/* EDUINS Virtual Lab – preview v1.0 */
:root{--navy:#0B1F3F;--blue:#0866E8;--blue-d:#0650B8;--yellow:#FFC928;--bg:#F2F8FF;--ink:#101F3B;--muted:#55647D;--line:#DCE6F4;--white:#fff;
--head:"Poppins",Inter,system-ui,sans-serif;--body:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;--r:16px;--sh:0 8px 24px rgba(11,31,63,.08)}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:var(--body);color:var(--ink);background:#fff;font-size:16px;line-height:1.55;-webkit-font-smoothing:antialiased}
img{max-width:100%;height:auto;display:block}a{color:var(--blue);text-decoration:none}
svg.ic{width:1.15em;height:1.15em;flex:none}.flip{transform:rotate(180deg)}
h1,h2,h3{font-family:var(--head);color:var(--navy);line-height:1.15;margin:0 0 .4em}
[lang="bn"]{font-family:"Noto Sans Bengali",var(--body)}
.wrap{width:100%;max-width:1200px;margin:0 auto;padding:0 20px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:-999px;top:0;background:var(--navy);color:#fff;padding:10px 16px;z-index:99}.skip:focus{left:0}
:focus-visible{outline:3px solid var(--yellow);outline-offset:2px;border-radius:6px}
/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;font:600 .95rem/1.2 var(--head);padding:11px 20px;border-radius:10px;border:2px solid transparent;cursor:pointer;transition:transform .15s,background .15s,box-shadow .15s;min-height:44px;text-align:center}
.btn:hover{transform:translateY(-1px)}
.btn-amber{background:var(--yellow);color:var(--navy);box-shadow:0 6px 16px rgba(255,201,40,.35)}.btn-amber:hover{background:#FFD54F;color:var(--navy)}
.btn-blue{background:var(--blue);color:#fff}.btn-blue:hover{background:var(--blue-d);color:#fff}
.btn-outline{border-color:var(--blue);color:var(--blue);background:#fff}.btn-outline:hover{background:var(--blue);color:#fff}
.btn-ghost{color:var(--navy);background:transparent}
.btn-soon{background:#E8EDF5;color:#6A7A93;cursor:default}.btn-soon:hover{transform:none}
.btn-sm{padding:8px 16px;font-size:.88rem;min-height:40px}.btn-lg{padding:15px 30px;font-size:1.08rem}.btn-block{width:100%}
/* topbar + header */
.topbar{background:var(--navy);color:#CBD7EA;font-size:.83rem}
.topbar-in{display:flex;justify-content:space-between;align-items:center;gap:12px;min-height:36px}
.tb-links{display:flex;gap:18px}.tb-links a{color:#fff;display:inline-flex;align-items:center;gap:6px}.tb-links svg{color:var(--yellow)}
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.97);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;gap:20px;min-height:72px}
.brand{display:inline-flex;flex-direction:column;align-items:flex-start;flex:none}
.brand img{height:44px;width:auto}
.brand-tag{display:block;margin:2px 0 0 6px;font:italic 700 .72rem/1.1 var(--head);color:var(--navy);white-space:nowrap}
.site-nav{display:flex;align-items:center;gap:18px;margin-left:auto}
.menu{list-style:none;margin:0;padding:0;display:flex;align-items:center;gap:2px}
.menu>li{position:relative}
.menu>li>a{display:block;padding:9px 12px;border-radius:9px;color:var(--navy);font:600 .93rem var(--head)}
.menu>li>a:hover,.menu>li>a.active{background:#E6F0FE;color:var(--blue)}
.has-drop{display:flex;align-items:center}
.drop-btn{background:none;border:0;padding:6px 4px;margin-left:-8px;color:var(--navy);cursor:pointer;border-radius:6px;display:grid;place-items:center;min-width:28px;min-height:36px}
.drop{list-style:none;margin:0;padding:8px;position:absolute;top:calc(100% + 6px);left:0;min-width:230px;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:0 18px 40px rgba(11,31,63,.16);opacity:0;visibility:hidden;transform:translateY(6px);transition:.16s;z-index:60}
.has-drop:hover .drop,.has-drop.open .drop,.has-drop:focus-within .drop{opacity:1;visibility:visible;transform:none}
