/* learn.vixtab.cz · styl. Font Arial, světlý a tmavý motiv. */
:root{
  --font: Arial, Helvetica, sans-serif;
  --navy:#0f2a5f; --navy2:#16387a; --navy3:#1d4aa0;
  --pri:#2563eb; --pri2:#1d4ed8; --pri-soft:#e0eaff;
  --acc:#0ea5e9; --term:#0b7cc4; --term-bg:#e6f4fd;
  --ok:#16a34a; --ok-soft:#dcfce7; --bad:#dc2626; --bad-soft:#fee2e2; --warn:#d97706; --warn-soft:#fef3c7;
  --bg:#f3f6fc; --surf:#ffffff; --surf2:#f7f9fe; --line:#dfe6f3; --line2:#c9d4ea;
  --txt:#0f1b33; --txt2:#475674; --txt3:#7a88a5;
  --side-bg:linear-gradient(180deg,#0f2a5f 0%,#13347a 100%); --side-txt:#c9d8f5; --side-act:#ffffff;
  --shadow:0 1px 2px rgba(15,42,95,.06),0 4px 16px rgba(15,42,95,.07);
  --shadow2:0 10px 40px rgba(15,42,95,.22);
  --r:14px; --r2:10px;
  --bounce:cubic-bezier(.34,1.56,.64,1);
  --plot-bg:#ffffff; --plot-grid:#e8eef8; --plot-axis:#8796b5;
}
[data-theme=dark]{
  --pri:#60a5fa; --pri2:#3b82f6; --pri-soft:#172a52;
  --term:#5cc8ff; --term-bg:#0f2a44;
  --ok:#4ade80; --ok-soft:#123222; --bad:#f87171; --bad-soft:#3a1616; --warn:#fbbf24; --warn-soft:#3a2c0c;
  --bg:#0a1224; --surf:#111c33; --surf2:#0e182c; --line:#1f2e4d; --line2:#2a3d63;
  --txt:#e6edfb; --txt2:#a8b6d4; --txt3:#7184a8;
  --side-bg:linear-gradient(180deg,#081633 0%,#0b1d42 100%);
  --shadow:0 1px 2px rgba(0,0,0,.3),0 4px 16px rgba(0,0,0,.25);
  --plot-bg:#0e182c; --plot-grid:#1b2946; --plot-axis:#5d6f94;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{font-family:var(--font);background:var(--bg);color:var(--txt);font-size:16px;line-height:1.55;-webkit-font-smoothing:antialiased}
button,input,select,textarea{font-family:var(--font);font-size:inherit;color:inherit}
a{color:var(--pri);text-decoration:none}
h1,h2,h3,h4{line-height:1.25;margin:0 0 .5em}
h1{font-size:1.75rem} h2{font-size:1.3rem} h3{font-size:1.1rem}
.katex{font-size:1.06em}
.katex-display{margin:.6em 0;overflow-x:auto;overflow-y:hidden;padding:2px 0}

