:root{
 --navy:#002F4E; --navy2:#013F63; --steel:#3E6E90; --sky:#74A4C1; --bronze:#B9793F; --bronze2:#C18653;
 --cream:#FBF7EC; --paper:#FFFFFF; --ink:#17242E; --muted:#5C6B76; --line:#E4Dccc; --line2:#DCE6EE;
 --ok:#1E7A46; --bad:#B23B3B; --skyfaint:#EAF1F7;
 --shadow:0 1px 2px rgba(0,32,60,.06),0 8px 24px rgba(0,32,60,.06);
 --disp:'Spectral',Georgia,serif; --body:'Public Sans',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
}
:root:not([data-theme="light"]){}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
 --navy:#071E33; --navy2:#0E2A44; --steel:#6E9CBC; --sky:#8FBAD6; --bronze:#D6975C; --bronze2:#E0A66A;
 --cream:#0A2439; --paper:#103150; --ink:#E9F0F6; --muted:#A6BAC9; --line:#264A67; --line2:#22415C;
 --skyfaint:#173D58; --shadow:0 1px 2px rgba(0,0,0,.28),0 10px 30px rgba(0,0,0,.4);
}}
:root[data-theme="dark"]{
 --navy:#071E33; --navy2:#0E2A44; --steel:#6E9CBC; --sky:#8FBAD6; --bronze:#D6975C; --bronze2:#E0A66A;
 --cream:#0A2439; --paper:#103150; --ink:#E9F0F6; --muted:#A6BAC9; --line:#264A67; --line2:#22415C;
 --skyfaint:#173D58; --shadow:0 1px 2px rgba(0,0,0,.28),0 10px 30px rgba(0,0,0,.4);
}
*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--cream);color:var(--ink);font-family:var(--body);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--steel)}
.app{display:grid;grid-template-columns:300px 1fr;min-height:100vh}
/* Sidebar */
.side{background:var(--navy);color:#EAF1F7;position:sticky;top:0;height:100vh;overflow-y:auto;padding:0 0 40px}
.brand{display:flex;align-items:center;gap:12px;padding:20px 22px 16px;border-bottom:1px solid rgba(255,255,255,.09);position:sticky;top:0;background:var(--navy);z-index:2}
.brand img{width:44px;height:44px;border-radius:50%;box-shadow:0 0 0 3px rgba(255,255,255,.08)}
.brand .bt{font-family:var(--disp);font-weight:700;font-size:17px;letter-spacing:.2px;line-height:1.15}
.brand .bs{font-size:10.5px;letter-spacing:2.5px;color:var(--sky);text-transform:uppercase;margin-top:2px}
.navgroup{padding:16px 14px 0}
.navgroup h5{margin:0 0 6px;padding:0 10px;font-size:10.5px;letter-spacing:2px;text-transform:uppercase;color:var(--sky);font-weight:700}
.navlink{display:flex;align-items:center;gap:9px;width:100%;text-align:left;background:none;border:0;color:#D7E4EE;font:inherit;font-size:14.5px;padding:8px 10px;border-radius:9px;cursor:pointer;transition:background .12s}
.navlink:hover{background:rgba(255,255,255,.07)}
.navlink.active{background:var(--bronze);color:#1a1207;font-weight:600}
.navlink .dot{width:16px;height:16px;border-radius:50%;border:2px solid rgba(255,255,255,.35);flex:0 0 auto;display:grid;place-items:center;font-size:10px}
.navlink.active .dot{border-color:#1a1207}
.navlink.done .dot{background:var(--sky);border-color:var(--sky);color:var(--navy)}
.navlink.active.done .dot{background:#1a1207;border-color:#1a1207;color:var(--bronze)}
/* Main */
.main{min-width:0}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 40px;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--cream) 80%,transparent);backdrop-filter:blur(6px);position:sticky;top:0;z-index:3}
.crumbs{font-size:12.5px;letter-spacing:1.5px;text-transform:uppercase;color:var(--muted);font-weight:600}
.prog{display:flex;align-items:center;gap:10px;font-size:13px;color:var(--muted)}
.progbar{width:150px;height:8px;border-radius:99px;background:var(--line2);overflow:hidden}
.progbar i{display:block;height:100%;background:linear-gradient(90deg,var(--steel),var(--bronze2));width:0;transition:width .4s}
.themebtn{border:1px solid var(--line);background:var(--paper);color:var(--ink);border-radius:9px;padding:7px 11px;cursor:pointer;font:inherit;font-size:13px}
