/* МАТАН? — токены */
:root{
  --bg: var(--tg-theme-bg-color, #0d1220);
  --surface: var(--tg-theme-secondary-bg-color, #171f31);
  --surface-2: #1e2740;
  --line: rgba(236,241,248,.09);
  --text: var(--tg-theme-text-color, #ecf1f8);
  --text-2: var(--tg-theme-hint-color, #93a1b5);
  --teal:#14b8a6; --teal-l:#5edcce; --amber:#ffb454; --amber-d:#f2960f;
  --ok:#34c77b; --err:#f0564a;
  --grid: rgba(236,241,248,.05);
  --paper:#fff; --paper-ink:#0d1220;
  --r-card:18px; --r-ctl:14px; --r-tile:12px;
  --shadow: 0 10px 30px -12px rgba(0,0,0,.7);
  --pad:18px;
}
/* светлая тема клиента */
body.light{
  --bg: var(--tg-theme-bg-color, #f4f7fb);
  --surface: var(--tg-theme-secondary-bg-color, #fff);
  --surface-2:#eaf0f7;
  --line: rgba(13,18,32,.1);
  --text: var(--tg-theme-text-color, #101827);
  --text-2: var(--tg-theme-hint-color, #5c6b80);
  --grid: rgba(13,18,32,.07);
  --shadow: 0 10px 30px -12px rgba(16,24,39,.25);
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{
  background:var(--bg); color:var(--text);
  font:400 15px/1.5 Rubik, system-ui, sans-serif;
  -webkit-font-smoothing:antialiased;
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:26px 26px;
}
.app{max-width:640px;margin:0 auto;padding:22px var(--pad) calc(26px + env(safe-area-inset-bottom))}
h1,h2,h3{font-family:Unbounded,sans-serif;letter-spacing:-.02em;margin:0}
p{margin:0;text-wrap:pretty}
a{color:var(--teal-l)}
a:hover{color:var(--teal)}
button,input{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--teal);outline-offset:2px}
.mono-num{font-family:Unbounded,sans-serif;font-weight:700}

/* служебное */
.eyebrow{font:600 11px/1 Rubik,sans-serif;letter-spacing:.14em;text-transform:uppercase;color:var(--text-2)}
.eyebrow.t{color:var(--teal-l)} .eyebrow.a{color:var(--amber)}
.hint{font:400 12px/1.45 Rubik,sans-serif;color:var(--text-2)}
.stack{display:flex;flex-direction:column}
.gap8{gap:8px} .gap10{gap:10px} .gap14{gap:14px} .gap18{gap:18px} .gap22{gap:22px}
.row{display:flex;align-items:center;gap:10px}
.between{display:flex;align-items:center;justify-content:space-between;gap:10px}

/* контролы */
.btn{min-height:48px;padding:0 18px;border-radius:var(--r-ctl);border:0;background:var(--teal);color:#04231f;font-weight:600;cursor:pointer;transition:transform .12s ease}
.btn:active{transform:scale(.96)}
.btn.amber{background:var(--amber);color:#2b1a03}
.btn.ghost{background:transparent;border:1px solid var(--line);color:var(--text)}
.btn[disabled]{opacity:.55;cursor:default}
.icon-btn{width:44px;height:44px;border-radius:var(--r-ctl);border:1px solid var(--line);background:var(--surface);color:var(--text);cursor:pointer;font-size:17px;transition:transform .12s ease}
.icon-btn:active{transform:scale(.96)}
.input{width:100%;height:48px;border-radius:var(--r-ctl);border:1px solid var(--line);background:var(--surface-2);color:var(--text);padding:0 14px}
.input.big{height:54px;font:700 22px/1 Unbounded,sans-serif}
.input[disabled]{opacity:.55}
.chips{display:flex;gap:8px;overflow-x:auto;scrollbar-width:none}
.chips::-webkit-scrollbar{display:none}
.chip{flex:0 0 auto;min-height:36px;padding:0 13px;border-radius:99px;border:1px solid var(--line);background:transparent;color:var(--text-2);cursor:pointer;display:flex;align-items:center;gap:7px}
.chip[aria-pressed="true"]{border-color:rgba(20,184,166,.5);background:rgba(20,184,166,.16);color:var(--teal-l)}
.chip .range{opacity:.6;font-size:11px}

