@font-face{font-family:Nunito;src:url(nunito.ttf) format("truetype");font-weight:200 1000;font-display:swap}
:root{--paper:#FFF9EE;--grid:#EFE5D0;--ink:#1F2A44;--blue:#2459D6;--orange:#E9791A;--green:#15865A;--cherry:#C81E3A;--muted:#5B6579;--sun:#FFE9A8;--mint:#E3F6EC;--card:#fff}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Nunito,system-ui,sans-serif;font-size:18px;line-height:1.5;color:var(--ink);background-color:var(--paper);
background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:40px 40px}
a{color:var(--blue)}a:hover{color:var(--ink)}
h1,h2,h3,h4,p,ul,ol{margin:0}
h1{font-size:clamp(28px,5vw,42px);line-height:1.15;font-weight:900}
h2{font-size:clamp(24px,4vw,30px);font-weight:900;margin-bottom:18px}
.wrap{max-width:1120px;margin:0 auto;padding:0 16px}
main.wrap{padding-top:24px;padding-bottom:56px;display:flex;flex-direction:column;gap:40px}
main>section{display:block}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}
.logo{display:inline-flex;align-items:center;font-weight:900;font-size:28px;color:var(--ink);letter-spacing:.01em}
.logo .chk{width:.66em;height:.66em;margin-left:.04em;margin-top:.12em}
.top{background:var(--card);border-bottom:2px solid var(--ink)}
.top .wrap,.foot .wrap{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px 20px;padding-top:10px;padding-bottom:10px}
.brand{text-decoration:none;padding:6px 0}
.top nav,.foot nav{display:flex;flex-wrap:wrap;align-items:center;gap:4px 20px}
.top nav a:not(.btn),.foot nav a{padding:10px 0;font-weight:700;color:var(--ink);text-decoration:none}
.top nav a:not(.btn):hover,.foot nav a:hover{text-decoration:underline}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:10px 20px;border-radius:12px;border:2px solid var(--ink);font:inherit;font-weight:800;text-decoration:none;cursor:pointer}
.btn.dark{background:var(--ink);color:#fff}.btn.blue{background:var(--blue);color:#fff}.btn.sun{background:var(--sun);color:var(--ink)}.btn.light{background:#fff;color:var(--ink)}
.btn:hover{filter:brightness(1.08);color:inherit}.btn.dark:hover,.btn.blue:hover{color:#fff}
.pill{display:inline-block;align-self:flex-start;background:var(--orange);color:var(--ink);font-weight:800;font-size:15px;padding:4px 14px;border-radius:999px}
.card{background:var(--card);border:2px solid var(--ink);border-radius:16px;padding:20px}
.crumbs{font-size:15px;color:var(--muted);display:flex;flex-wrap:wrap;gap:6px;margin-bottom:-20px}
.crumbs a{padding:6px 0}
.head{display:flex;flex-direction:column;gap:6px}.head p{color:var(--muted)}
/* головна */
.hero{display:flex;flex-direction:column;gap:16px;padding-top:16px}
.hero h1{font-size:clamp(32px,6vw,54px);max-width:800px}
.lead{font-size:20px;color:var(--muted);max-width:640px}
.find{display:flex;flex-wrap:wrap;gap:12px;align-items:flex-end;max-width:860px;margin-top:8px}
.find label{display:flex;flex-direction:column;gap:4px;font-size:15px;font-weight:800;flex:1 1 200px}
.find select,.find input{height:52px;border:2px solid var(--ink);border-radius:12px;padding:0 12px;font:inherit;font-weight:600;color:var(--ink);background:#fff;width:100%}
.find .btn{flex:1 1 200px;min-height:52px}
.find .msg{flex-basis:100%;font-weight:700}
.books,.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px}
.books{grid-template-columns:repeat(auto-fit,minmax(290px,1fr))}
.book{display:flex;flex-direction:column;border:2px solid var(--ink);border-radius:16px;overflow:hidden;text-decoration:none;color:var(--ink);background:#fff}
.book .band{background:var(--ink);color:#fff;padding:18px 20px;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 12px}
.book .band strong{font-size:34px;font-weight:900;line-height:1.1;border-bottom:5px solid var(--orange);padding-bottom:2px}
.book .band span{font-weight:800;line-height:1.2;text-align:right}.book .band em{font-style:normal;color:var(--sun);font-size:22px}
.book .meta{padding:16px 20px;display:flex;flex-direction:column;gap:6px}.book .meta span{color:var(--muted);font-size:16px}.book .meta b{color:var(--blue)}
.book:hover,.card.task:hover,.card.pn:hover{box-shadow:4px 4px 0 var(--ink);color:var(--ink)}
.card.task{display:flex;flex-direction:column;gap:6px;text-decoration:none;color:var(--ink)}
.card.task strong{font-size:30px;font-weight:900;line-height:1.1}.card.task>span:last-child{color:var(--muted)}
.how{list-style:none;padding:0;display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:20px;counter-reset:how}
.how li{counter-increment:how;display:flex;flex-direction:column;gap:4px}
.how li::before{content:counter(how);width:44px;height:44px;border-radius:50%;background:var(--sun);border:2px solid var(--ink);font-weight:900;display:flex;align-items:center;justify-content:center;margin-bottom:4px}
.how b{font-size:20px}.how span{color:var(--muted)}
.parents{display:flex;flex-wrap:wrap;gap:20px;align-items:center;justify-content:space-between}
.parents div{flex:1 1 380px}.parents h2{margin-bottom:6px}.parents p{color:var(--muted)}
