:root{
  --bg:#0f1115; --bg-alt:#161a22; --card:#1a1d24; --text:#e8eaed; --muted:#9aa0ab;
  --accent:#f5a623; --border:#272b34;
  --green:#2ecc71; --red:#ff8070; --code:#1c2230;
  --radius:10px; --maxw:760px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",sans-serif;
  background:var(--bg); color:var(--text); line-height:1.7; font-size:17px;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
main a,.site-footer a{text-decoration:underline;text-underline-offset:.16em}
main .btn{text-decoration:none}
:focus-visible{outline:2px solid var(--accent);outline-offset:4px}
:target,:focus{scroll-margin-top:140px;scroll-margin-bottom:30px}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}
.skip-link{position:absolute;left:-9999px}
.skip-link:focus{left:8px;top:8px;background:var(--accent);color:#000;padding:8px 12px;border-radius:6px;z-index:99}

/* шапка */
.site-header{position:sticky;top:0;z-index:20;background:rgba(15,17,21,.96);
  border-bottom:1px solid var(--border);backdrop-filter:blur(8px)}
.header-inner{display:flex;align-items:center;gap:18px;padding:14px 20px;flex-wrap:wrap}
.logo{font-weight:700;color:var(--text);letter-spacing:-.02em;white-space:nowrap}
.logo:hover{text-decoration:none;color:var(--accent)}
.main-nav{display:flex;gap:16px;flex-wrap:wrap;margin-left:auto}
.main-nav a{color:var(--muted);font-size:15px}
.main-nav a:hover,.main-nav a.active{color:var(--text);text-decoration:none}
.main-nav a.active{color:var(--accent)}
.lang-switch{border:1px solid var(--border);border-radius:999px;padding:4px 12px;
  font-size:13px;color:var(--muted);white-space:nowrap}
.lang-switch:hover{color:var(--text);border-color:var(--accent);text-decoration:none}

main{padding:40px 0 72px}
.breadcrumbs{font-size:14px;color:var(--muted);margin-bottom:20px}
.breadcrumbs a{color:var(--muted)}
.breadcrumbs a:hover{color:var(--text)}
.breadcrumbs .sep{margin:0 8px;opacity:.5}

/* типографика */
h1{font-size:clamp(1.7rem,4vw,2.2rem);line-height:1.22;letter-spacing:-.02em;margin-bottom:16px}
h2{font-size:clamp(1.25rem,3vw,1.5rem);line-height:1.3;margin:44px 0 14px;letter-spacing:-.01em}
h3{font-size:1.12rem;margin:28px 0 10px}
p{margin:16px 0}
.lead{font-size:1.08rem;color:var(--muted);margin-bottom:28px}
ul,ol{margin:16px 0 16px 22px}
li{margin:7px 0}
strong{color:#fff}
small{color:var(--muted)}

/* формулы */
.formula{background:var(--code);border-left:3px solid var(--accent);border-radius:0 8px 8px 0;
  padding:16px 20px;margin:22px 0;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;
  font-size:1rem;overflow-x:auto}
.formula .note{display:block;margin-top:8px;font-family:inherit;font-size:14px;color:var(--muted)}
code{background:var(--code);padding:2px 6px;border-radius:4px;
  font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.9em}

/* таблицы */
.table-wrap{overflow-x:auto;margin:24px 0;border:1px solid var(--border);border-radius:var(--radius)}
table{width:100%;border-collapse:collapse;font-size:15px;background:var(--card)}
th,td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--border);vertical-align:top}
th{background:var(--bg-alt);font-weight:600;font-size:13px;text-transform:uppercase;
  letter-spacing:.04em;color:var(--muted);white-space:nowrap}
tr:last-child td{border-bottom:none}
td.num{font-variant-numeric:tabular-nums;white-space:nowrap}

/* карточки и сетки */
.grid{display:grid;gap:16px;margin:26px 0}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid-3{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:20px 22px}
.card h3{margin-top:0;margin-bottom:8px}
.card p{color:var(--muted);font-size:15px;margin:8px 0 0}
.card-link{display:block}
.card-link:hover{text-decoration:none;border-color:var(--accent)}
.card-link:hover h3{color:var(--accent)}

/* выделения */
.note,.warn,.verdict{border-radius:var(--radius);padding:16px 20px;margin:24px 0;font-size:15.5px}
.note{background:var(--bg-alt);border-left:3px solid var(--accent)}
.warn{background:#2a1c1c;border-left:3px solid var(--red)}
.verdict{background:#16241d;border-left:3px solid var(--green)}
.note p:last-child,.warn p:last-child,.verdict p:last-child{margin-bottom:0}
.note p:first-child,.warn p:first-child,.verdict p:first-child{margin-top:0}
blockquote{border-left:3px solid var(--border);padding-left:18px;color:var(--muted);margin:22px 0}

