:root{--ink:#111318;--paper:#f4f0e7;--white:#fff;--red:#ef4136;--blue:#246bfd;--yellow:#ffd338;--green:#2cb67d;--orange:#ff833d;--muted:#666a73;--line:rgba(17,19,24,.18)}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:24px}
body{margin:0;background:var(--paper);color:var(--ink);font-family:Arial,"Noto Sans Hebrew",sans-serif;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}p{line-height:1.75}.content-width{width:min(1200px,calc(100% - 40px));margin-inline:auto}.skip-link{position:fixed;top:10px;right:10px;z-index:100;transform:translateY(-160%);background:#fff;padding:12px 18px;border:2px solid var(--ink)}.skip-link:focus{transform:none}
.site-header{width:min(1200px,calc(100% - 40px));height:84px;margin:auto;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:28px;border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:12px;font-size:24px;font-weight:900;direction:ltr;justify-self:start}.brand-mark{width:34px;height:34px;display:grid;grid-template-columns:1fr 1fr;gap:3px;transform:rotate(-8deg)}.brand-mark i{display:block;border-radius:2px;border:2px solid var(--ink)}.brand-mark i:nth-child(1){background:var(--red)}.brand-mark i:nth-child(2){background:var(--blue)}.brand-mark i:nth-child(3){background:var(--yellow)}.brand-mark i:nth-child(4){background:var(--green)}
.site-header nav{display:flex;gap:28px;font-size:14px;font-weight:700}.site-header nav a:hover,.site-header nav a:focus-visible{color:var(--blue)}.header-cta{justify-self:end;border:2px solid var(--ink);padding:11px 18px;font-size:14px;font-weight:800;box-shadow:4px 4px 0 var(--ink);transition:.2s}.header-cta:hover{transform:translate(2px,2px);box-shadow:2px 2px 0 var(--ink)}
.hero{min-height:660px;width:min(1200px,calc(100% - 40px));margin:auto;display:grid;grid-template-columns:1.08fr .92fr;align-items:center;gap:80px;padding:72px 0 78px}.eyebrow,.kicker,.mini-label{display:inline-block;color:var(--blue);font-size:13px;font-weight:900;letter-spacing:.06em}.hero h1{margin:16px 0 24px;font-size:clamp(54px,6.6vw,92px);line-height:.95;letter-spacing:-.055em;font-weight:950}.hero h1 em{color:var(--red);font-style:normal}.hero-copy>p{max-width:620px;margin:0;font-size:20px;color:#42464f}.hero-actions{display:flex;gap:14px;margin-top:30px;flex-wrap:wrap}.button{padding:15px 24px;font-weight:900;border:2px solid var(--ink);transition:.2s}.button-primary{color:#fff;background:var(--blue);box-shadow:5px 5px 0 var(--ink)}.button-primary:hover{transform:translate(2px,2px);box-shadow:3px 3px 0 var(--ink)}.button-secondary:hover{background:#fff}.hero-points{list-style:none;padding:0;margin:42px 0 0;display:flex;gap:38px}.hero-points li{display:flex;flex-direction:column;gap:3px}.hero-points strong{font-size:22px}.hero-points span{font-size:12px;color:#686b73}
.hero-visual{min-height:500px;display:grid;place-items:center;position:relative}.orbit{position:absolute;border:2px solid var(--ink);border-radius:50%;opacity:.16}.orbit-one{width:430px;height:430px}.orbit-two{width:330px;height:470px;transform:rotate(58deg)}.cube-card{position:relative;z-index:2;width:min(390px,88vw);padding:28px;background:#fff;border:3px solid var(--ink);box-shadow:18px 18px 0 var(--yellow);transform:rotate(2deg)}.cube-label{display:block;margin-bottom:18px;font-size:12px;font-weight:900}.cube-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;aspect-ratio:1;padding:11px;background:var(--ink);border-radius:7px}.cube-grid i{border-radius:5px;border:2px solid rgba(255,255,255,.24)}.red{background:var(--red)}.yellow{background:var(--yellow)}.blue{background:var(--blue)}.white{background:#f7f7f4}.green{background:var(--green)}.orange{background:var(--orange)}.cube-caption{display:flex;align-items:center;gap:12px;margin-top:19px}.cube-caption b{font-size:34px}.cube-caption span{font-size:12px;line-height:1.25;color:#60636b}
