@font-face{font-family:"SG";src:url(fonts/sg-400.woff2) format("woff2");font-weight:400;font-display:swap}
@font-face{font-family:"SG";src:url(fonts/sg-500.woff2) format("woff2");font-weight:500;font-display:swap}
@font-face{font-family:"SG";src:url(fonts/sg-600.woff2) format("woff2");font-weight:600;font-display:swap}
@font-face{font-family:"SG";src:url(fonts/sg-700.woff2) format("woff2");font-weight:700;font-display:swap}
@font-face{font-family:"SG";src:url(fonts/sg-800.woff2) format("woff2");font-weight:800;font-display:swap}

:root{
  --bg:#0D1424; --text:#EEF2FA; --muted:#A3AEC4;
  --glass:rgba(255,255,255,.065); --glass2:rgba(255,255,255,.085); --edge:rgba(255,255,255,.13);
  --hi:rgba(255,255,255,.22); --lo:rgba(0,0,0,.25); --shadow:rgba(0,0,0,.45); --chip:rgba(255,255,255,.14); --track:rgba(255,255,255,.10);
  --demand:#7AA7FF; --demandBg:rgba(122,167,255,.12); --demandEdge:rgba(122,167,255,.45);
  --supply:#F2B66D; --supplyBg:rgba(242,182,109,.10); --supplyEdge:rgba(242,182,109,.35);
  --ok:#6FDDB0; --okBg:rgba(111,221,176,.12); --bad:#FF8F86; --badBg:rgba(255,143,134,.12);
  --btn:#EEF2FA; --btnText:#0D1424; --axis:rgba(255,255,255,.12);
  --glowA:rgba(90,130,255,.30); --glowB:rgba(242,170,90,.20);
  color-scheme:dark;
}
:root[data-theme="light"]{
  --bg:#DCE3EE; --text:#0F1830; --muted:#4B5670;
  --glass:rgba(255,255,255,.50); --glass2:rgba(255,255,255,.64); --edge:rgba(255,255,255,.85);
  --hi:#fff; --lo:rgba(15,24,48,.06); --shadow:rgba(30,45,90,.16); --chip:rgba(15,24,48,.08); --track:rgba(15,24,48,.10);
  --demand:#2F5FD0; --demandBg:rgba(47,95,208,.10); --demandEdge:rgba(47,95,208,.35);
  --supply:#9A5216; --supplyBg:rgba(184,102,31,.10); --supplyEdge:rgba(184,102,31,.30);
  --ok:#0F7A52; --okBg:rgba(15,122,82,.10); --bad:#B3261E; --badBg:rgba(179,38,30,.08);
  --btn:#0F1830; --btnText:#F4F6FB; --axis:rgba(15,24,48,.14);
  --glowA:rgba(80,120,240,.28); --glowB:rgba(230,150,80,.24);
  color-scheme:light;
}
*{box-sizing:border-box}
html,body{margin:0}
body{
  min-height:100vh;color:var(--text);font:17px/1.55 "SG",system-ui,-apple-system,sans-serif;
  background:
    radial-gradient(1000px 700px at 90% -8%,var(--glowA),transparent 62%),
    radial-gradient(900px 700px at -8% 60%,var(--glowB),transparent 60%),
    var(--bg);
  background-attachment:fixed;
}
a{color:inherit}
button{font:inherit;color:inherit}
button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible{outline:2px solid var(--demand);outline-offset:3px}
.glass{background:var(--glass);border:1px solid var(--edge);-webkit-backdrop-filter:blur(26px) saturate(170%);backdrop-filter:blur(26px) saturate(170%);box-shadow:inset 0 1px 0 var(--hi)}
.muted{color:var(--muted)}