#app{display:flex;min-height:100vh}
#side{width:248px;flex:0 0 248px;background:var(--side-bg);color:var(--side-txt);position:sticky;top:0;height:100vh;display:flex;flex-direction:column;padding:16px 12px;z-index:30}
.brand{display:flex;align-items:center;gap:12px;color:#fff;padding:4px 8px 18px}
.brand-mark{width:40px;height:40px;border-radius:12px;background:#1e4fae;display:grid;place-items:center;font-size:24px;font-weight:700;color:#93c5fd;box-shadow:inset 0 0 0 1px rgba(255,255,255,.15)}
.brand-txt{display:flex;flex-direction:column;line-height:1.15}
.brand-txt b{font-size:1.15rem} .brand-txt small{color:#93b4ea;font-size:.78rem}
#nav{display:flex;flex-direction:column;gap:2px;overflow:auto}
#nav a{display:flex;align-items:center;gap:12px;color:var(--side-txt);padding:10px 12px;border-radius:10px;font-size:.95rem;transition:background .15s,transform .2s var(--bounce)}
#nav a:hover{background:rgba(255,255,255,.07)}
#nav a:active{transform:scale(.97)}
#nav a.act{background:rgba(96,165,250,.18);color:var(--side-act);box-shadow:inset 3px 0 0 #60a5fa}
#nav a .ni{width:22px;text-align:center;font-size:1.05rem;opacity:.95}
#nav a .nb{margin-left:auto;background:#ef4444;color:#fff;border-radius:99px;font-size:.7rem;padding:1px 7px;font-weight:700}
#nav .nsep{height:1px;background:rgba(255,255,255,.08);margin:8px 6px}
.side-foot{margin-top:auto;font-size:.78rem;color:#7e9bd0;padding:8px}
.side-foot .grade-mini{display:flex;align-items:center;gap:10px;background:rgba(255,255,255,.06);padding:10px;border-radius:12px;color:#dbe7ff}
.side-foot .grade-mini b{font-size:1.4rem;width:40px;height:40px;border-radius:10px;display:grid;place-items:center;background:#1e4fae;color:#fff}

#main{flex:1;min-width:0;display:flex;flex-direction:column}
#top{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:12px;padding:12px 24px;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.search-trigger{flex:1;min-width:0;max-width:560px;display:flex;align-items:center;gap:10px;background:var(--surf);border:1px solid var(--line);border-radius:12px;padding:9px 14px;color:var(--txt3);cursor:pointer;text-align:left;transition:border-color .15s,transform .2s var(--bounce)}
.search-trigger:hover{border-color:var(--pri)}
.search-trigger:active{transform:scale(.99)}
.search-trigger .s-txt{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
kbd{font-family:var(--font);font-size:.72rem;border:1px solid var(--line2);border-bottom-width:2px;border-radius:6px;padding:1px 6px;color:var(--txt3);background:var(--surf2)}
.top-actions{flex-shrink:0;margin-left:auto;display:flex;align-items:center;gap:8px}
#lang-sel{background:var(--surf);border:1px solid var(--line);border-radius:10px;padding:8px 8px;cursor:pointer}
.icon-btn{background:var(--surf);border:1px solid var(--line);border-radius:10px;width:40px;height:40px;cursor:pointer;display:grid;place-items:center;font-size:1.1rem;transition:transform .2s var(--bounce)}
.icon-btn:active{transform:scale(.9)}
.user-chip{display:flex;align-items:center;gap:8px;background:var(--surf);border:1px solid var(--line);border-radius:99px;padding:5px 12px 5px 5px;color:var(--txt);font-size:.9rem;max-width:180px;white-space:nowrap;overflow:hidden}
.user-chip .av{width:30px;height:30px;border-radius:50%;background:var(--navy3);color:#fff;display:grid;place-items:center;font-weight:700;flex:0 0 30px}
#view-wrap{flex:1;position:relative;overflow-x:hidden}
#view{padding:28px 32px 80px;max-width:1180px;margin:0 auto}
.only-mobile{display:none}
#bottom-nav{display:none}

/* přechody stránek: jen po interakci */
.pg-in-r{animation:pgInR .42s var(--bounce)}
.pg-in-l{animation:pgInL .42s var(--bounce)}
.pg-in-u{animation:pgInU .38s var(--bounce)}
@keyframes pgInR{from{opacity:0;transform:translateX(46px)}to{opacity:1;transform:none}}
@keyframes pgInL{from{opacity:0;transform:translateX(-46px)}to{opacity:1;transform:none}}
@keyframes pgInU{from{opacity:0;transform:translateY(22px) scale(.99)}to{opacity:1;transform:none}}
.pop-in{animation:popIn .32s var(--bounce)}
@keyframes popIn{from{opacity:0;transform:scale(.88) translateY(6px)}to{opacity:1;transform:none}}
.shake{animation:shake .4s}
@keyframes shake{20%,60%{transform:translateX(-6px)}40%,80%{transform:translateX(6px)}}
.jump{animation:jump .45s var(--bounce)}
@keyframes jump{0%{transform:scale(1)}40%{transform:scale(1.07)}100%{transform:scale(1)}}