.card{border:1px solid var(--line);border-radius:var(--r-card);background:var(--surface);box-shadow:var(--shadow);padding:14px}
.card.tap{cursor:pointer;text-align:left;width:100%;transition:transform .12s ease}
.card.tap:active{transform:scale(.97)}
.card.teal{border-color:rgba(20,184,166,.34);background:linear-gradient(150deg,rgba(20,184,166,.2),rgba(20,184,166,.05) 62%),var(--surface)}
.card.amberish{border-color:rgba(255,180,84,.32);background:linear-gradient(150deg,rgba(255,180,84,.16),rgba(255,180,84,.03) 62%),var(--surface)}
.paper{border-radius:var(--r-tile);background:var(--paper);color:var(--paper-ink);padding:14px}
.tag{padding:3px 7px;border-radius:7px;background:rgba(236,241,248,.07);color:var(--text-2);font:500 10px/1.2 Rubik,sans-serif}
.tag.t{background:rgba(20,184,166,.16);color:var(--teal-l)}
.tag.a{background:rgba(255,180,84,.16);color:var(--amber)}

/* главная */
.logo{display:flex;justify-content:center;align-items:baseline;font:900 46px/1 Unbounded,sans-serif;letter-spacing:-.03em}
.logo i{font-style:normal;color:var(--teal);display:inline-block;animation:q-bounce 1.15s cubic-bezier(.3,.7,.4,1) .25s both}
.axis{display:block;width:100%;max-width:280px;margin:0 auto;height:40px;overflow:visible}
.axis .ln{stroke:var(--text-2);stroke-width:1.6;stroke-linecap:round}
.axis .base{stroke-dasharray:420;animation:ax-draw .9s cubic-bezier(.22,.9,.3,1) .1s both}
.axis .tick{animation:ax-pop .24s ease both}
.axis .dot{fill:var(--teal);animation:dot-land .5s cubic-bezier(.3,.8,.3,1.2) 1s both}
.entry{display:flex;justify-content:space-between;gap:14px;padding:20px}
.entry h2{font-size:30px;font-weight:900}
.covers{position:relative;width:74px;height:92px;flex:0 0 auto}
.covers i{position:absolute;inset:0;border-radius:4px 9px 9px 4px;border:1px solid var(--line);background:var(--surface-2)}
.covers i:nth-child(1){transform:rotate(-11deg) translateX(-6px)}
.covers i:nth-child(2){transform:rotate(-4deg);background:rgba(20,184,166,.22);border-color:rgba(20,184,166,.4)}
.covers i:nth-child(3){transform:rotate(5deg) translateX(5px);background:var(--teal)}

/* сетки */
.grades{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.grade{aspect-ratio:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px}
.grade b{font:900 30px/1 Unbounded,sans-serif;color:var(--teal)}
.grade span{font-size:11px;color:var(--text-2)}
.book{display:flex;gap:13px;padding:12px}
.book .cover{flex:0 0 auto;width:62px;height:86px;border-radius:4px 8px 8px 4px;background:var(--surface-2);box-shadow:2px 2px 8px rgba(0,0,0,.35);display:flex;align-items:center;justify-content:center;font-size:10px;color:var(--text-2);text-align:center;overflow:hidden}
/* вписываем обложку в рамку: object-fit работает на самой картинке, а не на её контейнере */
.book .cover img{width:100%;height:100%;object-fit:cover;display:block}
.book .meta{min-width:0;display:flex;flex-direction:column;gap:5px}
.book b{font:600 15px/1.2 Rubik,sans-serif}
.nums{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
.num{aspect-ratio:1;border-radius:var(--r-tile);border:1px solid rgba(20,184,166,.45);background:rgba(20,184,166,.16);color:var(--text);font:700 15px/1 Unbounded,sans-serif;cursor:pointer;transition:transform .12s ease}
.num:active{transform:scale(.94)}
.num[data-empty="1"]{border-color:var(--line);background:transparent;color:#7d8b9e;opacity:.4}
.legend{display:flex;gap:14px;font:400 12px/1.4 Rubik,sans-serif;color:var(--text-2)}
.legend i{display:inline-block;width:12px;height:12px;border-radius:4px;margin-right:6px;vertical-align:-2px;background:rgba(20,184,166,.2);border:1px solid rgba(20,184,166,.45)}
.legend i.off{background:var(--surface);border-color:var(--line);opacity:.45}

