/* ============================================================
   FYZIKA — vzhled „školní sešit“
   čtverečkovaný papír · modré pero · žlutý zvýrazňovač · červené opravné pero
   ============================================================ */

:root{
  --paper:#FBFCFE; --grid:#DCE4F2; --ink:#1E3A8A; --text:#1B2233; --muted:#55607A;
  --hl:#FFE45C; --hl-text:#1B2233; --red:#C8322B; --green:#2E7D4F; --card:#FFFFFF; --line:#C9D3E6;
  --ok-bg:#E4F4EA; --bad-bg:#FBE6E4;
  color-scheme:light dark;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --paper:#131A27; --grid:#1D2738; --ink:#9DB8FF; --text:#E7EBF3; --muted:#A3AEC4;
    --hl:#5E5214; --hl-text:#FFF6C9; --red:#FF7B72; --green:#6FD39A; --card:#1A2232; --line:#2C3850;
    --ok-bg:#16301F; --bad-bg:#3A1C1A;
  }
}
:root[data-theme="dark"]{
  --paper:#131A27; --grid:#1D2738; --ink:#9DB8FF; --text:#E7EBF3; --muted:#A3AEC4;
  --hl:#5E5214; --hl-text:#FFF6C9; --red:#FF7B72; --green:#6FD39A; --card:#1A2232; --line:#2C3850;
  --ok-bg:#16301F; --bad-bg:#3A1C1A;
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-padding-top:env(safe-area-inset-top,0px);scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{
  margin:0;color:var(--text);font-family:"Atkinson Hyperlegible",Verdana,system-ui,sans-serif;
  font-size:18px;line-height:1.6;background-color:var(--paper);
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:24px 24px;
  padding-top:env(safe-area-inset-top,0px);
  overflow-wrap:break-word;
}
main{max-width:760px;margin:0 auto;padding:24px max(18px,env(safe-area-inset-right,0px)) 64px max(18px,env(safe-area-inset-left,0px))}

h1,h2,h3{line-height:1.2;color:var(--ink)}
h1{font-family:Kalam,"Comic Sans MS",cursive;font-size:clamp(2.6rem,9vw,4rem);margin:.2em 0 .1em;font-weight:700}
h2{font-size:1.6rem;margin:2.2em 0 .5em;padding-bottom:.2em;border-bottom:3px solid var(--ink)}
h3{font-size:1.2rem;margin:1.6em 0 .4em}
p{margin:.6em 0}
a{color:var(--ink)}
.lead{font-size:1.1rem;color:var(--muted);max-width:60ch}
.back{font-size:.95rem;margin:0 0 6px}

/* rozcestník */
.toc{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0 0;padding:0;list-style:none}
.toc a{display:inline-block;padding:6px 12px;border:2px solid var(--ink);border-radius:999px;text-decoration:none;font-weight:700;background:var(--card);font-size:.95rem}
a:focus-visible,button:focus-visible{outline:3px solid var(--red);outline-offset:2px}

/* komponenty */
.rule{background:var(--hl);color:var(--hl-text);padding:14px 16px;border-radius:4px;font-weight:700;margin:14px 0;box-shadow:0 0 0 1px rgba(0,0,0,.04)}
.box{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:14px 16px;margin:14px 0}
.ex{color:var(--muted)}
.ex strong{color:var(--text)}
.pen{font-family:Kalam,"Comic Sans MS",cursive;color:var(--ink);font-size:1.15rem;line-height:1.55}
.tip{border-left:4px solid var(--green);padding:6px 12px;margin:14px 0;background:var(--card)}
.tip b{color:var(--green)}
.two{display:grid;grid-template-columns:1fr 1fr;gap:12px}
@media (max-width:560px){.two{grid-template-columns:1fr}}
.two > *{min-width:0}
.two .box{margin:0}
.two h3{margin-top:0}
.scroll{overflow-x:auto;margin:14px 0;-webkit-overflow-scrolling:touch}
table{border-collapse:collapse;width:100%;min-width:520px;background:var(--card);font-size:.95rem}
th,td{border:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
th{color:var(--ink)}
svg{max-width:100%;height:auto;display:block}
.hand{font-family:Kalam,"Comic Sans MS",cursive}

/* animace autíček */
.demo{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:14px}
.btn{font:inherit;font-weight:700;background:var(--ink);color:var(--paper);border:0;border-radius:6px;padding:10px 18px;cursor:pointer}
.btn:disabled{opacity:.6;cursor:default}
.lane-label{font-size:15px;fill:var(--muted);font-family:"Atkinson Hyperlegible",Verdana,sans-serif}