/* základní prvky */
.card{background:var(--surf);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow);padding:20px}
.card.flat{box-shadow:none}
.card h2,.card h3{margin-top:0}
.grid{display:grid;gap:16px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}
.muted{color:var(--txt2)} .faint{color:var(--txt3);font-size:.88rem}
.small{font-size:.86rem}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid var(--line2);background:var(--surf);color:var(--txt);padding:9px 16px;border-radius:10px;cursor:pointer;font-weight:600;font-size:.94rem;transition:transform .22s var(--bounce),background .15s,border-color .15s;user-select:none;white-space:nowrap}
.btn:hover{border-color:var(--pri)}
.btn:active{transform:scale(.95)}
.btn.pri{background:var(--pri);border-color:var(--pri);color:#fff}
[data-theme=dark] .btn.pri{color:#071331}
.btn.pri:hover{background:var(--pri2)}
.btn.ghost{background:transparent;border-color:transparent}
.btn.ghost:hover{background:var(--surf2)}
.btn.ok{background:var(--ok);border-color:var(--ok);color:#fff}
.btn.bad{background:var(--bad);border-color:var(--bad);color:#fff}
.btn.sm{padding:6px 11px;font-size:.85rem;border-radius:8px}
.btn.lg{padding:13px 22px;font-size:1.02rem}
.btn[disabled]{opacity:.5;pointer-events:none}
.chip{display:inline-flex;align-items:center;gap:6px;padding:4px 11px;border-radius:99px;font-size:.8rem;background:var(--surf2);border:1px solid var(--line);color:var(--txt2);cursor:default;white-space:nowrap}
.chip.click{cursor:pointer;transition:transform .2s var(--bounce)}
.chip.click:active{transform:scale(.92)}
.chip.on{background:var(--pri);border-color:var(--pri);color:#fff}
[data-theme=dark] .chip.on{color:#071331}
.chip.ok{background:var(--ok-soft);color:var(--ok);border-color:transparent}
.chip.bad{background:var(--bad-soft);color:var(--bad);border-color:transparent}
.chip.warn{background:var(--warn-soft);color:var(--warn);border-color:transparent}
.chip.blue{background:var(--pri-soft);color:var(--pri);border-color:transparent}
input.inp,select.inp,textarea.inp{width:100%;background:var(--surf);border:1px solid var(--line2);border-radius:10px;padding:10px 12px;outline:none;transition:border-color .15s,box-shadow .15s}
input.inp:focus,select.inp:focus,textarea.inp:focus{border-color:var(--pri);box-shadow:0 0 0 3px color-mix(in srgb,var(--pri) 18%,transparent)}
label.lbl{display:block;font-size:.84rem;color:var(--txt2);margin:10px 0 4px;font-weight:600}
.page-head{display:flex;align-items:flex-end;gap:16px;flex-wrap:wrap;margin-bottom:22px}
.page-head h1{margin:0}
.page-head p{margin:4px 0 0;color:var(--txt2)}
.sec-title{font-size:.78rem;letter-spacing:.06em;text-transform:uppercase;color:var(--txt3);font-weight:700;margin:26px 0 10px}
.bar{height:8px;background:var(--surf2);border:1px solid var(--line);border-radius:99px;overflow:hidden}
.bar>i{display:block;height:100%;background:linear-gradient(90deg,var(--navy3),var(--pri));border-radius:99px;transition:width .5s var(--bounce)}
.bar.ok>i{background:var(--ok)} .bar.warn>i{background:var(--warn)} .bar.bad>i{background:var(--bad)}
.empty{padding:40px 20px;text-align:center;color:var(--txt3)}
.tabs{display:flex;gap:4px;background:var(--surf2);border:1px solid var(--line);border-radius:12px;padding:4px;flex-wrap:wrap}
.tabs button{border:0;background:transparent;padding:8px 14px;border-radius:9px;cursor:pointer;color:var(--txt2);font-weight:600;font-size:.9rem;transition:transform .2s var(--bounce)}
.tabs button.on{background:var(--surf);color:var(--txt);box-shadow:var(--shadow)}
.tabs button:active{transform:scale(.94)}
hr.sep{border:0;border-top:1px solid var(--line);margin:18px 0}
.kpi{display:flex;flex-direction:column;gap:2px}
.kpi b{font-size:1.7rem}
.kpi span{color:var(--txt3);font-size:.84rem}

