/* 25 Course hub. Loads after landing.css, responsive.css and mk.css */
.ch-hero{position:relative;padding:128px 0 56px;overflow:hidden;min-height:760px;box-sizing:border-box}
.ch-hero>.lp-wrap{position:relative;z-index:1;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:56px;align-items:center}
.ch-hero h1{margin:18px 0 0;font-size:64px;line-height:1.02;font-weight:600;letter-spacing:-.04em;text-wrap:balance}
.ch-sub{margin:20px 0 0;font-size:18px;line-height:28px;color:var(--text-secondary);max-width:540px;text-wrap:pretty}
.ch-sub b{color:var(--text-primary);font-weight:500}
/* email form */
.cf{margin-top:30px;max-width:540px}
.cf-row{display:flex;gap:8px}
.cf-row .lf-input{flex:1;min-width:0;height:var(--control-l,48px);font-size:16px}
.cf-row .lf-btn{flex:none}
.cf .hp{position:absolute!important;left:-9999px;width:1px;height:1px;overflow:hidden}
.cf-msg{min-height:20px;margin-top:8px;font-size:14px;line-height:20px}
.cf-msg.err{color:var(--danger)}
.cf-alt{display:inline-flex;width:max-content;max-width:100%;align-items:center;gap:6px;min-height:44px;font-size:15px;font-weight:500}
.cf-fine{margin:4px 0 0;font-size:13px;line-height:20px;color:var(--text-secondary);text-wrap:pretty}
.cf-eu{display:none;margin-top:12px;align-items:flex-start;gap:10px;font-size:14px;line-height:20px;color:var(--text-secondary);cursor:pointer}
.cf-eu input{width:18px;height:18px;margin:1px 0 0;accent-color:var(--primary);flex:none}
.eu .cf-eu{display:flex}
.cf[data-state="error"] .lf-input{border-color:var(--danger);box-shadow:0 0 0 1px var(--danger)}
.cf[data-state="sending"] .lf-btn--primary{opacity:.7;pointer-events:none}
.cf .lf-spinner{display:none;width:16px;height:16px}
.cf[data-state="sending"] .lf-spinner{display:inline-block}
.cf[data-state="sending"] .cf-go-ic{display:none}
.cf-done{display:none;padding:20px 22px;border-radius:14px;border:1px solid var(--border);background:var(--surface-raised)}
.cf-done b{display:flex;align-items:center;gap:10px;font-size:17px;line-height:24px;font-weight:560}
.cf-done b [data-icon]{color:var(--success);flex:none}
.cf-done div{display:flex;flex-wrap:wrap;gap:4px 20px;margin-top:8px}
.cf-done a{display:inline-flex;align-items:center;min-height:44px;font-size:15px;font-weight:500}
.cf[data-state="success"] .cf-done,.cf[data-state="already"] .cf-done{display:block}
.cf[data-state="success"] .cf-in,.cf[data-state="already"] .cf-in{display:none}
.cf .t-already,.cf[data-state="already"] .t-success{display:none}.cf[data-state="already"] .t-already{display:inline}
/* hero reel: a storyboard of real frames */
.reel{position:relative;height:640px;margin:-40px -24px -40px 0}
.reel-m{position:absolute;inset:0;overflow:hidden;border-radius:18px;-webkit-mask-image:linear-gradient(180deg,transparent,#000 14%,#000 80%,transparent),linear-gradient(90deg,transparent,#000 10%);-webkit-mask-composite:source-in;mask-image:linear-gradient(180deg,transparent,#000 14%,#000 80%,transparent),linear-gradient(90deg,transparent,#000 10%);mask-composite:intersect}
.reel-g{position:absolute;inset:-60px -40px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;transform:rotate(-7deg)}
.reel-c{display:flex;flex-direction:column;gap:14px}
.mo .reel-c{animation:reelUp 60s linear infinite}.mo .reel-c:nth-child(2){animation-name:reelDn;animation-duration:72s}.mo .reel-c:nth-child(3){animation-duration:66s}
@keyframes reelUp{from{transform:translateY(0)}to{transform:translateY(-50%)}}
@keyframes reelDn{from{transform:translateY(-50%)}to{transform:translateY(0)}}
