:root{
  --teal:#0d9488;--teal-bright:#13b6aa;--teal-deep:#057b8e;
  --navy:#082c46;--navy-deep:#061f32;
  --bg:#f7f9fa;--surface:#ffffff;--text:#111827;--muted:#44545c;--line:#e6edef;
  --radius:14px;--max:1080px;
}
@media (prefers-color-scheme:dark){
  :root{--bg:#0f1720;--surface:#16202b;--text:#e3e8ec;--muted:#b8c4cc;--line:#2a3742;}
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans","Noto Sans Bengali",sans-serif;color:var(--text);background:var(--bg)}
a{color:var(--teal);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}

/* header */
.site-header{background:var(--navy);color:#fff;position:sticky;top:0;z-index:10;box-shadow:0 2px 12px rgba(0,0,0,.18)}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:64px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:700;font-size:18px;letter-spacing:.2px}
.brand:hover{text-decoration:none}
.brand svg{width:34px;height:34px}
.nav{display:flex;gap:6px;flex-wrap:wrap}
.nav a{color:#cfe3ea;padding:8px 12px;border-radius:8px;font-size:15px}
.nav a:hover,.nav a[aria-current]{background:rgba(255,255,255,.1);color:#fff;text-decoration:none}
.nav .cta{background:var(--teal-bright);color:#03201c;font-weight:600}
.nav .cta:hover{background:#3fd1c6}
@media (max-width:720px){.nav a:not(.cta){display:none}}

/* hero */
.hero{background:linear-gradient(160deg,var(--navy) 0%,var(--navy-deep) 60%,#0b3a4e 100%);color:#fff;padding:72px 0 64px}
.hero .wrap{display:grid;grid-template-columns:1.2fr .8fr;gap:40px;align-items:center}
@media (max-width:820px){.hero .wrap{grid-template-columns:1fr}}
.hero h1{font-size:44px;line-height:1.15;margin:0 0 16px;letter-spacing:-.5px}
.hero p.lead{font-size:19px;color:#cfe3ea;margin:0 0 28px;max-width:560px}
.btn{display:inline-flex;align-items:center;gap:10px;padding:14px 22px;border-radius:12px;font-weight:600;font-size:16px;border:0;cursor:pointer}
.btn-primary{background:var(--teal-bright);color:#03201c}
.btn-primary:hover{background:#3fd1c6;text-decoration:none}
.btn-ghost{background:rgba(255,255,255,.08);color:#fff;border:1px solid rgba(255,255,255,.2)}
.btn-ghost:hover{background:rgba(255,255,255,.14);text-decoration:none}
.hero .meta{margin-top:14px;font-size:13px;color:#9fc3d4}
.phone{background:#0f1720;border-radius:34px;padding:14px;box-shadow:0 30px 60px rgba(0,0,0,.4);max-width:300px;margin:0 auto}
.phone .screen{background:#121b26;border-radius:24px;padding:18px 14px;min-height:420px;color:#e3e8ec;font-size:13px}
.phone .field{background:#1d2836;border:1px solid #2a3742;border-radius:10px;padding:12px;color:#8fa1ad;margin-bottom:10px}
.phone .row{display:flex;gap:8px;margin-bottom:16px}
.phone .row span{flex:1;text-align:center;padding:10px;border-radius:999px;border:1px solid #2a3742;color:#13b6aa;font-weight:600}
.phone .row span.solid{background:#13b6aa;color:#03201c;border-color:#13b6aa}
.phone .chips{display:flex;gap:6px;justify-content:center;margin:6px 0 18px}
.phone .chips i{font-style:normal;border:1px solid #2a3742;border-radius:8px;padding:4px 10px;color:#b8c4cc;font-size:12px}
.phone .card{display:flex;gap:10px;background:#1d2836;border-radius:12px;padding:10px;margin-bottom:8px}
.phone .card .thumb{width:64px;height:44px;border-radius:8px;background:linear-gradient(135deg,#0d9488,#082c46)}
.phone .card b{display:block;font-size:12px;margin-bottom:4px}
.phone .card small{color:#8fa1ad}
.phone .bar{height:4px;background:#2a3742;border-radius:4px;overflow:hidden;margin-top:6px}
.phone .bar i{display:block;height:100%;width:62%;background:#13b6aa}
.phone .tabs{display:flex;justify-content:space-around;margin-top:18px;padding-top:12px;border-top:1px solid #2a3742;color:#8fa1ad;font-size:11px}
.phone .tabs b{color:#13b6aa}

/* sections */
section{padding:56px 0}
section h2{font-size:30px;margin:0 0 8px;letter-spacing:-.3px}
section .sub{color:var(--muted);margin:0 0 28px;max-width:640px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:18px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px}
.card h3{margin:0 0 6px;font-size:18px}
.card p{margin:0;color:var(--muted)}
.card .ico{width:40px;height:40px;border-radius:10px;background:rgba(13,148,136,.12);display:flex;align-items:center;justify-content:center;margin-bottom:12px;color:var(--teal)}
.steps{counter-reset:s}
.steps .card{position:relative;padding-left:64px}
.steps .card::before{counter-increment:s;content:counter(s);position:absolute;left:20px;top:22px;width:30px;height:30px;border-radius:50%;background:var(--teal);color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center}
.faq details{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin-bottom:10px}
.faq summary{cursor:pointer;font-weight:600}
.faq p{margin:10px 0 0;color:var(--muted)}
.band{background:var(--navy);color:#fff;text-align:center;padding:56px 0}
.band h2{color:#fff}
.band p{color:#cfe3ea}
.notice{background:rgba(13,148,136,.1);border-left:4px solid var(--teal);padding:14px 18px;border-radius:8px;color:var(--text)}

/* prose pages */
.prose{max-width:760px}
.prose h1{font-size:36px;margin:0 0 6px}
.prose .date{color:var(--muted);margin-bottom:28px}
.prose h2{font-size:22px;margin:32px 0 8px}
.prose p,.prose li{color:var(--text)}
.prose ol,.prose ul{padding-left:22px}
.prose code{background:var(--line);padding:2px 6px;border-radius:6px;font-size:14px}

/* download page */
.dl{display:grid;grid-template-columns:1fr 1fr;gap:18px}
@media (max-width:720px){.dl{grid-template-columns:1fr}}
.dl .card{text-align:center;padding:32px 22px}
.dl .card .big{font-size:22px;font-weight:700;margin-bottom:6px}
.dl .card .small{color:var(--muted);font-size:14px;margin-bottom:18px}
.badge{display:inline-block;background:var(--line);color:var(--muted);border-radius:999px;padding:4px 12px;font-size:12px;font-weight:600}
table.spec{width:100%;border-collapse:collapse;margin-top:18px}
table.spec td{padding:10px 8px;border-bottom:1px solid var(--line)}
table.spec td:first-child{color:var(--muted);width:40%}

/* footer */
.site-footer{background:var(--navy-deep);color:#9fc3d4;padding:40px 0;font-size:14px}
.site-footer .wrap{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}
.site-footer a{color:#cfe3ea;margin-right:16px}
.site-footer .legal{max-width:520px}