/* pojmy v textu */
.term{color:var(--term);background:var(--term-bg);border-radius:5px;padding:0 3px;cursor:pointer;border-bottom:1.5px dotted var(--term);transition:background .15s}
.term:hover{background:color-mix(in srgb,var(--term) 22%,transparent)}
.no-terms .term{color:inherit;background:none;border:0;cursor:text;padding:0}

/* popover pojmu */
#layer{position:fixed;inset:0;pointer-events:none;z-index:100}
#layer>*{pointer-events:auto}
.popover{position:fixed;width:min(380px,calc(100vw - 24px));background:var(--surf);border:1px solid var(--line2);border-radius:14px;box-shadow:var(--shadow2);padding:16px 18px;z-index:120;max-height:70vh;overflow:auto}
.popover h4{margin:0 0 6px;font-size:1.05rem;color:var(--term);display:flex;gap:8px;align-items:center}
.popover .pv-sym{margin:6px 0;padding:8px 10px;background:var(--surf2);border-radius:8px}
.popover .pv-x{position:absolute;right:10px;top:8px;border:0;background:none;font-size:1.2rem;cursor:pointer;color:var(--txt3)}
.popover .pv-act{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap}
.popover .pv-alt{font-size:.8rem;color:var(--txt3);margin-top:6px}
.backdrop{position:fixed;inset:0;background:rgba(8,18,40,.45);z-index:110;animation:fadeIn .2s}
@keyframes fadeIn{from{opacity:0}}
.modal{position:fixed;left:50%;top:9vh;transform:translateX(-50%);width:min(620px,calc(100vw - 24px));max-height:84vh;overflow:auto;background:var(--surf);border-radius:18px;box-shadow:var(--shadow2);z-index:115;padding:22px}
.modal.wide{width:min(920px,calc(100vw - 24px))}
.modal .m-x{position:absolute;right:14px;top:12px;border:0;background:none;font-size:1.4rem;cursor:pointer;color:var(--txt3)}
.toast-wrap{position:fixed;bottom:22px;left:50%;transform:translateX(-50%);display:flex;flex-direction:column;gap:8px;z-index:130;align-items:center}
.toast{background:var(--navy);color:#fff;padding:10px 18px;border-radius:12px;box-shadow:var(--shadow2);font-size:.92rem;animation:popIn .3s var(--bounce)}
.toast.ok{background:#15803d}.toast.bad{background:#b91c1c}

