/* Статьи: та же гамма, что у лендинга и калькуляторов. Ширина текста — для чтения, не для экрана. */
:root{--bg:#fff;--ivory:#F4F5F7;--line:#E4E6EB;--text:#152242;--soft:#5E6779;--accent:#2B87DB;--accent-deep:#1B6FBF;
  --up:#22823F;--down:#C23A2E;--warn:#B06A0A;--shadow:0 1px 2px rgba(21,34,66,.06),0 10px 28px rgba(21,34,66,.07);
  --display:"Manrope",system-ui,sans-serif;--sans:"Golos Text",system-ui,sans-serif;--mono:"IBM Plex Mono",ui-monospace,monospace}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:18px/1.72 var(--sans);-webkit-font-smoothing:antialiased;overflow-wrap:break-word}
a{color:var(--accent-deep)}
.wrap{max-width:1040px;margin:0 auto;padding:0 24px}
@media (max-width:520px){.wrap{padding:0 16px}body{font-size:17px}}
header{border-bottom:1px solid var(--line);position:sticky;top:0;background:color-mix(in srgb,#fff 92%,transparent);backdrop-filter:blur(12px);z-index:5}
.bar{display:flex;align-items:center;gap:18px;padding:12px 0}
.brand{display:flex;align-items:center;gap:9px;font-family:var(--display);font-weight:800;font-size:20px;text-decoration:none;color:var(--text)}
.bar nav{display:flex;gap:4px;margin-left:auto}
.bar nav a{color:var(--soft);text-decoration:none;padding:6px 11px;border-radius:9px;font-size:15px}
.bar nav a:hover{background:#EAF3FC;color:var(--accent-deep)}
.bar .lsw{font-weight:700;font-size:13px;color:var(--text);text-decoration:none;border:1.5px solid var(--line);border-radius:9px;padding:6px 9px;margin-left:8px}.bar .lsw:hover{border-color:var(--accent-deep)}
@media (max-width:640px){.bar nav{display:none}.bar .btn{margin-left:auto}.bar .lsw{margin-left:auto}.bar .lsw + .btn{margin-left:8px}}
.btn{display:inline-flex;align-items:center;justify-content:center;padding:11px 20px;border-radius:12px;background:var(--accent);
  color:#fff;text-decoration:none;font-weight:600;font-size:15.5px;white-space:nowrap}
.btn:hover{background:var(--accent-deep)}
.btn.line{background:#fff;color:var(--text);border:1px solid var(--line)}
@media (max-width:420px){.bar .btn{padding:9px 13px;font-size:14px}}
.art{max-width:760px}
.crumbs{font-size:14px;color:var(--soft);margin:28px 0 0}
.crumbs a{color:var(--soft);text-decoration:none}.crumbs a:hover{color:var(--accent-deep)}
.meta{font-size:14px;color:var(--soft);margin:22px 0 10px}
.kicker{font-family:var(--mono);font-size:12.5px;color:var(--accent-deep);text-transform:uppercase;letter-spacing:.04em}
h1{font-family:var(--display);font-weight:800;font-size:clamp(31px,4.4vw,46px);line-height:1.1;letter-spacing:-.03em;margin:0 0 18px;text-wrap:balance}
h1.idx{margin-top:48px}
h2{font-family:var(--display);font-weight:800;font-size:clamp(23px,2.8vw,28px);line-height:1.2;letter-spacing:-.02em;margin:40px 0 12px;text-wrap:balance}
p{margin:0 0 16px;text-wrap:pretty}
.lead{font-size:clamp(18.5px,2vw,21px);color:var(--soft);line-height:1.6;margin-bottom:26px}
ul,ol{padding-left:22px;margin:0 0 18px}li{margin-bottom:8px}
.formula{font-family:var(--mono);font-size:15.5px;background:var(--ivory);border-radius:12px;padding:13px 16px;margin:4px 0 18px;line-height:1.5}
.t{width:100%;border-collapse:collapse;margin:6px 0 20px;font-size:16px}
.t th,.t td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);vertical-align:top}
.t th{font-size:13.5px;color:var(--soft);font-weight:600;background:var(--ivory)}
.num{font-family:var(--mono);white-space:nowrap}
.up{color:var(--up)}.down{color:var(--down)}.warn{color:var(--warn)}
.example{border:1px solid var(--line);border-radius:16px;padding:18px 20px;margin:6px 0 22px;box-shadow:var(--shadow)}
.ex-h{font-weight:600;margin-bottom:6px}
