:root{--ink:#0a0a0a;--g:#004225;--gd:#00331c;--line:#dde4df;--f:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif}
*{box-sizing:border-box;margin:0}
html{scroll-behavior:smooth}
body{font:17px/1.65 var(--f);color:var(--ink);background:#fff;-webkit-font-smoothing:antialiased}
a{color:var(--g)}
img{max-width:100%}
:focus-visible{outline:3px solid var(--g);outline-offset:3px}
html[data-lang="en"] [data-l="bn"],html[data-lang="bn"] [data-l="en"]{display:none!important}
:lang(bn){font-family:"Noto Sans Bengali","Nirmala UI","Kohinoor Bangla","Vrinda",sans-serif}
:lang(bn) p,:lang(bn) li,:lang(bn) td,:lang(bn) th{line-height:1.85}
:lang(bn) h1,:lang(bn) h2,:lang(bn) h3,:lang(bn) .tile b{letter-spacing:0;line-height:1.35}
:lang(bn) h1{font-size:clamp(2rem,5vw,3.4rem)}
.w{max-width:1100px;margin:0 auto;padding:0 24px}
header{position:sticky;top:0;z-index:9;background:rgba(255,255,255,.94);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.bar{display:flex;align-items:center;gap:10px;min-height:64px;flex-wrap:nowrap}
.logo{font-weight:700;color:var(--ink);text-decoration:none;font-size:1.1rem;margin-right:auto;white-space:nowrap;flex:0 0 auto}
.logo span{color:var(--g);font-weight:500}
nav{display:flex;gap:12px;font-size:.86rem;min-width:0;flex:0 1 auto}
nav a{text-decoration:none;color:#333;white-space:nowrap}
nav a:hover,nav a[aria-current]{color:var(--g)}
.lt{display:flex;border:1.5px solid var(--g);border-radius:999px;overflow:hidden}
.lt button{font:inherit;font-size:.8rem;font-weight:600;border:0;background:#fff;color:var(--g);padding:5px 10px;cursor:pointer}
.lt button[aria-pressed="true"]{background:var(--g);color:#fff}
.btn{display:inline-block;padding:12px 26px;border-radius:999px;background:var(--g);color:#fff;text-decoration:none;border:0;font:inherit;font-weight:600;cursor:pointer}
.btn:hover{background:var(--gd)}
.bar>.btn{padding:9px 14px;font-size:.86rem;white-space:nowrap;flex:0 0 auto}
.btn.o{background:none;color:var(--g);box-shadow:inset 0 0 0 1.5px var(--g)}
.btn.o:hover{background:#eef4f0}
.cta{display:flex;gap:14px;flex-wrap:wrap;margin-top:30px}
h1{font-size:clamp(2.6rem,6vw,4.6rem);line-height:1.03;letter-spacing:-.03em;margin-bottom:22px}
h2{font-size:clamp(1.9rem,4vw,3rem);line-height:1.1;letter-spacing:-.025em;margin-bottom:16px}
h3{font-size:1.3rem;line-height:1.25;margin-bottom:8px}
.sub{color:var(--g);font-size:1.2rem;max-width:46ch}
.hero{padding:84px 0 72px}
.hg,.c2{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.c3{display:grid;grid-template-columns:repeat(3,1fr);gap:36px}
.c4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
section{padding:80px 0;border-top:1px solid var(--line)}
section[id]{scroll-margin-top:72px}
.tile{text-decoration:none;color:var(--ink);display:block}
.tile b{display:block;font-size:1.12rem}
.tile span{color:var(--g);font-size:.95rem}
.img{aspect-ratio:4/3;border-radius:10px;margin-bottom:14px;overflow:hidden;background:#e9ecee}
.img img{width:100%;height:100%;object-fit:cover}
.hero .img{aspect-ratio:1;margin:0}
.sheet{background:repeating-linear-gradient(90deg,rgba(255,255,255,.2) 0 1px,rgba(0,0,0,.06) 1px 3px),linear-gradient(125deg,#9aa5ae,#eef1f3 40%,#a3adb6 65%,#dde2e6)}
.coil{background:radial-gradient(circle,#f4f6f7 0 13%,#8a959e 13.5% 15%,transparent 15.5%),repeating-radial-gradient(circle,#d3d9de 0 5px,#8d98a1 5px 7px),#e9ecee}