/* header */
.top{position:sticky;top:0;z-index:20;padding:max(12px,env(safe-area-inset-top)) 16px 0}
.topbar{max-width:1120px;margin:0 auto;min-height:56px;display:flex;align-items:center;justify-content:space-between;gap:10px;padding:0 8px 0 20px;border-radius:999px;box-shadow:inset 0 1px 0 var(--hi),0 10px 40px var(--shadow)}
.logo{font-weight:800;font-size:19px;letter-spacing:-.03em;text-decoration:none}
.logo span{color:var(--demand)}
.tools{display:flex;align-items:center;gap:4px;flex-wrap:wrap;justify-content:flex-end}
.seg{display:flex;gap:2px;padding:3px;border-radius:999px;background:var(--glass2);border:1px solid var(--edge)}
.seg button{min-height:36px;min-width:40px;border:0;border-radius:999px;background:transparent;color:var(--muted);font-weight:600;font-size:13px;cursor:pointer}
.seg button[aria-pressed="true"]{background:var(--chip);color:var(--text);font-weight:700}
.icon{width:42px;height:42px;border:0;border-radius:999px;background:transparent;display:flex;align-items:center;justify-content:center;cursor:pointer}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:56px;padding:0 30px;border-radius:999px;background:var(--btn);color:var(--btnText);font-weight:700;font-size:17px;text-decoration:none;border:0;cursor:pointer;transition:transform .35s cubic-bezier(.2,.8,.2,1),box-shadow .35s cubic-bezier(.2,.8,.2,1)}
.btn:hover{transform:scale(1.06);box-shadow:0 14px 40px var(--glowA)}
.btn:active{transform:scale(1.02)}
.btn.small{min-height:40px;padding:0 18px;font-size:14px}
.btn.small:hover{transform:scale(1.04)}
.btn.glassy{background:var(--glass);color:var(--text);border:1px solid var(--edge);box-shadow:inset 0 1px 0 var(--hi);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px)}

/* landing */
.wrap{max-width:1120px;margin:0 auto;padding:0 20px}
.hero{position:relative;overflow:hidden;padding:64px 0 88px}
.hero svg.graph{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}
.hero .wrap{position:relative;display:flex;flex-wrap:wrap;gap:40px;align-items:center}
.hero .copy{flex:1 1 460px;min-width:0;display:flex;flex-direction:column;gap:20px;padding:24px 0}
.kicker{font-weight:600;color:var(--muted)}
h1{margin:0;font-weight:800;font-size:clamp(42px,6.4vw,70px);line-height:.98;letter-spacing:-.045em;max-width:12ch}
.lead{margin:0;font-size:20px;line-height:1.45;color:var(--muted);max-width:30em}
.ctas{display:flex;flex-wrap:wrap;gap:12px;padding-top:4px}
.note{margin:0;font-size:14px;color:var(--muted)}
.qcard{flex:1 1 380px;min-width:0;max-width:500px;margin-left:auto;padding:26px;border-radius:32px;display:flex;flex-direction:column;gap:14px;box-shadow:inset 0 1px 0 var(--hi),inset 0 -1px 0 var(--lo),0 40px 100px var(--shadow)}
.chips{display:flex;gap:6px;flex-wrap:wrap}
.chip{font-size:12px;font-weight:600;padding:4px 11px;border-radius:999px;background:var(--chip)}
.chip.line{background:transparent;border:1px solid var(--edge);color:var(--muted);font-weight:500}
.mini-opt{border-radius:16px;padding:12px 16px;font-size:15px;border:1px solid var(--edge);background:var(--glass2)}
.mini-opt.ok{background:var(--okBg);border-color:var(--ok);font-weight:600}
.mini-opt b{margin-right:8px}
.mini-opt.ok b{color:var(--ok)}
.mini-sol{border-radius:18px;padding:14px 16px;background:var(--glass2);border:1px solid var(--edge);font-size:15px}
.mini-sol small{display:block;font-size:13px;font-weight:600;color:var(--muted);margin-bottom:4px}
.curve{stroke-dasharray:1500;animation:draw 1.8s cubic-bezier(.2,.7,.2,1) both}
.curve2{animation-delay:.15s}
.eq{transform-origin:626px 325px;animation:pop .5s 1.6s both}
@keyframes draw{from{stroke-dashoffset:1500}to{stroke-dashoffset:0}}
@keyframes pop{from{opacity:0;transform:scale(.4)}to{opacity:1;transform:scale(1)}}
section.block{padding:40px 0 88px}
h2{margin:0;font-weight:800;font-size:clamp(32px,4.4vw,46px);line-height:1.05;letter-spacing:-.04em}
.steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin-top:28px}
.step{padding:28px;border-radius:28px;display:flex;flex-direction:column;gap:10px}
.step .num{width:36px;height:36px;border-radius:999px;display:flex;align-items:center;justify-content:center;background:var(--chip);font-weight:800;font-size:15px}
.step h3{margin:0;font-size:23px;letter-spacing:-.025em}
.step p{margin:0;color:var(--muted)}
.split{display:flex;flex-wrap:wrap;gap:40px;align-items:flex-start}
.split > .side{flex:1 1 320px;min-width:0;display:flex;flex-direction:column;gap:14px}
.table{flex:2 1 560px;min-width:0;border-radius:32px;overflow:hidden;box-shadow:inset 0 1px 0 var(--hi),0 30px 80px var(--shadow)}
.trow{display:flex;gap:18px;align-items:center;padding:20px 24px;border-bottom:1px solid var(--edge)}
.trow .n{flex:0 0 36px;font-weight:800;font-size:26px;letter-spacing:-.03em;color:var(--muted)}
.trow .t{font-weight:700;font-size:18px;letter-spacing:-.015em}
.trow .d{font-size:15px;color:var(--muted)}
.trow .tag{margin-left:auto;flex:0 0 auto;font-size:13px;font-weight:700;padding:6px 12px;border-radius:999px;background:var(--chip)}
.trow .tag.free{background:var(--okBg);color:var(--ok)}
.tfoot{padding:18px 24px;font-size:15px;color:var(--muted)}
.price{max-width:560px;margin:0 auto;padding:40px 36px;border-radius:36px;display:flex;flex-direction:column;gap:16px;box-shadow:inset 0 1px 0 var(--hi),inset 0 -1px 0 var(--lo),0 40px 100px var(--shadow)}
.amount{display:flex;align-items:baseline;gap:12px;flex-wrap:wrap}
.amount b{font-weight:800;font-size:64px;letter-spacing:-.05em;line-height:1}
.amount s{font-size:19px;color:var(--muted)}
.incl div{display:flex;gap:12px;align-items:center;padding:12px 0;border-top:1px solid var(--edge)}
.faq{max-width:760px;margin:0 auto}
.faqlist{margin-top:20px;border-radius:28px;overflow:hidden}
.faqlist details{padding:20px 24px;border-bottom:1px solid var(--edge)}
.faqlist summary{font-size:18px;font-weight:700;cursor:pointer;letter-spacing:-.015em}
.faqlist p{margin:10px 0 0;color:var(--muted)}
footer.site{padding:0 20px 40px}
footer.site .in{max-width:1120px;margin:0 auto;padding-top:20px;border-top:1px solid var(--edge);display:flex;flex-wrap:wrap;justify-content:space-between;gap:14px;font-size:13px;color:var(--muted)}
footer.site nav{display:flex;flex-wrap:wrap;gap:18px}