.dark-intro{background:var(--ink);color:#fff;min-height:250px;padding:58px max(24px,calc((100vw - 1200px)/2));display:grid;grid-template-columns:80px 1fr 1fr;align-items:center;gap:54px}.section-number{color:var(--yellow);font-size:48px;font-weight:950}.dark-intro h2{max-width:570px;margin:7px 0 0;font-size:clamp(30px,3vw,46px);line-height:1.1}.dark-intro>p{max-width:490px;color:#c8cad0;font-size:17px}
.steps-section,.types-section,.faq-section{padding-top:110px;padding-bottom:110px}.section-heading{display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:end;margin-bottom:50px}.section-heading h2,.notation-copy h2,.progress-layout h2{margin:8px 0 0;font-size:clamp(38px,4.2vw,64px);line-height:1;letter-spacing:-.04em}.section-heading>p{max-width:540px;margin:0;color:#5c6068;font-size:17px}.steps-grid{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(2,1fr);gap:20px}.step-card{position:relative;min-height:300px;padding:32px;background:#fff;border:2px solid var(--ink);box-shadow:8px 8px 0 var(--ink);overflow:hidden}.step-card::before{content:"";position:absolute;top:0;left:0;width:10px;height:100%;background:var(--accent)}.step-card.accent-yellow{--accent:var(--yellow)}.step-card.accent-red{--accent:var(--red)}.step-card.accent-blue{--accent:var(--blue)}.step-card.accent-green{--accent:var(--green)}.step-card.accent-orange{--accent:var(--orange)}.step-card.final-step{grid-column:1/-1;min-height:250px}.step-index{font-size:13px;font-weight:900;color:var(--accent)}.step-card h3{font-size:27px;margin:18px 0 8px}.step-card p{color:#565a63;margin:0 0 20px}.step-card code{direction:ltr;display:inline-block;background:var(--ink);color:#fff;padding:10px 13px;font:700 15px/1.5 Consolas,monospace}.algorithm-pair{display:flex;flex-direction:column;align-items:flex-start;gap:8px}.step-card small{display:block;margin-top:14px;color:#686b73}.step-goal{display:inline-block;font-size:13px;font-weight:800;border-bottom:3px solid var(--accent);padding-bottom:3px}.practice-note{margin-top:28px;padding:28px 32px;border:2px dashed var(--ink);display:grid;grid-template-columns:180px 1fr;gap:30px;align-items:center}.practice-note b{font-size:22px}.practice-note p{margin:0;color:#565a63}
.notation-section{background:var(--blue);color:#fff;padding:105px 0}.notation-layout{display:grid;grid-template-columns:.78fr 1.22fr;gap:90px;align-items:center}.notation-copy .kicker{color:var(--yellow)}.notation-copy p{color:#e1e8ff;font-size:17px}.notation-copy>a{display:inline-block;margin-top:12px;border-bottom:2px solid var(--yellow);font-weight:800}.notation-board{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.notation-board>div{min-height:132px;background:#fff;color:var(--ink);border:2px solid var(--ink);padding:18px;display:flex;flex-direction:column}.notation-board b{font:900 36px/1 Arial;direction:ltr}.notation-board span{margin-top:auto;font-weight:800}.notation-board small{color:var(--muted);margin-top:4px}.notation-board .wide{grid-column:span 3;min-height:auto;display:grid;grid-template-columns:70px 1fr 1.3fr;align-items:center;gap:16px}.notation-board .wide span{margin:0}