.rfr{position:relative;margin:0;aspect-ratio:16/9;border-radius:8px;overflow:hidden;background:#141518;outline:1px solid rgba(255,255,255,.07)}
.rfr img{width:100%;height:100%;object-fit:cover;display:block}
.rfr figcaption{position:absolute;left:6px;top:6px;font:500 10px/16px var(--font-mono);padding:0 5px;border-radius:4px;background:var(--overlay-scrim-strong);color:#fff}
.rfr.on{outline:1.5px solid var(--primary);outline-offset:2px}
.reel-sb{position:absolute;left:-28px;bottom:26px;z-index:3;width:360px;box-shadow:0 40px 80px -24px rgba(0,0,0,.9),0 0 0 1px rgba(255,255,255,.04)}
.reel-sb .tl{border-bottom:0;padding-bottom:12px}
.reel-cap{position:absolute;right:8px;bottom:-6px;z-index:3;display:flex;align-items:center;gap:8px;font:500 12px/18px var(--font-mono);color:var(--text-secondary)}
.reel-cap::before{content:"";width:6px;height:6px;border-radius:1px;background:var(--primary)}
/* data strip */
.dstrip{position:relative;border-top:1px solid var(--border);border-bottom:1px solid var(--border);background:var(--surface-sunken)}
.dstrip-r{height:22px;display:flex;overflow:hidden;font:500 10px/22px var(--font-mono);color:rgba(255,255,255,.22);border-bottom:1px solid var(--border);-webkit-mask-image:linear-gradient(90deg,transparent,#000 12%,#000 88%,transparent);mask-image:linear-gradient(90deg,transparent,#000 12%,#000 88%,transparent)}
.dstrip-r span{flex:0 0 120px;padding-left:6px;border-left:1px solid rgba(255,255,255,.1)}
.dgrid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr))}
.dcell{padding:30px 24px 26px;border-left:1px solid var(--border);display:flex;flex-direction:column;gap:8px}
.dcell:first-child{border-left:0;padding-left:0}
.dcell b{font:500 44px/1 var(--font-mono);letter-spacing:-.04em;font-variant-numeric:tabular-nums}
.dcell.key b{color:var(--primary-text)}
.dcell span{font-size:14px;line-height:20px;color:var(--text-secondary);max-width:220px}
.dcap{padding:14px 0 18px;border-top:1px solid var(--border);font-size:13px;line-height:20px;color:var(--text-secondary)}
.dcap a{white-space:nowrap}
/* short answer */
.sa3{padding:40px 44px;display:grid;grid-template-columns:180px minmax(0,1fr);gap:32px}
.sa3 .sa-l{display:flex;align-items:flex-start;gap:10px;font:500 12px/20px var(--font-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--text-secondary)}
.sa3 p{margin:0;font-size:24px;line-height:36px;letter-spacing:-.015em;text-wrap:pretty}
.sa3 p mark{background:rgba(255,255,255,.08);color:var(--text-primary);padding:1px 6px;border-radius:4px;box-decoration-break:clone;-webkit-box-decoration-break:clone}
/* returning reader */
.cont{display:none;margin-bottom:20px;padding:14px 18px;border-radius:12px;border:1px solid var(--border);background:var(--surface-raised);align-items:center;justify-content:space-between;gap:16px;font-size:15px}
.cont.on{display:flex}.cont span{color:var(--text-secondary)}.cont a{display:inline-flex;align-items:center;gap:6px;min-height:44px;font-weight:500}
/* program */
.prog{list-style:none;margin:0;padding:0;border-top:1px solid var(--border)}
.prog li{border-bottom:1px solid var(--border)}
.pr{display:grid;grid-template-columns:120px minmax(0,1fr) 72px 220px 28px;gap:28px;align-items:center;padding:26px 0;color:inherit;transition:background .3s var(--lp-ease)}
.pr:hover{color:inherit;background:linear-gradient(90deg,transparent,rgba(255,255,255,.025) 30%,transparent)}
.pr-n{font:500 64px/1 var(--font-mono);letter-spacing:-.06em;color:var(--text-primary)}
.pr-n i{font-style:normal;color:var(--text-disabled);margin-right:2px}