.wrap{max-width:820px;margin:0 auto;padding:40px 40px 90px}
.eyebrow{font-size:12px;letter-spacing:2.5px;text-transform:uppercase;color:var(--bronze);font-weight:700}
h1{font-family:var(--disp);font-weight:700;font-size:clamp(30px,4vw,44px);line-height:1.08;margin:.35em 0 .1em;text-wrap:balance;letter-spacing:-.5px}
h2{font-family:var(--disp);font-weight:600;font-size:24px;margin:1.8em 0 .5em}
.lead{font-size:18px;color:var(--muted);max-width:62ch}
.content{margin-top:26px;font-size:16.5px}
.content p{margin:0 0 1.05em;max-width:66ch}
.content ul,.content ol{max-width:66ch;padding-left:1.25em;margin:0 0 1.2em}
.content li{margin:.4em 0}
.content strong{color:var(--ink)}
.content .note{background:var(--skyfaint);border-left:3px solid var(--sky);padding:12px 16px;border-radius:0 10px 10px 0;color:var(--muted);font-size:15px}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:8px 0 20px}
@media(max-width:720px){.cards{grid-template-columns:1fr}}
.card{background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:16px 16px 14px;box-shadow:var(--shadow);border-top:4px solid var(--bronze2)}
.card .tag{font-size:11px;letter-spacing:1.5px;text-transform:uppercase;color:var(--steel);font-weight:700}
.card h4{font-family:var(--disp);margin:.3em 0 .35em;font-size:19px;color:var(--navy)}
:root[data-theme="dark"] .card h4,:root:not([data-theme="light"]) .card h4{color:var(--sky)}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]) .card h4{color:var(--sky)}}
.card p{margin:0;font-size:14px;color:var(--muted)}
/* Quiz */
.quiz{margin-top:34px;background:var(--paper);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);overflow:hidden}
.quiz-h{background:var(--navy);color:#EAF1F7;padding:16px 22px;display:flex;align-items:center;justify-content:space-between}
.quiz-h .qt{font-family:var(--disp);font-size:18px;font-weight:600}
.quiz-h .qs{font-size:12px;letter-spacing:1.5px;text-transform:uppercase;color:var(--sky)}
.quiz-body{padding:8px 22px 22px}
.q{padding:18px 0;border-bottom:1px solid var(--line2)}
.q:last-child{border-bottom:0}
.q .qq{font-weight:600;margin:0 0 12px;font-size:16px}
.q .qq b{color:var(--bronze);font-family:var(--disp);margin-right:6px}
.opt{display:flex;align-items:flex-start;gap:11px;padding:10px 13px;border:1px solid var(--line2);border-radius:10px;margin:7px 0;cursor:pointer;transition:border-color .12s,background .12s;font-size:15px}
.opt:hover{border-color:var(--sky)}
.opt input{margin-top:3px;accent-color:var(--steel)}
.opt.correct{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 12%,transparent)}
.opt.wrong{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 12%,transparent)}
.opt .mk{margin-left:auto;font-weight:700}
.opt.correct .mk{color:var(--ok)}.opt.wrong .mk{color:var(--bad)}
.quiz-foot{display:flex;align-items:center;gap:16px;padding:18px 22px;border-top:1px solid var(--line2);background:var(--skyfaint)}
.btn{font:inherit;font-weight:600;font-size:15px;border:0;border-radius:11px;padding:11px 20px;cursor:pointer;background:var(--bronze);color:#1a1207;box-shadow:var(--shadow)}
.btn:hover{background:var(--bronze2)}
.btn.ghost{background:var(--paper);color:var(--ink);border:1px solid var(--line)}
.score{font-family:var(--disp);font-size:20px;font-weight:700}
.score small{font-family:var(--body);font-weight:500;font-size:13px;color:var(--muted);display:block}
.pagenav{display:flex;justify-content:space-between;margin-top:40px;gap:12px}
.pagenav button{flex:1;text-align:left;background:var(--paper);border:1px solid var(--line);border-radius:13px;padding:14px 18px;cursor:pointer;font:inherit;color:var(--ink);box-shadow:var(--shadow)}
.pagenav button.next{text-align:right}