.types-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}.types-grid article{min-height:370px;background:#fff;border:2px solid var(--ink);padding:24px;display:flex;flex-direction:column;transition:.2s}.types-grid article:hover{transform:translateY(-5px);box-shadow:0 8px 0 var(--ink)}.types-grid h3{font-size:24px;margin:18px 0 6px}.types-grid p{color:#60646c;font-size:14px;margin:0 0 18px}.types-grid article>b{font-size:12px;margin-top:auto}.difficulty{align-self:flex-start;padding:6px 9px;font-size:10px;font-weight:900;border:1px solid var(--ink)}.easy{background:#c8f1df}.classic{background:var(--yellow)}.medium{background:#dbe6ff}.hard{background:#ffd9d6}.mini-cube{width:92px;aspect-ratio:1;margin:26px auto 2px;background:repeating-linear-gradient(90deg,transparent 0 29%,var(--ink) 30% 34%,transparent 35% 64%,var(--ink) 65% 69%,transparent 70%),repeating-linear-gradient(0deg,var(--red) 0 29%,var(--ink) 30% 34%,var(--blue) 35% 64%,var(--ink) 65% 69%,var(--yellow) 70%);border:5px solid var(--ink);transform:rotate(-7deg);box-shadow:8px 8px 0 var(--green)}.cube-2{background:linear-gradient(90deg,var(--red) 0 46%,var(--ink) 47% 53%,var(--yellow) 54%),linear-gradient(var(--blue) 0 46%,var(--ink) 47% 53%,transparent 54%)}.cube-4{background-size:75% 75%;box-shadow:8px 8px 0 var(--orange)}.cube-5{transform:rotate(6deg);box-shadow:8px 8px 0 var(--red)}.shape{width:94px;height:94px;margin:25px auto 0;border:5px solid var(--ink)}.pyramid{clip-path:polygon(50% 0,100% 100%,0 100%);background:linear-gradient(135deg,var(--yellow),var(--green) 50%,var(--red) 51%)}.mega{clip-path:polygon(50% 0,95% 35%,78% 100%,22% 100%,5% 35%);background:conic-gradient(var(--red),var(--yellow),var(--green),var(--blue),var(--orange),var(--red))}.mirror{background:linear-gradient(135deg,#e8e8e8,#858585);transform:skew(-8deg) rotate(8deg);box-shadow:8px 8px 0 #c7c7c7}.skew{background:conic-gradient(from 45deg,var(--yellow),var(--blue),var(--red),var(--green),var(--yellow));transform:rotate(45deg);width:72px;height:72px;margin-top:35px}
.progress-section{background:var(--yellow);padding:105px 0}.progress-layout{display:grid;grid-template-columns:.7fr 1.3fr;gap:90px}.progress-layout .kicker{color:var(--ink)}.progress-list{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.progress-list article{border-top:3px solid var(--ink);padding-top:20px}.progress-list b{font-size:12px}.progress-list h3{font-size:21px;margin:28px 0 5px}.progress-list p{font-size:14px;margin:0;color:#42444a}
.faq-list{border-top:2px solid var(--ink)}details{border-bottom:2px solid var(--ink)}summary{cursor:pointer;list-style:none;padding:26px 0;font-size:21px;font-weight:800;display:flex;align-items:center;justify-content:space-between}summary::-webkit-details-marker{display:none}summary::after{content:"+";font-size:32px;font-weight:400}details[open] summary::after{content:"−"}details p{max-width:800px;margin:0 0 28px;color:#5a5e66}.source-note{border-top:1px solid var(--line);padding:28px 0 60px;display:grid;grid-template-columns:1fr auto;gap:40px;align-items:center}.source-note p{font-size:13px;color:#686b73}.source-note div{display:flex;gap:16px;flex-wrap:wrap}.source-note a{font-size:12px;font-weight:800;border-bottom:1px solid var(--ink)}
footer{background:var(--ink);color:#fff;padding:65px 0}.footer-layout{display:grid;grid-template-columns:1fr auto;gap:50px;align-items:start}.footer-brand .brand-mark i{border-color:#fff}.footer-layout>div>p{color:#9fa3ad}.footer-layout nav{display:flex;gap:24px;font-size:13px}.copyright{grid-column:1/-1;border-top:1px solid #383b42;padding-top:25px;margin:15px 0 0;font-size:12px;color:#8f939c}
.error-page{min-height:100vh;display:grid;place-items:center;padding:24px}.error-page .cube-card{max-width:560px;width:100%;transform:none}.error-page h1{font-size:clamp(38px,7vw,70px);line-height:1;margin:18px 0}.error-page p{margin-bottom:30px;color:#5c6068}