.pr h3{margin:0;font-size:28px;line-height:34px;font-weight:560;letter-spacing:-.025em}
.pr p{margin:6px 0 0;font-size:15px;line-height:22px;color:var(--text-secondary)}
.pr p b{font:500 11px/22px var(--font-mono);letter-spacing:.08em;text-transform:uppercase;color:var(--text-disabled);margin-right:8px}
.pr-m{font:500 13px var(--font-mono);color:var(--text-secondary);white-space:nowrap}
.pr-th{position:relative;aspect-ratio:16/9;border-radius:8px;overflow:hidden;outline:1px solid var(--border);transform:rotate(var(--r,2deg));transition:transform .4s var(--lp-ease),outline-color .3s}
.pr-th img{width:100%;height:100%;object-fit:cover;display:block;filter:grayscale(.35);transition:filter .4s}
.pr:hover .pr-th{transform:rotate(0) scale(1.04);outline-color:var(--border-strong)}.pr:hover .pr-th img{filter:none}
.pr-ar{color:var(--text-secondary);display:flex;transition:transform .3s var(--lp-ease),color .2s}
.pr:hover .pr-ar{transform:translateX(4px);color:var(--text-primary)}
.pr .done{display:none}
.pr.read .pr-n i{color:var(--success)}
.chal{margin-top:24px;padding:28px 32px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);gap:40px;align-items:center;color:inherit;transition:border-color .2s}
.chal:hover{color:inherit;border-color:var(--border-strong)}
.chal em{font:500 12px/16px var(--font-mono);font-style:normal;letter-spacing:.12em;text-transform:uppercase;color:var(--text-secondary)}
.chal h3{margin:8px 0 0;font-size:30px;line-height:36px;font-weight:560;letter-spacing:-.025em}
.chal p{margin:10px 0 0;font-size:15px;line-height:23px;color:var(--text-secondary);max-width:440px;text-wrap:pretty}
.chal-g{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:8px}
.chal-g span{position:relative;aspect-ratio:16/10;border-radius:6px;border:1px dashed var(--border-strong);display:flex;align-items:flex-end;padding:5px 7px;font:500 11px/1 var(--font-mono);color:var(--text-disabled);overflow:hidden}
.chal-g span img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.75}
.chal-g span.f{border:1px solid var(--border)}.chal-g span.f b{position:relative;z-index:1;color:#fff;font-weight:500;background:var(--overlay-scrim-strong);padding:2px 4px;border-radius:3px}
/* different */
.dif{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border-top:1px solid var(--border)}
.dif>div{padding:32px 32px 0 0;display:flex;flex-direction:column;gap:12px}
.dif>div+div{padding-left:32px;border-left:1px solid var(--border)}
.dif em{font:500 13px var(--font-mono);font-style:normal;color:var(--text-disabled)}
.dif b{font-size:24px;line-height:30px;font-weight:560;letter-spacing:-.02em}
.dif p{margin:0;font-size:16px;line-height:25px;color:var(--text-secondary);text-wrap:pretty}
/* extras */
.xg{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;align-items:start}
.xc{display:flex;flex-direction:column;overflow:hidden;height:340px}
.xc-h{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:10px 10px 10px 16px;border-bottom:1px solid var(--border);min-height:52px;box-sizing:border-box}
.xc pre{margin:0;padding:16px;font:400 12.5px/20px var(--font-mono);color:var(--text-primary);white-space:pre-wrap;overflow:hidden;flex:1;-webkit-mask-image:linear-gradient(180deg,#000 70%,transparent);mask-image:linear-gradient(180deg,#000 70%,transparent)}
.xc pre mark{background:var(--primary-subtle);color:var(--primary-text);border-radius:3px;padding:0 3px}
.xc .chk{flex:1;overflow:hidden;-webkit-mask-image:linear-gradient(180deg,#000 70%,transparent);mask-image:linear-gradient(180deg,#000 70%,transparent)}
