:root{
  --ink:#0f172a;--body:#334155;--muted:#64748b;--line:#e2e8f0;
  --bg:#f8fafc;--card:#ffffff;--accent:#4f46e5;--accent-d:#4338ca;
  --amber:#f59e0b;--green:#059669;
  --f:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;--wrap:1080px}
*,*::before,*::after{box-sizing:border-box}
body{margin:0;font-family:var(--f);color:var(--body);background:var(--bg);font-size:16px;line-height:1.7}
img{max-width:100%;height:auto;display:block}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 20px}
a{color:var(--accent)}
.skip{position:absolute;left:-9999px}.skip:focus{left:8px;top:8px;background:var(--accent);color:#fff;padding:8px 14px;z-index:100;border-radius:6px}
h1,h2,h3{color:var(--ink);line-height:1.25;font-weight:700;letter-spacing:-.015em}
/* header */
.hdr{background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:40}
.hdr-in{display:flex;align-items:center;gap:18px;min-height:60px}
.brand{margin-right:auto;display:flex;align-items:center;gap:9px;text-decoration:none;font-weight:800;color:var(--ink);font-size:1.05rem;letter-spacing:-.01em}
.brand .chip{width:26px;height:20px;background:linear-gradient(135deg,var(--accent),#7c3aed);border-radius:4px 8px 4px 4px;position:relative}
.brand .chip::after{content:"";position:absolute;right:3px;top:3px;width:8px;height:5px;background:var(--amber);border-radius:1px}
.nav{display:flex;gap:2px;flex-wrap:wrap}
.nav a{color:var(--body);text-decoration:none;padding:8px 12px;border-radius:8px;font-size:.9rem;font-weight:600}
.nav a:hover,.nav a[aria-current=page]{background:#eef2ff;color:var(--accent)}
.burger{display:none;background:none;border:0;flex-direction:column;gap:5px;cursor:pointer;padding:11px;min-width:44px;min-height:44px}
.burger span{width:22px;height:2px;background:var(--ink);display:block;border-radius:2px}
/* hero */
.hero{background:linear-gradient(160deg,#eef2ff 0%,#faf5ff 55%,var(--bg) 100%);padding:44px 0 30px;text-align:center}
.hero h1{font-size:clamp(1.5rem,4vw,2.3rem);margin:0 auto 10px;max-width:24ch}
.hero .sub{color:var(--muted);max-width:58ch;margin:0 auto;font-size:1.02rem}
/* calculator */
.calc{max-width:680px;margin:26px auto 0;background:var(--card);border:1px solid var(--line);border-radius:18px;padding:26px;box-shadow:0 18px 44px -22px rgba(79,70,229,.28);text-align:left}
.calc .row{margin-bottom:18px}
.calc label{display:block;font-weight:700;color:var(--ink);font-size:.9rem;margin-bottom:8px}
.seg{display:flex;gap:8px;flex-wrap:wrap}
.seg button{flex:1 1 auto;min-width:74px;padding:10px 8px;border:1.5px solid var(--line);background:#fff;border-radius:10px;font-family:var(--f);font-weight:600;font-size:.9rem;color:var(--body);cursor:pointer}
.seg button[aria-pressed=true]{border-color:var(--accent);background:#eef2ff;color:var(--accent)}
.calc select{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:10px;font-family:var(--f);font-size:1rem;background:#fff;color:var(--ink)}
.calc select:focus,.seg button:focus{outline:2px solid var(--accent);outline-offset:1px}
.result{background:linear-gradient(135deg,var(--accent),#7c3aed);border-radius:14px;color:#fff;padding:22px;text-align:center;margin-top:6px}
.result .big{font-size:clamp(1.9rem,5vw,2.7rem);font-weight:800;letter-spacing:-.02em;line-height:1.1}
.result .unit{opacity:.92;font-size:.95rem;margin-top:4px}
.result .alt{border-top:1px solid rgba(255,255,255,.28);margin-top:14px;padding-top:12px;font-size:.92rem;opacity:.95}
.calc .note{font-size:.8rem;color:var(--muted);margin:12px 0 0;text-align:center}
/* sections */
section{padding:44px 0}
.sec h2{font-size:1.55rem;margin:0 0 12px}
.answer-lead{font-size:1.06rem;background:#f0fdf4;border:1px solid #bbf7d0;border-left:4px solid var(--green);padding:14px 18px;border-radius:10px;color:#14532d;max-width:74ch}
/* tables */
table{border-collapse:collapse;width:100%;margin:20px 0;background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 1px 3px rgba(15,23,42,.08);font-size:.95rem}
th,td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--line)}
th{background:var(--ink);color:#fff;font-weight:700;font-size:.86rem;letter-spacing:.02em}
tbody tr:last-child td{border-bottom:0}
tbody tr:nth-child(even){background:#f8fafc}
td strong{color:var(--ink)}
/* capacity cards */
.cap-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin-top:20px}
.cap-card{background:#fff;border:1.5px solid var(--line);border-radius:14px;padding:18px 16px;text-align:center;text-decoration:none;transition:.15s}
.cap-card:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:0 12px 26px -16px rgba(79,70,229,.4)}
.cap-card .gb{font-size:1.45rem;font-weight:800;color:var(--ink)}
.cap-card .ph{font-size:.84rem;color:var(--muted);margin-top:3px}
/* FAQ */
.faq{max-width:800px}
.faq details{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px 20px;margin-bottom:12px}
.faq summary{font-weight:700;color:var(--ink);cursor:pointer}
.faq details p{margin:12px 0 0}
.crumbs{font-size:.82rem;color:var(--muted);padding:14px 0 0}
.crumbs a{color:var(--accent);text-decoration:none}
.prose{max-width:74ch}
.sib{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}
.sib a{background:#eef2ff;color:var(--accent);text-decoration:none;font-weight:600;font-size:.88rem;padding:8px 14px;border-radius:999px}
.sib a:hover{background:var(--accent);color:#fff}
/* footer */
.ftr{background:var(--ink);color:#94a3b8;padding:38px 0 22px;font-size:.9rem;margin-top:30px}
.ftr-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:30px;margin-bottom:22px}
.ftr h4{color:#fff;margin:0 0 10px;font-size:.95rem}
.ftr a{color:#cbd5e1;text-decoration:none}.ftr a:hover{color:#fff}
.ftr ul{list-style:none;margin:0;padding:0}.ftr li{padding:3px 0}
.ftr-bot{border-top:1px solid #1e293b;padding-top:16px;font-size:.8rem;text-align:center}
@media(max-width:760px){
  .nav{position:absolute;top:100%;left:0;right:0;background:#fff;flex-direction:column;display:none;padding:10px;border-bottom:1px solid var(--line)}
  .nav.open{display:flex}.burger{display:flex}
  .ftr-grid{grid-template-columns:1fr}
  th,td{padding:9px 10px;font-size:.86rem}
}