@media(max-width:1000px){.types-grid{grid-template-columns:repeat(2,1fr)}.notation-layout{grid-template-columns:1fr;gap:50px}.progress-layout{grid-template-columns:1fr}.site-header{grid-template-columns:1fr auto}.site-header nav{display:none}.hero{grid-template-columns:1fr;gap:20px;padding-top:54px}.hero-visual{min-height:430px}.dark-intro{grid-template-columns:55px 1fr}.dark-intro>p{grid-column:2}.section-heading{grid-template-columns:1fr;gap:20px}.progress-list{gap:22px}}
@media(max-width:650px){.content-width,.site-header,.hero{width:calc(100% - 28px)}.header-cta{display:none}.hero h1{font-size:48px}.hero-copy>p{font-size:17px}.hero-points{gap:20px}.hero-visual{min-height:390px}.orbit-one{width:310px;height:310px}.orbit-two{width:260px;height:350px}.cube-card{width:300px;padding:22px;box-shadow:11px 11px 0 var(--yellow)}.dark-intro{grid-template-columns:1fr;padding-block:48px;gap:12px}.dark-intro>p{grid-column:auto}.steps-section,.types-section,.faq-section{padding-top:75px;padding-bottom:75px}.steps-grid{grid-template-columns:1fr}.step-card.final-step{grid-column:auto}.step-card{padding:26px;min-height:0}.practice-note{grid-template-columns:1fr}.notation-section,.progress-section{padding:75px 0}.notation-board{grid-template-columns:repeat(2,1fr)}.notation-board .wide{grid-column:span 2;grid-template-columns:60px 1fr}.notation-board .wide small{grid-column:1/-1}.types-grid{grid-template-columns:1fr}.progress-list{grid-template-columns:1fr}.source-note,.footer-layout{grid-template-columns:1fr}.footer-layout nav{flex-wrap:wrap}.copyright{grid-column:auto}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}

/* Visual refresh — layered, playful and cube-inspired */
body{background:
  radial-gradient(circle at 8% 6%,rgba(255,211,56,.32),transparent 24rem),
  radial-gradient(circle at 92% 15%,rgba(36,107,253,.16),transparent 27rem),
  var(--paper);overflow-x:hidden}
body::before{content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;opacity:.16;background-image:radial-gradient(var(--ink) .65px,transparent .65px);background-size:18px 18px;mask-image:linear-gradient(to bottom,#000,transparent 58%)}
.site-header{position:sticky;top:14px;z-index:30;height:72px;margin-top:14px;padding:0 22px;border:1px solid rgba(17,19,24,.12);border-radius:22px;background:rgba(255,255,255,.82);box-shadow:0 12px 40px rgba(17,19,24,.08);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px)}
.brand{font-size:22px}.brand-mark{width:38px;height:38px;padding:4px;border-radius:10px;background:var(--ink);box-shadow:0 5px 0 rgba(17,19,24,.18)}.brand-mark i{border:0;border-radius:2px}.site-header nav{gap:6px;padding:5px;border-radius:15px;background:#f1eee7}.site-header nav a{padding:9px 13px;border-radius:11px;transition:.2s}.site-header nav a:hover,.site-header nav a:focus-visible{color:var(--ink);background:#fff;box-shadow:0 3px 12px rgba(17,19,24,.08)}
.header-cta{border:0;border-radius:13px;color:#fff;background:var(--ink);box-shadow:none;padding:12px 18px}.header-cta:hover{transform:translateY(-2px);box-shadow:0 7px 18px rgba(17,19,24,.18)}
.hero{position:relative;isolation:isolate;min-height:680px;margin-top:28px;padding:72px 64px;border:1px solid rgba(17,19,24,.14);border-radius:42px;background:linear-gradient(135deg,rgba(255,255,255,.96),rgba(255,255,255,.72));box-shadow:0 30px 80px rgba(17,19,24,.09);overflow:hidden}