.drop a{display:block;padding:9px 12px;border-radius:8px;color:var(--navy);font-weight:600;font-size:.92rem}
.drop a:hover,.drop a[aria-current]{background:#E6F0FE;color:var(--blue)}
.nav-cta{display:flex;gap:10px}
.nav-toggle{display:none;margin-left:auto;width:46px;height:46px;border:1px solid var(--line);border-radius:12px;background:#fff;flex-direction:column;justify-content:center;align-items:center;gap:5px;cursor:pointer}
.nav-toggle span{width:20px;height:2.5px;background:var(--navy);border-radius:2px;transition:.2s}
.nav-toggle[aria-expanded=true] span:nth-child(1){transform:translateY(7.5px) rotate(45deg)}.nav-toggle[aria-expanded=true] span:nth-child(2){opacity:0}.nav-toggle[aria-expanded=true] span:nth-child(3){transform:translateY(-7.5px) rotate(-45deg)}
/* crumbs */
.crumbs ol{list-style:none;margin:0;padding:14px 0 0;display:flex;flex-wrap:wrap;gap:6px;align-items:center;font-size:.9rem;color:#fff}
.crumbs li{display:flex;align-items:center;gap:6px}.crumbs li+li:before{content:"›";opacity:.7}
.crumbs a{color:#fff;font-weight:600;display:inline-flex}.crumbs li[aria-current]{opacity:.9}
/* heroes */
.vhero{position:relative;color:#fff;overflow:hidden;background:linear-gradient(100deg,#04112B 0%,#082A66 45%,#0A4FB8 100%)}
.vhero-bg{position:absolute;inset:0;background:radial-gradient(circle at 70% 40%,rgba(80,170,255,.35),transparent 55%),radial-gradient(rgba(255,255,255,.08) 1.2px,transparent 1.2px) 0 0/22px 22px;pointer-events:none}
.vhero-in{position:relative;display:grid;grid-template-columns:1.05fr 1fr;align-items:center;gap:24px}
.vhero-txt{position:relative;z-index:2;padding:44px 0}
.vhero-art{position:relative;align-self:stretch;display:flex;align-items:flex-end}
.vhero-art img{width:100%;height:100%;max-height:360px;object-fit:cover;object-position:center;border-radius:0;-webkit-mask-image:linear-gradient(90deg,transparent 0,#000 18%);mask-image:linear-gradient(90deg,transparent 0,#000 18%)}
.vh-h1{font:800 clamp(2.3rem,5vw,3.9rem)/1 var(--head);color:#fff;margin:0 0 10px;letter-spacing:-.01em}
.vh-h1 .y{color:var(--yellow)}.vh-h1.sm{font-size:clamp(1.8rem,4vw,2.8rem);margin-top:12px}
.vh-tag{font:700 clamp(1.15rem,2.2vw,1.45rem) var(--head);color:#7CC2FF;margin:0 0 10px}
.vh-lead{max-width:560px;margin:0 0 20px;color:#DCE8FA}
.vh-feats{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:12px 18px}
.vh-feats li{display:flex;align-items:center;gap:8px;font-size:.85rem;line-height:1.25;font-weight:600}
.vh-feats span{width:36px;height:36px;border-radius:9px;display:grid;place-items:center;background:rgba(43,140,255,.35);border:1px solid rgba(255,255,255,.25)}
.hand{position:absolute;font:700 1.25rem/1.2 Kalam,cursive;color:#fff;transform:rotate(-8deg);text-shadow:0 2px 8px rgba(0,0,0,.4);margin:0}
.hand span{color:var(--yellow);border-bottom:3px solid var(--yellow)}
.hand-1{left:4%;top:12%;background:rgba(8,40,100,.55);border:1px solid rgba(120,190,255,.5);padding:10px 14px;border-radius:10px}
.hand-2{left:2%;top:16%}
.sticker{position:absolute;right:3%;bottom:16%;background:var(--yellow);color:var(--navy);font:700 1.1rem/1.1 Kalam,cursive;padding:10px 16px;transform:rotate(-10deg);margin:0;box-shadow:0 6px 18px rgba(0,0,0,.3)}
.vhero-board .vhero-in{grid-template-columns:1fr 1fr}
.bhead{display:flex;align-items:center;gap:22px;padding:26px 0 34px}
.bseal{flex:none;display:grid;place-items:center;width:64px;height:64px;border-radius:50%;background:#fff;color:var(--navy);font:800 .78rem var(--head);border:3px solid var(--bc,#1878C7);box-shadow:inset 0 0 0 3px #fff,inset 0 0 0 5px var(--bc,#1878C7)}
.bseal.big{width:118px;height:118px;font-size:1.25rem;border-width:4px}