.ex-r{display:flex;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px solid var(--line)}
.ex-r b{font-family:var(--mono);font-weight:600}
.ex-r.tot{border-bottom:0;border-top:2px solid var(--line);margin-top:4px;font-weight:600}
.ex-n{font-size:13.5px;color:var(--soft);margin:8px 0 0}
.faq{margin-top:44px;border-top:1px solid var(--line);padding-top:6px}
details{border-bottom:1px solid var(--line);padding:14px 0}
summary{cursor:pointer;font-weight:600;list-style:none;display:flex;justify-content:space-between;gap:16px}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";font-family:var(--mono);color:var(--soft)}details[open] summary::after{content:"–"}
details p{margin:10px 0 0;color:var(--soft)}
.cta{margin:40px 0;padding:26px;border-radius:20px;background:linear-gradient(180deg,#EAF3FC,#F7FAFE);border:1px solid #DCEBFB}
.cta b{font-family:var(--display);font-size:22px;display:block;margin-bottom:6px}
.cta p{color:var(--soft);margin-bottom:16px}
.cta .btn{margin:0 8px 8px 0}
.more h2{margin-top:10px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-bottom:56px}
.cards.big{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.card{display:flex;flex-direction:column;gap:8px;padding:20px;border:1px solid var(--line);border-radius:16px;text-decoration:none;color:var(--text);box-shadow:var(--shadow);min-width:0}
.card:hover{border-color:var(--accent)}
.card b{font-family:var(--display);font-size:19px;line-height:1.25}
.card .d{font-size:15px;color:var(--soft);line-height:1.5}
footer{padding:28px 0 48px;border-top:1px solid var(--line);color:var(--soft);font-size:14px;line-height:1.6}
footer a{color:var(--soft)}
h2.grp{margin:34px 0 14px}
.cards.big{margin-bottom:8px}

/* ── Подача v210: вывод в одну строку, ✓/✗, термин, шпаргалка, схемы ──
   Приём взят у сильных обучающих каналов: одна мысль — один блок, вывод — отдельной
   плашкой, «как не надо» рядом с «как надо», в конце — шпаргалка, которую хочется сохранить. */
.key{position:relative;display:block;background:#1F7A3D;color:#fff;border-radius:14px;padding:14px 18px 14px 66px;margin:8px 0 22px;font-size:17px;line-height:1.5}
.key::before{content:"";position:absolute;left:18px;top:50%;margin-top:-11px;width:22px;height:22px;background:#fff;opacity:.95;
  -webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 18h6M10 21h4M12 3a6 6 0 0 0-3.6 10.8c.6.5 1 1.2 1 2V17h5.2v-1.2c0-.8.4-1.5 1-2A6 6 0 0 0 12 3z'/%3E%3C/svg%3E") center/contain no-repeat;
          mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 18h6M10 21h4M12 3a6 6 0 0 0-3.6 10.8c.6.5 1 1.2 1 2V17h5.2v-1.2c0-.8.4-1.5 1-2A6 6 0 0 0 12 3z'/%3E%3C/svg%3E") center/contain no-repeat;
  }
.key::after{content:"";position:absolute;left:52px;top:12px;bottom:12px;width:2px;background:rgba(255,255,255,.45);border-radius:2px}
.key b{font-weight:700}
.term{border-left:3px solid var(--accent);background:#F3F8FD;border-radius:0 12px 12px 0;padding:11px 16px;margin:4px 0 18px;font-size:16.5px;line-height:1.55}
.term b{color:var(--accent-deep)}
.vs{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:8px 0 22px}
@media (max-width:620px){.vs{grid-template-columns:1fr}}
.vs>div{border:1px solid var(--line);border-radius:16px;padding:14px 16px 4px;box-shadow:var(--shadow);background:#fff;min-width:0}
.vs-h{display:flex;align-items:center;gap:8px;font-weight:700;font-size:16.5px;line-height:1.3;margin-bottom:8px}
.vs-h::before{flex:0 0 22px;height:22px;border-radius:50%;color:#fff;font-size:13px;display:grid;place-items:center;font-weight:800}
.vs-bad .vs-h{color:var(--down)}.vs-bad .vs-h::before{content:"✕";background:var(--down)}
