/* ============================================================
   INSTITUTE LIBRARY v2 — design system
   Structure inspired by the information architecture of leading
   exam-resource platforms; identity is entirely Neurogenetics
   Institute: dark, calm, neuroscience-inspired, neural background.
   Titles centred + blue, body text left-aligned, British English.
   ============================================================ */
:root{
  --bg:#05070A; --card:#0A0D12; --card2:#0D1420; --line:rgba(255,255,255,.10);
  --line2:rgba(255,255,255,.18); --txt:#F2F8FC; --dim:#a1a1aa; --dim2:#71717a;
  --ac:#5EC8FF; --ac-deep:#0E86C8; --green:#34D399; --purple:#A78BFA; --amber:#FBBF24;
  --ac-08:rgba(94,200,255,.08); --ac-15:rgba(94,200,255,.15); --ac-35:rgba(94,200,255,.35);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--txt);font-family:Inter,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;font-size:15.5px;line-height:1.65;text-align:left}
#neural-canvas{position:fixed;inset:0;z-index:-1;opacity:.5}
a{color:var(--ac)}
h1,h2,h3{line-height:1.25}
img{max-width:100%}

/* ---------- topbar ---------- */
.v2-topbar{position:sticky;top:0;z-index:50;display:flex;align-items:center;gap:20px;padding:10px 22px;background:rgba(5,7,10,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.v2-topbar .tb-brand{display:flex;align-items:center;gap:9px;text-decoration:none;color:var(--txt);font-weight:700;font-size:14.5px;white-space:nowrap}
.v2-topbar .tb-brand img{height:30px;width:auto}
.v2-topbar .tb-links{display:flex;gap:16px;align-items:center;flex-wrap:wrap;font-size:13.5px}
.v2-topbar .tb-links a{color:rgba(255,255,255,.72);text-decoration:none;font-weight:600}
.v2-topbar .tb-links a:hover,.v2-topbar .tb-links a.on{color:var(--ac)}
.v2-topbar .tb-right{margin-left:auto;display:flex;gap:14px;align-items:center;font-size:13.5px}
.v2-topbar .tb-right a{color:rgba(255,255,255,.72);text-decoration:none;font-weight:600}
.tb-cta{background:var(--ac);color:#05070A!important;padding:8px 18px;border-radius:999px;font-weight:700!important}

/* ---------- layout shell: sidebar | tree | main ---------- */
.v2-shell{display:grid;grid-template-columns:230px 300px minmax(0,1fr);gap:0;min-height:calc(100vh - 52px)}
.v2-shell.full{grid-template-columns:minmax(0,1fr)}
.v2-side{border-right:1px solid var(--line);padding:20px 14px;background:rgba(10,13,18,.6)}
.v2-side .grp{margin-bottom:20px}
.v2-side .grp-h{font-size:11px;font-weight:800;letter-spacing:.14em;text-transform:uppercase;color:var(--dim2);padding:0 10px;margin-bottom:6px}
.v2-side a.it{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:9px;color:rgba(255,255,255,.75);text-decoration:none;font-size:13.8px;font-weight:600}
.v2-side a.it:hover{background:var(--ac-08);color:var(--txt)}
.v2-side a.it.on{background:var(--ac-15);color:var(--ac)}
.v2-side a.it .ic{width:17px;text-align:center;opacity:.85}