/* hledání */
.search-modal{position:fixed;left:50%;top:8vh;transform:translateX(-50%);width:min(720px,calc(100vw - 20px));background:var(--surf);border-radius:18px;box-shadow:var(--shadow2);z-index:125;overflow:hidden;display:flex;flex-direction:column;max-height:80vh}
.search-modal .sm-in{display:flex;align-items:center;gap:10px;padding:14px 18px;border-bottom:1px solid var(--line)}
.search-modal input{flex:1;border:0;outline:0;background:transparent;font-size:1.12rem}
.search-modal .sm-filters{display:flex;gap:6px;padding:8px 14px;border-bottom:1px solid var(--line);flex-wrap:wrap}
.search-modal .sm-res{overflow:auto;padding:6px}
.sr-item{display:flex;gap:12px;padding:10px 12px;border-radius:10px;cursor:pointer;align-items:flex-start}
.sr-item.sel,.sr-item:hover{background:var(--pri-soft)}
.sr-item .sr-ico{width:30px;height:30px;border-radius:8px;display:grid;place-items:center;background:var(--surf2);flex:0 0 30px;font-size:.95rem}
.sr-item .sr-t{font-weight:700}
.sr-item .sr-s{font-size:.85rem;color:var(--txt2);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.sr-item mark{background:color-mix(in srgb,var(--acc) 30%,transparent);color:inherit;border-radius:3px;padding:0 1px}
.sr-group{font-size:.74rem;text-transform:uppercase;letter-spacing:.06em;color:var(--txt3);padding:10px 12px 4px;font-weight:700}

/* dashboard */
.hero{background:linear-gradient(135deg,#0f2a5f 0%,#1d4aa0 70%,#2563eb 100%);color:#fff;border-radius:20px;padding:26px 28px;display:flex;gap:24px;align-items:center;flex-wrap:wrap;box-shadow:var(--shadow)}
.hero h1{color:#fff;margin:0 0 6px}
.hero p{margin:0;color:#c7d8fb}
.hero .btn{background:rgba(255,255,255,.14);border-color:rgba(255,255,255,.25);color:#fff}
.hero .btn.pri{background:#fff;color:var(--navy);border-color:#fff}
.grade-ring{width:116px;height:116px;position:relative;flex:0 0 116px}
.grade-ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.grade-ring .gr-c{position:absolute;inset:0;display:grid;place-items:center;text-align:center;line-height:1}
.grade-ring .gr-c b{font-size:2.3rem;display:block}
.grade-ring .gr-c small{font-size:.72rem;opacity:.8}
.topic-tile{display:flex;flex-direction:column;gap:10px;cursor:pointer;transition:transform .25s var(--bounce),border-color .15s}
.topic-tile:hover{border-color:var(--pri);transform:translateY(-2px)}
.topic-tile:active{transform:scale(.98)}
.topic-tile .tt-top{display:flex;gap:10px;align-items:center}
.topic-tile .tt-ico{width:42px;height:42px;border-radius:12px;background:var(--pri-soft);color:var(--pri);display:grid;place-items:center;font-size:1.2rem;font-weight:700;flex:0 0 42px}
.topic-tile .tt-w{font-size:.75rem;color:var(--txt3);font-weight:700;text-transform:uppercase;letter-spacing:.05em}
.topic-tile h3{margin:0;font-size:1.02rem}
.topic-tile.now{border-color:var(--pri);box-shadow:0 0 0 3px color-mix(in srgb,var(--pri) 15%,transparent),var(--shadow)}
.week-list{display:flex;flex-direction:column;gap:8px}
.week-row{display:grid;grid-template-columns:90px 1fr auto;gap:14px;align-items:center;padding:12px 16px;border-radius:12px;background:var(--surf);border:1px solid var(--line);cursor:pointer;transition:transform .2s var(--bounce)}
.week-row:active{transform:scale(.99)}
.week-row.now{border-color:var(--pri);background:var(--pri-soft)}
.week-row.test{border-left:4px solid var(--warn)}
.week-row .wk{font-weight:700;color:var(--txt2);font-size:.9rem}
.week-row .wk small{display:block;color:var(--txt3);font-weight:400;font-size:.76rem}