.vh-kick{font:700 clamp(1.2rem,2.4vw,1.75rem) var(--head);margin:0}
.vh-board{font:800 clamp(2.6rem,6vw,4.6rem)/1 var(--head);color:#fff;margin:2px 0 10px}
.vh-pill{display:inline-block;background:var(--yellow);color:var(--navy);font:700 clamp(.85rem,1.6vw,1.05rem) var(--head);padding:7px 16px;border-radius:999px;margin:0 0 10px}
.vh-dots{margin:0;font-size:.9rem;color:#DCE8FA}
.vhero-slim .wrap{padding-bottom:30px}
/* sections */
.sec{padding:44px 0}.sec-tint{background:var(--bg)}
.sh{font:800 clamp(1.5rem,3vw,2.1rem) var(--head);margin:0 0 4px}.sh span{color:var(--blue)}.sh.sm{font-size:1.25rem}
.ss{color:var(--muted);margin:0 0 22px}
.sh-row{display:flex;justify-content:space-between;align-items:flex-end;gap:16px;flex-wrap:wrap;margin-bottom:6px}
/* board cards */
.bcards{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.bcard{position:relative;display:flex;align-items:center;gap:16px;padding:22px;border-radius:18px;background:linear-gradient(120deg,#fff 40%,#E3EEFD);border:1px solid var(--line);box-shadow:var(--sh);color:var(--ink);transition:transform .18s,box-shadow .18s}
.bcard:hover{transform:translateY(-3px);box-shadow:0 16px 36px rgba(11,31,63,.14)}
.bcard .bseal{--bc:var(--c)}
.bcard-txt{display:flex;flex-direction:column;gap:4px;flex:1;min-width:0}
.bcard strong{font:800 1.25rem var(--head);color:var(--navy)}.bcard small{color:var(--muted);font-size:.85rem;line-height:1.3}
.pill{align-self:flex-start;background:var(--c);color:#fff;font-size:.78rem;font-weight:700;padding:4px 12px;border-radius:999px;margin-top:4px}
.go{flex:none;width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:var(--blue);color:#fff}
/* subject cards */
.scards{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.scard{position:relative;display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:var(--sh);color:var(--ink);transition:transform .18s,box-shadow .18s,border-color .18s}
.scard:hover{transform:translateY(-3px);box-shadow:0 14px 32px rgba(11,31,63,.14)}
.scard.on{border-color:var(--blue);box-shadow:0 0 0 3px rgba(8,102,232,.25)}
.scard.dim{opacity:.45}
.scard-img{aspect-ratio:10/3.1;overflow:hidden;background:#0B1F3F}.scard-img img{width:100%;height:100%;object-fit:cover}
.scard-body{display:flex;align-items:center;gap:10px;padding:12px 14px}
.scard-ic{flex:none;width:38px;height:38px;border-radius:50%;display:grid;place-items:center;background:var(--c);color:#fff}
.scard-ic svg{width:21px;height:21px}
.scard-txt{flex:1;min-width:0;display:flex;flex-direction:column}.scard-txt strong{font:700 1rem var(--head);color:var(--navy)}
.scard-txt small{color:var(--muted);font-size:.78rem;line-height:1.3}
.scard .go{width:28px;height:28px}.scard .go svg{width:15px;height:15px}
.scard-n{position:absolute;top:8px;right:8px;background:rgba(11,31,63,.78);color:#fff;font-size:.7rem;font-weight:700;padding:3px 8px;border-radius:999px}
/* experiment cards */
.xcards{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.xcard{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden;box-shadow:var(--sh)}
.xcard[hidden]{display:none}
.xcard-img{position:relative;display:block;aspect-ratio:16/5.3;overflow:hidden;background:#0B1F3F}.xcard-img img{width:100%;height:100%;object-fit:cover;transition:transform .3s}
.xcard:hover .xcard-img img{transform:scale(1.04)}
.is-soon .xcard-img img{filter:grayscale(.35) brightness(.85)}
.soon-tag{position:absolute;right:10px;top:10px;background:var(--yellow);color:var(--navy);font:700 .75rem var(--head);padding:4px 10px;border-radius:999px}
.xcard-body{display:flex;flex-direction:column;gap:8px;padding:16px 18px 18px;flex:1}
.xcard-h{font-size:1.06rem;margin:0}.xcard-h a{color:var(--navy)}.xcard-h a:hover{color:var(--blue)}