/* topic tree */
.v2-tree{border-right:1px solid var(--line);padding:18px 12px;background:rgba(8,11,16,.55);overflow-y:auto}
.v2-tree .tt-h{display:flex;align-items:center;justify-content:space-between;padding:0 6px 10px}
.v2-tree .tt-h b{font-size:14.5px}
.v2-tree .tt-h a{font-size:12px;color:var(--dim);text-decoration:none}
.t-node{border:1px solid transparent;border-radius:11px;margin-bottom:6px}
.t-node>.t-head{display:flex;align-items:center;gap:9px;width:100%;text-align:left;background:none;border:0;color:var(--txt);font:inherit;font-weight:700;font-size:13.6px;padding:10px;border-radius:11px;cursor:pointer}
.t-node>.t-head:hover{background:rgba(255,255,255,.04)}
.t-node.open{border-color:var(--line);background:var(--card)}
.t-node .bullet{width:15px;height:15px;border-radius:50%;border:2px solid var(--dim2);flex:0 0 auto;display:inline-block}
.t-node.done .bullet{background:var(--green);border-color:var(--green)}
.t-node.active .bullet{background:var(--ac);border-color:var(--ac)}
.t-node .chev{margin-left:auto;color:var(--dim2);transition:transform .18s}
.t-node.open .chev{transform:rotate(180deg)}
.t-node .t-cnt{font-weight:600;color:var(--dim2);font-size:11.5px;display:block}
.t-sub{display:none;padding:2px 6px 8px}
.t-node.open .t-sub{display:block}
.t-sub a{display:block;padding:7px 10px 7px 30px;border-radius:8px;color:rgba(255,255,255,.72);text-decoration:none;font-size:13px}
.t-sub a:hover{color:var(--ac);background:var(--ac-08)}
.t-sub a.on{color:var(--ac);background:var(--ac-15);font-weight:700}

/* main column */
.v2-main{padding:26px clamp(18px,4vw,44px) 80px;max-width:980px}
.crumbs{display:flex;flex-wrap:wrap;gap:6px;align-items:center;font-size:12.8px;color:var(--dim2);margin-bottom:14px}
.crumbs a{color:var(--dim);text-decoration:none;font-weight:600}
.crumbs a:hover{color:var(--ac)}
.crumbs .sep{color:var(--dim2)}
.crumbs .here{color:var(--ac);font-weight:700}

/* hero block (course/topic/subtopic heads) */
.hero-kicker{font-size:12px;font-weight:800;letter-spacing:.16em;text-transform:uppercase;color:var(--ac);text-align:center}
.v2-main h1.title{font-size:clamp(24px,3.4vw,34px);font-weight:800;text-align:center;color:var(--ac);margin:6px 0 10px}
.lede{color:var(--dim);text-align:center;max-width:640px;margin:0 auto 16px}
.head-meta{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin:0 0 22px}
.pill{display:inline-flex;align-items:center;gap:7px;border:1px solid var(--line2);border-radius:999px;padding:6px 14px;font-size:12.8px;font-weight:700;color:var(--dim)}
.pill b{color:var(--txt)}
.pill.blue{border-color:var(--ac-35);color:var(--ac)}
.pill.green{border-color:rgba(52,211,153,.4);color:var(--green)}

/* NGI loop strip */
.loop{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:0 0 26px}
.loop .step{background:var(--card);border:1px solid var(--line);border-radius:13px;padding:12px 10px;text-align:center}
.loop .step .n{font-size:11px;font-weight:800;letter-spacing:.12em;color:var(--dim2)}
.loop .step .t{font-weight:800;font-size:14.5px;margin-top:2px}
.loop .step.k1 .t{color:var(--ac)} .loop .step.k2 .t{color:var(--green)}
.loop .step.k3 .t{color:var(--purple)} .loop .step.k4 .t{color:var(--amber)}
.loop .step .d{font-size:11.8px;color:var(--dim2);margin-top:2px}

/* section blocks */
.sec-h{display:flex;align-items:center;gap:12px;margin:34px 0 14px}
.sec-h h2{font-size:21px;font-weight:800;margin:0;text-align:center;flex:1;color:var(--txt)}
.sec-h .rule{height:1px;background:var(--line);flex:1}
.sec-h .tag{font-size:11px;font-weight:800;letter-spacing:.14em;color:var(--ac);white-space:nowrap}

/* resource cards */
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.res-card{display:flex;flex-direction:column;gap:8px;background:var(--card);border:1px solid var(--line);border-radius:15px;padding:18px;text-decoration:none;color:var(--txt);transition:border-color .15s, transform .15s}
.res-card:hover{border-color:var(--ac-35);transform:translateY(-2px)}
.res-card .ric{font-size:22px}
.res-card b{font-size:15px}
.res-card p{margin:0;font-size:12.8px;color:var(--dim)}
.res-card .cta{margin-top:auto;font-size:13px;font-weight:700;color:var(--ac)}
.res-card.soon{opacity:.62}
.res-card.soon .cta{color:var(--dim2)}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 24px;border-radius:999px;background:var(--ac);color:#05070A;font-size:14px;font-weight:800;text-decoration:none;border:0;cursor:pointer;font-family:inherit}
.btn:hover{opacity:.92}
.btn.ghost{background:transparent;border:1px solid var(--ac-35);color:var(--ac);font-weight:700}
.btn.green{background:var(--green)}
.btn.big{padding:14px 30px;font-size:15px}