.xc .chk-r{grid-template-columns:18px minmax(0,1fr);cursor:pointer;line-height:19px}
.xc .chk-r input{width:16px;height:16px;margin:0;accent-color:var(--success)}
.xc .chk-r input:checked+span{color:var(--text-secondary);text-decoration:line-through}
.xform{margin-top:16px;padding:32px 36px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);gap:40px;align-items:center}
.xform h3{margin:0;font-size:28px;line-height:34px;font-weight:560;letter-spacing:-.025em;text-wrap:balance}
.xform p{margin:8px 0 0;font-size:15px;line-height:23px;color:var(--text-secondary)}
.xform .cf{margin-top:0;max-width:none}
/* how a video is made */
.mk{display:grid;grid-template-columns:300px minmax(0,1fr);gap:32px;align-items:start}
.mk-st{display:flex;flex-direction:column;gap:4px;position:relative}
.mk-st button{all:unset;box-sizing:border-box;cursor:pointer;display:grid;grid-template-columns:36px minmax(0,1fr);gap:4px 10px;padding:14px 16px;border-radius:12px;border:1px solid transparent;color:var(--text-secondary);transition:background .2s,border-color .2s,color .2s;min-height:44px}
.mk-st button:focus-visible{outline:2px solid var(--focus-ring);outline-offset:2px}
.mk-st button em{font:500 13px/22px var(--font-mono);font-style:normal}
.mk-st button b{font-size:16px;line-height:22px;font-weight:560}
.mk-st button span{grid-column:2;font-size:14px;line-height:20px;max-height:0;overflow:hidden;transition:max-height .4s var(--lp-ease)}
.mk-st button.on{background:var(--surface-raised);border-color:var(--border);color:var(--text-primary)}
.mk-st button.on em{color:var(--primary-text)}
.mk-st button.on span{max-height:80px;color:var(--text-secondary)}
.mk-st button .bar{grid-column:1/-1;height:2px;border-radius:1px;background:var(--border);margin-top:8px;overflow:hidden;display:none}
.mk-st button.on .bar{display:block}.mk-st button .bar i{display:block;height:100%;width:0;background:var(--primary)}
.mo .mk-st button.on.run .bar i{animation:mkbar 5s linear forwards}
@keyframes mkbar{to{width:100%}}
.mk-v{position:relative;aspect-ratio:16/10}
.mk-p{position:absolute;inset:0;opacity:0;pointer-events:none;transition:opacity .5s var(--lp-ease)}
.mk-p.on{opacity:1;pointer-events:auto}
.mk-p>.ui{height:100%;box-sizing:border-box}
.mk-sw .scn{transition:border-color .3s}
.mk-cap{margin:18px 0 0;font-size:18px;line-height:26px;font-weight:500;letter-spacing:-.01em;display:flex;align-items:center;gap:10px}
.mk-cap::before{content:"";width:6px;height:6px;border-radius:1px;background:var(--primary)}
.real{margin-top:40px;display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);gap:32px;align-items:center}
.real .exc-f{cursor:pointer}
.real .exc-f img{width:100%;height:100%;object-fit:cover;display:block}
.real .exc-play{opacity:1;transform:none}
.real .exc-f video{width:100%;height:100%;display:block;background:#000}
.real-t em{font:500 12px/16px var(--font-mono);font-style:normal;letter-spacing:.12em;text-transform:uppercase;color:var(--text-secondary)}
.real-t h3{margin:8px 0 0;font-size:26px;line-height:32px;font-weight:560;letter-spacing:-.02em}
.real-t p{margin:10px 0 0;font-size:15px;line-height:23px;color:var(--text-secondary)}
.price{margin-top:22px;padding-top:18px;border-top:1px solid var(--border);font-size:18px;line-height:27px;letter-spacing:-.01em}
.price small{display:block;margin-top:6px;font-size:13px;line-height:20px;color:var(--text-secondary);letter-spacing:0}
/* not for */
.nf{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.nfc{padding:24px;display:flex;flex-direction:column;gap:12px}
.nfc .lf-badge{align-self:flex-start}
