:root{
  --bg:#f5f3ec; --grid:rgba(40,80,170,.075); --card:#ffffff; --card2:#faf9f5;
  --ink:#1a1e2a; --muted:#5b6274; --line:#dcdfe7;
  --accent:#6a45ff; --accent-ink:#ffffff; --hl:rgba(106,69,255,.09);
  --a1:#0a9fc0; --a2:#e0336f; --a3:#df9200; --a4:#2f9e58;
  --ok:#15803d; --ok-bg:rgba(21,128,61,.10); --bad:#c62828; --bad-bg:rgba(198,40,40,.09);
  --shadow:0 1px 2px rgba(20,25,40,.06),0 8px 28px rgba(20,25,40,.07);
  --paper:#ffffff; --paper-ink:#111;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0d1120; --grid:rgba(140,170,255,.055); --card:#151a2c; --card2:#11162a;
    --ink:#e8ebf4; --muted:#98a1b9; --line:#283050;
    --accent:#9d87ff; --accent-ink:#0d1120; --hl:rgba(157,135,255,.13);
    --a1:#3fd0ee; --a2:#ff5c95; --a3:#ffc23d; --a4:#4ade80;
    --ok:#34d399; --ok-bg:rgba(52,211,153,.12); --bad:#f87171; --bad-bg:rgba(248,113,113,.12);
    --shadow:0 1px 2px rgba(0,0,0,.3),0 10px 30px rgba(0,0,0,.35);
    --paper:#f7f6f1; --paper-ink:#111;
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0d1120; --grid:rgba(140,170,255,.055); --card:#151a2c; --card2:#11162a;
  --ink:#e8ebf4; --muted:#98a1b9; --line:#283050;
  --accent:#9d87ff; --accent-ink:#0d1120; --hl:rgba(157,135,255,.13);
  --a1:#3fd0ee; --a2:#ff5c95; --a3:#ffc23d; --a4:#4ade80;
  --ok:#34d399; --ok-bg:rgba(52,211,153,.12); --bad:#f87171; --bad-bg:rgba(248,113,113,.12);
  --shadow:0 1px 2px rgba(0,0,0,.3),0 10px 30px rgba(0,0,0,.35);
  --paper:#f7f6f1; --paper-ink:#111;
  color-scheme:dark;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0; background-color:var(--bg); color:var(--ink);
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:24px 24px;
  font:16px/1.6 "Space Grotesk",system-ui,-apple-system,"Segoe UI",sans-serif;
  overflow-x:hidden;
}
.m,i.m{font-family:"STIX Two Text","Cambria Math",Georgia,serif;font-style:italic}
.wrap{max-width:1040px;margin:0 auto;padding:0 16px}
h1,h2,h3{line-height:1.15;letter-spacing:-.02em;margin:0 0 .5em}
h2{font-size:clamp(1.6rem,4.5vw,2.3rem)}
h3{font-size:1.2rem}
p{margin:0 0 1em}
a{color:var(--accent)}
.muted{color:var(--muted)}
button{font:inherit;color:inherit}
.btn{
  display:inline-flex;align-items:center;gap:.45em;border:0;cursor:pointer;
  background:var(--accent);color:var(--accent-ink);font-weight:700;
  padding:.7em 1.15em;border-radius:12px;text-decoration:none;
  transition:transform .15s ease,box-shadow .15s ease,background .2s;
  box-shadow:0 4px 14px color-mix(in srgb,var(--accent) 35%,transparent);
}
.btn:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0) scale(.98)}
.btn.ghost{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--line)}
.btn.ghost:hover{box-shadow:inset 0 0 0 1.5px var(--accent);color:var(--accent)}
.btn.small{padding:.45em .8em;font-size:.9rem;border-radius:10px}
.btn:disabled{opacity:.45;cursor:default;transform:none}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:20px}
.pill{display:inline-block;font-size:.78rem;font-weight:700;letter-spacing:.04em;text-transform:uppercase;padding:.25em .7em;border-radius:99px;background:var(--hl);color:var(--accent)}

/* ułamki */
.fr{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;line-height:1.05;margin:0 .12em;font-size:.92em}
.fr>span:first-child{border-bottom:1.5px solid currentColor;padding:0 .2em .08em}
.fr>span:last-child{padding:.08em .2em 0}