.chips{display:flex;flex-wrap:wrap;gap:6px;margin:0}
.chip{font-size:.75rem;font-weight:600;padding:3px 10px;border-radius:999px;background:#EEF2F8;color:#33435E}
.chip-sub{background:color-mix(in srgb,var(--c) 14%,#fff);color:var(--c)}
.xcard-p{margin:0;color:var(--muted);font-size:.9rem;flex:1}
.xcard .btn{align-self:flex-start}
.empty{background:#FFF8E1;border:1px solid #FFE08A;border-radius:12px;padding:14px 16px;margin:14px 0 0}
.verify-note{display:flex;gap:8px;align-items:flex-start;margin:18px 0 0;font-size:.82rem;color:var(--muted)}
.verify-note svg{margin-top:2px}
.filter-note{margin:12px 0 0;font-size:.88rem;color:var(--muted);font-weight:600}
.active-filters{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 14px}
.active-filters button{border:1px solid var(--blue);background:#E6F0FE;color:var(--blue);font-weight:600;font-size:.85rem;border-radius:999px;padding:6px 12px;cursor:pointer;min-height:34px}
/* class cards */
.ccards{display:grid;gap:16px}.cc-2{grid-template-columns:repeat(2,1fr)}.cc-4{grid-template-columns:repeat(4,1fr)}
.ccard{display:flex;align-items:center;gap:14px;padding:20px 18px;border-radius:16px;border:3px solid transparent;color:#fff;text-align:left;cursor:pointer;font:inherit;box-shadow:0 10px 24px rgba(11,31,63,.18);transition:transform .15s,box-shadow .15s}
.ccard:hover{transform:translateY(-2px)}
.cc0{background:linear-gradient(120deg,#0A3D9C,#1667D9)}.cc1{background:linear-gradient(120deg,#5A2FC2,#7B4DE0)}.cc2{background:linear-gradient(120deg,#0B6E6E,#14A3A0)}.cc3{background:linear-gradient(120deg,#9B2FC2,#D04FD8)}
.cc-2 .cc0{background:linear-gradient(120deg,#0A3D9C,#1667D9)}
.ccard[aria-pressed=true]{border-color:var(--yellow);box-shadow:0 0 0 4px rgba(255,201,40,.45),0 12px 28px rgba(11,31,63,.25)}
.ccard .cap{flex:none;width:54px;height:54px;border-radius:50%;border:2px solid rgba(255,255,255,.85);display:grid;place-items:center}.ccard .cap svg{width:28px;height:28px}
.ccard strong{display:block;font:700 1.45rem var(--head)}.ccard small{opacity:.9;font-size:.85rem}
.ccard>span:nth-child(2){flex:1}
.ccard .go{background:#fff;color:var(--navy)}
/* board layout + sidebar */
.board-layout{display:block}.board-layout.has-side{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:28px;align-items:start}
.side{padding-top:44px;display:grid;gap:18px;position:sticky;top:90px}
.side-box{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px;box-shadow:var(--sh)}
.side-box h2{display:flex;align-items:center;gap:8px;font-size:1.1rem;margin:0 0 12px}.side-box h2 svg{color:var(--blue)}
.side-box p{margin:0 0 12px;color:var(--muted);font-size:.92rem}
.side-about{display:flex;gap:12px;align-items:flex-start}.side-about .bseal{--bc:#1878C7}
.ticks{list-style:none;margin:0;padding:0;display:grid;gap:8px}.ticks li{display:flex;gap:8px;align-items:flex-start;font-size:.92rem}.ticks svg{color:#1E8E4F;margin-top:3px}
.kf{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.kf div{display:flex;flex-direction:column;align-items:center;text-align:center;gap:6px;border:1px solid var(--line);border-radius:12px;padding:10px 4px;font-size:.78rem;font-weight:600}
.kf svg{width:26px;height:26px;color:var(--blue)}
/* how it works */
.steps6{list-style:none;margin:20px 0 0;padding:0;display:grid;grid-template-columns:repeat(6,1fr);gap:14px}
.steps6 li{display:flex;flex-direction:column;gap:8px;position:relative}
.steps6 .n{width:40px;height:40px;border-radius:50%;display:grid;place-items:center;background:#DDF7EC;color:#0E8F5E;font:800 1.05rem var(--head);border:2px solid #9BE3C5}
.steps6 h3{font-size:.95rem;margin:0}.steps6 p{margin:0;font-size:.84rem;color:var(--muted)}
/* why + dashboard */
