:root{--bg:#070914;--bg2:#0d1124;--tx:#eef1ff;--mu:#97a0c4;--gl:rgba(255,255,255,.055);--bd:rgba(255,255,255,.12);--a:#4f8cff;--b:#9b5cff;--g:linear-gradient(120deg,#4f8cff,#9b5cff);--ok:#3ddc97;--bad:#ff6b81;box-sizing:border-box;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px)}
:root[data-theme=light]{--bg:#f3f5ff;--bg2:#e6eaff;--tx:#10142b;--mu:#555d82;--gl:rgba(255,255,255,.7);--bd:rgba(30,40,100,.14)}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#070914}}
*,*::before,*::after{box-sizing:inherit}html{scroll-behavior:smooth;scroll-padding-top:calc(80px + env(safe-area-inset-top,0px));height:auto}
body{margin:0;font:16px/1.6 Inter,system-ui,sans-serif;background:var(--bg);color:var(--tx);overflow-x:hidden;transition:background .4s,color .4s}
body::before{content:"";position:fixed;inset:0;z-index:-2;background:radial-gradient(60% 50% at 15% 10%,rgba(79,140,255,.22),transparent),radial-gradient(50% 50% at 90% 30%,rgba(155,92,255,.2),transparent),linear-gradient(var(--bg),var(--bg2))}
a{color:inherit;text-decoration:none}button{font:inherit;color:inherit;cursor:pointer}
:focus-visible{outline:2px solid var(--a);outline-offset:3px;border-radius:8px}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;z-index:99;background:var(--a);padding:8px 14px;border-radius:8px}
.wrap{width:min(1160px,92%);margin:auto}section{padding:clamp(56px,9vw,110px) 0}
h1,h2,h3{line-height:1.1;margin:0;letter-spacing:-.03em}h2{font-size:clamp(28px,4.5vw,46px);margin-bottom:12px}
.sub{color:var(--mu);max-width:58ch;margin:0 0 36px}
.glass{background:var(--gl);border:1px solid var(--bd);border-radius:22px;backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);transition:transform .35s,border-color .35s,box-shadow .35s}
.glass.hov:hover{transform:translateY(-6px);border-color:var(--a);box-shadow:0 18px 50px -18px rgba(79,140,255,.55)}
.btn{border:1px solid var(--bd);background:var(--gl);padding:12px 22px;border-radius:999px;font-weight:600;transition:.3s;display:inline-block}
.btn:hover{transform:translateY(-2px);border-color:var(--a)}.btn.pri{background:var(--g);border:0;color:#fff;box-shadow:0 10px 30px -10px #6a6cff}
/* loader */
#ld{position:fixed;inset:0;z-index:100;background:var(--bg);display:grid;place-items:center;transition:opacity .6s,visibility .6s}#ld.off{opacity:0;visibility:hidden}
.ring{width:54px;height:54px;border-radius:50%;border:3px solid var(--bd);border-top-color:var(--a);animation:sp 1s linear infinite}@keyframes sp{to{transform:rotate(360deg)}}
/* nav */
header{position:fixed;top:0;left:0;right:0;z-index:50;padding-top:env(safe-area-inset-top,0px)}
nav{display:flex;align-items:center;gap:14px;margin:12px auto;padding:10px 16px;width:min(1160px,94%)}
.logo{font-weight:800;font-size:20px;letter-spacing:-.04em;display:flex;gap:8px;align-items:center}.logo i{width:26px;height:26px;border-radius:8px;background:var(--g);display:inline-block;box-shadow:0 0 18px var(--b)}
.links{display:flex;gap:4px;margin-left:auto}.links a{padding:6px 11px;border-radius:99px;color:var(--mu);font-size:14px}.links a:hover{color:var(--tx);background:var(--gl)}
.tools{display:flex;gap:8px;align-items:center}
.tools input,.tools select{background:var(--gl);border:1px solid var(--bd);color:var(--tx);border-radius:99px;padding:7px 13px;font:inherit;font-size:14px;width:130px}
.tools select{width:auto}.ib{width:38px;height:38px;border-radius:50%;border:1px solid var(--bd);background:var(--gl)}