/* ===== zadanie ===== */
.task{position:relative;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px 18px 14px;margin:0 0 16px}
.thead{display:flex;gap:12px;align-items:flex-start}
.tnum{flex:none;display:inline-grid;place-items:center;min-width:28px;height:28px;padding:0 6px;border-radius:7px;background:var(--ink);color:var(--bg);font-weight:700;font-size:.9rem;margin-top:2px}
.ttext{flex:1;font-family:"STIX Two Text",Georgia,serif;font-size:1.12rem;line-height:1.55}
.ttext i{font-family:"STIX Two Text",Georgia,serif}
.tpts{flex:none;font-size:.85rem;color:var(--muted);white-space:nowrap;margin-top:4px}
.tfig{margin:10px 0 4px;display:flex;justify-content:center}
.tfig svg{width:100%;max-width:340px;height:auto}
.tfig svg text{font-family:"STIX Two Text",Georgia,serif}
.tans{margin-top:12px}
.tans.choices{display:grid;gap:8px}
.tans.choices.row{grid-template-columns:repeat(4,minmax(0,1fr))}
@media (max-width:620px){.tans.choices.row{grid-template-columns:repeat(2,minmax(0,1fr))}}
.choice{
  text-align:left;cursor:pointer;background:var(--card2);border:1.5px solid var(--line);border-radius:12px;
  padding:.6em .8em;font-family:"STIX Two Text",Georgia,serif;font-size:1.05rem;transition:border-color .15s,background .15s,transform .15s;
  display:flex;gap:.4em;align-items:center;min-height:48px
}
.choice:hover{border-color:var(--accent)}
.choice .cl{font-family:"Space Grotesk",sans-serif;font-weight:700}
.choice.sel{border-color:var(--accent);background:var(--hl)}
.choice.ok{border-color:var(--ok);background:var(--ok-bg)}
.choice.bad{border-color:var(--bad);background:var(--bad-bg)}
.choice.right{border-color:var(--ok);border-style:dashed}
.task.locked .choice{cursor:default}
.field{display:inline-flex;align-items:center;gap:8px;margin:0 14px 8px 0;flex-wrap:wrap}
.field .fl{font-family:"STIX Two Text",Georgia,serif;font-size:1.05rem}
.field input{
  width:7.5em;font:600 1.05rem "Space Grotesk",sans-serif;color:var(--ink);background:var(--card2);
  border:1.5px solid var(--line);border-radius:10px;padding:.45em .6em;outline:none;transition:border-color .15s,box-shadow .15s
}
.field input:focus{border-color:var(--accent);box-shadow:0 0 0 4px var(--hl)}
.field.ok input{border-color:var(--ok);background:var(--ok-bg)}
.field.bad input{border-color:var(--bad);background:var(--bad-bg)}
.field .fu{color:var(--muted)}
.hint{font-size:.82rem;color:var(--muted);margin:2px 0 0}
.tbtns{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}
.tfeed{min-height:0;font-weight:700;margin-top:8px}
.tfeed.ok{color:var(--ok)} .tfeed.bad{color:var(--bad)}
.tfeed:empty{display:none}
.tsteps{margin-top:12px;border-top:1px dashed var(--line);padding-top:12px}
.tsteps ol{margin:0;padding:0;list-style:none;counter-reset:st}
.tsteps li{
  counter-increment:st;position:relative;padding:8px 10px 8px 44px;margin:0 0 6px;border-radius:10px;background:var(--card2);
  font-family:"STIX Two Text",Georgia,serif;font-size:1.05rem;animation:stepIn .45s cubic-bezier(.2,.9,.3,1.2) both
}
.tsteps li::before{content:counter(st);position:absolute;left:10px;top:8px;width:24px;height:24px;border-radius:50%;background:var(--accent);color:var(--accent-ink);font:700 .8rem/24px "Space Grotesk",sans-serif;text-align:center}
.tsteps li b{color:var(--accent)}
.tsteps li.trap{background:var(--bad-bg)}
.tsteps li.trap::before{content:"!";background:var(--bad)}
.stepbtns{display:flex;gap:8px;flex-wrap:wrap;margin-top:6px}
@keyframes stepIn{from{opacity:0;transform:translateY(10px) scale(.98)}to{opacity:1;transform:none}}
@keyframes pop{0%{transform:scale(1)}40%{transform:scale(1.04)}100%{transform:scale(1)}}
@keyframes shake{0%,100%{transform:none}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}
.task.pop{animation:pop .4s ease}
.task.shake{animation:shake .35s ease}
.selfcheck{display:flex;gap:10px;align-items:flex-start;margin-top:10px;padding:10px 12px;border-radius:10px;background:var(--hl);font-size:.95rem;cursor:pointer}
.selfcheck input{width:20px;height:20px;margin-top:2px;accent-color:var(--accent)}

/* konfetti */
#confetti{position:fixed;inset:0;pointer-events:none;z-index:99}

/* przełącznik motywu */
.theme-btn{position:fixed;right:14px;bottom:14px;z-index:50;width:46px;height:46px;border-radius:50%;border:1px solid var(--line);background:var(--card);box-shadow:var(--shadow);cursor:pointer;font-size:1.2rem}
@media print{.theme-btn,#confetti{display:none!important}}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}html{scroll-behavior:auto}}