/* dělení zlata */
.split-row{display:grid;grid-template-columns:220px 1fr;gap:16px;align-items:center}
@media (max-width:560px){.split-row{grid-template-columns:1fr}.split-row svg{max-width:220px;margin:0 auto}}
.split-size{font-size:1.5rem;font-weight:700;color:var(--ink);margin:0}
.split-meta{color:var(--muted);font-size:.95rem;margin:0}
.split-msg{min-height:3.2em;margin:.4em 0 .8em}
.btn.ghost{background:transparent;color:var(--ink);border:2px solid var(--ink);padding:8px 14px;margin-left:6px}
.btns{display:flex;flex-wrap:wrap;gap:8px}
.btns .btn.ghost{margin-left:0}

/* částice – barevné značky */
.chip{display:inline-flex;align-items:center;justify-content:center;width:1.6em;height:1.6em;border-radius:50%;font-weight:700;font-size:.85em;vertical-align:middle;margin-right:.3em;color:#fff}
.chip.p{background:#C8322B}
.chip.n{background:#E8C420;color:#1B2233}
.chip.e{background:#2F6FEB}

/* veličiny a jednotky */
.vel{color:var(--ink);font-weight:700}
.jed{color:var(--green);font-weight:700}
.formula{display:flex;flex-wrap:wrap;justify-content:center;align-items:flex-start;gap:6px 10px;background:var(--card);border:1px solid var(--line);border-radius:8px;padding:16px 10px;margin:14px 0}
.formula .part{display:flex;flex-direction:column;align-items:center;text-align:center;max-width:9.5em}
.formula .big{font-family:Kalam,"Comic Sans MS",cursive;font-size:2.4rem;line-height:1.1;padding:0 .15em;border-bottom:4px solid currentColor}
.formula .cap{font-size:.85rem;color:var(--muted);margin-top:6px;line-height:1.3}
.formula .v{color:var(--ink)} .formula .j{color:var(--green)} .formula .n{color:var(--text)} .formula .eq{color:var(--muted);border-color:transparent}
.sorter{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:14px;text-align:center}
.sorter .card-word{font-family:Kalam,"Comic Sans MS",cursive;font-size:2rem;color:var(--text);margin:.2em 0;min-height:1.5em}
.sorter .ctx{color:var(--muted);font-size:.95rem;min-height:1.4em;margin:0}
.sorter .choices{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:12px 0 8px}
.sorter .choices button{font:inherit;font-weight:700;padding:10px 8px;border:2px solid var(--line);border-radius:6px;background:var(--paper);color:var(--text);cursor:pointer}
.sorter .choices button:last-child{grid-column:1 / -1}
.sorter .choices button.right{border-color:var(--green);background:var(--ok-bg)}
.sorter .choices button.wrong{border-color:var(--red);background:var(--bad-bg)}
.sorter .fb{min-height:3em;margin:.3em 0}

/* počítej sám (generátor příkladů) */
.calc{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:14px 16px;margin:14px 0}
.calc-chips{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:8px}
.calc-chips button{font:inherit;font-size:.88rem;font-weight:700;padding:5px 11px;border:2px solid var(--ink);border-radius:999px;background:var(--card);color:var(--ink);cursor:pointer}
.calc-chips button.on{background:var(--ink);color:var(--paper)}
.calc-score{color:var(--muted);font-size:.9rem;margin:.2em 0}
.calc-text{font-size:1.1rem;font-weight:700;margin:.5em 0 .7em}
.calc-row{display:flex;align-items:center;gap:10px;margin-bottom:10px}
.calc-row input{font:inherit;font-size:1.2rem;width:9em;max-width:60%;padding:8px 10px;border:2px solid var(--line);border-radius:6px;background:var(--paper);color:var(--text)}
.calc-row input.right{border-color:var(--green);background:var(--ok-bg)}
.calc-row input.wrong{border-color:var(--red);background:var(--bad-bg)}
.calc-unit{font-weight:700;font-size:1.1rem}
.calc-fb b.ok{color:var(--green)} .calc-fb b.no{color:var(--red)}
.calc-fb .pen{margin:.3em 0 0}
@media print{.calc{display:none !important}}