.hero::before{content:"";position:absolute;z-index:-1;width:360px;height:360px;left:-130px;top:-150px;border:70px solid rgba(239,65,54,.08);border-radius:50%}.hero::after{content:"";position:absolute;z-index:-1;inset:auto -60px -90px auto;width:310px;height:310px;background:var(--yellow);border-radius:42% 58% 61% 39%/43% 34% 66% 57%;opacity:.3;transform:rotate(24deg)}
.eyebrow{padding:8px 12px;border:1px solid rgba(36,107,253,.25);border-radius:999px;background:#eef3ff;letter-spacing:.035em}.hero h1{font-size:clamp(58px,6.5vw,94px);line-height:.92;text-wrap:balance}.hero h1 em{position:relative;display:inline-block}.hero h1 em::after{content:"";position:absolute;right:0;bottom:-9px;width:68%;height:7px;border-radius:999px;background:var(--yellow);transform:rotate(-1deg)}
.hero-copy>p{font-size:19px}.button{border:0;border-radius:14px;padding:16px 24px}.button-primary{box-shadow:0 8px 0 #133f99,0 15px 28px rgba(36,107,253,.22)}.button-primary:hover{transform:translateY(3px);box-shadow:0 5px 0 #133f99,0 10px 20px rgba(36,107,253,.2)}.button-secondary{border:1px solid rgba(17,19,24,.17);background:#fff;box-shadow:0 8px 24px rgba(17,19,24,.06)}
.hero-points{width:max-content;max-width:100%;gap:0;border:1px solid rgba(17,19,24,.12);border-radius:16px;background:rgba(255,255,255,.7);overflow:hidden}.hero-points li{min-width:120px;padding:13px 18px}.hero-points li+li{border-right:1px solid rgba(17,19,24,.1)}
.hero-visual{perspective:1100px}.orbit{border-style:dashed;opacity:.2;animation:orbitSpin 28s linear infinite}.orbit-two{animation-direction:reverse;animation-duration:35s}.cube-card{width:min(390px,88vw);padding:25px;border:1px solid rgba(17,19,24,.14);border-radius:28px;background:linear-gradient(145deg,#fff,#f2f4f8);box-shadow:28px 28px 0 var(--yellow),0 42px 70px rgba(17,19,24,.2);transform:rotateX(6deg) rotateY(-8deg) rotateZ(3deg);transition:transform .5s cubic-bezier(.2,.8,.2,1),box-shadow .5s;animation:cubeFloat 5s ease-in-out infinite}.cube-card::before{content:"";position:absolute;inset:9px;border:1px solid rgba(17,19,24,.05);border-radius:21px;pointer-events:none}.cube-card:hover{transform:rotateX(1deg) rotateY(-2deg) rotateZ(0) translateY(-8px);box-shadow:18px 24px 0 var(--yellow),0 38px 70px rgba(17,19,24,.23)}
.cube-label{width:max-content;padding:7px 10px;border-radius:999px;background:var(--ink);color:#fff}.cube-grid{position:relative;gap:9px;padding:12px;border-radius:14px;background:linear-gradient(145deg,#0c0e12,#252933);box-shadow:inset 0 0 0 2px #000,0 16px 28px rgba(17,19,24,.25)}.cube-grid i{border:0;border-radius:8px;box-shadow:inset 0 3px 0 rgba(255,255,255,.3),inset 0 -5px 0 rgba(0,0,0,.16),0 2px 2px #000}.cube-caption{justify-content:space-between}.cube-caption b{font-size:38px;letter-spacing:-.06em}
.dark-intro{position:relative;width:min(1240px,calc(100% - 20px));margin:20px auto 0;padding-inline:max(34px,calc((100% - 1120px)/2));border-radius:34px;background:linear-gradient(125deg,#111318,#222633 70%,#182343);overflow:hidden}.dark-intro::after{content:"";position:absolute;width:230px;height:230px;left:4%;bottom:-180px;border:55px solid var(--blue);border-radius:50%;opacity:.5}.dark-intro .section-number{font-size:72px;opacity:.22}.dark-intro h2{text-wrap:balance}
.steps-section,.types-section,.faq-section{padding-top:125px}.section-heading{position:relative}.section-heading h2,.notation-copy h2,.progress-layout h2{text-wrap:balance}.section-heading h2::after{content:"";display:block;width:74px;height:6px;margin-top:18px;border-radius:99px;background:linear-gradient(90deg,var(--red),var(--yellow))}
