/* Layout: one-column phone app, bottom tab bar, big answer buttons. Colors from the tricolour: crvena (red) accent, plava (blue) ink. */
:root{
  --bg:#f2f4f8; --surface:#ffffff; --ink:#14213d; --muted:#5d6a82; --line:#d9deea;
  --crvena:#c4343b; --crvena-soft:#fbe9ea; --plava:#1f4ea1; --plava-soft:#e6edfb;
  --ok:#1f7a4d; --ok-soft:#e2f4ea; --bad:#b3261e; --bad-soft:#fde8e6;
  --f-display:'Literata',Georgia,'Times New Roman',serif;
  --f-body:'Onest',-apple-system,'Segoe UI',Roboto,sans-serif;
  --f-mono:'IBM Plex Mono',ui-monospace,Menlo,monospace;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0f1624; --surface:#18223a; --ink:#e8ecf6; --muted:#9aa7c2; --line:#2a3656;
  --crvena:#ef6f75; --crvena-soft:#3a1f27; --plava:#7ea6f2; --plava-soft:#1c2c52;
  --ok:#6fd3a0; --ok-soft:#173528; --bad:#ff8f86; --bad-soft:#3c1e1e; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0f1624; --surface:#18223a; --ink:#e8ecf6; --muted:#9aa7c2; --line:#2a3656;
  --crvena:#ef6f75; --crvena-soft:#3a1f27; --plava:#7ea6f2; --plava-soft:#1c2c52;
  --ok:#6fd3a0; --ok-soft:#173528; --bad:#ff8f86; --bad-soft:#3c1e1e; color-scheme:dark}
*{box-sizing:border-box}
html,body{height:100%}
body{background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.45;
  padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px));
  padding-block:16px 96px;-webkit-text-size-adjust:100%}
#app{max-width:560px;margin:0 auto;display:flex;flex-direction:column;gap:14px}
h1,h2,h3{font-family:var(--f-display);margin:0;text-wrap:balance;line-height:1.2}
h1{font-size:28px}h2{font-size:22px}h3{font-size:17px}
p{margin:0}
.mono{font-family:var(--f-mono)}
.muted{color:var(--muted)}
.small{font-size:13px}
.label{font-family:var(--f-mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:16px;display:flex;flex-direction:column;gap:10px;min-width:0}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.spread{justify-content:space-between}
button{font:inherit;color:inherit;cursor:pointer}
.btn{border:1px solid var(--line);background:var(--surface);border-radius:12px;padding:13px 14px;min-height:48px;text-align:left;display:block;width:100%}
.btn:active{transform:scale(.99)}
.btn.primary{background:var(--plava);border-color:var(--plava);color:var(--bg);text-align:center;font-weight:600}
.btn.ghost{background:transparent;text-align:center}
.btn.ok{background:var(--ok-soft);border-color:var(--ok)}
.btn.bad{background:var(--bad-soft);border-color:var(--bad)}
.btn[disabled]{opacity:.7;cursor:default}
:focus-visible{outline:3px solid var(--crvena);outline-offset:2px}
.opts{display:flex;flex-direction:column;gap:8px}
.sr{font-family:var(--f-display);font-size:24px;font-weight:700}
.sent{font-family:var(--f-display);font-size:21px;line-height:1.4}
.blank{display:inline-block;min-width:3.2em;border-bottom:2px solid var(--crvena);text-align:center;color:var(--crvena)}
.pill{font-family:var(--f-mono);font-size:11px;padding:3px 8px;border-radius:999px;background:var(--plava-soft);color:var(--plava);white-space:nowrap}
.pill.r{background:var(--crvena-soft);color:var(--crvena)}
.bar{height:6px;border-radius:99px;background:var(--line);overflow:hidden}
.bar>i{display:block;height:100%;background:var(--plava)}
.expl{background:var(--plava-soft);border-radius:10px;padding:10px 12px;font-size:14px}
.expl.bad{background:var(--bad-soft)}.expl.ok{background:var(--ok-soft)}
input[type=text]{font:inherit;color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:13px 14px;width:100%;min-height:48px}
.tbl{overflow-x:auto;max-width:100%}
table{border-collapse:collapse;font-size:14px;min-width:100%}
th,td{border-bottom:1px solid var(--line);padding:8px 10px;text-align:left;white-space:nowrap}
th{font-family:var(--f-mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:500}
td b{color:var(--crvena)}
.tabs{position:fixed;left:0;right:0;bottom:0;z-index:5;background:var(--surface);border-top:1px solid var(--line);
  display:grid;grid-template-columns:repeat(4,1fr);
  padding:6px max(8px,env(safe-area-inset-right,0px)) calc(6px + env(safe-area-inset-bottom,0px)) max(8px,env(safe-area-inset-left,0px))}
.tab{background:none;border:0;padding:8px 2px;border-radius:10px;font-size:12px;color:var(--muted);display:flex;flex-direction:column;align-items:center;gap:2px;min-height:48px}
.tab b{font-family:var(--f-display);font-size:18px;font-weight:700}
.tab[aria-current=true]{color:var(--plava);background:var(--plava-soft)}
.dot{width:8px;height:8px;border-radius:50%;background:var(--crvena);display:inline-block}
.stat{flex:1 1 90px;min-width:0}
.stat b{font-family:var(--f-display);font-size:26px;display:block}
.toast{position:fixed;left:50%;transform:translateX(-50%);bottom:calc(84px + env(safe-area-inset-bottom,0px));background:var(--ink);color:var(--bg);padding:9px 14px;border-radius:99px;font-size:13px;z-index:9}
@media (prefers-reduced-motion:no-preference){.btn{transition:transform .08s}}