/* legal pages */
.legal{max-width:760px;margin:24px auto 64px;padding:32px;border-radius:32px}
.legal h1{font-size:40px;max-width:none;margin-bottom:8px}
.legal h2{font-size:22px;margin:28px 0 8px;letter-spacing:-.02em}
.legal p,.legal li{color:var(--text)}
.legal .muted{color:var(--muted)}

@media (max-width:600px){
  .topbar{padding:0 6px 0 16px}
  .logo{font-size:17px}
  .tools .btn.small{display:none}
  .qcard,.price,.legal{padding:22px}
}
@media (prefers-reduced-motion:reduce){.curve,.eq{animation:none}}

/* landing v2 */
.hero.center .wrap{justify-content:center;text-align:center}
.hero.center .copy{align-items:center;flex:0 1 820px;padding:72px 0 40px}
.hero.center h1{max-width:13ch}
.hero.center .lead{max-width:26em}
.hero.center .ctas{justify-content:center;padding-top:10px}
.howlist{display:flex;flex-direction:column;gap:20px;margin-top:36px}
.how{display:flex;flex-wrap:wrap;gap:32px;align-items:center;padding:32px;border-radius:32px}
.how .txt{flex:1 1 280px;min-width:0;display:flex;flex-direction:column;gap:10px}
.how .txt h3{margin:0;font-size:26px;letter-spacing:-.03em}
.how .txt p{margin:0;color:var(--muted);font-size:18px;max-width:24em}
.how .num{width:40px;height:40px;border-radius:999px;display:flex;align-items:center;justify-content:center;background:var(--chip);font-weight:800}
.how .demo{flex:1.3 1 340px;min-width:0;padding:20px;border-radius:22px;background:var(--glass2);border:1px solid var(--edge);display:flex;flex-direction:column;gap:10px;font-size:15px}
.demo .q{margin:0;font-weight:500}
.demo .rule{padding:12px 14px;border-radius:14px;background:var(--supplyBg);border:1px solid var(--supplyEdge)}
.demo .rule small,.demo .ex small{display:block;font-size:12px;font-weight:700;color:var(--supply);margin-bottom:2px}
.demo .ex small{color:var(--muted)}
.demo .row2{display:flex;gap:8px;flex-wrap:wrap}
.trow .chev{margin-left:auto;color:var(--muted)}
@media (prefers-reduced-motion:reduce){.btn{transition:none}.btn:hover{transform:none}}