/* úvod ve stylu dějepisu: karty hodin s datem a ikonou */
.hero{text-align:center;margin-bottom:6px}
.hero .eyebrow{font-size:.78rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);font-weight:700}
.hero h1{margin:.1em 0 .05em}
.hero .lead{margin:0 auto;max-width:none}
.sec{display:flex;align-items:center;gap:8px;flex-wrap:wrap;font-size:.92rem;font-weight:800;letter-spacing:.09em;margin:28px 0 12px;text-transform:uppercase;color:var(--ink)}
.sec small{font-weight:600;color:var(--muted);text-transform:none;letter-spacing:0;font-size:.9rem}
.lgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(290px,1fr));gap:12px}
.lcard{display:flex;gap:12px;align-items:center;border-radius:14px;padding:13px 15px 13px 18px;text-decoration:none;color:#fff;background:var(--c);box-shadow:0 3px 10px rgba(0,0,0,.18);transition:transform .13s}
.lcard:hover{transform:translateY(-3px)}
.lcard:focus-visible{outline:3px solid var(--red);outline-offset:3px}
.lcard .lc-txt{flex:1;min-width:0}
.lcard b.t{display:flex;align-items:center;gap:8px;font-size:1.08rem;font-weight:700;flex-wrap:wrap;line-height:1.25}
.lcard p{margin:6px 0 0;font-size:.86rem;opacity:.95;line-height:1.4}
.lcard p b{font-weight:700}
.when{font-size:.7rem;font-weight:700;background:rgba(255,255,255,.28);border-radius:999px;padding:2px 9px;white-space:nowrap}
.licon{width:58px;height:58px;border-radius:12px;flex:0 0 auto;display:grid;place-items:center;font-size:1.9rem;background:rgba(255,255,255,.92);border:2px solid rgba(255,255,255,.55);box-shadow:0 2px 6px rgba(0,0,0,.18)}
.minirow{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.mini{display:inline-block;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:7px 14px;font-size:.88rem;font-weight:700;text-decoration:none;color:var(--ink)}
.mini:hover{border-color:var(--ink)}
@media (prefers-reduced-motion:reduce){.lcard{transition:none}.lcard:hover{transform:none}}

/* úvod: barevné dlaždice kapitol (styl jako zeměpis) */
.gradehead{font-size:1rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);border-bottom:none;margin:28px 0 10px;padding:0;display:flex;align-items:center;gap:8px}
.chaptiles{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
@media (max-width:760px){.chaptiles{grid-template-columns:1fr 1fr}}
@media (max-width:480px){.chaptiles{grid-template-columns:1fr}}
.ctile{display:block;text-decoration:none;color:#fff;background:var(--c);border-radius:14px;padding:14px 16px;box-shadow:0 1px 3px rgba(0,0,0,.08),0 8px 20px rgba(0,0,0,.08);transition:transform .15s}
.ctile:hover{transform:translateY(-2px)}
.ctile:focus-visible{outline:3px solid var(--red);outline-offset:3px}
.ctile b{display:block;font-size:1.2rem;line-height:1.25}
.ctile span{display:block;font-size:.9rem;opacity:.95;margin-top:4px;line-height:1.35}
@media (prefers-reduced-motion:reduce){.ctile{transition:none}.ctile:hover{transform:none}}

/* úvod: dlaždice ročníků */
.grades{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:20px 0}
@media (max-width:560px){.grades{grid-template-columns:1fr}}
.grade{display:block;text-decoration:none;background:var(--card);border:2px solid var(--ink);border-radius:12px;padding:18px 20px;color:var(--text)}
.grade:hover{background:var(--ok-bg)}
.grade .big{display:block;font-family:Kalam,"Comic Sans MS",cursive;font-size:2.6rem;font-weight:700;color:var(--ink);line-height:1.1}
.grade p{margin:.5em 0 0;color:var(--muted);font-size:.95rem}
.grade .go{display:inline-block;margin-top:.7em;font-weight:700;color:var(--ink)}

/* ročník: karty kapitol */
.chapter{background:var(--card);border:1px solid var(--line);border-left:6px solid var(--ink);border-radius:8px;padding:14px 16px;margin:16px 0}
.chapter h2{border-bottom:none;margin:0 0 .2em;font-size:1.35rem;display:flex;gap:10px;align-items:center}
.chnum{flex:none;width:1.8em;height:1.8em;border-radius:50%;background:var(--ink);color:var(--paper);display:inline-flex;align-items:center;justify-content:center;font-size:1rem}
.chapter .ex{margin:.2em 0 .5em}
.topics{margin:.3em 0 .9em;padding-left:1.3em;columns:2;column-gap:24px}
@media (max-width:560px){.topics{columns:1}}
.topics li{margin:.2em 0;break-inside:avoid}
.actions{display:flex;flex-wrap:wrap;gap:8px}
.act{display:inline-block;padding:6px 12px;border-radius:999px;border:2px solid var(--ink);text-decoration:none;font-weight:700;font-size:.92rem;background:var(--card);color:var(--ink)}
.act.main{background:var(--ink);color:var(--paper)}