/* підручник */
.legend{color:var(--muted);font-size:16px;display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:-24px}
.dot{display:inline-block;width:9px;height:9px;border-radius:50%;background:var(--orange)}.dot.long{background:var(--green)}
.h{font-size:24px;font-weight:900;margin-bottom:16px}.h.s{font-size:19px;margin-bottom:12px}
.topic{margin-bottom:-20px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(64px,1fr));gap:8px}
.grid.wide{grid-template-columns:repeat(auto-fill,minmax(76px,1fr))}
.num{position:relative;display:flex;align-items:center;justify-content:center;min-height:48px;border:2px solid var(--ink);border-radius:10px;background:var(--paper);color:var(--ink);font-weight:800;text-decoration:none}
.num:hover{background:var(--sun)}.num.cur{background:var(--ink);color:#fff}
.num .dot{position:absolute;top:5px;right:5px;width:7px;height:7px}
/* завдання */
.cols{display:flex;flex-wrap:wrap;gap:28px;align-items:flex-start}
article{flex:999 1 520px;min-width:0;display:flex;flex-direction:column;gap:20px}
aside{flex:1 1 260px;min-width:0;display:flex;flex-direction:column;gap:20px}
.more{display:inline-block;margin-top:12px;padding:8px 0;font-weight:800}
.part{margin:12px 0 -4px;font-size:24px}
.yt{position:relative;display:block;width:100%;aspect-ratio:16/9;border:2px solid var(--ink);border-radius:16px;overflow:hidden;background:var(--ink)}
.yt.short{aspect-ratio:9/16;max-width:340px}
.yt img{width:100%;height:100%;object-fit:cover;display:block}
.yt .play{position:absolute;inset:0;margin:auto;width:76px;height:76px;border-radius:50%;background:var(--green);border:4px solid #fff}
.yt .play::after{content:"";position:absolute;left:29px;top:20px;border-left:24px solid #fff;border-top:14px solid transparent;border-bottom:14px solid transparent}
iframe.yt{border:2px solid var(--ink)}
.lbl{font-size:14px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:6px}
.cond .ctitle{font-size:22px;font-weight:900;margin-bottom:8px}
.cond ul{padding-left:22px;display:flex;flex-direction:column;gap:10px;font-size:19px;font-weight:600}
.cond ul.exprs{list-style:none;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px;font-size:21px;font-weight:800}
.cond .q{margin-top:12px;font-weight:800;color:var(--blue)}
.steps{list-style:none;padding:0;counter-reset:st;display:flex;flex-direction:column;gap:22px}
.steps>li{counter-increment:st;position:relative;padding-left:52px;display:flex;flex-direction:column;gap:10px;min-height:38px}
.steps>li::before{content:counter(st);position:absolute;left:0;top:0;width:38px;height:38px;border-radius:50%;background:var(--sun);border:2px solid var(--ink);font-weight:900;display:flex;align-items:center;justify-content:center}
.steps h4,.ex h4{font-size:20px;font-weight:900;padding-top:4px}
.ml{font-size:22px;font-weight:800;overflow-x:auto;padding:4px 0;white-space:nowrap}
.note{color:var(--muted);font-size:17px;font-weight:600}
.ex{padding:16px 0;border-top:2px dashed var(--grid)}.ex:first-of-type{border-top:0;padding-top:0}.ex:last-child{padding-bottom:0}
.ex h4{font-size:22px;margin-bottom:10px}
.mini{padding-left:22px;display:flex;flex-direction:column;gap:8px}.mini .cap{color:var(--muted);font-size:17px;font-weight:700}
.ans{margin-top:10px;font-size:20px}
.answer{background:var(--mint);border:2px solid var(--green);border-radius:16px;padding:16px 20px;font-size:21px;font-weight:700}
.rule{background:var(--sun);border:2px solid var(--ink);border-radius:16px;padding:16px 20px}.rule b{font-weight:900}.rule p{font-weight:600}
.fr{display:inline-flex;flex-direction:column;align-items:center;vertical-align:middle;line-height:1.15;margin:0 2px;font-size:.92em}
.fr>span:first-child{border-bottom:2px solid currentColor;padding:0 4px}.fr>span:last-child{padding:0 4px}
.c-g{color:var(--green)}.c-c{color:var(--cherry)}.c-b{color:var(--blue)}.c-o{color:#B4560B}.c-m{color:var(--muted)}
.bar{display:flex;max-width:520px;border:2px solid var(--ink);border-radius:6px;overflow:hidden}
.bar i{flex:1;height:34px;border-right:1px solid var(--ink);background:#fff}.bar i:last-child{border-right:0}
.prevnext{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.card.pn{padding:14px 18px;font-weight:900;text-decoration:none;color:var(--ink)}.card.pn.r{text-align:right}
.sub{background:var(--ink);color:#fff;border-radius:16px;padding:22px;display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between}
.sub b{font-size:22px;font-weight:900}.sub p{color:#D5DCEA}.row{display:flex;flex-wrap:wrap;gap:10px}
.err a{display:inline-block;padding:10px 0;font-size:16px}
.ad-slot:not([hidden]){min-height:250px}
.prose{display:flex;flex-direction:column;gap:12px;max-width:800px}.prose h2{font-size:22px;margin:12px 0 0}
.foot{background:var(--ink);color:#D5DCEA;margin-top:8px}
.foot .wrap{padding-top:24px;padding-bottom:24px}
.foot .logo{color:#fff}.foot p{font-size:15px}.foot nav a{color:#D5DCEA}