.why-grid{display:grid;grid-template-columns:1.2fr 1fr;gap:28px;align-items:start}
.wcards{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:16px}
.wcard{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px;text-align:center;box-shadow:var(--sh)}
.wcard span{display:grid;place-items:center;width:46px;height:46px;margin:0 auto 8px;border-radius:12px;background:#E6F0FE;color:var(--blue)}.wcard span svg{width:24px;height:24px}
.wcard h3{font-size:.92rem;margin:0 0 4px}.wcard p{margin:0;font-size:.8rem;color:var(--muted)}
.dash-h{display:flex;justify-content:space-between;align-items:center;gap:10px}
.sample{background:#FFF3CD;color:#7A5A00;font-size:.75rem;font-weight:700;padding:4px 10px;border-radius:999px}
.dash-box{display:grid;grid-template-columns:140px 1fr;background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden;box-shadow:var(--sh);margin-top:12px}
.dash-side{background:var(--navy);padding:14px 10px;color:#C9D6EA}.dash-side img{width:100px;margin:0 0 12px}
.dash-side ul{list-style:none;margin:0;padding:0;font-size:.78rem;display:grid;gap:4px}.dash-side li{padding:7px 8px;border-radius:7px}.dash-side li.on{background:rgba(255,255,255,.12);color:#fff}
.dash-main{padding:14px}
.dstats{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.dstats div{background:#F4F8FF;border-radius:10px;padding:10px 8px;text-align:center}.dstats b{display:block;font:800 1.3rem var(--head);color:var(--blue)}.dstats small{font-size:.68rem;color:var(--muted);line-height:1.2;display:block}
.dlabel{font-weight:700;font-size:.85rem;margin:14px 0 8px}
.dcont{display:flex;align-items:center;gap:10px;border:1px solid var(--line);border-radius:12px;padding:8px}.dcont img{width:70px;height:46px;object-fit:cover;border-radius:8px}
.dcont div{flex:1;min-width:0;display:flex;flex-direction:column;gap:3px}.dcont strong{font-size:.85rem}.dcont small{font-size:.75rem;color:var(--muted)}
.bar{display:block;height:7px;background:#E6ECF5;border-radius:9px;overflow:hidden}.bar i{display:block;height:100%;background:#1E8E4F;border-radius:9px}
.pct{font-weight:700;font-size:.85rem}
.dnote{display:flex;gap:6px;font-size:.75rem;color:var(--muted);margin:10px 0 0}
/* CTA */
.cta-band{background:linear-gradient(100deg,#04112B,#082A66 55%,#0A4FB8);color:#fff;padding:38px 0}
.cta-in{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap}
.cta-band h2{color:#fff;font-size:clamp(1.5rem,3vw,2.1rem);margin:0 0 6px}.cta-band h2 span{color:var(--yellow)}.cta-band p{margin:0;color:#DCE8FA}
/* catalog filters */
.fbar{display:grid;gap:10px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:14px;margin-bottom:6px}
.fbar>div{display:flex;flex-wrap:wrap;gap:8px;align-items:center}.flabel{font-weight:700;font-size:.85rem;min-width:62px}
.fchip{border:1px solid var(--line);background:#fff;border-radius:999px;padding:7px 14px;font:600 .85rem var(--body);color:var(--navy);cursor:pointer;min-height:38px}
.fchip[aria-pressed=true]{background:var(--blue);border-color:var(--blue);color:#fff}
/* lab page */
.lab-hero{background:linear-gradient(100deg,#04112B,#082A66 55%,#0A4FB8);color:#fff;padding-bottom:26px}
.lab-head{display:flex;align-items:center;gap:16px;margin-top:14px}
.lab-ic{flex:none;width:58px;height:58px;border-radius:16px;display:grid;place-items:center;background:var(--c);color:#fff;box-shadow:0 8px 20px rgba(0,0,0,.3)}.lab-ic svg{width:30px;height:30px}
.lab-head h1{color:#fff;font-size:clamp(1.5rem,3.4vw,2.3rem);margin:0 0 8px}
.lab-head .chip{background:rgba(255,255,255,.14);color:#fff}.lab-head .chip-sub{background:var(--yellow);color:var(--navy)}
.lab-sec{padding-top:24px}
.lab-tabs{display:flex;gap:6px;flex-wrap:wrap;border-bottom:2px solid var(--line);margin-bottom:18px}
