:root{
    --teal:#157264; --teal-deep:#0E574E; --teal-tint:#EAF5F2;
    --honey:#F2A65A; --honey-deep:#E8973A;
    --ink:#13201D; --ink-2:#26332F; --mut:#56655F;
    --line:#E3ECE9; --line-soft:#EEF3F0;
    --bg:#F7FAF9; --bg-2:#F0F6F4; --panel:#FFFFFF;
    --disp:'Roboto',system-ui,-apple-system,sans-serif;
    --sans:'Roboto',system-ui,-apple-system,sans-serif;
    --bn:'SolaimanLipi','Noto Sans Bengali','Hind Siliguri',sans-serif;
  }
  *{box-sizing:border-box;margin:0;padding:0}
  html{scroll-behavior:smooth}
  body{font-family:var(--sans);background:var(--bg);color:var(--ink-2);font-size:16.5px;line-height:1.7;-webkit-font-smoothing:antialiased}
  a{color:var(--teal);text-decoration:none}
  a:hover{text-decoration:underline}
  img{max-width:100%;display:block}
  :focus-visible{outline:3px solid color-mix(in srgb,var(--teal) 55%,transparent);outline-offset:2px;border-radius:6px}
  .wrap{max-width:min(94vw,1280px);margin:0 auto;padding:0 clamp(22px,3vw,48px)}
  .mark{flex:none;border-radius:9px;box-shadow:0 6px 14px -6px rgba(16,90,80,.5)}

  /* ---------- header ---------- */
  .nav{position:sticky;top:0;z-index:100;background:color-mix(in srgb,var(--bg) 88%,transparent);
    backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
  .nav-in{display:flex;align-items:center;justify-content:space-between;height:66px}
  .brand{display:flex;align-items:center;gap:11px;color:var(--ink)}
  .brand:hover{text-decoration:none}
  .brand .nm{font-family:var(--disp);font-weight:700;font-size:19px;letter-spacing:-.02em;white-space:nowrap}
  .brand .nm i{font-style:normal;color:var(--teal)}
  .brand .by{font-size:12px;color:var(--mut);font-weight:500;margin-left:1px;white-space:nowrap}
  .nav-back{font-family:var(--disp);font-size:14px;font-weight:700;color:var(--teal-deep);background:var(--teal-tint);
    border:1px solid #D4ECE5;border-radius:999px;padding:8px 16px;white-space:nowrap}
  .nav-back:hover{text-decoration:none;background:#DCF1EB}

  /* ---------- document ---------- */
  .doc{max-width:min(94vw,1280px);margin:0 auto;padding:clamp(38px,4.2vw,68px) clamp(22px,3vw,48px) clamp(56px,5vw,92px)}
  .doc-head{padding-bottom:30px;border-bottom:1px solid var(--line)}
  .doc-head h1{font-family:var(--disp);font-size:clamp(30px,3.6vw,48px);font-weight:700;letter-spacing:-.03em;line-height:1.1;color:var(--ink)}
  .doc-head .updated{display:inline-flex;align-items:center;gap:8px;margin-top:16px;font-family:var(--disp);font-size:13px;font-weight:700;
    color:var(--teal-deep);background:var(--teal-tint);border:1px solid #D4ECE5;border-radius:999px;padding:6px 14px}
  .doc-head .updated .dot{width:7px;height:7px;border-radius:50%;background:var(--teal)}
  .doc-head p.lede{margin-top:20px;color:var(--mut);font-size:clamp(16.5px,1.2vw,18px);max-width:84ch}

  .note{display:flex;gap:13px;align-items:flex-start;margin-top:22px;background:#FCF4EA;border:1px solid #F4E1C9;
    border-radius:14px;padding:16px 18px;max-width:86ch}
  .note svg{flex:none;color:var(--honey-deep);margin-top:2px}
  .note p{margin:0;font-size:14.5px;color:#7A5A2E;line-height:1.6}
  .note b{color:#5E461F}

  .doc-grid{display:grid;grid-template-columns:272px minmax(0,1fr);gap:clamp(36px,5vw,88px);align-items:start;margin-top:clamp(30px,3.4vw,50px)}
  .toc{position:sticky;top:88px;display:flex;flex-direction:column}
  .toc h4{font-family:var(--disp);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--mut);font-weight:700;margin:0 0 12px 14px}
  .toc a{color:var(--mut);font-size:13.5px;font-weight:600;padding:7px 14px;border-left:2px solid var(--line);line-height:1.4}
  .toc a:hover{color:var(--teal);border-left-color:var(--teal);text-decoration:none;background:var(--teal-tint)}
  .doc-body{max-width:84ch}
  .doc-body > h2:first-child{margin-top:0}

  .doc h2{font-family:var(--disp);font-size:21px;font-weight:700;letter-spacing:-.02em;line-height:1.25;margin:40px 0 12px;color:var(--ink);scroll-margin-top:84px}
  .doc h2 .n{color:var(--teal);font-variant-numeric:tabular-nums;margin-right:7px}
  .doc h3{font-family:var(--disp);font-size:16.5px;font-weight:700;margin:22px 0 8px;color:var(--ink)}
  .doc p{margin:0 0 14px;color:var(--ink-2)}
  .doc ul{margin:0 0 14px;padding-left:4px;color:var(--ink-2);list-style:none}
  .doc ul li{margin-bottom:9px;padding-left:26px;position:relative}
  .doc ul li::before{content:"";position:absolute;left:4px;top:10px;width:7px;height:7px;border-radius:50%;background:var(--teal);opacity:.55}
  .doc strong{color:var(--ink);font-weight:700}

  .callout{background:var(--teal-tint);border:1px solid #D4ECE5;border-radius:14px;padding:18px 20px;margin:4px 0 16px;
    display:flex;gap:13px;align-items:flex-start}
  .callout svg{flex:none;color:var(--teal);margin-top:2px}
  .callout p{margin:0;font-size:15px;color:var(--teal-deep)}
  .callout p strong{color:var(--teal-deep)}

  .contact-card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:24px;margin-top:14px}
  .contact-card .row{display:flex;gap:10px;padding:8px 0;font-size:15.5px;flex-wrap:wrap;border-bottom:1px solid var(--line-soft)}
  .contact-card .row:last-child{border-bottom:none}
  .contact-card .k{font-family:var(--disp);font-weight:700;color:var(--ink);min-width:96px}
  .ph-ch{color:var(--honey-deep);font-weight:600}

  /* ---------- footer ---------- */
  .footer{background:var(--ink);color:#DCE6E2;padding:36px 0 30px;margin-top:24px}
  .footer a{color:rgba(220,230,226,.74)}
  .footer a:hover{color:#fff;text-decoration:none}
  .footer-in{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px}
  .f-brand{display:flex;align-items:center;gap:10px}
  .f-brand .nm{font-family:var(--disp);font-weight:700;font-size:17px;color:#fff}
  .f-brand .nm i{font-style:normal;color:var(--honey)}
  .f-links{display:flex;gap:22px;font-size:14px;flex-wrap:wrap}
  .f-copy{font-size:12.5px;color:rgba(220,230,226,.5);width:100%;margin-top:14px;padding-top:16px;
    border-top:1px solid rgba(255,255,255,.1);display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px}

  @media (max-width:980px){
    .doc-grid{display:block}
    .toc{display:none}
  }
  @media (max-width:600px){
    .doc{padding:36px 20px 56px}
    .brand .by{display:none}
  }