/* přehled: hodina po hodině */
.lessons{padding-left:2.4em;margin:10px 0}
.lessons li{margin:.35em 0;padding-left:.2em}
.lessons li::marker{color:var(--ink);font-weight:700}
.lessons a{font-weight:700}

/* otázky a odpovědi (odpověď se rozbalí kliknutím) */
.qa{background:var(--card);border:1px solid var(--line);border-radius:8px;margin:10px 0}
.qa summary{cursor:pointer;padding:12px 16px;font-weight:700;list-style:none;display:flex;gap:12px;align-items:flex-start}
.qa summary::-webkit-details-marker{display:none}
.qa summary::before{content:"?";flex:none;width:1.6em;height:1.6em;border-radius:50%;background:var(--ink);color:var(--paper);display:inline-flex;align-items:center;justify-content:center;font-size:.9rem}
.qa[open] summary::before{content:"✓";background:var(--green)}
.qa summary:focus-visible{outline:3px solid var(--red);outline-offset:2px;border-radius:8px}
.qa .ans{padding:0 16px 12px calc(16px + 1.6em + 12px)}
.qa .ans .pen{margin:.1em 0 .3em}
.qa .ans .ex{margin:.2em 0 0;font-size:.95rem}
.qa-tools{margin:8px 0 4px}

/* opravy v sešitě */
.fix{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:12px 16px;margin:12px 0}
.fix .was{font-family:Kalam,"Comic Sans MS",cursive;text-decoration:line-through;text-decoration-color:var(--red);text-decoration-thickness:2px;color:var(--muted)}
.fix .is{font-family:Kalam,"Comic Sans MS",cursive;color:var(--red);font-size:1.15rem}

/* test */
.q{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:14px 16px;margin:14px 0}
.q .num{font-weight:700;color:var(--ink);margin-right:.3em}
.q .opts{display:grid;gap:8px;margin-top:10px}
.q button.opt{font:inherit;text-align:left;padding:10px 12px;border:2px solid var(--line);border-radius:6px;background:var(--paper);color:var(--text);cursor:pointer;width:100%}
.q button.opt:hover:not(:disabled){border-color:var(--ink)}
.q button.opt:disabled{cursor:default;opacity:1}
.q button.opt.right{border-color:var(--green);background:var(--ok-bg)}
.q button.opt.wrong{border-color:var(--red);background:var(--bad-bg)}
.q .why{display:none;margin:10px 0 0;font-size:.95rem}
.q.done .why{display:block}
.q .why b.ok{color:var(--green)}
.q .why b.no{color:var(--red)}
.score{position:sticky;bottom:calc(10px + env(safe-area-inset-bottom,0px));z-index:5;background:var(--ink);color:var(--paper);border-radius:10px;padding:10px 14px;display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:20px;font-weight:700}
.score small{display:block;font-weight:400;opacity:.85;font-size:.85rem}
.score button{font:inherit;font-weight:700;background:var(--paper);color:var(--ink);border:0;border-radius:6px;padding:6px 12px;cursor:pointer;flex:none}
.score button:focus-visible{outline-color:var(--paper)}

/* tahák */
.cheat{background:var(--card);border:2px solid var(--ink);border-radius:8px;padding:16px}
.cheat h3{margin-top:.6em}
.cheat ul{margin:.3em 0;padding-left:1.2em}
.print-row{margin:10px 0 0}

footer{margin-top:40px;color:var(--muted);font-size:.9rem}

/* ---------- panel výběru tisku (stejně jako dějepis) ---------- */
.print-btn{font:inherit;font-weight:700;display:inline-block;padding:6px 12px;border:2px solid var(--ink);border-radius:999px;background:var(--ink);color:var(--paper);cursor:pointer;font-size:.95rem;margin-top:10px}
.print-panel{margin-top:10px;background:var(--card);border:1px solid var(--line);border-radius:8px;padding:12px 16px;display:flex;flex-wrap:wrap;gap:8px 18px;align-items:center;font-size:.95rem;text-align:left}
.print-panel[hidden]{display:none}
.print-panel b{width:100%}
.print-panel label{display:flex;gap:7px;align-items:center;cursor:pointer}
.print-panel .pp-btns{width:100%;display:flex;flex-wrap:wrap;gap:8px;margin-top:4px}
.print-panel .pp-note{width:100%;margin:0;color:var(--muted);font-size:.85rem}