.lab-tabs button{display:inline-flex;align-items:center;gap:7px;background:none;border:0;border-bottom:3px solid transparent;margin-bottom:-2px;padding:12px 14px;font:700 .95rem var(--head);color:var(--muted);cursor:pointer;min-height:46px}
.lab-tabs button[aria-selected=true]{color:var(--blue);border-bottom-color:var(--blue)}
.lab-grid{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(280px,1fr);gap:20px;align-items:start}
.stage{background:#0B1F3F;border-radius:16px;overflow:hidden;box-shadow:var(--sh);position:relative}
.stage.light{background:#F7FAFF;border:1px solid var(--line)}
.stage canvas,.stage svg.sim{display:block;width:100%;height:auto}
.panel{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px;box-shadow:var(--sh);display:grid;gap:14px}
.panel h2{font-size:1.05rem;margin:0}
.ctl{display:grid;gap:6px}.ctl label,.ctl .lbl{font-weight:700;font-size:.88rem;display:flex;justify-content:space-between;gap:10px}
.ctl output{color:var(--blue);font-family:var(--head)}
.ctl input[type=range]{width:100%;accent-color:var(--blue);height:28px}
.ctl select,.ctl input[type=text],.ctl input[type=number]{font:inherit;padding:9px 10px;border:1px solid var(--line);border-radius:10px;min-height:42px;width:100%;background:#fff}
.seg{display:flex;flex-wrap:wrap;gap:6px}
.seg button{border:1px solid var(--line);background:#fff;border-radius:9px;padding:8px 12px;font:600 .85rem var(--body);cursor:pointer;min-height:40px;color:var(--navy)}
.seg button[aria-pressed=true]{background:var(--blue);color:#fff;border-color:var(--blue)}
.readout{background:#F4F8FF;border:1px solid #D6E4FA;border-radius:12px;padding:12px 14px;display:grid;gap:6px;font-size:.92rem}
.readout div{display:flex;justify-content:space-between;gap:10px}.readout b{font-family:var(--head);color:var(--navy)}
.callout{border-radius:12px;padding:12px 14px;font-size:.9rem;font-weight:600}
.callout.ok{background:#E3F7EC;color:#11663F}.callout.warn{background:#FFF3CD;color:#7A5A00}.callout.info{background:#E6F0FE;color:#0B4FB0}
.obs{width:100%;border-collapse:collapse;font-size:.88rem}.obs th,.obs td{border:1px solid var(--line);padding:6px 8px;text-align:center}.obs th{background:#F4F8FF}
.obs-wrap{max-height:220px;overflow:auto;border-radius:10px}
.btn-row{display:flex;flex-wrap:wrap;gap:8px}
.mini-graph{background:#fff;border:1px solid var(--line);border-radius:12px}
.prose{max-width:860px}.prose h2{font-size:1.3rem;margin:1.2em 0 .4em}.prose h2:first-child{margin-top:0}.prose p,.prose li{color:#2B3A55}
.prose .formula{background:#F4F8FF;border-left:4px solid var(--blue);padding:10px 14px;border-radius:8px;font-family:var(--head);font-weight:600;color:var(--navy)}
.prose ol li{margin-bottom:6px}
.keybox{background:#FFF8E1;border:1px solid #FFE08A;border-radius:12px;padding:12px 16px;margin-top:14px}.keybox h3{font-size:1rem;margin:0 0 6px}
.quiz{display:grid;gap:16px;max-width:860px}
.qcard{border:1px solid var(--line);border-radius:14px;padding:16px;background:#fff;box-shadow:var(--sh)}
.qcard h3{font-size:1rem;margin:0 0 10px}
.qopts{display:grid;gap:8px}
.qopts button{text-align:left;border:1.5px solid var(--line);background:#fff;border-radius:10px;padding:10px 12px;font:500 .95rem var(--body);cursor:pointer;min-height:44px;color:var(--ink)}
.qopts button:hover:not(:disabled){border-color:var(--blue)}
.qopts button.right{border-color:#1E8E4F;background:#E3F7EC}.qopts button.wrong{border-color:#E23B3B;background:#FDECEC}
.qexp{margin:10px 0 0;font-size:.9rem;color:#2B3A55;background:#F4F8FF;border-radius:10px;padding:10px 12px}
.qscore{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;background:var(--navy);color:#fff;border-radius:14px;padding:16px 18px}
