:root{
  --midnight:#1F1B3A; --deep:#120F26; --track:#3A3466; --mint:#B9F3E4; --mint-deep:#127A64;
  --violet:#7C6CF2; --violet-deep:#6A5AE0; --coral:#FF7A59; --cloud:#F7F7FB;
  --ink:#1F1B3A; --ink-2:#4B4868; --muted:#77748F; --line:rgba(31,27,58,.10); --on-dark:#C9C6E0;
}
*{box-sizing:border-box}
body{margin:0;background:var(--cloud);color:var(--ink);font:400 18px/1.75 Inter,system-ui,-apple-system,sans-serif;-webkit-font-smoothing:antialiased}
a{color:var(--violet-deep)}
img{max-width:100%;height:auto;display:block}
.wrap{max-width:1180px;margin:0 auto;padding-inline:max(20px,env(safe-area-inset-left,0px))}
.btn{display:inline-flex;align-items:center;justify-content:center;border-radius:999px;padding:13px 22px;font:600 16px Inter,sans-serif;text-decoration:none;transition:transform .15s,background .15s}
.btn:hover{transform:translateY(-1px)}
.btn-mint{background:var(--mint);color:var(--midnight)}
.btn-line{color:#fff;border:1px solid rgba(255,255,255,.28)}
.btn-line:hover{border-color:var(--mint);color:var(--mint)}
a:focus-visible,.btn:focus-visible{outline:3px solid var(--violet);outline-offset:2px}
/* nav */
.nav{position:sticky;top:0;z-index:50;background:rgba(18,15,38,.92);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;height:64px}
.logo{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font:600 22px Sora,sans-serif;letter-spacing:-.025em}
.logo svg{width:28px;height:28px}
.nav-links{display:flex;align-items:center;gap:22px;font-size:15px}
.nav-links a:not(.btn){color:var(--on-dark);text-decoration:none}
.nav-links a:not(.btn):hover{color:#fff}
.nav-links .btn{padding:9px 16px;font-size:14px}
/* article */
.post-head{background:var(--midnight);color:#fff;padding:64px 0 72px}
.post-head .inner,.post{max-width:720px;margin:0 auto;padding-inline:20px}
.kicker{font:600 13px Inter,sans-serif;letter-spacing:.08em;text-transform:uppercase;color:var(--mint);text-decoration:none}
h1{font:600 clamp(34px,5vw,52px)/1.08 Sora,sans-serif;letter-spacing:-.03em;margin:14px 0 18px;text-wrap:balance}
.dek{font-size:20px;line-height:1.55;color:var(--on-dark);margin:0}
.byline{margin-top:26px;font-size:15px;color:var(--on-dark)}
.byline strong{color:#fff;font-weight:600}
.post{padding-top:48px;padding-bottom:40px}
.post p{margin:0 0 20px;color:var(--ink-2)}
.post p.big{font:500 22px/1.5 Sora,sans-serif;letter-spacing:-.01em;color:var(--ink)}
.post h2{font:600 28px/1.2 Sora,sans-serif;letter-spacing:-.02em;margin:52px 0 16px;color:var(--ink)}
.post h2 .n{color:var(--violet-deep);margin-right:8px}
.post strong{color:var(--ink)}
.post ul{padding-left:22px;margin:0 0 22px;color:var(--ink-2)}
.post li{margin-bottom:8px}
.post table{width:100%;border-collapse:collapse;margin:8px 0 8px;background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden;font-size:17px}
.post th,.post td{padding:12px 18px;text-align:left;border-bottom:1px solid var(--line)}
.post th{font:600 13px Inter,sans-serif;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);background:var(--cloud)}
.post td.num,.post th.num{text-align:right;font-variant-numeric:tabular-nums}
.post tr.total td{font-weight:700;color:var(--ink);border-bottom:none}
.note{font-size:14px;color:var(--muted);margin:0 0 24px}
.math{background:#fff;border:1px solid var(--line);border-radius:20px;padding:24px 26px;margin:8px 0 24px}
.math .formula{font:600 18px Sora,sans-serif;color:var(--ink);margin-bottom:14px}
.math dl{display:grid;grid-template-columns:1fr auto;gap:8px 16px;margin:0;font-variant-numeric:tabular-nums}
.math dt{color:var(--ink-2)} .math dd{margin:0;text-align:right;font-weight:600;color:var(--ink)}
.math dd.hl{color:var(--mint-deep)}
.pull{border-left:4px solid var(--mint-deep);padding:4px 0 4px 20px;margin:28px 0;font:600 22px/1.4 Sora,sans-serif;color:var(--ink);letter-spacing:-.01em}
.cta{background:var(--midnight);color:#fff;border-radius:28px;padding:36px;margin:40px 0}
.cta h3{font:600 26px/1.2 Sora,sans-serif;letter-spacing:-.02em;margin:0 0 10px}
.cta p{color:var(--on-dark);margin:0 0 22px}
.cta .row{display:flex;gap:12px;flex-wrap:wrap}
.sign{font:600 20px Sora,sans-serif;color:var(--ink);margin-top:32px}
/* index */
.list{max-width:720px;margin:0 auto;padding:48px 20px 40px;display:grid;gap:18px}
.card{display:block;background:#fff;border:1px solid var(--line);border-radius:22px;padding:28px;text-decoration:none;color:var(--ink);box-shadow:0 1px 2px rgba(31,27,58,.05),0 12px 32px rgba(31,27,58,.06);transition:transform .15s}
.card:hover{transform:translateY(-2px)}
.card .meta{font-size:14px;color:var(--muted)}
.card h2{font:600 24px/1.25 Sora,sans-serif;letter-spacing:-.02em;margin:8px 0}
.card p{margin:0;color:var(--ink-2);font-size:17px}
footer{padding:40px 0 56px;color:var(--muted);font-size:14px}
footer .wrap{display:flex;gap:20px;justify-content:space-between;flex-wrap:wrap;align-items:center}
footer a{color:var(--muted);text-decoration:none;margin-right:18px}
@media(max-width:640px){
  body{font-size:17px}
  .nav-links .hide-sm{display:none}
  .post-head{padding:44px 0 52px}
  .post h2{font-size:24px;margin-top:40px}
  .cta{padding:26px;border-radius:22px}
  .post th,.post td{padding:10px 12px}
}