#mb{display:none}
@media(max-width:900px){.links{position:fixed;inset:70px 4% auto;flex-direction:column;padding:14px;background:var(--bg2);border:1px solid var(--bd);border-radius:20px;display:none}.links.open{display:flex}#mb{display:block}.tools input{width:90px}.links a{font-size:16px;padding:12px}}
@media(max-width:480px){.tools input{display:none}}
/* hero */
#hero{min-height:100svh;display:grid;align-items:center;position:relative;padding-top:120px;overflow:hidden}
#cv{position:absolute;inset:0;width:100%;height:100%;z-index:-1}
.orb{position:absolute;border-radius:50%;filter:blur(70px);opacity:.5;z-index:-1;transition:transform .2s}
.hero h1,#hero h1{font-size:clamp(40px,8vw,92px);font-weight:800;max-width:15ch}
#hero h1 span{background:var(--g);-webkit-background-clip:text;background-clip:text;color:transparent}
#hero p{font-size:clamp(17px,2vw,21px);color:var(--mu);max-width:52ch;margin:22px 0 32px}
.row{display:flex;gap:12px;flex-wrap:wrap}
/* stats */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.stat{padding:26px;text-align:center}.stat b{font-size:clamp(30px,4vw,46px);font-weight:800;background:var(--g);-webkit-background-clip:text;background-clip:text;color:transparent;display:block}.stat span{color:var(--mu);font-size:14px}
.grid{display:grid;gap:18px}.g4{grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}.g3{grid-template-columns:repeat(auto-fit,minmax(300px,1fr))}
.card{padding:28px}.card h3{font-size:20px;margin:16px 0 8px}.card p{color:var(--mu);margin:0 0 16px;font-size:15px}
.ic{width:52px;height:52px;border-radius:16px;display:grid;place-items:center;font-size:24px;background:linear-gradient(135deg,rgba(79,140,255,.3),rgba(155,92,255,.3));border:1px solid var(--bd)}
.empty{padding:40px;text-align:center;color:var(--mu);grid-column:1/-1}
/* tutor */
.chat{max-width:760px;margin:auto;padding:20px;box-shadow:0 0 80px -30px var(--b)}
.msgs{height:300px;overflow:auto;display:flex;flex-direction:column;gap:12px;padding:6px}.m{padding:12px 16px;border-radius:16px;max-width:85%;font-size:15px;animation:pop .35s}
.m.u{align-self:flex-end;background:var(--g);color:#fff}.m.a{background:var(--gl);border:1px solid var(--bd)}
@keyframes pop{from{opacity:0;transform:translateY(8px)}}
.cin{display:flex;gap:8px;margin-top:12px}.cin input{flex:1;background:var(--gl);border:1px solid var(--bd);border-radius:99px;padding:12px 18px;color:var(--tx);font:inherit}
.dots span{display:inline-block;width:6px;height:6px;margin:0 2px;border-radius:50%;background:var(--a);animation:bl 1s infinite}.dots span:nth-child(2){animation-delay:.15s}.dots span:nth-child(3){animation-delay:.3s}@keyframes bl{50%{opacity:.2;transform:translateY(-4px)}}
/* dash */
.dash{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:18px}.dash .card{display:flex;flex-direction:column;align-items:center;text-align:center}
.big{font-size:44px;font-weight:800}.bars{display:flex;align-items:flex-end;gap:8px;height:120px;width:100%}.bars div{flex:1;border-radius:8px 8px 0 0;background:var(--g);min-height:4px;transition:height 1s;position:relative}.bars small{position:absolute;bottom:-20px;left:50%;transform:translateX(-50%);font-size:10px;color:var(--mu)}
svg.rg circle{fill:none;stroke-width:12;stroke-linecap:round}
/* leaderboard */