/* решение */
.solve-head b{display:block;font:900 30px/1 Unbounded,sans-serif}
.solution{position:relative;overflow:hidden;border-color:rgba(20,184,166,.3)}
/* фон решения — однотонный, без клетки */
.solution .rule{display:none}
.solution .pen{height:1px;flex:1 1 auto;background:linear-gradient(90deg,var(--teal),transparent);animation:pen .7s cubic-bezier(.22,.9,.3,1) .1s both}
.step{display:flex;gap:11px;animation:step-in .38s cubic-bezier(.22,.9,.3,1) both}
.step>b{flex:0 0 auto;width:24px;height:24px;border-radius:8px;background:rgba(20,184,166,.18);color:var(--teal-l);font:700 12px/24px Unbounded,sans-serif;text-align:center}
.step .paper{padding:10px 12px;font:700 16px/1.2 Unbounded,sans-serif}
.answer{display:flex;align-items:center;justify-content:space-between;border:1.5px solid var(--teal);border-radius:var(--r-card);background:linear-gradient(150deg,rgba(20,184,166,.22),rgba(20,184,166,.06));padding:16px;animation:answer-pop .42s cubic-bezier(.3,.8,.3,1.1) .86s both}
.answer b{font:900 30px/1 Unbounded,sans-serif}
/* длинный ответ («а) x ≠ 2; б) любое y…») не влезает крупным кеглем */
.answer.long{flex-direction:column;align-items:flex-start;gap:8px}
.answer.long b{font:700 17px/1.45 Rubik,sans-serif;word-break:break-word}
.step .paper{white-space:pre-wrap}
/* условие задачи — картинка из учебника */
.paper img{width:100%;height:auto;display:block;border-radius:6px}
.step-note{color:var(--text-2);font:400 13px/1.5 Rubik,sans-serif}
/* плитка номера: залитая — есть разбор, контурная — только ответ */
.num[data-full="0"]{background:transparent;border-color:rgba(20,184,166,.28);color:var(--text-2)}
.legend i.part{background:transparent;border-color:rgba(20,184,166,.28)}

/* ОГЭ */
.topic{display:flex;gap:13px;padding:14px;animation:rise .34s cubic-bezier(.22,.9,.3,1) both}
.topic .n{flex:0 0 auto;width:44px;height:44px;border-radius:var(--r-ctl);background:rgba(255,180,84,.14);color:var(--amber);font:900 19px/44px Unbounded,sans-serif;text-align:center}
.bar{flex:1 1 auto;height:6px;border-radius:99px;background:var(--surface-2);overflow:hidden}
.bar i{display:block;height:100%;border-radius:99px;background:var(--amber)}
.ring{position:relative;width:84px;height:84px;flex:0 0 auto}
.ring svg{transform:rotate(-90deg)}
.ring .track{stroke:var(--surface-2)}
.ring .val{stroke:var(--amber);stroke-linecap:round;stroke-dasharray:314;animation:ring 1.1s cubic-bezier(.22,.9,.3,1) .15s both}
.ring .lbl{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.ring .lbl b{font:700 18px/1 Unbounded,sans-serif}
.ring .lbl span{font-size:9px;color:var(--text-2)}
.theory-card{border:1px solid var(--line);border-radius:var(--r-card);background:var(--paper);min-height:420px;display:flex;align-items:center;justify-content:center;color:#8a97a8;font-size:12px;overflow:hidden}
.theory-card img{width:100%;height:auto;display:block}
.pager{display:flex;align-items:center;justify-content:center;gap:16px}
.pager b{font:700 16px/1 Unbounded,sans-serif;min-width:64px;text-align:center}
.choice{display:flex;align-items:center;gap:11px;min-height:48px;padding:11px 13px;border-radius:var(--r-ctl);border:1.5px solid var(--line);background:transparent;color:var(--text);cursor:pointer;text-align:left;transition:transform .12s ease}
.choice:active{transform:scale(.97)}
.choice b{flex:0 0 auto;width:26px;height:26px;border-radius:9px;background:rgba(236,241,248,.07);color:var(--text-2);font:700 13px/26px Unbounded,sans-serif;text-align:center}
.choice[data-state="ok"]{border-color:var(--ok);background:rgba(52,199,123,.14)}
.choice[data-state="ok"] b{background:var(--ok);color:#04231f}
.choice[data-state="bad"]{border-color:var(--err);background:rgba(240,86,74,.12)}
.choice[data-state="bad"] b{background:var(--err);color:#2a0c09}
.verdict{border-radius:var(--r-card);padding:14px;animation:rise .3s cubic-bezier(.22,.9,.3,1) both}
.verdict.ok{border:1.5px solid var(--ok);background:rgba(52,199,123,.12)}
.verdict.bad{border:1.5px solid var(--err);background:rgba(240,86,74,.12)}
.verdict b{font:700 16px/1 Unbounded,sans-serif}
.verdict.ok b{color:var(--ok)} .verdict.bad b{color:var(--err)}
.hintbox{border-radius:var(--r-ctl);border:1px dashed rgba(255,180,84,.5);background:rgba(255,180,84,.08);padding:12px;font-size:13px;animation:rise .28s ease both}
.shake{animation:shake .42s cubic-bezier(.36,.07,.19,.97) both}
.confetti{position:fixed;inset:0;overflow:hidden;pointer-events:none;z-index:20}
.confetti i{position:absolute;top:-14px;border-radius:2px;animation:confetti-fall 1.4s cubic-bezier(.3,.7,.4,1) both}

