:root {
  --bg:#EEF1F6; --plate:#FFFFFF; --ink:#1E2148; --muted:#565C7D; --line:#D3D9E6; --soft:#E4E8F3;
  --on:#FFC53D; --on-ink:#3B2A00; --off:#B3BACB; --off-ink:#262B40;
  --ok:#0B7A4C; --bad:#C9362E; --accent:#3D46E0; --accent-d:#2A31A8; --accent-ink:#FFFFFF;
  --head:'Fredoka','Trebuchet MS',system-ui,sans-serif;
  --body:'Atkinson Hyperlegible','Segoe UI',system-ui,sans-serif;
  --navh:0px; --safe-top:env(safe-area-inset-top,0px); --safe-bottom:env(safe-area-inset-bottom,0px);
  box-sizing:border-box;
}
@media (prefers-color-scheme:dark) {
  :root:not([data-theme="light"]) {
    --bg:#141633; --plate:#1E2147; --ink:#EDEFFF; --muted:#A9AED0; --line:#3D427D; --soft:#292D5D;
    --off:#4F5582; --off-ink:#F0F2FF; --ok:#55D99A; --bad:#FF8075; --accent:#858CFF; --accent-d:#555DDA; --accent-ink:#0E1030;
  }
}
:root[data-theme="dark"] {
  --bg:#141633; --plate:#1E2147; --ink:#EDEFFF; --muted:#A9AED0; --line:#3D427D; --soft:#292D5D;
  --off:#4F5582; --off-ink:#F0F2FF; --ok:#55D99A; --bad:#FF8075; --accent:#858CFF; --accent-d:#555DDA; --accent-ink:#0E1030;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:5rem;background:var(--bg)}
body{margin:0;background:var(--bg);color:var(--ink);font:1.125rem/1.58 var(--body);padding-bottom:var(--navh);overflow-wrap:anywhere}
[hidden]{display:none!important}
button{font:inherit;color:inherit;touch-action:manipulation}
a{color:var(--accent)}
:focus-visible{outline:3px solid var(--accent);outline-offset:3px}
h1,h2,h3{font-family:var(--head);font-weight:600;line-height:1.15;margin:0}
h1{font-size:clamp(2.05rem,5vw,3rem)} h2{font-size:1.6rem} p{margin:0 0 .8rem}
.fx{font-family:var(--head);font-weight:600;white-space:nowrap}.muted{color:var(--muted)}
.plate{background:var(--plate);border:1px solid var(--line);border-radius:18px;box-shadow:0 3px 0 var(--line)}
.skip{position:fixed;left:1rem;top:calc(.5rem + var(--safe-top));z-index:100;background:var(--ink);color:var(--bg);padding:.7rem 1rem;border-radius:10px;transform:translateY(-180%)}
.skip:focus{transform:none}
.pill{display:inline-grid;place-items:center;min-width:1.9em;height:1.55em;padding:0 .45em;border-radius:999px;font:600 .95em/1 var(--head);vertical-align:.05em}
.pill.w{background:var(--on);color:var(--on-ink)}.pill.f{background:var(--off);color:var(--off-ink)}
.bulb{--s:110px;width:var(--s);height:var(--s);border-radius:50%;background:var(--off);position:relative;margin:0 auto calc(var(--s)*.3);transition:background-color .25s,box-shadow .25s}
.bulb::after{content:'';position:absolute;left:50%;top:92%;transform:translateX(-50%);width:40%;height:28%;border-radius:0 0 12px 12px;background:repeating-linear-gradient(var(--muted) 0 5px,var(--line) 5px 8px)}
.bulb.on{background:var(--on);box-shadow:0 0 0 calc(var(--s)*.09) color-mix(in srgb,var(--on) 30%,transparent),0 0 calc(var(--s)*.6) calc(var(--s)*.15) color-mix(in srgb,var(--on) 50%,transparent)}
.bulb.sm{--s:56px}.bulb.xs{--s:18px;margin:0}.bulb.xs::after{display:none}

.top{position:sticky;top:0;z-index:20;background:var(--bg);border-bottom:1px solid var(--line);padding-top:var(--safe-top)}
.top-in{max-width:1040px;margin:0 auto;display:flex;align-items:center;gap:.7rem;padding:.45rem 1.25rem}