/* ---------- TISK ---------- */
@media print{
  /* skutečné okraje stránky; URL a čísla stránek vypni v tiskovém dialogu
     volbou „Záhlaví a zápatí“ (prohlížeč si to pamatuje) */
  @page{margin:14mm 12mm}
  *{-webkit-print-color-adjust:exact;print-color-adjust:exact}
  :root{--paper:#fff;--card:#fff;--text:#000;--muted:#333;--ink:#1E3A8A;--hl:#FFE45C;--hl-text:#000;--red:#C8322B;--green:#2E7D4F;--line:#999}
  body{background:#fff !important;background-image:none !important;font-size:12pt;padding:0}
  main{max-width:none;padding:0}

  /* skrýt ovládání a interaktivní části */
  .toc,.back,.lead,.btn,.btns,.score,.print-btn,.print-panel,.print-row,.noprint,
  #procvic,#tridicka,details.box,.qa-tools,footer,
  header .ex,input[type=range],select,.sorter{display:none !important}
  a{color:inherit;text-decoration:none}
  h1{font-size:2rem;margin-bottom:.2em}

  /* malé celky nedělit, nadpisy nenechat osamocené na konci stránky */
  h2,h3{break-after:avoid;page-break-after:avoid}
  .rule,.box,.fix,.tip,.formula,.cheat,svg,tr,li,.demo{break-inside:avoid;page-break-inside:avoid}
  .two{break-inside:avoid}
  .scroll{overflow:visible !important}
  table{min-width:0;font-size:10.5pt}

  /* tahák na vlastní stránce, první vytištěná část stránku nezalamuje */
  #tahak{break-before:page;page-break-before:always}
  #tahak h2{margin-top:0}
  .cheat{font-size:11pt;line-height:1.45;padding:10px 14px}
  .first-print{break-before:auto !important;page-break-before:auto !important}
  .first-print h2{margin-top:0}
}

/* ================================================================
   VZHLED PRO STARŠÍ (podle přírodopisu): krémový papír, patkové
   nadpisy, tlumené barvy, bez čtverečků a ručního písma
   ================================================================ */
:root{
  --paper:#f4f1ea; --grid:transparent; --ink:#1f3a5f; --text:#1e2622; --muted:#6b6f63;
  --hl:#f6e7b4; --hl-text:#2b2418; --red:#b5402f; --green:#2f7d4f; --card:#fffdf9; --line:#e3ddcf;
  --ok-bg:#e6f2ea; --bad-bg:#f8e6e2;
  --shadow:0 2px 12px rgba(60,50,30,.08);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --paper:#15191f; --grid:transparent; --ink:#9db8e6; --text:#e8e6e1; --muted:#a8a69e;
    --hl:#4a4126; --hl-text:#f6edd2; --red:#ef8a7a; --green:#7fcf9c; --card:#1d222a; --line:#2f3640;
    --ok-bg:#1d3326; --bad-bg:#3a221e;
  }
}
body{font-family:Inter,system-ui,-apple-system,"Segoe UI",sans-serif;font-size:17px;line-height:1.6;background-image:none}
main{max-width:860px}
h1,h2,h3{font-family:"Playfair Display",Georgia,serif;letter-spacing:.005em}
h1{font-size:clamp(2.2rem,7vw,3.2rem);font-weight:700}
h2{font-size:1.55rem;border-bottom:2px solid var(--line);font-weight:700}
h3{font-size:1.18rem}
.pen,.hand,.fix .is,.fix .was,.formula .big,.sorter .card-word,.grade .big{font-family:Inter,system-ui,sans-serif}
.pen{font-size:1.02rem;font-weight:500;color:var(--ink)}
.box,.tip,.fix,.q,.demo,.calc,.qa,.cheat,.sorter{border-radius:12px}
.box,.calc,.qa,.q,.demo{box-shadow:var(--shadow)}
.rule{border-radius:10px;font-weight:600;border-left:4px solid #d8b94a}
.tip{border-left-width:4px;border-radius:0 12px 12px 0}
.lead{font-size:1.05rem}
a{color:var(--ink)}
.btn{border-radius:10px}
.toc a{border-width:1px;font-weight:600}

/* záložky sekcí na stránkách kapitol */
body.has-tabs main > header nav{display:none}
.sectabs{position:sticky;top:0;z-index:20;display:flex;gap:6px;overflow-x:auto;scrollbar-width:thin;
  background:var(--paper);padding:10px 0 10px;margin:8px 0 6px;border-bottom:1px solid var(--line);-webkit-overflow-scrolling:touch}
.sectabs a{flex:none;white-space:nowrap;text-decoration:none;font-weight:600;font-size:.9rem;color:var(--text);
  background:var(--card);border:1px solid var(--line);border-radius:10px;padding:7px 12px}
.sectabs a:hover{border-color:var(--ink)}
.sectabs a.on{background:var(--ink);border-color:var(--ink);color:var(--paper)}
main > section.tab-off{display:none}
main > section > h2:first-child{margin-top:.9em}
.secnav{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;margin:28px 0 0;padding-top:14px;border-top:1px solid var(--line)}
.secnav a{text-decoration:none}