.steps-grid{gap:24px}.step-card{min-height:310px;padding:36px;border:1px solid rgba(17,19,24,.12);border-radius:26px;box-shadow:0 14px 40px rgba(17,19,24,.07);transition:transform .25s,box-shadow .25s}.step-card::before{top:0;right:0;left:0;width:100%;height:8px}.step-card::after{content:attr(data-step);position:absolute;left:20px;bottom:-20px;color:rgba(17,19,24,.035);font-size:130px;font-weight:950;line-height:1}.step-card:hover{transform:translateY(-6px);box-shadow:0 24px 50px rgba(17,19,24,.12)}.step-card h3{font-size:29px}.step-card code{position:relative;z-index:1;border-radius:10px;background:linear-gradient(135deg,#111318,#2a2e39);box-shadow:0 5px 12px rgba(17,19,24,.18)}.practice-note{border:0;border-radius:22px;background:linear-gradient(120deg,#fff7ce,#fff);box-shadow:0 14px 36px rgba(17,19,24,.07)}
.notation-section{position:relative;background:linear-gradient(135deg,#174fc3,#246bfd 48%,#4f82ff);overflow:hidden}.notation-section::before{content:"R U R′ U′";position:absolute;left:-25px;top:35px;color:rgba(255,255,255,.08);font:900 110px/1 Consolas,monospace;direction:ltr;transform:rotate(-8deg)}.notation-copy{position:relative;z-index:1}.notation-board{position:relative;z-index:1;gap:13px}.notation-board>div{border:0;border-radius:18px;box-shadow:0 12px 28px rgba(7,31,83,.22);transition:transform .2s}.notation-board>div:hover{transform:translateY(-4px)}.notation-board b{color:var(--blue)}
.types-grid{gap:22px}.types-grid article{min-height:385px;border:1px solid rgba(17,19,24,.12);border-radius:25px;box-shadow:0 12px 32px rgba(17,19,24,.06);overflow:hidden}.types-grid article:hover{transform:translateY(-7px);box-shadow:0 22px 46px rgba(17,19,24,.13)}.difficulty{border:0;border-radius:999px;padding:7px 11px}.mini-cube,.shape{filter:drop-shadow(0 13px 10px rgba(17,19,24,.16))}
.progress-section{position:relative;background:linear-gradient(120deg,#ffd338,#ffe780);overflow:hidden}.progress-section::after{content:"";position:absolute;width:360px;height:360px;left:-130px;top:-150px;border-radius:50%;border:70px solid rgba(239,65,54,.15)}.progress-layout{position:relative;z-index:1}.progress-list article{padding:25px;border:1px solid rgba(17,19,24,.13);border-radius:20px;background:rgba(255,255,255,.5);backdrop-filter:blur(6px)}.progress-list article>b{display:grid;place-items:center;width:35px;height:35px;border-radius:10px;background:var(--ink);color:#fff}.progress-list h3{margin-top:24px}
.faq-list{border:0;display:grid;gap:12px}.faq-list details{border:1px solid rgba(17,19,24,.12);border-radius:18px;background:#fff;box-shadow:0 8px 22px rgba(17,19,24,.045);overflow:hidden}.faq-list summary{padding:23px 25px}.faq-list details p{padding:0 25px 24px;margin:0}.faq-list details[open]{box-shadow:0 16px 34px rgba(17,19,24,.08)}.faq-list details[open] summary{color:var(--blue)}
.source-note{border-top:0;border-radius:18px;background:rgba(255,255,255,.55);padding:22px 26px;margin-bottom:70px}.source-note a{padding:8px 10px;border:0;border-radius:10px;background:#fff}
footer{position:relative;padding-top:75px;background:linear-gradient(145deg,#0e1014,#191c24);overflow:hidden}footer::before{content:"";position:absolute;inset:0;opacity:.09;background-image:linear-gradient(45deg,transparent 46%,#fff 47% 53%,transparent 54%);background-size:28px 28px}.footer-layout{position:relative}.footer-brand .brand-mark{background:#fff}.footer-brand .brand-mark i{border:0}
@keyframes cubeFloat{0%,100%{translate:0 0}50%{translate:0 -12px}}@keyframes orbitSpin{to{rotate:360deg}}