.brand{display:flex;align-items:center;gap:.55rem;min-width:44px;min-height:44px;padding:.3rem .2rem;font:600 1.35rem/1 var(--head);color:var(--ink);text-decoration:none;white-space:nowrap}
nav{display:flex;gap:.2rem;margin-left:auto}
nav a{position:relative;display:flex;align-items:center;justify-content:center;min-height:44px;padding:.45rem .75rem;border-radius:999px;text-decoration:none;color:var(--muted);font-weight:700;white-space:nowrap}
nav a[aria-current="page"]{background:var(--ink);color:var(--bg)}nav .ico{display:none}
.nav-badge{position:absolute;right:.2rem;top:.15rem;min-width:1.2rem;height:1.2rem;padding:0 .25rem;border-radius:999px;background:var(--bad);color:#fff;font-size:.72rem;line-height:1.2rem;text-align:center}
.tools{display:flex;gap:.35rem}.tool-btn{min-width:44px;height:44px;border:1px solid var(--line);background:var(--plate);border-radius:12px;cursor:pointer;font-weight:700}.tool-btn.round{border-radius:50%}.tool-btn[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
body.focus nav{display:none}body.focus .tools{margin-left:auto}
main{max-width:980px;margin:0 auto;padding:1.6rem 1.25rem 4rem}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;min-height:50px;padding:.7rem 1.4rem;border:0;border-radius:14px;background:var(--accent);color:var(--accent-ink);font:600 1.1rem/1.2 var(--head);cursor:pointer;box-shadow:0 4px 0 var(--accent-d);text-decoration:none;text-align:center}
.btn:active:not(:disabled){transform:translateY(3px);box-shadow:0 1px 0 var(--accent-d)}.btn:disabled{background:var(--soft);color:var(--muted);box-shadow:0 4px 0 var(--line);cursor:default}
.btn.ghost{background:var(--plate);color:var(--ink);box-shadow:0 4px 0 var(--line);border:1px solid var(--line)}.btn.danger{background:var(--bad);color:#fff;box-shadow:0 4px 0 color-mix(in srgb,var(--bad) 70%,#000)}
.btn.big{width:100%;max-width:24rem;min-height:56px;font-size:1.2rem}.row{display:flex;flex-wrap:wrap;gap:.8rem;align-items:center}
.linkbtn{display:inline-flex;align-items:center;min-height:44px;background:none;border:0;color:var(--accent);font-weight:700;cursor:pointer;padding:.5rem .2rem;text-decoration:underline;text-underline-offset:3px}
.tip a{display:inline-flex;align-items:center;min-height:44px}
.page-lead{color:var(--muted);font-size:1.15rem;max-width:48ch;margin:.6rem 0 1.4rem}
.hero{display:grid;grid-template-columns:1.3fr 1fr;gap:1.5rem;align-items:center;padding:2rem 2.2rem}.hero p{font-size:1.2rem;color:var(--muted);max-width:32ch;margin:.9rem 0 1.4rem}.hero-lamp{background:none;border:0;cursor:pointer;display:flex;flex-direction:column;align-items:center;gap:.4rem;padding:1rem;min-height:44px}.hero-lamp .bulb{--s:150px}.hero-lamp small{color:var(--muted)}
.sec-title{margin:2.4rem 0 1rem}.path{list-style:none;margin:0;padding:0;position:relative;max-width:42rem}.path::before{content:'';position:absolute;left:31px;top:30px;bottom:30px;width:4px;background:var(--line);border-radius:2px}.path li{position:relative;margin-bottom:.7rem}.lrow{display:flex;align-items:center;gap:1rem;width:100%;min-height:74px;text-align:left;background:none;border:0;cursor:pointer;padding:.35rem;border-radius:16px}.lrow .num{flex:none;width:66px;height:66px;border-radius:50%;display:grid;place-items:center;font:600 1.5rem var(--head);background:var(--plate);border:3px solid