/* úvod: hero a záložky */
.hero{background:linear-gradient(135deg,#1f3a5f,#2c5a7a);color:#fff;border-radius:16px;padding:26px 22px;margin:6px 0 4px;text-align:left}
.hero .eyebrow{color:rgba(255,255,255,.75)}
.hero h1{color:#fff;margin:.1em 0}
.hero .lead{color:rgba(255,255,255,.88)}
.lcard{border-radius:14px}
.sec{font-family:Inter,system-ui,sans-serif}

/* podklad k tisku */
.sheet{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:18px 20px;box-shadow:var(--shadow)}
.sheet h3{margin:.9em 0 .35em;font-size:1.1rem;border-bottom:1px solid var(--line);padding-bottom:.15em}
.sheet h3:first-child{margin-top:0}
.sheet .cols{display:grid;grid-template-columns:1fr 1fr;gap:4px 22px}
@media (max-width:620px){.sheet .cols{grid-template-columns:1fr}}
.sheet table{min-width:0;font-size:.92rem}
.sheet th,.sheet td{padding:5px 8px}
.fbox{border:1px solid var(--line);border-radius:10px;padding:8px 12px;margin:6px 0;background:var(--paper)}
.fbox b{display:block;font-size:.85rem;color:var(--muted);font-weight:600}
.fbox .f{font-family:"Playfair Display",Georgia,serif;font-size:1.25rem;color:var(--ink)}
.sheet ul{margin:.2em 0;padding-left:1.15em}
.sheet li{margin:.15em 0}

@media print{
  :root{--paper:#fff;--card:#fff;--line:#bbb}
  .sectabs,.secnav{display:none !important}
  main > section.tab-off:not(.noprint){display:block !important}
  .hero{background:none !important;color:#000;padding:0}
  .hero h1,.hero .lead,.hero .eyebrow{color:#000}
  .sheet{box-shadow:none;border:none;padding:0;font-size:10.5pt;line-height:1.38}
  .sheet .cols{grid-template-columns:1fr 1fr !important}
  .sheet h3{font-size:12pt;margin:.55em 0 .25em}
  .fbox{padding:4px 9px;margin:4px 0}
  .fbox .f{font-size:13pt}
  .sheet table{font-size:9.5pt}
  .sheet th,.sheet td{padding:3px 6px}
  #vzorce{break-before:auto}
  #vzorce > h2{display:none}
}

/* reálné fotky */
figure.photo{margin:14px 0;background:var(--card);border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow)}
figure.photo img{display:block;width:100%;aspect-ratio:3/2;object-fit:cover;background:var(--line)}
figure.photo figcaption{padding:7px 12px 9px;font-size:.82rem;color:var(--muted);line-height:1.35}
figure.photo figcaption b{display:block;color:var(--text);font-size:.92rem;font-weight:600}
figure.photo figcaption a{color:var(--muted);text-decoration:none}
figure.photo figcaption a:hover{text-decoration:underline}
.photos{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px;margin:14px 0}
.photos figure.photo{margin:0}
figure.photo.wide img{aspect-ratio:16/7}
.licon.has-photo{padding:0;overflow:hidden;background:none}
.licon.has-photo img{width:100%;height:100%;object-fit:cover;display:block}
.photo-credits{font-size:.75rem;color:var(--muted);margin-top:18px;line-height:1.5}
.photo-credits a{color:var(--muted)}
@media print{
  figure.photo{box-shadow:none;break-inside:avoid}
  figure.photo img{max-height:55mm}
  .photo-credits{font-size:7pt}
}

/* tisk bez záhlaví a zápatí prohlížeče (datum, název, adresa, číslo strany):
   nulové okraje stránky → prohlížeč nemá kam je vytisknout; okraj textu
   dělá odsazení obsahu, které se opakuje na každé stránce */
@media print{
  @page{margin:0}
  html,body{margin:0 !important;padding:0 !important}
  main{padding:14mm 13mm !important;box-decoration-break:clone;-webkit-box-decoration-break:clone}
}

/* matematika: vždy světlý vzhled (tmavý režim vypnutý atributem data-theme="light") */
:root[data-theme="light"]{color-scheme:light}