.qscore b{font:800 1.5rem var(--head);color:var(--yellow)}
.lab-back{display:flex;gap:10px;flex-wrap:wrap;margin-top:26px}
/* game pieces */
.match{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.match button{border:1.5px solid var(--line);background:#fff;border-radius:10px;padding:12px;font:600 1.05rem "Noto Sans Bengali",var(--body);cursor:pointer;min-height:48px;color:var(--navy)}
.match button.sel{border-color:var(--blue);background:#E6F0FE}.match button.done{border-color:#1E8E4F;background:#E3F7EC;color:#11663F;cursor:default}
.match button.bad{animation:shake .35s}@keyframes shake{25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}
.tl{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.tl li{display:flex;align-items:center;gap:10px;border:1px solid var(--line);border-radius:12px;padding:10px 12px;background:#fff}
.tl .yr{flex:none;font:800 1rem var(--head);color:#fff;background:#E2622B;border-radius:8px;padding:4px 8px;min-width:58px;text-align:center}
.tl .mv{display:flex;gap:4px;margin-left:auto}.tl .mv button{border:1px solid var(--line);background:#fff;border-radius:8px;min-width:40px;min-height:40px;cursor:pointer;font-size:1rem}
.bits{display:grid;grid-template-columns:repeat(8,1fr);gap:6px}
.bits button{display:flex;flex-direction:column;align-items:center;gap:2px;border:1.5px solid var(--line);border-radius:10px;background:#fff;padding:8px 2px;cursor:pointer;font:700 1.3rem var(--head);color:var(--navy);min-height:56px}
.bits button small{font:500 .65rem var(--body);color:var(--muted)}
.bits button[aria-pressed=true]{background:var(--blue);color:#fff;border-color:var(--blue)}.bits button[aria-pressed=true] small{color:#DCE8FA}
.punnett{display:grid;grid-template-columns:repeat(3,1fr);gap:4px;max-width:330px}
.punnett div{display:grid;place-items:center;min-height:64px;border-radius:10px;font:800 1.3rem var(--head)}
.punnett .h{background:#E6F0FE;color:var(--blue)}.punnett .x{background:transparent}.punnett .c{background:#E3F7EC;color:#11663F}.punnett .c.dw{background:#FFF3CD;color:#7A5A00}
/* footer */
.site-footer{background:#081733;color:#B9C7DD;padding-top:40px;font-size:.92rem}
.foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1.2fr;gap:28px}
.foot-logo{display:inline-flex;flex-direction:column;align-items:center;background:#fff;border-radius:12px;padding:8px 14px;margin-bottom:12px}.foot-logo img{width:150px}.foot-logo .brand-tag{margin:3px 0 0}
.foot-h{color:#fff;font-size:1rem;margin:0 0 10px}
.site-footer ul{list-style:none;margin:0;padding:0;display:grid;gap:8px}.site-footer a{color:#B9C7DD;display:inline-flex;align-items:center;gap:6px}.site-footer a:hover{color:#fff}
.foot-bottom{border-top:1px solid rgba(255,255,255,.1);margin-top:30px;padding:16px 0;text-align:center;font-size:.85rem}
/* responsive */
@media (max-width:1100px){
 .menu>li>a{padding:9px 9px;font-size:.88rem}.nav-cta .btn{padding:9px 14px}
 .scards{grid-template-columns:repeat(3,1fr)}.steps6{grid-template-columns:repeat(3,1fr)}
 .board-layout.has-side{grid-template-columns:1fr}.side{position:static;padding-top:0;padding-bottom:40px;grid-template-columns:1fr 1fr}
 .why-grid{grid-template-columns:1fr}.cc-4{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:980px){
 .nav-toggle{display:flex}
 .site-nav{position:fixed;inset:72px 0 auto 0;max-height:calc(100vh - 72px);overflow:auto;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 20px 40px rgba(11,31,63,.15);flex-direction:column;align-items:stretch;padding:12px 20px 20px;display:none;margin:0}
 .site-nav.open{display:flex}
 .menu{flex-direction:column;align-items:stretch}.menu>li>a{padding:12px 10px;font-size:1rem}