var(--line);position:relative;z-index:1}.lrow.done .num{background:var(--on);border-color:var(--on);color:var(--on-ink)}.lrow.next .num{background:var(--accent);border-color:var(--accent);color:var(--accent-ink);box-shadow:0 0 0 6px color-mix(in srgb,var(--accent) 22%,transparent)}.lrow .t{display:block;font:600 1.2rem/1.25 var(--head)}.lrow .d{display:block;color:var(--muted);font-size:1rem}.lrow .stars{margin-left:auto;white-space:nowrap}.lrow.next .t::after{content:'Hier geht es weiter';display:inline-block;margin-left:.6rem;font:700 .75rem/1 var(--body);padding:.3rem .5rem;border-radius:999px;background:var(--accent);color:var(--accent-ink);vertical-align:.2em}.star{color:var(--line)}.star.on{color:#B87700}

.player{max-width:46rem;margin:0 auto;min-height:calc(100dvh - 8rem);display:flex;flex-direction:column}.p-top{display:flex;align-items:center;gap:.9rem;margin-bottom:1.6rem}.icon-btn{width:44px;height:44px;border-radius:50%;border:1px solid var(--line);background:var(--plate);cursor:pointer;font-size:1.1rem;flex:none}.p-bar{flex:1;height:14px;background:var(--soft);border-radius:7px;overflow:hidden}.p-bar i{display:block;height:100%;background:var(--on);border-radius:7px;transition:width .3s}.p-count{color:var(--muted);font-weight:700;white-space:nowrap}.p-body{flex:1}.p-title{font-size:1.9rem;margin-bottom:1rem}.p-text{font-size:1.2rem}.p-text p{max-width:40ch}.big-rule{font:600 1.35rem/1.35 var(--head);background:color-mix(in srgb,var(--on) 25%,var(--plate));border-radius:14px;padding:.9rem 1.1rem;max-width:none!important}.tip,.ru-help{background:var(--soft);border-radius:14px;padding:.8rem 1rem;font-size:1.05rem;max-width:none!important}.ru-help{border-left:5px solid var(--accent);margin:.8rem 0}.ru-help b{font-family:var(--head)}.ex-list{display:grid;gap:.5rem;margin:1rem 0 1.1rem}.ex-list>div{display:flex;justify-content:space-between;align-items:center;gap:1rem;background:var(--plate);border:1px solid var(--line);border-radius:12px;padding:.65rem 1rem}.tag{font:700 .9rem/1 var(--body);padding:.35rem .6rem;border-radius:999px;background:var(--soft);white-space:nowrap}.lamps{display:flex;gap:2.5rem;justify-content:center;margin:1.5rem 0}.lamps figure{margin:0;text-align:center}.steps{padding-left:1.4rem}.steps li{margin-bottom:.4rem}.p-foot{position:sticky;bottom:0;background:var(--bg);padding:1rem 0 calc(1rem + var(--safe-bottom));margin-top:1.5rem;border-top:1px solid var(--line);z-index:5}.p-foot .note{color:var(--muted);margin:0 0 .7rem;font-weight:700}.p-end{text-align:center;padding:2rem 0}.p-end .bulb{--s:130px}.p-end h2{font-size:2.2rem;margin-bottom:.6rem}.p-end .stars{font-size:2.4rem;letter-spacing:.2rem;margin:.3rem 0 .8rem}.p-end .row{justify-content:center;flex-direction:column}
.q-lead{color:var(--muted);font-weight:700;margin-bottom:.5rem}.q-text{font:500 1.5rem/1.45 var(--head);margin-bottom:1.3rem}.q-text p{margin:0 0 .4rem}.q-say{font-style:italic}.again{display:inline-block;font-weight:700;color:var(--accent);margin-bottom:.6rem}.opts{display:grid;gap:.7rem}.opts.two{grid-template-columns:1fr 1fr}.opt{display:flex;align-items:center;gap:.8rem;width:100%;min-height:56px;padding:.7rem 1rem;border:2px solid var(--line);border-radius:14px;background:var(--plate);box-shadow:0 3px 0 