/* ================================================================
   MATEMATIKA — vzhled podle dějepisu
   krémový papír s jemnými tečkami, patkové nadpisy, karty se stínem,
   záložky jako „pilulky“, které se zalomí (žádný vodorovný posuvník)
   ================================================================ */
:root,:root[data-theme="light"]{
  --paper:#f6f2ea; --card:#fffdf8; --line:#e6dfd0; --ink:#23407a; --text:#22252c; --muted:#6f6a5f;
  --hl:#fbe7a6; --hl-text:#2a2416; --red:#b5402f; --green:#2f7d4f; --ok-bg:#e7f2ea; --bad-bg:#f8e7e2;
  --accent:#c07a2c; --shadow:0 2px 12px rgba(80,55,30,.09);
}
body{background-color:var(--paper);
  background-image:radial-gradient(rgba(35,64,122,.07) 1px,transparent 1px);background-size:22px 22px}
main{max-width:900px}

/* hlavička jako v dějepise */
main > header .back{margin:0 0 6px}
main > header .back a{color:var(--accent);font-weight:600;font-size:.88rem;text-decoration:none}
main > header .back a:hover{text-decoration:underline}
main > header > p.pen{font-size:.74rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);font-weight:600}
main > header h1{margin:.15em 0 .2em;color:var(--text)}
main > header .lead{color:var(--muted)}
h2{border-bottom:none;color:var(--ink)}
h2::after{content:"";display:block;width:56px;height:3px;border-radius:2px;background:var(--accent);margin-top:6px}

/* záložky: pilulky, zalamují se, nelepí se nahoru */
.sectabs{position:static;flex-wrap:wrap;overflow:visible;gap:8px;background:none;border-bottom:none;padding:4px 0 2px;margin:12px 0 4px}
.sectabs a{white-space:normal;flex:0 1 auto;max-width:100%;overflow-wrap:anywhere;border-radius:999px;padding:8px 14px;font-size:.9rem;font-weight:600;
  background:var(--card);border:1px solid var(--line);color:var(--text);box-shadow:var(--shadow);transition:border-color .15s}
.sectabs a:hover{border-color:var(--ink)}
.sectabs a.on{background:var(--ink);border-color:var(--ink);color:#fff}
.print-btn{border-radius:999px;background:var(--card);color:var(--text);border:1px solid var(--line);box-shadow:var(--shadow);font-weight:600}
.print-btn:hover{border-color:var(--ink)}

/* karty */
.box,.demo,.q,.qa,.cheat,.fix,.calc,.print-panel{background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}
.cheat{border:1px solid var(--line)}
.tip{background:var(--card);border:1px solid var(--line);border-left:5px solid var(--accent);border-radius:0 14px 14px 0;box-shadow:var(--shadow)}
.rule{background:#eef2fa;color:var(--ink);border:none;border-left:5px solid var(--ink);border-radius:0 12px 12px 0;font-weight:700}
.score{background:var(--ink);border-radius:14px}
table{background:var(--card);border-radius:10px;overflow:hidden}
th{background:#eef2fa;color:var(--ink)}
.btn{border-radius:999px}
@media (prefers-reduced-motion:reduce){.sectabs a{transition:none}}
@media print{
  body{background-image:none !important}
  h2::after{display:none}
  .box,.demo,.q,.qa,.cheat,.fix,.tip{box-shadow:none}
}

/* ---------- matematický vizuál: čtverečkovaný papír, mapa učiva, tabule ---------- */
body{background-color:var(--paper);
  background-image:linear-gradient(rgba(35,64,122,.11) 1px,transparent 1px),linear-gradient(90deg,rgba(35,64,122,.11) 1px,transparent 1px),
                   linear-gradient(rgba(35,64,122,.05) 1px,transparent 1px),linear-gradient(90deg,rgba(35,64,122,.05) 1px,transparent 1px);
  background-size:120px 120px,120px 120px,24px 24px,24px 24px}
main > header{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:18px 20px 16px}