 .has-drop{flex-wrap:wrap}.has-drop>a{flex:1}.drop-btn{margin:0;min-width:46px;min-height:46px}
 .drop{position:static;opacity:1;visibility:visible;transform:none;box-shadow:none;border:0;padding:0 0 6px 14px;display:none;width:100%}
 .has-drop.open .drop{display:block}.has-drop:hover .drop{opacity:1}
 .nav-cta{flex-direction:column}.nav-cta .btn{width:100%}
 .vhero-in,.vhero-board .vhero-in{grid-template-columns:1fr}
 .vhero-txt{padding:30px 0 10px}.vhero-art img{max-height:300px;-webkit-mask-image:none;mask-image:none;border-radius:16px}
 .vhero-art{margin-bottom:24px}
 .bcards{grid-template-columns:1fr}.xcards{grid-template-columns:repeat(2,1fr)}
 .lab-grid{grid-template-columns:1fr}.foot-grid{grid-template-columns:1fr 1fr}
 .tb-txt{display:none}.topbar-in{justify-content:center}
}
@media (max-width:640px){
 .wrap{padding:0 16px}.sec{padding:32px 0}
 .scards{grid-template-columns:repeat(2,1fr);gap:10px}.scard-txt small{display:none}.scard-body{padding:10px;gap:8px}.scard-ic{width:32px;height:32px}.scard .go{display:none}
 .xcards{grid-template-columns:1fr}.steps6{grid-template-columns:1fr 1fr}
 .cc-2,.cc-4{grid-template-columns:1fr}.ccard strong{font-size:1.2rem}
 .wcards{grid-template-columns:1fr 1fr}.side{grid-template-columns:1fr}
 .bhead{gap:14px}.bseal.big{width:80px;height:80px;font-size:.9rem}
 .dash-box{grid-template-columns:1fr}.dash-side{display:none}.dstats{grid-template-columns:1fr 1fr}
 .hand{font-size:1rem}.sticker{font-size:.95rem}
 .foot-grid{grid-template-columns:1fr}.tb-links{gap:12px;font-size:.78rem}
 .match{grid-template-columns:1fr 1fr}.bits button{font-size:1.05rem}
}
@media (max-width:380px){.brand img{height:34px}.brand-tag{font-size:.66rem}.steps6{grid-template-columns:1fr}.vh-feats li{font-size:.8rem}.tb-links a:last-child span{font-size:.72rem}}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
/* v1.0 fixes */
.scards-9{grid-template-columns:repeat(3,1fr)}
.has-side .scards{grid-template-columns:repeat(3,1fr)}
.dash-side .dlogo{background:#fff;border-radius:8px;padding:4px 6px;width:110px}
@media (max-width:640px){.scards-9,.has-side .scards{grid-template-columns:repeat(2,1fr)}}
/* v1.1 – customer care band, WhatsApp */
.btn-wa{background:#25D366;color:#fff}.btn-wa:hover{background:#1DA851;color:#fff}
.help-band{background:linear-gradient(100deg,#FFF6D6,#FFE9A6);border-top:1px solid #F5D774;border-bottom:1px solid #F5D774;padding:26px 0}
.help-in{display:flex;align-items:center;gap:18px;flex-wrap:wrap}
.help-ic{flex:none;width:56px;height:56px;border-radius:50%;display:grid;place-items:center;background:var(--navy);color:var(--yellow)}.help-ic svg{width:28px;height:28px}
.help-txt{flex:1;min-width:240px}.help-txt h2{font-size:1.25rem;margin:0 0 4px}.help-txt p{margin:0;color:#4A3B00;font-size:.95rem}.help-bn{margin-top:4px!important;font-weight:600}
.help-btns{display:flex;gap:10px;flex-wrap:wrap}
.notice-more{display:flex;gap:8px;align-items:flex-start;background:#FFF8E1;border:1px solid #FFE08A;border-radius:12px;padding:10px 14px;margin:-6px 0 18px;font-size:.92rem;color:#4A3B00}
.notice-more svg{margin-top:3px;color:#B07D00}.notice-more a{font-weight:700}
.wa-float{position:fixed;right:18px;bottom:18px;z-index:70;display:flex;align-items:center;gap:8px;background:#25D366;color:#fff;border-radius:999px;padding:10px 16px 10px 12px;font:700 .95rem var(--head);box-shadow:0 10px 26px rgba(0,0,0,.25)}
.wa-float svg{width:28px;height:28px}.wa-float:hover{background:#1DA851;color:#fff}
@media (max-width:640px){.wa-float span{display:none}.wa-float{padding:12px;right:14px;bottom:14px}.help-btns{width:100%}.help-btns .btn{flex:1}.foot-bottom{padding-bottom:70px}}
@media (max-width:640px){.help-ic{display:none}.help-txt h2{font-size:1.1rem}}