:root{
  --bg:#07111e;
  --bg2:#0d1729;
  --card:#13203a;
  --card2:#162845;
  --line:#284363;
  --text:#edf4ff;
  --muted:#9eb2d2;
  --accent:#6ea9ff;
  --accent2:#8bf1d2;
  --good:#91f3be;
  --radius:22px;
  --shadow:0 18px 40px rgba(0,0,0,.28);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
  color:var(--text);
  background:
    radial-gradient(circle at top right, rgba(110,169,255,.14), transparent 25%),
    radial-gradient(circle at top left, rgba(139,241,210,.08), transparent 20%),
    linear-gradient(180deg,#07111e,#0b1322 35%,#09111d 100%);
  min-height:100vh;
}
body.light{
  --bg:#f5f9ff;
  --bg2:#edf4ff;
  --card:#ffffff;
  --card2:#f8fbff;
  --line:#c1d6ef;
  --text:#13243b;
  --muted:#5d708c;
  --accent:#2f78ef;
  --accent2:#0ea286;
  background:linear-gradient(180deg,#f5f9ff,#edf4ff 100%);
}
a{color:inherit;text-decoration:none}
.container{width:min(1160px,calc(100% - 28px));margin:0 auto;padding:26px 0 48px}
.nav{
  display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;
  margin-bottom:18px;padding:14px 16px;border:1px solid rgba(255,255,255,.08);
  background:rgba(9,17,29,.74);backdrop-filter:blur(10px);border-radius:18px;
}
body.light .nav, body.light .hero, body.light .card, body.light .footer{
  background:rgba(255,255,255,.92);border-color:rgba(19,36,59,.10);
  box-shadow:0 16px 36px rgba(41,73,128,.08);
}
.nav-left{display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.brand{font-weight:800;letter-spacing:.01em}
.nav-links{display:flex;gap:10px;flex-wrap:wrap}
.nav-links a{
  padding:10px 12px;border-radius:999px;color:var(--muted);
  border:1px solid rgba(255,255,255,.08);background:rgba(255,255,255,.03);font-size:14px;
}
body.light .nav-links a{border-color:rgba(19,36,59,.09);background:rgba(19,36,59,.03)}
.btn{
  appearance:none;border:none;cursor:pointer;border-radius:14px;padding:11px 14px;
  font-size:14px;font-weight:700;
}
.btn.primary{background:linear-gradient(135deg,var(--accent),#8bb5ff);color:#09111d}
.btn.ghost{background:transparent;color:var(--muted);border:1px solid rgba(255,255,255,.1)}
body.light .btn.ghost{border-color:rgba(19,36,59,.12)}
.hero,.card,.footer{
  background:linear-gradient(180deg,rgba(19,32,58,.95),rgba(12,21,37,.98));
  border:1px solid rgba(255,255,255,.08);border-radius:28px;box-shadow:var(--shadow);
}
.hero{padding:26px;margin-bottom:18px}
.eyebrow{
  display:inline-flex;padding:8px 12px;border-radius:999px;font-size:12px;
  text-transform:uppercase;letter-spacing:.06em;color:var(--accent2);
  background:rgba(139,241,210,.08);border:1px solid rgba(139,241,210,.18)
}
h1{margin:12px 0 10px;font-size:clamp(32px,4.8vw,58px);line-height:1.03;letter-spacing:-.03em}
.lead{color:var(--muted);font-size:17px;max-width:760px;margin:0}
.grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:16px;margin-top:20px
}
.tool-card{
  border:1px solid rgba(255,255,255,.08);border-radius:18px;padding:16px;
  background:rgba(255,255,255,.03);
}
body.light .tool-card, body.light .result, body.light .diagram, body.light .stat{
  background:rgba(19,36,59,.03);border-color:rgba(19,36,59,.08)
}
.tool-card h3{margin:0 0 8px;font-size:20px}
.tool-card p{margin:0 0 12px;color:var(--muted);font-size:14px;min-height:40px}
.tool-card a{display:inline-flex}
.page-head{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;flex-wrap:wrap;margin-bottom:10px}
.page-head h1{font-size:clamp(28px,4.2vw,48px);margin:0}
.badge{
  font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:var(--accent2);
  padding:7px 10px;border-radius:999px;border:1px solid rgba(139,241,210,.16);background:rgba(139,241,210,.08)
}
.card{padding:20px}
.description{color:var(--muted);margin:0 0 16px}
.fields{display:grid;grid-template-columns:1fr 1fr;gap:12px}
label{display:block;font-size:12px;color:var(--muted);margin-bottom:6px}
input,select{
  width:100%;padding:12px 13px;font-size:15px;color:var(--text);background:#0c172a;
  border:1px solid rgba(255,255,255,.09);border-radius:14px;outline:none
}
body.light input, body.light select{background:#fff;color:var(--text);border-color:rgba(19,36,59,.12)}
.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px}
.result{
  margin-top:14px;padding:14px;border-radius:16px;min-height:76px;
  border:1px solid rgba(255,255,255,.08);background:rgba(255,255,255,.03)
}
.result strong{color:var(--good)}
.muted{color:var(--muted);font-size:12px}
.result-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-top:10px}
.stat{
  padding:10px 12px;border-radius:14px;border:1px solid rgba(255,255,255,.05);
  background:rgba(255,255,255,.03)
}
.label{font-size:12px;color:var(--muted);margin-bottom:4px}
.value{font-size:18px;font-weight:800}
.diagram{
  margin-top:12px;padding:12px;border-radius:16px;border:1px solid rgba(255,255,255,.06);
  background:linear-gradient(180deg,rgba(10,18,30,.72),rgba(7,12,21,.9))
}
.diagram svg{width:100%;height:auto;display:block}
.footer{margin-top:18px;padding:18px;color:var(--muted);font-size:13px;line-height:1.55}
.back{display:inline-flex;align-items:center;gap:8px;color:var(--muted);margin-bottom:14px}
@media (max-width:720px){
  .fields,.result-grid{grid-template-columns:1fr}
  .container{width:min(100% - 20px,1160px)}
}