/* explore-by-topic accordion (course page) */
.acc{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--card)}
.acc-item + .acc-item{border-top:1px solid var(--line)}
.acc-head{display:flex;align-items:center;gap:12px;width:100%;background:none;border:0;color:var(--txt);font:inherit;text-align:left;padding:15px 18px;cursor:pointer}
.acc-head:hover{background:rgba(255,255,255,.03)}
.acc-head .no{flex:0 0 34px;height:34px;border-radius:10px;background:var(--ac-08);border:1px solid var(--ac-35);color:var(--ac);display:inline-flex;align-items:center;justify-content:center;font-weight:800;font-size:14px}
.acc-head .nm{font-weight:700;font-size:15px}
.acc-head .ct{margin-left:auto;color:var(--dim2);font-size:12.3px;font-weight:600;text-align:right}
.acc-head .chev{color:var(--dim2);transition:transform .18s;margin-left:8px}
.acc-item.open .acc-head .chev{transform:rotate(180deg)}
.acc-body{display:none;padding:4px 18px 14px 64px}
.acc-item.open .acc-body{display:block}
.acc-body a{display:block;padding:8px 10px;border-radius:8px;color:rgba(255,255,255,.75);text-decoration:none;font-size:13.6px}
.acc-body a:hover{background:var(--ac-08);color:var(--ac)}
.acc-body .st-note{font-size:11.8px;color:var(--dim2)}

/* spec map */
.spec-list{border:1px solid var(--line);border-radius:14px;background:var(--card);overflow:hidden}
.spec-item{display:flex;gap:12px;padding:12px 16px;border-top:1px solid var(--line);align-items:baseline}
.spec-item:first-child{border-top:0}
.spec-item .ref{flex:0 0 64px;font-weight:800;color:var(--ac);font-size:13.5px}
.spec-item .ob{font-size:13.8px;color:rgba(255,255,255,.85)}
.spec-item .eq{display:inline-block;background:var(--ac-08);border:1px solid var(--ac-35);color:var(--ac);border-radius:8px;padding:1px 9px;font-weight:700;font-size:12.8px;margin-left:8px;white-space:nowrap}
.spec-sub-h{padding:10px 16px 6px;font-weight:800;color:var(--txt);font-size:14.5px;background:var(--card2)}
.spec-status{display:inline-block;font-size:10.8px;font-weight:800;letter-spacing:.1em;border-radius:99px;padding:3px 10px;margin-left:10px;vertical-align:middle}
.spec-status.ok{background:rgba(52,211,153,.12);border:1px solid rgba(52,211,153,.4);color:var(--green)}
.spec-status.pending{background:rgba(251,191,36,.1);border:1px solid rgba(251,191,36,.35);color:var(--amber)}

/* subtopic resource rows (Learn / Practise / Check / Exam) */
.zone{margin:0 0 30px}
.zone-h{display:flex;align-items:center;gap:10px;margin:0 0 12px}
.zone-h .zn{font-size:11px;font-weight:800;letter-spacing:.14em;text-transform:uppercase;color:var(--dim2)}
.zone-h b{font-size:17.5px}
.zone-h .rule{height:1px;background:var(--line);flex:1}
.file-row{display:flex;align-items:center;gap:14px;background:var(--card);border:1px solid var(--line);border-radius:13px;padding:14px 16px;text-decoration:none;color:var(--txt)}
.file-row:hover{border-color:var(--ac-35)}
.file-row + .file-row{margin-top:10px}
.file-row .fic{font-size:20px}
.file-row b{font-size:14.2px;display:block}
.file-row small{color:var(--dim2);font-size:12px}
.file-row .meta{color:var(--dim2);font-size:12px;margin-left:auto;white-space:nowrap}
.file-row .arrow{color:var(--ac);font-weight:800;margin-left:6px}
.file-row.soon{opacity:.6;pointer-events:none}
.badge{display:inline-block;font-size:10.5px;font-weight:800;letter-spacing:.08em;border-radius:99px;padding:3px 10px;vertical-align:middle}
.badge.new{background:rgba(52,211,153,.12);border:1px solid rgba(52,211,153,.4);color:var(--green)}
.badge.soon{background:rgba(255,255,255,.06);border:1px solid var(--line2);color:var(--dim)}