var(--line);font-weight:700;font-size:1.15rem;text-align:left;cursor:pointer}.opt .key{display:none;flex:none;width:1.6rem;height:1.6rem;border-radius:6px;border:1px solid var(--line);font-size:.8rem;line-height:1.5rem;text-align:center;color:var(--muted)}.opt.sel{border-color:var(--accent);box-shadow:0 3px 0 var(--accent);background:color-mix(in srgb,var(--accent) 9%,var(--plate))}.opt.right{border-color:var(--ok);box-shadow:0 3px 0 var(--ok);background:color-mix(in srgb,var(--ok) 12%,var(--plate))}.opt.wrong{border-color:var(--bad);box-shadow:0 3px 0 var(--bad);background:color-mix(in srgb,var(--bad) 10%,var(--plate))}.opt:disabled{cursor:default}.hint{background:var(--soft);border-radius:12px;padding:.7rem 1rem;margin-top:.8rem}.fb{border-radius:16px;padding:1rem 1.2rem;margin-bottom:1rem;border:2px solid}.fb.ok{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 10%,var(--plate))}.fb.no{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 8%,var(--plate))}.fb-title{font:600 1.35rem var(--head);margin-bottom:.3rem}.fb.ok .fb-title{color:var(--ok)}.fb.no .fb-title{color:var(--bad)}.fb-ex{line-height:1.75}.fb-ex .scroll{margin-top:.6rem}

.board{padding:1.3rem;margin-top:1rem}.circuit{display:block;width:100%;max-width:420px;margin:0 auto 1rem}.circuit .wire{stroke:var(--off);stroke-width:5;fill:none;stroke-linecap:round;transition:stroke .25s}.circuit.live .wire{stroke:var(--on)}.circuit .blade{stroke:var(--ink);stroke-width:6;stroke-linecap:round;transform-box:view-box;transition:transform .2s}.circuit .pin{fill:var(--ink)}.circuit .lamp-c{fill:var(--off);transition:fill .25s}.circuit.live .lamp-c{fill:var(--on);filter:drop-shadow(0 0 10px var(--on))}.circuit text{font:600 17px var(--head);fill:var(--muted)}.switches{display:flex;justify-content:center;gap:1.4rem;flex-wrap:wrap;margin-bottom:1rem}.sw{display:flex;flex-direction:column;align-items:center;gap:.4rem;background:none;border:0;cursor:pointer;padding:.3rem;border-radius:12px;min-width:90px;min-height:92px}.sw-lbl{font:600 1.05rem/1.2 var(--head);text-align:center}.sw-track{width:78px;height:44px;border-radius:999px;background:var(--off);position:relative;transition:background-color .2s}.sw-track::after{content:'';position:absolute;top:5px;left:5px;width:34px;height:34px;border-radius:50%;background:#fff;box-shadow:0 2px 3px rgba(0,0,0,.25);transition:left .2s}.sw[aria-checked="true"] .sw-track{background:var(--on)}.sw[aria-checked="true"] .sw-track::after{left:39px}.result{display:flex;align-items:center;justify-content:center;gap:1rem;margin:.4rem 0 1.2rem}.result .bulb{margin:0 0 18px}.res-lbl{margin:0;color:var(--muted);font-weight:700}.res-val{margin:0;font:600 1.4rem var(--head)}
.scroll{overflow-x:auto;max-width:100%;-webkit-overflow-scrolling:touch}.tbl{border-collapse:separate;border-spacing:0;background:var(--plate);border:1px solid var(--line);border-radius:12px;overflow:hidden;margin:0 auto}.tbl th{font:600 1.1rem var(--head);padding:.55rem .9rem;border-bottom:2px solid var(--line);white-space:nowrap}.tbl td{text-align:center;padding:.35rem .6rem;border-top:1px solid var(--line);height:48px;min-width:3.2rem}.tbl th+th,.tbl td+td{border-left:1px solid var(--line)}.tbl .res{border-left:3px solid var(--ink)!important}.tbl tr.cur td{background:color-mix(in srgb,var(--on) 22%,var(--plate))}.tbl .tried{color:var(--ok);font-weight:700}.tcell{width:100%;min-width:44px;min-height:44px;border:2px dashed var(--line);border-radius:10px;background:var(--bg);cursor:pointer;font:600 1.2rem var(--head);color:var(--muted)}.tcell.set{border-style:solid;background:var(--plate)}.tcell.ok{border-color:var(--ok)}.tcell.bad{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 12%,var(--plate))}