.nfc b{font-size:20px;line-height:27px;font-weight:560;letter-spacing:-.015em;text-wrap:balance}
.nfc p{margin:0;font-size:15px;line-height:23px;color:var(--text-secondary);text-wrap:pretty}
/* final */
.fin .cf{margin:32px auto 0;max-width:520px}
.fin .cf-fine,.fin .cf-alt-w{text-align:center;justify-content:center}
.fin .cf-alt-w{display:flex}
.fin-k{display:flex;justify-content:center;margin-bottom:22px}
/* demo state switcher (design file only, not shipped) */
.demo{position:fixed;right:16px;bottom:16px;z-index:90;display:flex;align-items:center;gap:8px;padding:8px 8px 8px 12px;border-radius:12px;border:1px solid var(--border-strong);background:rgba(17,18,19,.92);backdrop-filter:blur(10px);font:500 12px var(--font-mono);color:var(--text-secondary)}
.demo select{height:32px;border-radius:8px;border:1px solid var(--border);background:var(--surface);color:var(--text-primary);font:500 12px var(--font-mono);padding:0 8px}
.demo button{all:unset;cursor:pointer;width:28px;height:28px;display:flex;align-items:center;justify-content:center;border-radius:6px}
.demo button:hover{background:var(--surface-hover);color:var(--text-primary)}
:focus-visible{outline:2px solid var(--focus-ring);outline-offset:2px}
@media (max-width:1080px){
.ch-hero>.lp-wrap{grid-template-columns:minmax(0,1fr);gap:40px}
.ch-hero{min-height:0}.reel{height:420px;margin:0 -24px}
.reel-sb{left:16px}
.pr{grid-template-columns:88px minmax(0,1fr) 160px 24px}.pr-m{display:none}.pr-n{font-size:48px}
.mk{grid-template-columns:minmax(0,1fr)}.mk-st{flex-direction:row;overflow-x:auto}.mk-st button{flex:1 0 200px}
.xg{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}.xg .xc:nth-child(3){grid-column:1/-1}
}
@media (max-width:760px){
.ch-hero{padding:96px 0 32px}
.ch-hero h1{font-size:36px;margin-top:12px;letter-spacing:-.035em}
.ch-sub{font-size:15px;line-height:23px;margin-top:12px}
.cf{margin-top:20px}.cf-row{flex-direction:column}.cf-row .lf-btn{width:100%;justify-content:center}
.reel{height:300px;margin:0 -16px}.reel-g{gap:8px;inset:-30px -20px}.reel-c{gap:8px}
.reel-sb{width:280px;left:16px;bottom:16px}.reel-sb .tl-r:nth-child(3){display:none}
.reel-cap{right:16px;bottom:-26px}
.dgrid{grid-template-columns:repeat(2,minmax(0,1fr))}
.dcell{padding:22px 16px 20px}.dcell:nth-child(odd){border-left:0;padding-left:0}.dcell:nth-child(n+3){border-top:1px solid var(--border)}
.dcell b{font-size:30px}.dcell span{font-size:13px;line-height:18px}
.sa3{grid-template-columns:minmax(0,1fr);gap:14px;padding:22px 20px}.sa3 p{font-size:18px;line-height:28px}
.pr{grid-template-columns:52px minmax(0,1fr) 20px;gap:14px;padding:20px 0;min-height:44px}
.pr-th{display:none}.pr-n{font-size:30px}.pr h3{font-size:19px;line-height:25px}.pr p{font-size:14px;line-height:20px}
.chal{grid-template-columns:minmax(0,1fr);gap:20px;padding:22px 20px}.chal h3{font-size:24px;line-height:30px}
.dif{grid-template-columns:minmax(0,1fr)}.dif>div,.dif>div+div{padding:24px 0;border-left:0;border-bottom:1px solid var(--border)}.dif b{font-size:20px;line-height:26px}
.xg{grid-template-columns:minmax(0,1fr)}.xc{height:280px}
.xform{grid-template-columns:minmax(0,1fr);gap:18px;padding:22px 20px}.xform h3{font-size:22px;line-height:28px}
.mk-st button{flex:1 0 168px;padding:12px}.mk-st button span{display:none}
.mk-v{aspect-ratio:auto;height:440px}
.real{grid-template-columns:minmax(0,1fr);gap:20px}
.nf{grid-template-columns:minmax(0,1fr)}
.fin h2{font-size:38px}
.demo{left:8px;right:8px;bottom:8px}
}
@media (prefers-reduced-motion:reduce){.reel-c{animation:none!important}}