/* synapse callout */
.syn-callout{display:flex;align-items:center;gap:18px;background:linear-gradient(135deg,rgba(94,200,255,.12),rgba(167,139,250,.10));border:1px solid var(--ac-35);border-radius:16px;padding:18px 22px;margin:6px 0 8px}
.syn-callout .sci{font-size:26px}
.syn-callout b{font-size:15.5px;display:block}
.syn-callout p{margin:2px 0 0;color:var(--dim);font-size:13px}
.syn-callout .btn{margin-left:auto;white-space:nowrap}

/* insight / exam focus boxes (on subtopic pages) */
.ngi-insight{border:1px solid rgba(167,139,250,.4);background:rgba(167,139,250,.07);border-radius:14px;padding:16px 20px;margin:14px 0}
.ngi-insight .ih{font-size:11.5px;font-weight:800;letter-spacing:.13em;text-transform:uppercase;color:var(--purple);margin-bottom:6px}
.ngi-insight p{margin:0;color:rgba(255,255,255,.88);font-size:14px}
.exam-focus{border:1px solid rgba(52,211,153,.35);background:rgba(52,211,153,.06);border-radius:14px;padding:16px 20px;margin:14px 0}
.exam-focus .ih{font-size:11.5px;font-weight:800;letter-spacing:.13em;text-transform:uppercase;color:var(--green);margin-bottom:6px}
.exam-focus ul{margin:0;padding-left:20px}
.exam-focus li{font-size:13.8px;color:rgba(255,255,255,.85);margin:3px 0}

/* home page */
.v2-home{max-width:1060px;margin:0 auto;padding:40px 20px 90px}
.q-card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px;margin-top:18px}
.q-card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:24px;text-decoration:none;color:var(--txt);text-align:center}
.q-card:hover{border-color:var(--ac-35)}
.q-card .qi{font-size:30px}
.q-card b{display:block;font-size:17px;margin-top:8px}
.q-card small{color:var(--dim2);font-size:12.5px}
.board-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px;justify-content:center}
.board-chip{border:1px solid var(--line2);border-radius:999px;padding:9px 20px;color:var(--txt);text-decoration:none;font-weight:700;font-size:14px}
.board-chip:hover{border-color:var(--ac-35);color:var(--ac)}
.course-card{display:flex;align-items:center;gap:14px;background:var(--card);border:1px solid var(--line);border-radius:15px;padding:18px 20px;text-decoration:none;color:var(--txt)}
.course-card:hover{border-color:var(--ac-35)}
.course-card .ci{font-size:24px}
.course-card b{font-size:15.5px;display:block}
.course-card small{color:var(--dim2)}
.course-card .go{margin-left:auto;color:var(--ac);font-weight:800}
.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px;margin-top:16px}

/* footer */
.v2-footer{border-top:1px solid var(--line);padding:26px 22px;text-align:center;color:var(--dim2);font-size:12.5px}
.v2-footer a{color:var(--dim);text-decoration:none}
.v2-footer .foot-brand{font-weight:700;color:var(--dim);font-size:13.5px;margin:4px 0}

/* search box (course page) */
.searchbar{display:flex;gap:10px;max-width:560px;margin:0 auto 26px}
.searchbar input{flex:1;background:var(--card2);border:1px solid var(--ac-35);border-radius:12px;color:var(--txt);padding:12px 16px;font:inherit;font-size:14px}
.searchbar input:focus{outline:0;border-color:var(--ac);box-shadow:0 0 0 3px var(--ac-15)}

/* responsive */
.menu-toggle{display:none}
@media (max-width:1100px){
  .v2-shell{grid-template-columns:230px minmax(0,1fr)}
  .v2-tree{display:none}
}
@media (max-width:820px){
  .v2-shell{grid-template-columns:minmax(0,1fr)}
  .v2-side{display:none}
  .loop{grid-template-columns:repeat(2,1fr)}
  .v2-main h1.title{font-size:24px}
}