.pagenav .pl{font-size:11px;letter-spacing:1.5px;text-transform:uppercase;color:var(--muted);font-weight:700}
.pagenav .pt{font-family:var(--disp);font-size:17px;color:var(--navy);margin-top:2px}
:root[data-theme="dark"] .pagenav .pt{color:var(--sky)}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]) .pagenav .pt{color:var(--sky)}}
.pagenav button:disabled{opacity:.35;cursor:default}
.mobtoggle{display:none}
@media(max-width:860px){
 .app{grid-template-columns:1fr}
 .side{position:fixed;left:0;top:0;width:280px;transform:translateX(-100%);transition:transform .2s;z-index:20}
 .side.open{transform:none}
 .mobtoggle{display:inline-grid;place-items:center;width:38px;height:38px;border-radius:9px;border:1px solid var(--line);background:var(--paper);cursor:pointer}
 .wrap{padding:28px 20px 80px}.topbar{padding:12px 18px}
}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}
:focus-visible{outline:2px solid var(--bronze);outline-offset:2px}
/* section heads */
.shead{display:flex;align-items:center;gap:10px;margin:38px 0 14px}
.shead .ic{width:28px;height:28px;border-radius:7px;background:var(--navy);color:var(--bronze2);display:grid;place-items:center;font-size:15px;flex:0 0 auto}
.shead h2{font-family:var(--disp);font-size:22px;margin:0;color:var(--ink)}
.shead .sub{font-size:13px;color:var(--muted)}
/* slide viewer */
.viewer{border:1px solid var(--line);border-radius:16px;overflow:hidden;box-shadow:var(--shadow);background:var(--navy)}
.viewer .stage{position:relative;background:#0b1a26;aspect-ratio:16/9}
.viewer .stage img{width:100%;height:100%;object-fit:contain;display:block}
.viewer .ctl{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:10px 14px;background:var(--navy);color:#EAF1F7}
.viewer .ctl .count{font-size:12.5px;letter-spacing:1.5px;text-transform:uppercase;color:var(--sky);font-variant-numeric:tabular-nums}
.vbtn{border:1px solid rgba(255,255,255,.25);background:rgba(255,255,255,.06);color:#EAF1F7;border-radius:9px;padding:7px 14px;cursor:pointer;font:inherit;font-size:14px}
.vbtn:hover{background:rgba(255,255,255,.14)}
.vbtn:disabled{opacity:.3;cursor:default}
.dots{display:flex;gap:5px;flex-wrap:wrap;justify-content:center}
.dots i{width:7px;height:7px;border-radius:50%;background:rgba(255,255,255,.28);cursor:pointer}
.dots i.on{background:var(--bronze2)}
.vfs{padding:7px 11px}
.viewer:fullscreen,.viewer:-webkit-full-screen,.viewer.fspseudo{width:100vw;height:100vh;display:flex;flex-direction:column;border-radius:0}
.viewer.fspseudo{position:fixed;inset:0;z-index:9999}
.viewer:fullscreen .stage,.viewer:-webkit-full-screen .stage,.viewer.fspseudo .stage{flex:1 1 auto;aspect-ratio:auto;min-height:0}
.viewer:fullscreen .stage img,.viewer:-webkit-full-screen .stage img,.viewer.fspseudo .stage img{width:100%;height:100%;object-fit:contain}
.viewer:fullscreen .ctl,.viewer.fspseudo .ctl{flex:0 0 auto}
/* resources */
.resrow{display:flex;flex-wrap:wrap;gap:12px;align-items:stretch}
.resource{display:flex;gap:12px;align-items:center;border:1px solid var(--line);background:var(--paper);border-radius:13px;padding:12px 16px;box-shadow:var(--shadow);text-decoration:none;color:var(--ink);flex:1;min-width:230px}
.resource:hover{border-color:var(--sky)}
.resource .ri{width:38px;height:38px;border-radius:9px;background:var(--skyfaint);color:var(--steel);display:grid;place-items:center;font-size:18px;flex:0 0 auto}
.resource .rt{font-weight:600;font-size:14.5px}
.resource .rs{font-size:12px;color:var(--muted)}
.opthumb{margin-top:14px;border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow);max-width:520px}
.opthumb img{width:100%;display:block}
/* quiz CTA + view */
