:root{--navy:#0b2a5b;--navy2:#16408a;--gold:#f5b301;--bg:#f3f6fc;--text:#1a2540;--mut:#5a6a85;--line:#dbe3f1;--white:#fff}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Hind Siliguri","Noto Sans Bengali",system-ui,sans-serif;background:var(--bg);color:var(--text);line-height:1.7;font-size:16px}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.container{width:100%;max-width:1100px;margin:0 auto;padding:0 16px}
:focus-visible{outline:3px solid var(--gold);outline-offset:2px}

/* header */
.site-header{background:var(--navy);color:var(--white);position:sticky;top:0;z-index:50}
.nav{display:flex;align-items:center;justify-content:space-between;height:60px}
.logo{font-weight:700;font-size:1.25rem}
.logo b{color:var(--gold)}
.menu-btn{background:none;border:1px solid #ffffff55;color:#fff;font-size:1.3rem;border-radius:8px;padding:2px 12px;cursor:pointer}
.nav-links{display:none;position:absolute;top:60px;left:0;right:0;background:var(--navy);flex-direction:column;padding:8px 16px 16px;border-top:1px solid #ffffff22}
.nav-links.open{display:flex}
.nav-links a{padding:10px 0;border-bottom:1px solid #ffffff18}
.nav-links a.active{color:var(--gold)}

/* buttons */
.btn{display:inline-block;border:0;border-radius:10px;padding:11px 20px;font:inherit;font-weight:600;cursor:pointer;text-align:center}
.btn-gold{background:var(--gold);color:var(--navy)}
.btn-navy{background:var(--navy);color:#fff}
.btn-line{border:2px solid #fff;color:#fff}
.btn-wa{background:#1fa855;color:#fff}
.btn-block{display:block;width:100%}

/* hero */
.hero{background:var(--navy);color:#fff;padding:44px 0 52px}
.hero h1{font-size:1.9rem;line-height:1.35;margin-bottom:12px}
.hero p{color:#cdd9f2;max-width:560px;margin-bottom:22px}
.search-row{display:flex;gap:8px;max-width:520px}
.search-row input{flex:1;min-width:0;padding:12px 14px;border-radius:10px;border:0;font:inherit}
.hero-stats{display:flex;gap:22px;margin-top:26px;color:#cdd9f2;font-size:.95rem;flex-wrap:wrap}
.hero-stats strong{display:block;color:#fff;font-size:1.3rem}

/* sections */
.section{padding:40px 0}
.section h2{color:var(--navy);font-size:1.5rem;margin-bottom:4px}
.section .sub{color:var(--mut);margin-bottom:20px}
.cat-grid,.grid{display:grid;gap:16px;grid-template-columns:1fr}
.cat{background:#fff;border:1px solid var(--line);border-left:5px solid var(--navy);border-radius:12px;padding:18px;display:flex;gap:14px;align-items:center}
.cat .ic{font-size:2rem}
.cat strong{color:var(--navy);display:block;font-size:1.15rem}
.cat span{color:var(--mut);font-size:.9rem}

/* course card */
.card{background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;display:flex;flex-direction:column}
.thumb{aspect-ratio:16/9;background:linear-gradient(135deg,var(--navy),var(--navy2));display:flex;align-items:center;justify-content:center;font-size:3rem;overflow:hidden}
.thumb img{width:100%;height:100%;object-fit:cover}
.card-body{padding:16px;display:flex;flex-direction:column;gap:8px;flex:1}
.tag{align-self:flex-start;background:#e6edfb;color:var(--navy);font-size:.8rem;padding:2px 10px;border-radius:99px;font-weight:600}
.card h3{font-size:1.1rem;line-height:1.45;color:var(--navy)}
.card p{color:var(--mut);font-size:.95rem;flex:1}
.price{font-weight:700;color:var(--navy)}
.card-actions{display:flex;gap:8px}
.card-actions .btn{flex:1;padding:10px 8px;font-size:.95rem}

/* filter */
.filters{background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px;margin-bottom:20px}
.filters input{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:10px;font:inherit;margin-bottom:10px}
.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{border:1px solid var(--navy);background:#fff;color:var(--navy);padding:6px 16px;border-radius:99px;font:inherit;cursor:pointer}
.chip.on{background:var(--navy);color:#fff}
.empty{text-align:center;color:var(--mut);padding:30px 0}

/* detail & pages */
.detail{display:grid;gap:22px}
.panel{background:#fff;border:1px solid var(--line);border-radius:14px;padding:20px}
.panel h1{color:var(--navy);font-size:1.5rem;line-height:1.4;margin:8px 0}
.panel h2{color:var(--navy);font-size:1.15rem;margin:18px 0 8px}
.facts{list-style:none;display:grid;gap:6px;margin:12px 0}
.facts li{display:flex;justify-content:space-between;border-bottom:1px dashed var(--line);padding:4px 0}
.checks{list-style:none}
.checks li:before{content:"✔ ";color:#1fa855}
.page-head{background:var(--navy);color:#fff;padding:30px 0}
.page-head h1{font-size:1.6rem}
.prose p{margin-bottom:14px}
.notice{background:#fff8e1;border:1px solid #f1d98a;border-radius:10px;padding:12px 14px;font-size:.92rem;margin-top:14px}
.crumb{font-size:.9rem;color:var(--mut);margin-bottom:12px}

/* footer & whatsapp */
.site-footer{background:var(--navy);color:#cdd9f2;padding:30px 0 80px;margin-top:30px;font-size:.92rem}
.site-footer .links{display:flex;flex-wrap:wrap;gap:6px 18px;margin:10px 0}
.site-footer .links a{color:#fff}
.wa-float{position:fixed;right:16px;bottom:16px;z-index:60;background:#1fa855;color:#fff;border-radius:99px;padding:12px 18px;font-weight:600;box-shadow:0 4px 14px #0004}

@media(min-width:700px){
  .hero h1{font-size:2.6rem}
  .cat-grid,.grid{grid-template-columns:repeat(2,1fr)}
  .detail{grid-template-columns:1.6fr 1fr;align-items:start}
}
@media(min-width:960px){
  .menu-btn{display:none}
  .nav-links{display:flex;position:static;flex-direction:row;gap:22px;padding:0;border:0;background:none}
  .nav-links a{border:0;padding:0}
  .cat-grid,.grid{grid-template-columns:repeat(3,1fr)}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}