/* lekce */
.lesson{max-width:860px;min-width:0}
.blk,.box,.viz-wrap,.card{min-width:0}
.prob-q{overflow-x:auto}
.lesson-head{margin-bottom:18px}
.lesson-nav-top{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:12px}
.toc{position:sticky;top:84px;font-size:.88rem}
.toc a{display:block;padding:5px 10px;border-left:2px solid var(--line);color:var(--txt2)}
.toc a:hover{color:var(--pri);border-color:var(--pri)}
.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 220px;gap:28px}
.blk{margin:0 0 16px}
.blk p{margin:0 0 10px}
.blk-h{margin:30px 0 12px;font-size:1.3rem;scroll-margin-top:90px}
.box{border-radius:14px;padding:14px 18px;border:1px solid var(--line);background:var(--surf);position:relative}
.box .box-lbl{font-size:.74rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;margin-bottom:6px;display:flex;gap:8px;align-items:center}
.box.def{border-left:4px solid var(--pri)} .box.def .box-lbl{color:var(--pri)}
.box.thm{border-left:4px solid #7c3aed} .box.thm .box-lbl{color:#7c3aed}
[data-theme=dark] .box.thm{border-left-color:#a78bfa}[data-theme=dark] .box.thm .box-lbl{color:#a78bfa}
.box.note{background:var(--surf2)} .box.note .box-lbl{color:var(--txt2)}
.box.warn{border-left:4px solid var(--warn);background:var(--warn-soft)} .box.warn .box-lbl{color:var(--warn)}
.box.tip{border-left:4px solid var(--ok);background:var(--ok-soft)} .box.tip .box-lbl{color:var(--ok)}
.box.q{border:2px dashed color-mix(in srgb,var(--acc) 60%,transparent);background:color-mix(in srgb,var(--acc) 6%,var(--surf))}
.box.q .box-lbl{color:var(--acc)}
.box.q .q-text{font-weight:700;font-size:1.04rem;margin-bottom:6px}
.box.ex .box-lbl{color:var(--txt2)}
.box ul,.box ol{margin:6px 0;padding-left:22px}
.blk ul,.blk ol{padding-left:22px;margin:6px 0}
.blk li{margin:3px 0}
.collapse-btn{margin-top:8px}
.viz-wrap{border:1px solid var(--line);border-radius:16px;background:var(--surf);overflow:hidden}
.viz-head{display:flex;align-items:center;gap:10px;padding:12px 16px;border-bottom:1px solid var(--line);background:var(--surf2)}
.viz-head b{flex:1}
.viz-body{padding:14px 16px}
.viz-hint{font-size:.84rem;color:var(--txt3);margin-top:6px}
.lesson-foot{display:flex;gap:10px;flex-wrap:wrap;margin-top:30px;padding-top:20px;border-top:1px solid var(--line)}
table.tt{border-collapse:collapse;margin:6px 0;font-size:.95rem}
table.tt th,table.tt td{border:1px solid var(--line2);padding:5px 12px;text-align:center}
table.tt th{background:var(--surf2)}
table.tt td.t1{color:var(--ok);font-weight:700} table.tt td.t0{color:var(--bad)}

