/* Локальные системные шрифты: никаких внешних запросов за шрифтами. */
:root{--bg:#f7f5f0;--paper:#fffefa;--ink:#24251f;--muted:#77786f;--accent:#cf7055;--line:#e6e1d7}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,'Segoe UI',sans-serif;line-height:1.6}a{color:inherit}
.topbar,footer{width:min(1160px,calc(100% - 40px));margin:auto}.topbar{padding:23px 0;display:flex;justify-content:space-between;align-items:center}.brand{text-decoration:none;font-weight:800;letter-spacing:-.05em;display:flex;gap:8px;align-items:center}.brand i{color:var(--accent);font-style:normal}.mark{background:var(--ink);color:white;border-radius:12px;padding:3px 10px;font-size:23px}nav{display:flex;gap:25px}nav a{text-decoration:none;color:var(--muted);font-size:13px;font-weight:700}
.hero{width:min(1160px,calc(100% - 40px));margin:18px auto 95px;padding:60px 70px;min-height:520px;border-radius:36px;background:var(--paper);display:grid;grid-template-columns:1fr 1fr;align-items:center;box-shadow:0 18px 55px #332d2010;overflow:hidden}.eyebrow{font-size:10px;letter-spacing:.18em;font-weight:800;color:var(--accent)}h1{font-size:clamp(45px,6vw,74px);line-height:1.02;letter-spacing:-.07em;margin:22px 0}h1 em{font-style:normal;color:var(--accent)}.hero p{color:var(--muted);font-size:15px;max-width:500px}.button{display:inline-flex;gap:20px;align-items:center;background:var(--ink);color:white;text-decoration:none;padding:13px 19px;border-radius:99px;font-size:13px;font-weight:700;margin-top:12px}.button b{font-size:18px}.hero .subnote{font-size:11px;margin-top:28px}.art{height:340px;position:relative;display:grid;place-items:center}.sigma{font-size:230px;font-weight:800;color:#efe7d8}.formula{position:absolute;padding:15px 19px;border-radius:15px;background:white;box-shadow:0 12px 30px #332a1b13;font-weight:800;font-size:16px}.f1{top:25px;left:0;transform:rotate(-7deg)}.f2{right:0;top:130px;transform:rotate(6deg)}.f3{left:35px;bottom:20px;transform:rotate(4deg)}.spark{position:absolute;right:25px;bottom:20px;color:var(--accent);font-size:27px}
.section{width:min(1160px,calc(100% - 40px));margin:0 auto 100px}.heading{display:flex;align-items:end;justify-content:space-between;gap:30px;margin-bottom:28px}.heading h2,.log-section h2,.closing h2{font-size:clamp(34px,4vw,48px);line-height:1.08;letter-spacing:-.06em;margin:10px 0 0}.heading>p{max-width:300px;color:var(--muted);font-size:13px}.panel{background:var(--paper);border:1px solid var(--line);border-radius:25px;padding:24px}.multiplication-wrap{overflow-x:auto}.multiplication{width:100%;border-collapse:separate;border-spacing:5px;table-layout:fixed;text-align:center;font-size:13px;font-weight:700}.multiplication th,.multiplication td{padding:10px 4px;border-radius:9px;background:var(--bg)}.multiplication thead th,.multiplication tbody th{background:#f0dfd2;color:var(--accent)}.multiplication td{background:#fff; border:1px solid var(--line)}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.topic{padding:25px;border-radius:24px;min-height:285px;position:relative}.topic small{position:absolute;right:22px;top:19px;color:#777;font-size:10px}.peach{background:#f3dfd4}.lilac{background:#e9e2f1}.mint{background:#e1eadf}.blue{background:#dfe9ef}.yellow{background:#f3e9c7}.pink{background:#f0dcdf}.icon{font-size:29px;font-weight:800;margin-bottom:20px}.topic h3{font-size:21px;margin:0 0 6px}.topic p{font-size:12px;color:#5f6059}.formula-line{padding:11px 12px;border-radius:11px;background:#ffffffa8;font-weight:800;font-size:13px;margin:13px 0}.topic p.example{margin-bottom:0}.example b{color:var(--ink)}
.log-section{width:min(1160px,calc(100% - 40px));margin:0 auto 100px;border-radius:32px;overflow:hidden;background:#252620;color:white;display:grid;grid-template-columns:1fr 1fr}.log-left,.log-right{padding:52px}.log-left .eyebrow,.log-right .eyebrow{color:#e7a18a}.log-section h2{margin:18px 0}.log-left>p{font-size:13px;color:#c9c9bf}.equation{font-size:33px;font-weight:800;color:#f1c5b4;margin:25px 0}.equation sub,.big-equation sub{font-size:18px}.log-right{background:#30312a}.big-equation{font-size:42px;font-weight:800;color:#f1c5b4;margin:17px 0 25px}.step{display:flex;gap:12px;align-items:center;margin:12px 0}.step>b{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;background:#48493f;color:#f1c5b4}.step p{font-size:13px;color:#d5d5cb;margin:0}.condition{border:1px solid #ffffff20;border-radius:13px;padding:14px;margin-top:25px;color:#c9c9bf;font-size:11px}
.closing{width:min(900px,calc(100% - 40px));margin:0 auto 85px;display:flex;align-items:center;gap:22px}.closing>span{display:grid;place-items:center;flex:0 0 65px;height:65px;border-radius:20px;background:#f0dfc0;color:var(--accent);font-size:29px}.closing h2{font-size:29px;margin:0 0 6px}.closing p{font-size:13px;color:var(--muted);margin:0}footer{padding:24px 0 38px;border-top:1px solid var(--line);display:flex;justify-content:space-between;color:var(--muted);font-size:11px}
@media(max-width:850px){.hero{grid-template-columns:1fr;padding:45px}.art{margin-top:20px}.grid{grid-template-columns:repeat(2,1fr)}.log-section{grid-template-columns:1fr}.multiplication{font-size:12px;border-spacing:3px}.multiplication th,.multiplication td{padding:8px 2px}}
@media(max-width:600px){nav{display:none}.topbar,footer{width:calc(100% - 28px)}.hero,.section,.log-section{width:calc(100% - 28px)}.hero{padding:30px 23px;margin:10px auto 70px}h1{font-size:47px}.art{transform:scale(.82);transform-origin:top center;margin-bottom:-55px}.section{margin-bottom:70px}.heading{display:block}.heading>p{margin-top:12px}.multiplication{min-width:620px;font-size:12px}.grid{grid-template-columns:1fr}.topic{min-height:245px}.log-section{margin-bottom:70px}.log-left,.log-right{padding:30px 24px}.closing{align-items:flex-start;width:calc(100% - 36px)}footer{flex-direction:column;gap:7px}}