/* пример в гривне */
.example{background:var(--bg-alt);border:1px solid var(--border);border-radius:var(--radius);
  padding:18px 20px;margin:24px 0}
.example h3,.example h4{margin:0 0 12px;font-size:14px;text-transform:uppercase;letter-spacing:.05em;color:var(--accent)}
.example dl{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:7px 16px;margin:0;font-size:15.5px}
.example dt{color:var(--muted)}
.example dt,.example dd{min-width:0;overflow-wrap:anywhere}
.example dd{font-variant-numeric:tabular-nums;text-align:right;font-weight:600}
.example .total{border-top:1px solid var(--border);padding-top:9px;margin-top:4px;
  grid-column:1/-1;display:flex;flex-wrap:wrap;justify-content:space-between;gap:6px 16px;color:var(--text)}
.example .total span,.example .total b{min-width:0;max-width:100%;overflow-wrap:anywhere}
.example .total b{font-variant-numeric:tabular-nums}

/* FAQ */
.faq details{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);
  padding:16px 20px;margin-bottom:10px}
.faq summary{cursor:pointer;font-weight:600;color:var(--text);list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";float:right;color:var(--accent);font-weight:400}
.faq details[open] summary::after{content:"−"}
.faq summary:hover{color:var(--accent)}
.faq p{margin:12px 0 0;color:var(--muted);font-size:15.5px}
.faq-actions{margin-bottom:14px}

/* калькулятор */
.calculator{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);
  padding:24px;margin:28px 0}
.calculator .fields{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,200px),1fr));gap:16px}
.calculator .fields>div{min-width:0}
.calculator label{display:block;font-size:14px;color:var(--muted);margin-bottom:6px}
.calculator input,.calculator select{width:100%;padding:11px 13px;background:var(--bg);
  border:1px solid var(--border);border-radius:8px;color:var(--text);font-size:16px;
  font-variant-numeric:tabular-nums}
.calculator input:focus,.calculator select:focus{border-color:var(--accent)}
.calculator [aria-invalid="true"]{border-color:var(--red)}
.calculator .hint{font-size:13px;color:var(--muted);margin-top:5px}
.calculator .actions{margin-top:20px;display:flex;gap:12px;flex-wrap:wrap}
.btn{display:inline-block;background:var(--accent);color:#0f1115;border:none;
  padding:12px 22px;border-radius:8px;font-size:15px;font-weight:600;cursor:pointer}
.btn:hover{background:#ffb84d}
.btn-secondary{background:transparent;color:var(--muted);border:1px solid var(--border)}
.btn-secondary:hover{color:var(--text);border-color:var(--accent);background:transparent}
.result{margin-top:22px;padding:18px;background:var(--bg);border:1px solid var(--border);
  border-radius:8px}
.result:empty{display:none}
.result .row{display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;gap:6px 16px;padding:7px 0;
  border-bottom:1px dashed var(--border);font-size:15.5px}
.result .row:last-child{border-bottom:none}
.result .row span{flex:1 1 11rem;min-width:0;overflow-wrap:anywhere}
.result .row b{flex:0 1 auto;min-width:0;max-width:100%;font-variant-numeric:tabular-nums;white-space:normal;overflow-wrap:anywhere;text-align:right}
.result .model-note{color:var(--muted);font-size:14px;margin:12px 0 0;overflow-wrap:anywhere}
.result .model-note.warning{color:var(--red)}
.result .err{color:var(--red);font-size:15.5px}
.result .head{font-size:13px;text-transform:uppercase;letter-spacing:.05em;
  color:var(--muted);padding-bottom:8px;border-bottom:1px solid var(--border);margin-bottom:4px}
.positive{color:var(--green)}
.negative{color:var(--red)}

/* CTA — мягкий, один на страницу */
.cta{background:var(--bg-alt);border:1px solid var(--border);border-radius:var(--radius);
  padding:18px 20px;margin:32px 0;font-size:15.5px}
.cta p{margin:0;color:var(--muted)}
.cta a{font-weight:600}
.cta-line{margin:18px 0 0;font-size:14.5px;color:var(--muted)}

/* футер */
.site-footer{border-top:1px solid var(--border);padding:28px 0;color:var(--muted);font-size:14px}
.site-footer p{margin:0 0 10px}
.footer-links{display:flex;flex-wrap:wrap;gap:8px 16px}
.footer-links a{margin-right:0;overflow-wrap:anywhere}

@media (max-width:640px){
  body{font-size:16px}
  .header-inner{padding:12px 16px;gap:12px}
  .main-nav{gap:12px;font-size:14px;width:100%;margin-left:0}
  main{padding:28px 0 56px}
  h2{margin-top:36px}
  .calculator{padding:18px}
  th,td{padding:10px 12px}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}