/* příklady */
.prob{position:relative}
.prob-meta{display:flex;gap:6px;flex-wrap:wrap;align-items:center;margin-bottom:10px}
.prob-q{font-size:1.05rem}
.prob-q .katex-display{font-size:1.04em}
.ans-area{margin-top:16px;display:flex;flex-direction:column;gap:10px}
.ans-row{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.ans-row .inp{max-width:360px}
.ans-prev{min-height:26px;color:var(--txt2);font-size:.95rem}
.ans-help{font-size:.8rem;color:var(--txt3)}
.mat-in{display:inline-grid;gap:4px;padding:6px 10px;border-left:2px solid var(--txt2);border-right:2px solid var(--txt2);border-radius:8px}
.mat-in input{width:64px;text-align:center;padding:6px;border:1px solid var(--line2);border-radius:6px;background:var(--surf)}
.verdict{border-radius:12px;padding:12px 16px;font-weight:700;display:flex;gap:10px;align-items:center}
.verdict.ok{background:var(--ok-soft);color:var(--ok)}
.verdict.bad{background:var(--bad-soft);color:var(--bad)}
.verdict.part{background:var(--warn-soft);color:var(--warn)}
.verdict .v-ans{font-weight:400;color:var(--txt)}
.steps{margin-top:14px;display:flex;flex-direction:column;gap:8px}
.steps-head{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.step{border:1px solid var(--line);border-radius:12px;background:var(--surf);overflow:hidden}
.step-main{display:flex;gap:12px;padding:12px 14px;cursor:pointer;align-items:flex-start}
.step-main:hover{background:var(--surf2)}
.step-n{width:28px;height:28px;border-radius:50%;background:var(--pri-soft);color:var(--pri);display:grid;place-items:center;font-weight:700;font-size:.85rem;flex:0 0 28px}
.step-body{flex:1;min-width:0}
.step-more{font-size:.78rem;color:var(--pri);font-weight:700;white-space:nowrap;margin-top:4px}
.step-detail{padding:2px 16px 14px 54px;color:var(--txt2);border-top:1px dashed var(--line)}
.step-detail p{margin:8px 0}
.step.open .step-more{color:var(--txt3)}
.self-grade{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.prob-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px;align-items:center}
.save-menu{display:flex;gap:6px;flex-wrap:wrap}
.practice-top{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-bottom:16px}
.streak{font-weight:700;color:var(--warn)}
.topic-pick{display:flex;flex-wrap:wrap;gap:8px}

/* testy */
.test-bar{position:sticky;top:66px;z-index:10;display:flex;align-items:center;gap:14px;background:var(--surf);border:1px solid var(--line);border-radius:14px;padding:10px 16px;box-shadow:var(--shadow);margin-bottom:16px;flex-wrap:wrap}
.timer{font-variant-numeric:tabular-nums;font-weight:700;font-size:1.15rem}
.timer.low{color:var(--bad)}
.test-q-nav{display:flex;gap:6px;flex-wrap:wrap}
.test-q-nav button{width:34px;height:34px;border-radius:9px;border:1px solid var(--line2);background:var(--surf);cursor:pointer;font-weight:700;transition:transform .2s var(--bounce)}
.test-q-nav button.on{background:var(--pri);color:#fff;border-color:var(--pri)}
.test-q-nav button.done{border-color:var(--ok);color:var(--ok)}
.test-q-nav button:active{transform:scale(.9)}
.paper{background:var(--surf);border:1px solid var(--line);border-radius:16px;padding:22px 26px;margin-bottom:16px}
.paper .pq-h{display:flex;gap:10px;align-items:center;margin-bottom:8px}
.paper .pq-pts{margin-left:auto}
.notepad{width:100%;min-height:110px;resize:vertical}
.res-big{font-size:3rem;font-weight:700;line-height:1}

/* profil */
.stat-row{display:grid;grid-template-columns:minmax(140px,1.4fr) 3fr 56px;gap:12px;align-items:center;padding:8px 0;border-bottom:1px solid var(--line)}
.stat-row:last-child{border-bottom:0}
.hist-row{display:flex;gap:12px;align-items:center;padding:10px 0;border-bottom:1px solid var(--line)}

/* vzorce */
.f-item{display:grid;grid-template-columns:minmax(150px,240px) 1fr;gap:16px;padding:12px 0;border-bottom:1px solid var(--line);align-items:center}
.f-item:last-child{border-bottom:0}
.f-name{font-weight:700}
.f-note{font-size:.84rem;color:var(--txt2)}

/* pojmy */
.gl-letter{font-size:1.4rem;font-weight:700;color:var(--pri);margin:22px 0 8px}
.gl-item{padding:12px 16px;border:1px solid var(--line);border-radius:12px;background:var(--surf);margin-bottom:8px;cursor:pointer;transition:transform .2s var(--bounce),border-color .15s}
.gl-item:hover{border-color:var(--term)}
.gl-item:active{transform:scale(.99)}
.gl-item b{color:var(--term)}
.gl-item.hl{border-color:var(--term);box-shadow:0 0 0 3px color-mix(in srgb,var(--term) 18%,transparent)}