.quizcta{margin:34px 0 0;background:linear-gradient(120deg,var(--navy),var(--navy2));border-radius:16px;padding:24px 26px;display:flex;align-items:center;justify-content:space-between;gap:18px;box-shadow:var(--shadow);flex-wrap:wrap}
.quizcta .qc-t{color:#fff}
.quizcta .qc-t b{font-family:var(--disp);font-size:20px;display:block}
.quizcta .qc-t span{color:var(--ice,#AECBDF);font-size:14px}
.quizcta.done-badge .qc-t span{color:#B9E4C9}
.backbtn{background:none;border:0;color:var(--steel);font:inherit;font-weight:600;cursor:pointer;font-size:14px;padding:4px 0;margin-bottom:6px}
.backbtn:hover{color:var(--bronze)}
/* role + badges */
.tbadge{display:inline-block;font-size:9.5px;letter-spacing:1px;text-transform:uppercase;font-weight:700;color:var(--bronze2);border:1px solid var(--bronze2);border-radius:99px;padding:1px 7px;margin-left:8px;vertical-align:middle}
.navlink .tbadge{margin-left:auto}
.rolepill{font:inherit;font-size:12.5px;font-weight:600;border:1px solid var(--line);background:var(--paper);color:var(--ink);border-radius:99px;padding:6px 13px;cursor:pointer}
.rolepill.teacher{border-color:var(--bronze2);color:var(--bronze);background:color-mix(in srgb,var(--bronze2) 12%,var(--paper))}
.rolepill:hover{border-color:var(--sky)}
/* quiz lock */
.side.navlock{position:relative}
.side.navlock .navgroup{pointer-events:none;opacity:.38;filter:grayscale(.3)}
.side.navlock::after{content:"🔒 Locked during quiz";position:sticky;bottom:0;display:block;margin-top:8px;padding:12px 14px;font-size:12px;letter-spacing:.5px;color:var(--sky);background:linear-gradient(180deg,transparent,rgba(0,0,0,.25));text-align:center}
.quiznote{display:inline-block;background:var(--skyfaint);border:1px solid var(--line2);border-left:3px solid var(--bronze2);border-radius:0 9px 9px 0;padding:9px 14px;font-size:13.5px;color:var(--muted);margin:-6px 0 4px}
/* jeopardy */
.jboard{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;margin-top:8px}
.jcat{background:var(--navy);color:#EAF1F7;font-family:var(--disp);font-weight:600;font-size:13.5px;text-align:center;padding:12px 8px;border-radius:9px;min-height:64px;display:grid;place-items:center;border-top:3px solid var(--bronze2)}
.jtile{font-family:var(--disp);font-weight:700;font-size:24px;color:var(--bronze2);background:var(--navy2);border:1px solid var(--line);border-radius:9px;padding:18px 8px;cursor:pointer;transition:background .15s,color .15s,transform .05s}
.jtile:hover{background:var(--steel);color:#fff}
.jtile:active{transform:scale(.97)}
.jtile.used{background:var(--skyfaint);color:var(--muted);border-style:dashed;box-shadow:none}
.jtile.used:hover{background:var(--skyfaint);color:var(--muted)}
.jbtns{margin-top:14px}
.jmodal{position:fixed;inset:0;background:rgba(0,20,40,.72);display:grid;place-items:center;z-index:9999;padding:24px}
.jmodal[hidden]{display:none}
.jm-card{background:var(--paper);border:1px solid var(--line);border-radius:18px;max-width:760px;width:100%;padding:30px 34px;box-shadow:var(--shadow)}
.jm-val{font-size:12.5px;letter-spacing:2px;text-transform:uppercase;color:var(--bronze);font-weight:700;margin-bottom:14px}
.jm-clue{font-family:var(--disp);font-size:26px;line-height:1.3;color:var(--ink);margin-bottom:18px;text-wrap:balance}
.jm-ans{background:var(--skyfaint);border-left:4px solid var(--ok);border-radius:0 10px 10px 0;padding:14px 18px;font-size:17px;color:var(--ink);margin-bottom:20px}
.jm-ans[hidden]{display:none}
.jm-ctl{display:flex;gap:12px}
/* role-play */
.rpwrap{margin-top:6px;display:flex;flex-direction:column;gap:24px}
.rpcard{border:1px solid var(--line);border-radius:16px;overflow:hidden;box-shadow:var(--shadow);background:var(--paper)}
.rphd{background:var(--navy);color:#fff;padding:16px 22px}
