:root{
  --bg:#f7f9fc;--surface:#fff;--sunk:#eef3f9;--ink:#121822;--muted:#5a6578;--line:#e1e7ef;
  --blue:#0a84f0;--blue-ink:#0067c7;--shadow:0 1px 2px rgb(16 24 40 / .04),0 18px 40px -18px rgb(16 24 40 / .16);
}
:root[data-mode="dark"]{
  --bg:#0b1018;--surface:#111925;--sunk:#0e1520;--ink:#e9eef5;--muted:#98a4b7;--line:#1f2b3b;
  --blue:#3aa0ff;--blue-ink:#7cc0ff;--shadow:0 1px 2px rgb(0 0 0 / .3),0 18px 40px -18px rgb(0 0 0 / .6);
  color-scheme:dark;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:"Tiro Bangla","Noto Serif Bengali",Georgia,serif;line-height:1.65}
a{color:var(--blue-ink);text-decoration:none}
a:hover{text-decoration:underline}
.top{position:sticky;top:0;z-index:5;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 6vw;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.top nav{display:flex;align-items:center;gap:16px;font-size:.95rem}
.top nav a{color:var(--ink)}
.logo{height:34px;width:auto;display:block}
.logo-d{display:none}
:root[data-mode="dark"] .logo-l{display:none}
:root[data-mode="dark"] .logo-d{display:block}
.theme{border:1px solid var(--line);background:var(--surface);color:var(--ink);width:36px;height:36px;border-radius:50%;cursor:pointer;font-size:1rem}
.wrap{width:min(760px,92vw);margin:36px auto 64px}
.kicker{color:var(--blue-ink);font-size:.92rem;margin:0 0 6px}
h1{font-size:clamp(1.8rem,4vw,2.5rem);line-height:1.25;margin:0 0 8px}
.updated{color:var(--muted);margin:0 0 22px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:22px 24px}
.card h2{font-size:1.2rem;margin:22px 0 6px}
.card h2:first-child{margin-top:0}
.card p,.card li{margin:0 0 10px}
.card ul,.card ol{padding-left:1.2rem}
.facts{list-style:none;padding:0;margin:18px 0;display:grid;gap:10px}
.facts li{background:var(--sunk);border-radius:12px;padding:12px 14px}
.facts b{display:block;font-size:.82rem;color:var(--muted)}
.btn{display:inline-flex;align-items:center;justify-content:center;background:var(--blue);color:#fff;border-radius:999px;padding:10px 18px;font:inherit;text-decoration:none}
.btn:hover{text-decoration:none;filter:brightness(1.05)}
.ft{background:#0c121c;color:#d5deea;margin-top:20px}
.ft a{color:#d5deea}
.ft-in{width:min(980px,92vw);margin:0 auto;padding:36px 0 22px;display:grid;gap:18px}
.ft h2{margin:0;font-size:1rem;color:#fff}
.ft ul{list-style:none;padding:0;margin:8px 0 0;display:grid;gap:6px}
.ft .cols{display:grid;grid-template-columns:1.2fr 1fr;gap:24px}
.ft small{color:#8ea0b8}
@media (max-width:640px){.ft .cols{grid-template-columns:1fr}.top nav a:not(.keep){display:none}}