/* grafy a nástroje */
.plot{width:100%;border:1px solid var(--line);border-radius:12px;background:var(--plot-bg);display:block;touch-action:none;cursor:crosshair}
.ctrl-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:10px 18px;margin-top:12px}
.slider{display:flex;flex-direction:column;gap:2px;font-size:.86rem}
.slider .sl-top{display:flex;justify-content:space-between;color:var(--txt2)}
.slider .sl-top b{color:var(--txt);font-variant-numeric:tabular-nums}
input[type=range]{width:100%;accent-color:var(--pri)}
.viz-out{margin-top:10px;padding:10px 14px;background:var(--surf2);border-radius:10px;font-size:.95rem}
.mx-edit{display:inline-grid;gap:4px}
.mx-edit input{width:56px;text-align:center;padding:5px;border:1px solid var(--line2);border-radius:6px;background:var(--surf)}
.gem-mat{display:inline-block;padding:4px 12px;border-left:2px solid var(--txt);border-right:2px solid var(--txt);border-radius:10px;font-variant-numeric:tabular-nums}
.gem-mat table{border-collapse:collapse}
.gem-mat td{padding:4px 10px;text-align:right;min-width:44px}
.gem-mat td.sepc{border-left:1.5px solid var(--txt2)}
.gem-mat tr.hl td{background:var(--pri-soft)}
.gem-hist{font-size:.85rem;color:var(--txt2);display:flex;flex-direction:column;gap:2px;max-height:160px;overflow:auto}
.venn svg{width:100%;max-width:520px;display:block;margin:0 auto}
.mm-wrap{display:flex;gap:18px;align-items:center;flex-wrap:wrap;font-variant-numeric:tabular-nums}
.mm-cell{transition:background .15s}
.mm-cell.hl{background:var(--pri-soft);border-radius:6px}
.mm-cell.res{cursor:pointer}

/* responsivita */
@media (max-width:1100px){.lesson-layout{grid-template-columns:minmax(0,1fr)}.toc{display:none}.g4{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:860px){
  #side{position:fixed;left:0;top:0;transform:translateX(-105%);transition:transform .35s var(--bounce);box-shadow:var(--shadow2)}
  #side.open{transform:none}
  .only-mobile{display:grid}
  #view{padding:18px 14px 110px}
  #top{padding:10px 12px}
  .search-trigger kbd{display:none}
  .user-chip span.un{display:none}
  .user-chip{padding:4px}
  #top{gap:8px}
  #lang-sel{padding:8px 4px}
  .icon-btn{width:38px;height:38px}
  .search-trigger{padding:9px 10px}
  .g2,.g3,.g4{grid-template-columns:1fr}
  #bottom-nav{display:flex;position:fixed;left:0;right:0;bottom:0;background:var(--surf);border-top:1px solid var(--line);z-index:40;padding:6px 4px calc(6px + env(safe-area-inset-bottom))}
  #bottom-nav a{flex:1;display:flex;flex-direction:column;align-items:center;font-size:.7rem;color:var(--txt3);padding:4px;gap:2px;transition:transform .2s var(--bounce)}
  #bottom-nav a:active{transform:scale(.9)}
  #bottom-nav a .ni{font-size:1.2rem}
  #bottom-nav a.act{color:var(--pri)}
  .f-item{grid-template-columns:1fr;gap:4px}
  .stat-row{grid-template-columns:1fr 1.5fr 44px}
  .week-row{grid-template-columns:70px 1fr}
  .week-row>*:nth-child(3){grid-column:1/-1}
  .hero{padding:20px}
  .paper{padding:16px}
  .step-detail{padding-left:16px}
}
@media print{#side,#top,#bottom-nav,.lesson-foot,.prob-actions{display:none!important}#view{padding:0}.card,.box{box-shadow:none}}