.pod{display:grid;grid-template-columns:1fr 1.15fr 1fr;gap:14px;align-items:end;margin-bottom:18px}.pod .glass{text-align:center;padding:22px 10px}.pod .p1{padding-block:40px;border-color:#ffd166;box-shadow:0 0 50px -15px #ffd166}.av{width:56px;height:56px;border-radius:50%;margin:0 auto 10px;display:grid;place-items:center;font-weight:800;background:var(--g);color:#fff}
.lb{padding:8px 18px}.lb li{display:flex;gap:14px;padding:12px 0;border-bottom:1px solid var(--bd);list-style:none}.lb li:last-child{border:0}.lb li b{margin-left:auto}.lb ol{margin:0;padding:0}.lb .me{color:var(--a);font-weight:700}
/* challenge */
.ch{padding:30px;max-width:760px;margin:auto}.timer{font-variant-numeric:tabular-nums;font-size:30px;font-weight:800}.opts{display:grid;gap:10px;margin-top:18px}
.opt{text-align:left;padding:14px 18px;border-radius:14px;border:1px solid var(--bd);background:var(--gl);transition:.25s}.opt:hover:not(:disabled){border-color:var(--a);transform:translateX(4px)}.opt.ok{border-color:var(--ok);background:rgba(61,220,151,.15)}.opt.no{border-color:var(--bad);background:rgba(255,107,129,.15)}
/* carousel */
.car{display:flex;gap:18px;overflow-x:auto;scroll-snap-type:x mandatory;padding:6px 2px 16px;scrollbar-width:none}.car::-webkit-scrollbar{display:none}.car .card{flex:0 0 min(380px,85%);scroll-snap-align:start}
.car q{display:block;font-size:17px;quotes:none}.who{margin-top:18px;color:var(--mu);font-size:14px}
/* modal */
dialog{border:1px solid var(--bd);background:var(--bg2);color:var(--tx);border-radius:24px;width:min(560px,92%);padding:28px}dialog::backdrop{background:rgba(3,5,15,.7);backdrop-filter:blur(6px)}
.pb{height:6px;background:var(--bd);border-radius:9px;overflow:hidden;margin-bottom:18px}.pb i{display:block;height:100%;background:var(--g);transition:width .4s}
footer{border-top:1px solid var(--bd);padding:48px 0 30px;color:var(--mu)}.fg{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:28px}.fg h4{color:var(--tx);margin:0 0 10px}.fg a{display:block;padding:3px 0}.fg a:hover{color:var(--tx)}
@media(max-width:800px){.stats{grid-template-columns:1fr 1fr}.fg{grid-template-columns:1fr 1fr}.pod{grid-template-columns:1fr 1fr 1fr;gap:8px}.pod .glass{padding:16px 4px;font-size:13px}.btn{padding:12px 18px}}
.rv{opacity:0;transform:translateY(28px);transition:opacity .8s,transform .8s}.rv.in{opacity:1;transform:none}
#cur{position:fixed;width:300px;height:300px;margin:-150px 0 0 -150px;border-radius:50%;background:radial-gradient(circle,rgba(120,110,255,.16),transparent 65%);pointer-events:none;z-index:-1}
#toast{position:fixed;bottom:22px;left:50%;transform:translate(-50%,120px);padding:12px 22px;border-radius:99px;background:var(--bg2);border:1px solid var(--a);transition:.4s;z-index:90}#toast.on{transform:translate(-50%,0)}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}.rv{opacity:1;transform:none}html{scroll-behavior:auto}}
/* --- Django auth + nav --- */
#au{padding:7px 14px;font-size:14px;max-width:130px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.fi{width:100%;background:var(--gl);border:1px solid var(--bd);color:var(--tx);border-radius:14px;padding:13px 16px;font:inherit}
.auth{width:min(420px,100%);padding:32px}.auth h1{font-size:28px;margin:18px 0 20px}.auth form{display:grid;gap:12px}
.auth .err{color:var(--bad);font-size:14px;margin:0}.auth small,.auth .help{color:var(--mu);font-size:12px}.auth ul{margin:4px 0 0;padding-left:18px}
@media(max-width:480px){#au{max-width:84px;padding:7px 10px}.logo{font-size:17px}}