.hero.center svg.graph{top:34%;height:90%;opacity:.9}

/* header flag language picker (langfab.js) */
:root{--lf-surface:var(--glass2);--lf-surface-solid:#141d33;--lf-line:var(--edge);--lf-ink:var(--text);--lf-hover:rgba(255,255,255,.07);--lf-active:rgba(122,167,255,.16);--lf-active-ink:#9DBBFF;--lf-shadow:rgba(0,0,0,.5)}
:root[data-theme="light"]{--lf-surface-solid:#fff;--lf-hover:rgba(15,24,48,.05);--lf-active:rgba(36,67,184,.10);--lf-active-ink:#2443B8;--lf-shadow:rgba(30,45,90,.2)}
#langfab{display:inline-flex;margin:0 2px}
@media (max-width:600px){.seg button{min-width:32px}.tools{gap:2px}.icon{width:38px;height:38px}}

/* hero proof line */
.proof{list-style:none;margin:6px 0 0;padding:0;display:flex;flex-wrap:wrap;justify-content:center;gap:10px 26px;font-size:15px;color:var(--muted)}
.proof li{display:flex;align-items:center;gap:8px}
.proof svg{color:var(--ok);flex:0 0 auto}

/* how-you-learn: soft vertical stepper */
.flow{position:relative;display:flex;flex-direction:column;gap:56px;margin-top:44px}
.flow::before{content:"";position:absolute;inset-inline-start:11px;top:24px;bottom:24px;width:2px;border-radius:2px;background:linear-gradient(var(--demand),var(--supply));opacity:.45}
.fstep{position:relative;display:grid;grid-template-columns:24px minmax(0,1fr) minmax(0,1.25fr);gap:28px;align-items:center}
.fstep .dot{width:16px;height:16px;border-radius:999px;background:var(--demand);box-shadow:0 0 0 7px var(--bg),0 0 22px var(--demand);justify-self:center}
.fstep:nth-child(2) .dot{background:color-mix(in srgb,var(--demand) 50%,var(--supply));box-shadow:0 0 0 7px var(--bg),0 0 22px color-mix(in srgb,var(--demand) 50%,var(--supply))}
.fstep:nth-child(3) .dot{background:var(--supply);box-shadow:0 0 0 7px var(--bg),0 0 22px var(--supply)}
.fstep h3{margin:0 0 6px;font-size:26px;letter-spacing:-.03em}
.fstep p.d{margin:0;color:var(--muted);font-size:18px;max-width:24em}
.fdemo{padding:22px;border-radius:26px;display:flex;flex-direction:column;gap:10px;font-size:15px;box-shadow:inset 0 1px 0 var(--hi),0 24px 60px var(--shadow)}
.fdemo .q{margin:0;font-weight:500}
.fdemo .rule{padding:12px 14px;border-radius:16px;background:var(--supplyBg)}
.fdemo .rule small{display:block;font-size:12px;font-weight:700;color:var(--supply);margin-bottom:2px}
@media (max-width:820px){
  .fstep{grid-template-columns:24px minmax(0,1fr);gap:18px 20px;align-items:start}
  .fstep .dot{margin-top:10px}
  .fstep .fdemo{grid-column:2}
}
.hero svg.graph{-webkit-mask-image:linear-gradient(#000 55%,transparent 98%);mask-image:linear-gradient(#000 55%,transparent 98%)}

/* subject tiles */
.subjects{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;margin-top:22px}
.subj{display:flex;flex-direction:column;justify-content:space-between;gap:18px;min-height:132px;padding:22px;border-radius:24px;text-decoration:none;color:var(--text);opacity:.6}
.subj.on{opacity:1;transition:transform .25s cubic-bezier(.2,.8,.2,1),box-shadow .25s}
.subj.on:hover{transform:scale(1.03);box-shadow:0 18px 50px var(--glowA)}
.subj .sn{font-size:21px;font-weight:800;letter-spacing:-.01em}
.subj .tag{align-self:flex-start}
.subjects{grid-template-columns:repeat(3,minmax(0,1fr))}
@media (max-width:820px){.subjects{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.subj{min-height:112px;padding:16px;border-radius:20px}.subj .sn{font-size:17px}}
.subj .tag{font-size:13px;font-weight:700;padding:5px 11px;border-radius:999px;background:var(--glass2);border:1px solid var(--edge);color:var(--muted)}
.subj.on .tag{background:var(--ok);border-color:transparent;color:#0D1424}