:root{padding-top:env(safe-area-inset-top,0px)}
.lvl{display:flex;align-items:baseline;gap:10px;margin-top:6px}
.lvl h2{font-size:20px}
.lesson{display:flex;gap:12px;align-items:center}
.lesson .num{font-family:var(--f-display);font-weight:700;font-size:20px;width:34px;height:34px;border-radius:50%;border:2px solid var(--line);display:grid;place-items:center;flex:none}
.lesson.done .num{background:var(--ok);border-color:var(--ok);color:var(--bg)}
.lesson.next .num{border-color:var(--crvena);color:var(--crvena)}
.lesson.soon{opacity:.5}
.lesson .tt{min-width:0;flex:1}
.steps{display:flex;gap:6px}
.steps i{flex:1;height:6px;border-radius:99px;background:var(--line)}
.steps i.on{background:var(--plava)}
.wrow{display:flex;gap:10px;align-items:center;border-bottom:1px solid var(--line);padding:8px 0}
.wrow:last-child{border-bottom:0}
.wrow .wt{flex:1;min-width:0}
.play{flex:none;width:46px;height:46px;border-radius:50%;border:1px solid var(--line);background:var(--plava-soft);color:var(--plava);font-size:16px;display:grid;place-items:center}
.toks{display:flex;flex-wrap:wrap;gap:8px}
.tok{border:1px solid var(--line);background:var(--surface);border-radius:10px;padding:10px 12px;font-family:var(--f-display);font-size:18px;min-height:44px}
.built{min-height:56px;border:1px dashed var(--line);border-radius:12px;padding:8px;display:flex;flex-wrap:wrap;gap:8px}
.car-big{display:flex;gap:10px}
.car-big button{flex:1;min-height:64px;font-size:18px}
.cue{min-height:96px;display:flex;flex-direction:column;gap:6px;justify-content:center}
input[type=range]{width:100%}
textarea{font:inherit;color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:10px;width:100%;min-height:90px}
details summary{cursor:pointer;min-height:44px;display:flex;align-items:center}

/* ---- v2: readability + slide-up menu ---- */
:root{--muted:#4b5872}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){--muted:#aab6d0}}
:root[data-theme="dark"]{--muted:#aab6d0}
body{font-size:17px;line-height:1.6;padding-block:18px calc(56px + env(safe-area-inset-bottom,0px))}
#app{gap:18px}
h1{font-size:30px;line-height:1.2}
h2{font-size:24px}
h3{font-size:19px;margin-bottom:2px}
.card{padding:18px;gap:12px}
.card p{line-height:1.65;margin:0}
.card p+p{margin-top:.7em}
.card p b{color:var(--plava);font-weight:600}
.small{font-size:14px}
.label{font-size:12px;letter-spacing:.07em}
.sent{font-size:22px;line-height:1.5}
.btn{padding:14px 16px;font-size:17px;line-height:1.4}
.expl{font-size:16px;line-height:1.6;padding:12px 14px}
.expl b{color:inherit}
.pill{font-size:12px}
.wrow{padding:13px 0;gap:14px}
.wrow .wt{line-height:1.5}
.lesson .tt{line-height:1.45}
.lesson .tt b{font-size:17px}
th,td{padding:10px 12px;font-size:15px}
th{font-size:12px}
.opts{gap:10px}
.row{gap:12px}
.toks,.built{gap:10px}
.tok{font-size:19px;padding:11px 14px}
.toast{bottom:calc(64px + env(safe-area-inset-bottom,0px))}

/* slide-up menu: hidden by default, opened by tapping the bottom handle */
.handle{position:fixed;left:0;right:0;bottom:0;z-index:7;height:calc(34px + env(safe-area-inset-bottom,0px));padding-bottom:env(safe-area-inset-bottom,0px);
  background:var(--surface);border:0;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:center;gap:10px;color:var(--muted);font-size:14px;cursor:pointer}
.handle i{width:44px;height:5px;border-radius:99px;background:var(--line);display:block}
.handle .dot{position:static}
.tabs{bottom:calc(34px + env(safe-area-inset-bottom,0px));padding:6px 8px;transform:translateY(160%);visibility:hidden;border-top:1px solid var(--line);box-shadow:0 -6px 20px rgba(0,0,0,.12)}
.tabs.open{transform:none;visibility:visible}
@media (prefers-reduced-motion:no-preference){.tabs{transition:transform .18s ease,visibility .18s}}
.tab{min-height:48px;padding:6px 2px;font-size:15px;gap:0;flex-direction:row;justify-content:center}
.tab b{font-size:15px;display:none}

/* v3: let the page scroll to the very end (fixed height clipped the bottom padding on iOS) */
html,body{height:auto;min-height:100%}
#app{padding-bottom:calc(110px + env(safe-area-inset-bottom,0px))}
body{padding-block:18px 0}