.chips{display:flex;gap:.5rem;overflow-x:auto;padding:.2rem .1rem .6rem;scrollbar-width:none;margin-bottom:.6rem}.chip{flex:none;border:2px solid var(--line);background:var(--plate);border-radius:999px;padding:.5rem 1rem;font-weight:700;cursor:pointer;min-height:48px}.chip[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:var(--bg)}.stats{display:flex;gap:1.5rem;color:var(--muted);font-weight:700;margin:.2rem 0 1rem}.card{padding:1.5rem;max-width:46rem}.card-foot{margin-top:1.3rem}
.tests{display:grid;gap:1rem;grid-template-columns:repeat(auto-fit,minmax(min(16rem,100%),1fr));max-width:46rem}.tcard{padding:1.3rem;display:flex;flex-direction:column;gap:.3rem}.tcard p{margin:0}.tbest{margin-top:auto!important;padding:.7rem 0;font-weight:700}.run-head{display:flex;justify-content:space-between;align-items:center;gap:1rem;margin-bottom:.8rem;max-width:46rem}.timer{font:600 1.5rem var(--head);background:var(--plate);border:1px solid var(--line);border-radius:12px;padding:.35rem .8rem;min-width:106px;text-align:center}.timer.low{color:var(--bad);border-color:var(--bad)}.dots{display:flex;flex-wrap:wrap;gap:.4rem;margin:.8rem 0 1.1rem;max-width:46rem}.dot{width:44px;height:44px;border-radius:50%;border:2px solid var(--line);background:var(--plate);font-weight:700;font-size:.9rem;cursor:pointer;color:var(--muted)}.dot.done{background:var(--on);border-color:var(--on);color:var(--on-ink)}.dot.cur{border-color:var(--accent);box-shadow:0 0 0 2px var(--accent)}.res-head{display:flex;align-items:center;gap:1.6rem;flex-wrap:wrap;padding:1.5rem;max-width:46rem;margin:1rem 0}.res-head .bulb{--s:100px;margin-bottom:30px}.grade{font:600 2.6rem/1 var(--head)}.trow{display:grid;grid-template-columns:11rem 1fr 3.5rem 5rem;align-items:center;gap:.8rem;padding:.55rem 0;border-bottom:1px solid var(--line);max-width:46rem}.tbar{height:12px;background:var(--soft);border-radius:6px;overflow:hidden}.tbar i{display:block;height:100%;border-radius:6px}.review{list-style:none;padding:0;margin:0;display:grid;gap:.8rem;max-width:46rem}.rv{padding:1rem 1.2rem;border-left:6px solid var(--ok)}.rv.bad{border-left-color:var(--bad)}.rv .q-text{font-size:1.15rem;margin-bottom:.6rem}.rv p{margin:.25rem 0}.check{display:flex;align-items:center;gap:.6rem;min-height:44px;margin:.6rem 0 1rem;cursor:pointer;font-weight:700}.check input{width:1.4rem;height:1.4rem}.good{color:var(--ok);font-weight:700}.warn{color:var(--bad);font-weight:700}
.spick{display:grid;gap:1rem;grid-template-columns:repeat(auto-fit,minmax(min(19rem,100%),1fr))}.sp{padding:1.2rem 1.3rem}.sp-head{display:flex;align-items:center;gap:.9rem;margin-bottom:.6rem}.sp-sym{font:600 2.4rem/1 var(--head);width:3.2rem;height:3.2rem;display:grid;place-items:center;background:var(--soft);border-radius:12px;flex:none}.sp-head small{display:block;color:var(--muted);font-size:1rem}.sp .rule{font-weight:700}.sp .tbl{margin:.6rem 0 0}