.rphd .rpn{font-size:11px;letter-spacing:2px;text-transform:uppercase;color:var(--bronze2);font-weight:700}
.rphd h3{font-family:var(--disp);font-size:20px;margin:2px 0 0}
.rpbox{margin:16px 22px;background:var(--card,var(--skyfaint));border:1px solid var(--line2);border-radius:12px;padding:12px 16px}
.rpbox.good{background:color-mix(in srgb,var(--ok) 9%,transparent);border-color:color-mix(in srgb,var(--ok) 30%,transparent)}
.rpbox .rpbt{font-size:11px;letter-spacing:1.5px;text-transform:uppercase;font-weight:700;color:var(--steel);margin-bottom:6px}
.rpbox.good .rpbt{color:var(--ok)}
.rpbox ul{margin:0;padding-left:18px}.rpbox li{font-size:14.5px;margin:4px 0}
.rpturns{margin:12px 22px;display:flex;flex-direction:column;gap:10px}
.turn{display:flex;gap:12px;align-items:flex-start}
.turn .wl{flex:0 0 62px;font-size:10.5px;letter-spacing:1px;font-weight:700;text-transform:uppercase;padding:5px 8px;border-radius:7px;text-align:center;color:#fff}
.turn.ag .wl{background:var(--steel)}.turn.ca .wl{background:var(--bad)}
.turn .tt{font-size:15px;line-height:1.5;padding-top:3px}
.turn .coach{margin-top:5px;font-size:13px;color:var(--muted);font-style:italic;border-left:2px solid var(--bronze2);padding-left:9px}
/* student progress */
.sptable{overflow-x:auto;border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}
.sptable table{width:100%;border-collapse:collapse;font-size:14.5px}
.sptable th{background:var(--navy);color:#EAF1F7;text-align:left;padding:12px 16px;font-size:12px;letter-spacing:1px;text-transform:uppercase}
.sptable td{padding:12px 16px;border-top:1px solid var(--line2)}
.sptable td.nm{font-weight:600;font-family:var(--disp)}
.sptable .pbar{display:inline-block;width:90px;height:8px;border-radius:99px;background:var(--line2);overflow:hidden;vertical-align:middle;margin-right:8px}
.sptable .pbar i{display:block;height:100%;background:linear-gradient(90deg,var(--steel),var(--bronze2))}
/* ---------- auth screen ---------- */
.auth{position:fixed;inset:0;display:grid;place-items:center;background:var(--cream);padding:24px;z-index:50}
.auth-card{width:100%;max-width:420px;background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:30px 30px 26px}
.auth-brand{display:flex;align-items:center;gap:13px;margin-bottom:20px}
.auth-brand img{width:52px;height:52px;border-radius:50%}
.auth-brand .ab-t{font-family:var(--disp);font-weight:700;font-size:19px;color:var(--ink)}
.auth-brand .ab-s{font-size:11px;letter-spacing:2.5px;text-transform:uppercase;color:var(--steel);font-weight:700}
.auth-tabs{display:flex;gap:6px;background:var(--skyfaint);border-radius:11px;padding:4px;margin-bottom:20px}
.auth-tabs button{flex:1;border:0;background:none;font:inherit;font-weight:600;font-size:14px;color:var(--muted);padding:9px;border-radius:8px;cursor:pointer}
.auth-tabs button.on{background:var(--paper);color:var(--ink);box-shadow:var(--shadow)}
.auth form{display:flex;flex-direction:column;gap:13px}
.auth label{display:flex;flex-direction:column;gap:5px;font-size:12.5px;font-weight:600;color:var(--muted);letter-spacing:.3px}
.auth label.teach span{font-weight:400;text-transform:none;letter-spacing:0}
.auth input{font:inherit;font-size:15px;color:var(--ink);background:var(--cream);border:1px solid var(--line);border-radius:10px;padding:11px 13px}
.auth input:focus{outline:2px solid var(--bronze);outline-offset:1px;border-color:var(--bronze)}
.btn.wide{width:100%;justify-content:center;margin-top:6px;padding:12px}
.auth-err{background:color-mix(in srgb,var(--bad) 12%,transparent);border:1px solid color-mix(in srgb,var(--bad) 40%,transparent);color:var(--bad);border-radius:10px;padding:10px 13px;font-size:13.5px;margin:14px 0 0}