:root{
  --bg:#0f172a; --card:#111827; --text:#e5e7eb; --muted:#9ca3af;
  --accent:#22c55e; --accent2:#60a5fa; --danger:#ef4444;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,"Helvetica Neue",Arial}
a{color:var(--accent2);text-decoration:none}
.site-header{display:flex;justify-content:space-between;align-items:center;padding:16px 24px;background:#0b1220;position:sticky;top:0;z-index:10;border-bottom:1px solid #1f2937}
.logo{font-weight:700;letter-spacing:.5px}
.nav ul{display:flex;gap:16px;list-style:none;margin:0;padding:0}
.nav button{display:none}
@media(max-width:840px){
  .nav button{display:block;background:transparent;border:1px solid #1f2937;color:var(--text);padding:6px 10px;border-radius:6px}
  .nav ul{display:none;flex-direction:column;position:absolute;right:16px;top:56px;background:#0b1220;padding:12px;border:1px solid #1f2937;border-radius:8px}
  .nav ul.open{display:flex}
}
.hero{padding:64px 24px;text-align:center;background:linear-gradient(120deg,#0b1220,#0f172a)}
.hero h1{font-size:2rem;margin-bottom:12px}
.cta{display:inline-block;margin-top:12px;background:var(--accent);color:#052e1a;padding:10px 16px;border-radius:8px;font-weight:600}
.content{padding:40px 24px;max-width:1100px;margin:0 auto}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px}
article{background:var(--card);padding:16px;border:1px solid #1f2937;border-radius:10px}
.table-wrap{overflow-x:auto;background:var(--card);border:1px solid #1f2937;border-radius:10px;margin:12px 0}
table{width:100%;border-collapse:collapse}
th,td{padding:12px;border-bottom:1px solid #1f2937;text-align:left}
th{color:var(--muted);font-weight:600}
.tools{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px}
.tool{background:var(--card);padding:16px;border:1px solid #1f2937;border-radius:10px}
label{display:block;margin:8px 0;color:var(--muted)}
input{width:100%;padding:10px;border-radius:8px;border:1px solid #374151;background:#0b1220;color:var(--text)}
button{background:var(--accent2);color:#061a2e;border:none;border-radius:8px;padding:10px 14px;font-weight:600;cursor:pointer}
button:hover{filter:brightness(1.1)}
.result{margin-top:10px;padding:10px;border:1px dashed #334155;border-radius:8px}
.glossary{columns:2;column-gap:24px}
details{background:var(--card);padding:12px;border-radius:10px;border:1px solid #1f2937;margin-bottom:10px}
.site-footer{padding:24px;text-align:center;color:var(--muted);border-top:1px solid #1f2937}
.note{color:var(--muted);font-size:.9rem}
.math{display:inline-block;background:#0b1220;padding:6px 8px;border-radius:6px;border:1px solid #1f2937}