.vs-good .vs-h{color:var(--up)}.vs-good .vs-h::before{content:"✓";background:var(--up)}
.vs p{font-size:15.5px;line-height:1.55;margin:8px 0 12px}
.scheme{position:relative;margin:4px 0 10px;border-radius:12px;border:1px solid var(--line);overflow:hidden;
  background-color:#FBFCFE;background-image:linear-gradient(var(--line) 1px,transparent 1px),linear-gradient(90deg,var(--line) 1px,transparent 1px);background-size:18px 18px;background-position:-1px -1px}
.scheme svg{display:block;width:100%;height:auto}
.scheme .sc-tag{position:absolute;top:6px;right:9px;font:500 11px/1 var(--mono);color:var(--soft);background:#FBFCFE;padding:2px 4px;border-radius:4px}
.art>article>.scheme{margin:8px 0 22px}
.sc-up{fill:#22A35A;stroke:#22A35A}.sc-dn{fill:#D9473B;stroke:#D9473B}.sc-fade{opacity:.32}
.sc-band{fill:#F6C344;opacity:.32}.sc-lvl{stroke:#D99A0B;stroke-width:1.4;stroke-dasharray:5 4;fill:none}
.sc-stop{stroke:#D9473B;stroke-width:1.4;stroke-dasharray:4 3;fill:none}.sc-in{stroke:#2B87DB;stroke-width:1.4;stroke-dasharray:4 3;fill:none}
.sc-tp{stroke:#22A35A;stroke-width:1.4;stroke-dasharray:4 3;fill:none}
.sc-ring-dn{fill:none;stroke:#D9473B;stroke-width:2}.sc-ring-up{fill:none;stroke:#22A35A;stroke-width:2}
.sc-t{font:600 11.5px var(--sans);fill:#5E6779}.sc-t.dn{fill:#D9473B}.sc-t.up{fill:#1F8A4C}.sc-t.in{fill:#1B6FBF}.sc-t.big{font-size:13px;font-weight:700}
.sc-eq{fill:none;stroke:#2B87DB;stroke-width:2.2;stroke-linejoin:round}.sc-dd{fill:#D9473B;opacity:.14}
.sc-bar-dn{fill:#D9473B;opacity:.85}.sc-bar-up{fill:#22A35A;opacity:.85}.sc-axis{stroke:#B9C0CC;stroke-width:1}
.cheat{border:1px solid var(--line);border-radius:18px;padding:20px 22px 8px;margin:30px 0 22px;box-shadow:var(--shadow);background:#fff}
.cheat h2{margin:0 0 4px;font-size:22px}
.cheat .cheat-sub{color:var(--soft);font-size:15px;margin:0 0 14px}
.cheat ol{list-style:none;padding:0;margin:0;counter-reset:ck}
.cheat li{counter-increment:ck;position:relative;padding:12px 0 12px 46px;border-top:1px solid var(--line);margin:0;line-height:1.5}
.cheat li::before{content:counter(ck);position:absolute;left:0;top:12px;width:30px;height:30px;border-radius:9px;background:#EAF3FC;color:var(--accent-deep);
  font:700 15px/30px var(--display);text-align:center}
.cheat li b{display:block;font-size:17px}
.cheat li span{color:var(--soft);font-size:15.5px}
.cheat-foot{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px;border-top:1px solid var(--line);padding:14px 0 12px;font-size:14.5px;color:var(--soft)}
.cheat-add{display:inline-flex;align-items:center;gap:6px;padding:9px 15px;border-radius:11px;background:var(--accent);color:#fff;text-decoration:none;font-weight:600;font-size:14.5px}
.cheat-add:hover{background:var(--accent-deep)}
.kv{border:1px solid var(--line);border-radius:14px;margin:6px 0 20px;overflow:hidden}
.kv div{display:grid;grid-template-columns:110px 1fr;gap:12px;padding:10px 16px;border-top:1px solid var(--line);font-size:16px;line-height:1.5}
.kv div:first-child{border-top:0}.kv dt,.kv .k{font-weight:700;color:var(--accent-deep)}
.card .ck{font-size:13px;color:var(--up);font-weight:600}
.art h3{font-family:var(--display);font-weight:800;font-size:20px;line-height:1.3;margin:28px 0 10px}
/* v235: обложки статей */
.art .cover{margin:6px 0 22px}
.art .cover img{display:block;width:100%;height:auto;border-radius:18px;border:1px solid var(--line);box-shadow:var(--shadow)}
.card .thumb{display:block;width:calc(100% + 40px);margin:-20px -20px 4px;aspect-ratio:1200/630;object-fit:cover;border-radius:16px 16px 0 0;border-bottom:1px solid var(--line)}