.pipe{background:radial-gradient(circle,#f7f8f9 0 20%,#8a959e 21% 23%,#d3d9de 24% 38%,#7f8a93 39% 41%,transparent 42%),#e9ecee}
.rods{background:repeating-linear-gradient(90deg,#d6dce0 0 30px,#8d98a1 30px 33px,#eef1f3 33px 36px)}
.alu{background:linear-gradient(135deg,#d9dee2,#fafbfb 45%,#c3cacf)}
.cop{background:repeating-linear-gradient(90deg,rgba(255,255,255,.12) 0 1px,rgba(0,0,0,.08) 1px 3px),linear-gradient(135deg,#7b3f1d,#dc8f5c 45%,#a85a2c 70%,#e6a678)}
.brs{background:repeating-linear-gradient(90deg,rgba(255,255,255,.12) 0 1px,rgba(0,0,0,.07) 1px 3px),linear-gradient(135deg,#86661c,#ead06c 45%,#b08a2c 70%,#efd783)}
.mirror{background:linear-gradient(120deg,#6b7782,#f7fafc 30%,#8a96a0 52%,#fbfdfe 78%,#74808b)}
.hair{background:repeating-linear-gradient(90deg,rgba(255,255,255,.25) 0 1px,rgba(0,0,0,.09) 1px 3px),linear-gradient(135deg,#aab4bd,#e3e8eb 50%,#a3adb6)}
.etch{background:repeating-linear-gradient(45deg,rgba(0,0,0,.11) 0 2px,transparent 2px 9px),repeating-linear-gradient(-45deg,rgba(255,255,255,.4) 0 2px,transparent 2px 9px),linear-gradient(135deg,#9aa5ae,#d9e0e4)}
.pvd{background:linear-gradient(125deg,#6e4f2a,#e0be86 40%,#9a7440 65%,#d9b57c)}
.rows{list-style:none;padding:0;border-top:1px solid var(--line);margin-top:18px}
.rows li{padding:12px 0;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;gap:16px}
.rows span{color:var(--g);text-align:right}
.ind{display:flex;flex-wrap:wrap;gap:10px 34px;font-size:1.45rem;font-weight:600;letter-spacing:-.01em}
.art{max-width:720px}
.art h1{font-size:clamp(2.2rem,5vw,3.6rem)}
.art h2{font-size:1.7rem;margin-top:48px}
.art h3{margin-top:26px}
.art p,.art ul{margin-bottom:18px}
.art ul{padding-left:22px}
.art li{margin-bottom:8px}
.note{border-left:3px solid var(--g);padding:4px 0 4px 18px;color:var(--g);margin:28px 0}
.tw{overflow-x:auto;margin:22px 0 30px}
table{border-collapse:collapse;width:100%;font-size:.96rem}
th,td{padding:12px 14px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
th{color:var(--g);font-weight:600;border-bottom:2px solid var(--g)}
td:first-child{font-weight:600}
form{display:grid;gap:14px}
label{font-size:.92rem;color:var(--g)}
input,textarea{width:100%;padding:13px 14px;border-radius:8px;border:1px solid #b9c6bd;font:inherit;margin-top:6px;background:#fff;color:var(--ink)}
.det p{margin-bottom:18px}
.det b{display:block}
footer{border-top:1px solid var(--line);padding:36px 0;font-size:.92rem}
footer .w{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap}
footer a{margin-right:18px;display:inline-block}
@media (min-width:861px) and (max-width:1100px){
.bar{flex-wrap:wrap;padding-top:8px}
.logo{margin-right:auto}
.bar>.btn{margin-left:auto}
nav{order:3;flex:1 0 100%;width:100%;overflow-x:auto;gap:18px;padding:0 0 10px}
}
@media(max-width:860px){
.hg,.c2,.c3{grid-template-columns:1fr;gap:32px}
.c4{grid-template-columns:repeat(2,1fr)}
.hero{padding:48px 0}
section{padding:56px 0}
.bar{flex-wrap:wrap;gap:10px;padding-top:8px}
.bar>.btn{order:2;padding:8px 12px;font-size:.82rem;margin-left:0}
nav{order:3;flex:1 1 180px;width:auto;min-width:0;overflow-x:auto;gap:16px;padding:0 0 10px}
.lt{order:3;flex:0 0 auto}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}