.error-list{display:grid;gap:.8rem;max-width:46rem;margin:1rem 0}.error-item{padding:1rem 1.2rem;display:flex;gap:1rem;align-items:center}.error-item>div{flex:1;min-width:0}.error-item p{margin:.2rem 0}.count{display:inline-block;background:var(--soft);border-radius:999px;padding:.2rem .6rem;font-weight:700}.empty{text-align:center;max-width:38rem;padding:2rem}.empty .bulb{--s:90px}.toast{position:fixed;left:50%;bottom:calc(1rem + var(--navh));transform:translateX(-50%);z-index:80;background:var(--ink);color:var(--bg);padding:.7rem 1rem;border-radius:12px;box-shadow:0 5px 20px rgba(0,0,0,.2);font-weight:700}.noscript{padding:1rem;background:#fff3cd;color:#3d2d00}

@media (hover:hover){.lrow:hover{background:var(--soft)}.opt:not(:disabled):hover{border-color:var(--accent)}}
@media (hover:hover) and (pointer:fine){.opt .key{display:inline-block}}
@media (max-width:820px){.brand span:last-child{display:none}nav a{padding:.45rem .6rem}}
@media (max-width:699px){
  :root{--navh:calc(4.5rem + var(--safe-bottom))}body.focus{--navh:0px}.top-in{padding:.45rem 1rem}.brand span:last-child{display:inline}
  nav{position:fixed;left:0;right:0;bottom:0;z-index:30;background:var(--plate);border-top:1px solid var(--line);margin:0;display:grid;grid-template-columns:repeat(5,1fr);gap:.1rem;padding:.3rem .25rem calc(.3rem + var(--safe-bottom))}
  nav a{flex-direction:column;gap:.05rem;padding:.25rem 0;border-radius:12px;font-size:.72rem;min-height:3.65rem}nav a[aria-current="page"]{background:var(--soft);color:var(--ink)}nav .ico{display:block;font-size:1.25rem;line-height:1.1}.nav-badge{right:calc(50% - 1.45rem);top:.1rem}
  main{padding:1.1rem 1rem 2rem}.hero{grid-template-columns:1fr;padding:1.4rem;text-align:center}.hero p{margin-left:auto;margin-right:auto}.hero-lamp{order:-1;padding:.5rem}.hero-lamp .bulb{--s:100px}.hero .btn{width:100%}.lrow .num{width:54px;height:54px;font-size:1.25rem}.path::before{left:25px}.lrow.next .t::after{display:block;width:fit-content;margin:.3rem 0 0}.p-title{font-size:1.55rem}.p-text{font-size:1.1rem}.q-text{font-size:1.3rem}.btn.big{max-width:none}.card{padding:1.1rem}.trow{grid-template-columns:1fr 3rem 4.5rem}.trow .tbar{grid-column:1 / -1;grid-row:2}.tbl th{padding:.5rem .6rem}.tbl td{padding:.3rem .35rem}.sw-track{width:84px;height:46px}.sw-track::after{width:36px;height:36px}.sw[aria-checked="true"] .sw-track::after{left:43px}.error-item{align-items:flex-start;flex-direction:column}.error-item .btn{width:100%}
}
@media (max-width:390px){.brand span:last-child{display:none}.tools{margin-left:auto}.opts.two{grid-template-columns:1fr}.ex-list>div{align-items:flex-start;flex-direction:column;gap:.35rem}.lamps{gap:1.5rem}}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition:none!important;scroll-behavior:auto!important}}
@media (forced-colors:active){.pill,.dot.done,.lrow.done .num{border:2px solid currentColor}.bulb{border:3px solid currentColor}}
.lrow.next .t::after{content:none}
.continue-tag{display:inline-block;margin-left:.6rem;font:700 .75rem/1 var(--body);padding:.3rem .5rem;border-radius:999px;background:var(--accent);color:var(--accent-ink);vertical-align:.2em}
@media (max-width:699px){.continue-tag{display:block;width:fit-content;margin:.3rem 0 0}}