;gap:14px;align-items:flex-start;text-align:left;background:#fff;border-radius:16px;padding:15px 16px;min-height:56px;cursor:pointer;font-size:18px;line-height:1.4;
  box-shadow:0 4px 0 var(--mist-2),0 10px 22px -12px hsl(var(--sh)/.25);transition:transform .12s var(--ease-out),box-shadow .12s var(--ease-out),background .2s,opacity .2s}
.opt:hover{transform:translateY(-1px)}.opt:active{transform:translateY(3px);box-shadow:0 1px 0 var(--mist-2)}
.opt .k{font-family:var(--sans);font-weight:700;font-size:14px;color:var(--muted);min-width:18px;padding-top:3px}
.opt.right{background:var(--ok);color:#fff;box-shadow:0 4px 0 #123f22}.opt.right .k{color:#fff}
.opt.wrong{background:var(--nobg);color:var(--verm);box-shadow:0 4px 0 #f1c9be;animation:shake .35s}
.opt.dim{opacity:.45}.opt[disabled]{cursor:default}
@keyframes shake{25%{transform:translateX(-5px)}75%{transform:translateX(5px)}}
.fb{margin-top:16px;border-radius:18px;padding:16px 18px;background:var(--mist);animation:rise .35s var(--ease-out)}
@keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.fb .verdict{font-family:var(--sans);font-weight:700;font-size:16px}.fb.ok .verdict{color:var(--ok)}.fb.no .verdict{color:var(--verm)}
.fb .verdict span{font-weight:500;color:var(--muted);margin-left:6px}
.fb ul{list-style:none;margin-top:10px;display:grid;gap:6px}
.fb .why li{padding-left:16px;position:relative}.fb .why li::before{content:"";position:absolute;left:0;top:.7em;width:6px;height:6px;border-radius:50%;background:var(--deck)}
.fb .trap li{background:#fff;border-radius:12px;padding:8px 12px}.fb .trap b{font-family:var(--sans);font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--verm);margin-right:6px}
.fb .where{margin-top:12px;font-family:var(--sans);font-weight:600;font-size:14px;color:var(--deck)}
.fb .also,.fb .again-note{margin-top:6px;font-family:var(--sans);font-size:13px;color:var(--muted)}
.conf{display:flex;align-items:center;gap:8px;margin-top:14px;font-family:var(--sans);font-size:13px;color:var(--muted);flex-wrap:wrap}
.conf button{font-weight:600;font-size:14px;border-radius:999px;padding:9px 14px;min-height:40px;cursor:pointer;background:#fff;color:var(--ink-soft);box-shadow:0 2px 0 var(--mist-2)}
.conf button[aria-checked="true"]{background:var(--ink);color:#fff;box-shadow:0 2px 0 #000}
.qnav{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:20px;padding-bottom:8px}
.qnav .lnk[hidden]+.btn{margin-left:auto}
.qnav .btn{min-width:150px}
/* summary */
.sum{padding-top:8px}.sum h2{font-size:clamp(40px,10vw,58px);margin-top:6px}
.ring{--p:0;display:grid;grid-template-columns:auto 1fr;align-items:center;gap:16px;margin-top:20px;font-family:var(--sans);color:var(--muted);font-size:14px}
.ring b{width:92px;height:92px;border-radius:50%;display:grid;place-items:center;font-family:var(--display);font-weight:400;font-size:28px;color:var(--ink);
  background:radial-gradient(closest-side,#fff 78%,transparent 79% 100%),conic-gradient(var(--deck) calc(var(--p)*100%),var(--mist) 0)}
.nextrev{margin-top:16px;font-size:17px}
.sum h3,.deckgrid h2{font-family:var(--sans);font-size:15px;font-weight:700;margin-top:26px}
.weak{list-style:none;margin-top:10px;display:grid;gap:8px}
.weak li{display:flex;justify-content:space-between;gap:12px;background:var(--mist);border-radius:14px;padding:12px 14px;font-size:16px}
.weak li .w{min-width:0}.weak li .c{font-family:var(--sans);font-size:13px;color:var(--verm);white-space:nowrap}
.leech{margin-top:12px;font-family:var(--sans);font-size:14px;color:var(--hot);background:var(--hotbg);border-radius:14px;padding:12px 14px}
.sumbtns{display:grid;gap:10px;margin-top:22px}
.savehint{margin-top:10px;font-family:var(--sans);font-size:13px;color:var(--muted);text-align:center}
.nextcard{display:grid;gap:4px;margin-top:14px;padding:16px 18px;border-radius:18px;background:#fff;box-shadow:var(--e2)}
.nextcard b{font-family:var(--sans);font-size:16px}.nextcard span:last-child{font-family:var(--sans);font-size:13px;color:var(--muted)}
.deckgrid{margin-top:26px}.deckgrid .dh{display:flex;justify-content:space-between;align-items:baseline;gap:12px}.deckgrid .dh span{font-family:var(--sans);font-size:13px;color:var(--muted)}
.cells{display:grid;grid-template-columns:repeat(auto-fill,minmax(64px,1fr));gap:8px;margin-top:12px}
.cell{--m:0;border-radius:12px;padding:8px 6px;text-align:center;font-family:var(--sans);background:color-mix(in srgb,var(--deck) calc(var(--m)*100%),var(--mist));color:var(--ink)}
.cell.dark{color:#fff}
.cell b{display:block;font-size:13px}.cell span{display:block;font-size:11px}
.cell.me{box-shadow:0 0 0 3px var(--verm) inset}
.cell.ghost{background:transparent;box-shadow:0 0 0 1.5px var(--mist-2) inset;color:var(--muted)}
.hint{font-family:var(--sans);font-size:12px;color:var(--muted);margin-top:8px}
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));transform:translate(-50%,20px);opacity:0;background:var(--ink);color:#fff;font-family:var(--sans);font-size:14px;border-radius:12px;padding:12px 16px;transition:opacity .25s var(--ease-out),transform .25s var(--ease-out);pointer-events:none;z-index:99}
.toast.show{opacity:1;transform:translate(-50%,0)}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
.skip{position:absolute;left:12px;top:-60px;z-index:200;background:var(--ink);color:#fff;font-family:var(--sans);font-weight:600;font-size:14px;padding:10px 14px;border-radius:10px}
.skip:focus{top:calc(10px + env(safe-area-inset-top,0px))}
.cardhead .chap{font-family:var(--sans);font-size:13px;font-weight:600;color:var(--muted);margin-bottom:8px}
.fb .where .part{font-style:normal;font-weight:600;font-size:12px;background:#fff;border-radius:999px;padding:2px 8px;margin-left:6px;color:var(--ink-soft)}