.mathmap{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:10px 14px 6px;margin:4px 0 14px}
.mm-row{display:flex;align-items:flex-start;gap:6px 10px;flex-wrap:wrap;padding:4px 0}
.mm-row + .mm-row{border-top:1px dashed var(--line);margin-top:4px;padding-top:8px}
.mm-label{flex:0 0 100%;font-size:.7rem;letter-spacing:.12em;text-transform:uppercase;font-weight:700;color:var(--muted)}
.mm-line{flex:1;display:flex;justify-content:space-between;position:relative;min-width:0}
.mm-line::before{content:"";position:absolute;left:4px;right:2px;top:17px;height:3px;border-radius:2px;background:var(--ink);opacity:.35}
.mm-line::after{content:"";position:absolute;right:-6px;top:12px;border:6.5px solid transparent;border-left:9px solid var(--ink);opacity:.35}
.mm-pt{position:relative;flex:1 1 0;min-width:0;display:flex;flex-direction:column;align-items:center;gap:3px;text-decoration:none;color:var(--text)}
.mm-dot{width:36px;height:36px;border-radius:50%;display:grid;place-items:center;font-size:17px;background:var(--card);border:2px solid var(--ink);box-shadow:0 2px 5px rgba(35,64,122,.18);transition:transform .15s}
.mm-pt:hover .mm-dot,.mm-pt:focus-visible .mm-dot{transform:scale(1.12)}
.mm-pt.on .mm-dot{background:var(--hl);border-color:var(--accent);box-shadow:0 0 0 4px rgba(192,122,44,.25);transform:scale(1.15)}
.mm-txt{font-size:.66rem;line-height:1.15;text-align:center;color:var(--muted);font-weight:600;hyphens:manual;overflow-wrap:normal}
.mm-txt b{display:block;color:var(--accent);font-size:.66rem}
.mm-pt.on .mm-txt{color:var(--text);font-weight:800}

.chalk{display:flex;flex-wrap:wrap;justify-content:center;align-items:center;gap:8px 26px;margin:12px 0 14px;padding:14px 18px;
  background:radial-gradient(ellipse at 30% 20%,#3d5c4a,#2c4537 70%);border:7px solid #8b6a43;border-radius:10px;
  box-shadow:inset 0 0 18px rgba(0,0,0,.35),0 2px 8px rgba(60,40,20,.2)}
.chalk span{font-family:Kalam,"Comic Sans MS",cursive;font-size:1.2rem;color:#f2efe4;transform:rotate(var(--r,0deg));text-shadow:0 0 1px rgba(255,255,255,.5);white-space:nowrap}
.chalk sub{font-size:.7em}
@media (max-width:480px){.chalk span{font-size:1.05rem}.chalk{gap:6px 18px}}
@media (prefers-reduced-motion:reduce){.mm-dot{transition:none}}
@media print{.mathmap,.chalk{display:none !important} main > header{border:none;box-shadow:none;padding:0;background:none}}

/* ---------- barva tématu, kroužky zvládnutí (Khan Academy), výsledek testu ---------- */
main > header{border-top:6px solid var(--topic,var(--accent))}
h2::after{background:var(--topic,var(--accent))}
.sectabs a.on{background:var(--topic,var(--ink));border-color:var(--topic,var(--ink))}
.mm-line::before{top:20px}
.mm-line::after{top:15px}
.mm-ring{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;
  background:conic-gradient(var(--green) calc(var(--p,0) * 1%),rgba(35,64,122,.13) 0)}
.mm-ring .mm-dot{width:34px;height:34px;border:2px solid var(--c,var(--ink));box-shadow:none}
.mm-pt:hover .mm-ring,.mm-pt:focus-visible .mm-ring{transform:scale(1.1)}
.mm-pt:hover .mm-dot,.mm-pt:focus-visible .mm-dot{transform:none}
.mm-ring{transition:transform .15s}
.mm-pt.on .mm-ring{transform:scale(1.15);box-shadow:0 0 0 4px rgba(192,122,44,.25)}
.mm-pt.on .mm-dot{background:var(--hl);border-color:var(--c);box-shadow:none;transform:none}
.mm-pt.done .mm-ring::after{content:"✓";position:absolute;right:-3px;bottom:-3px;width:16px;height:16px;border-radius:50%;
  background:var(--green);color:#fff;font-size:10px;font-weight:800;display:grid;place-items:center}
.mm-pt.done .mm-ring{position:relative}
.quiz-done{display:flex;gap:14px;align-items:center;margin:16px 0 0;padding:14px 18px;border-radius:16px;
  background:var(--card);border:2px solid var(--topic,var(--ink));box-shadow:var(--shadow);animation:qdpop .35s ease}
.quiz-done .qd-ico{font-size:2.4rem}
.quiz-done b{font-size:1.25rem;color:var(--topic,var(--ink))}
.quiz-done p{margin:.15em 0 0;color:var(--muted)}
@keyframes qdpop{from{transform:scale(.94);opacity:0}to{transform:none;opacity:1}}
@media (prefers-reduced-motion:reduce){.quiz-done{animation:none}.mm-ring{transition:none}}
@media print{.quiz-done{display:none !important}}

/* žádné vodorovné posouvání tabulek – na mobilu se zmenší písmo a buňky */
table{min-width:0 !important}
@media (max-width:520px){
  table{font-size:.82rem}
  th,td{padding:6px 5px;hyphens:auto;-webkit-hyphens:auto;overflow-wrap:break-word}
}