/* состояния */
.center{min-height:60vh;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:15px;text-align:center}
.spinner{width:26px;height:26px;animation:spin .9s linear infinite}
.skel{height:86px;border-radius:var(--r-card);background:var(--surface);animation:skel 1.2s ease-in-out infinite}
.skel:nth-child(2){animation-delay:.15s} .skel:nth-child(3){animation-delay:.3s}
.view{animation:view-in .34s cubic-bezier(.22,.9,.3,1) both}

@keyframes view-in{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
@keyframes rise{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}
@keyframes q-bounce{0%{transform:translateY(0)}22%{transform:translateY(-16px) rotate(-6deg)}44%{transform:translateY(0)}60%{transform:translateY(-7px)}78%{transform:translateY(0)}88%{transform:translateY(-2px)}100%{transform:translateY(0)}}
@keyframes ax-draw{from{stroke-dashoffset:420}to{stroke-dashoffset:0}}
@keyframes ax-pop{from{opacity:0;transform:scaleY(.2)}to{opacity:1;transform:none}}
@keyframes dot-land{0%{opacity:0;transform:translate(-26px,-22px) scale(.4)}70%{opacity:1;transform:translate(0,0) scale(1.35)}100%{opacity:1;transform:none}}
@keyframes confetti-fall{0%{opacity:1;transform:translateY(0) rotate(0)}100%{opacity:0;transform:translateY(90vh) rotate(540deg)}}
@keyframes shake{0%,100%{transform:translateX(0)}18%{transform:translateX(-8px)}36%{transform:translateX(7px)}54%{transform:translateX(-5px)}72%{transform:translateX(3px)}}
@keyframes ring{from{stroke-dashoffset:314}}
@keyframes spin{to{transform:rotate(360deg)}}
@keyframes step-in{from{opacity:0;transform:translateY(9px)}to{opacity:1;transform:none}}
@keyframes answer-pop{0%{opacity:0;transform:scale(.9)}64%{opacity:1;transform:scale(1.04)}100%{opacity:1;transform:scale(1)}}
@keyframes pen{from{width:0}to{width:100%}}
@keyframes skel{0%,100%{opacity:.35}50%{opacity:.7}}

@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}

/* ---------- условие во весь экран по тапу ---------- */
.paper img{cursor:zoom-in}
.zoom-view{position:fixed;inset:0;z-index:80;display:flex;align-items:center;justify-content:center;
  padding:16px;background:rgba(6,9,16,.92);animation:view-in .22s ease both;cursor:zoom-out}
.zoom-view img{max-width:100%;max-height:82vh;border-radius:12px;background:#fff;
  box-shadow:0 24px 60px -20px rgba(0,0,0,.8);animation:zoom-in .26s cubic-bezier(.22,.9,.3,1) both}
.zoom-view .close{position:absolute;top:calc(14px + env(safe-area-inset-top));right:16px;
  width:40px;height:40px;border-radius:50%;border:1px solid rgba(236,241,248,.2);
  background:rgba(23,31,49,.9);color:#ecf1f8;font:400 20px/1 Rubik,sans-serif;cursor:pointer}
.zoom-view .tip{position:absolute;bottom:calc(22px + env(safe-area-inset-bottom));
  color:#93a1b5;font:400 13px/1 Rubik,sans-serif}
@keyframes zoom-in{from{opacity:0;transform:scale(.94)}to{opacity:1;transform:none}}

/* чертёж внутри шага: своя клетка нарисована в самом SVG */
.paper.figure{padding:10px}
.paper.figure svg{display:block;width:100%;height:auto}

/* шапка номера: подпись параграфа в одну строку, длинную — многоточием,
   иначе заголовок разъезжается на два-три ряда и ломает вёрстку карточки */
.solve-head{gap:12px}
.solve-head .hint{display:block;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.solve-head>div:first-child{min-width:0}
.eyebrow{white-space:nowrap}