@media(max-width:1000px){.site-header{top:8px}.hero{padding:58px 44px}.hero-visual{margin-top:10px}.dark-intro{width:calc(100% - 20px)}.steps-grid{grid-template-columns:1fr 1fr}.types-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:650px){body::before{display:none}.site-header{top:7px;width:calc(100% - 20px);height:64px;margin-top:7px;padding:0 15px;border-radius:17px}.brand-mark{width:34px;height:34px}.hero{width:calc(100% - 20px);margin-top:12px;padding:48px 23px 54px;border-radius:28px}.hero h1{font-size:49px}.hero h1 em::after{height:5px}.hero-points{width:100%;display:grid;grid-template-columns:repeat(3,1fr)}.hero-points li{min-width:0;padding:11px 8px}.hero-points strong{font-size:18px}.hero-points span{font-size:10px}.hero-visual{min-height:420px}.cube-card{width:min(295px,78vw);padding:20px;box-shadow:16px 17px 0 var(--yellow),0 30px 55px rgba(17,19,24,.18)}.dark-intro{margin-top:12px;border-radius:25px}.steps-grid{grid-template-columns:1fr}.step-card{padding:28px;border-radius:21px}.notation-board>div{border-radius:14px}.types-grid{grid-template-columns:1fr}.source-note{width:calc(100% - 28px);margin-bottom:50px}.progress-list article{padding:22px}}
@media(prefers-reduced-motion:reduce){.cube-card,.orbit{animation:none!important}}

/* Beginner-friendly visual guide */
.basics-section{padding-top:105px}.compact-heading{margin-bottom:35px}.parts-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.parts-grid article{display:grid;grid-template-columns:110px 1fr;gap:22px;align-items:center;min-height:180px;padding:25px;border:1px solid rgba(17,19,24,.12);border-radius:24px;background:#fff;box-shadow:0 12px 30px rgba(17,19,24,.06)}.parts-grid article>div:last-child>span{font-size:11px;font-weight:900;color:var(--blue)}.parts-grid h3{font-size:26px;margin:4px 0}.parts-grid p{font-size:14px;color:#62666e;margin:0}.part-graphic{position:relative;width:90px;height:90px;display:grid;place-items:center;filter:drop-shadow(0 12px 9px rgba(17,19,24,.16))}.part-graphic i{position:absolute;display:block;border:5px solid var(--ink);border-radius:8px}.center-piece i{width:66px;height:66px;background:var(--yellow)}.edge-piece i:first-child{width:56px;height:70px;right:9px;background:var(--blue);transform:skewY(-18deg)}.edge-piece i:last-child{width:52px;height:70px;left:6px;background:var(--red);transform:skewY(18deg)}.corner-piece i:nth-child(1){width:58px;height:58px;right:16px;top:4px;background:var(--yellow);transform:rotate(45deg) scaleY(.65)}.corner-piece i:nth-child(2){width:50px;height:64px;right:5px;bottom:3px;background:var(--blue);transform:skewY(-24deg)}.corner-piece i:nth-child(3){width:50px;height:64px;left:5px;bottom:3px;background:var(--red);transform:skewY(24deg)}
.hold-cube-tip{display:grid;grid-template-columns:130px 1fr;gap:24px;align-items:center;margin-top:20px;padding:22px 28px;border-radius:22px;background:var(--ink);color:#fff}.hold-cube-tip p{margin:4px 0 0;color:#c8cad0}.hold-visual{position:relative;width:110px;height:90px}.hold-visual b,.hold-visual i{position:absolute;display:grid;place-items:center;width:58px;height:58px;border:3px solid #fff;font-style:normal;font-size:26px}.hold-visual b{top:0;right:28px;background:var(--yellow);color:var(--ink);transform:skewX(-34deg) scaleY(.7)}.hold-visual i{bottom:0;right:12px;background:var(--red)}.hold-visual span,.hold-visual small{position:absolute;font-size:10px;color:#c9cbd1}.hold-visual span{top:0;left:0}.hold-visual small{bottom:2px;left:0}
.steps-grid{align-items:start}.step-card{display:flex;flex-direction:column}.step-graphic{position:relative;z-index:1;min-height:145px;margin:18px 0 22px;padding:18px;display:flex;align-items:center;justify-content:center;gap:18px;border-radius:18px;background:linear-gradient(145deg,#f4f6fa,#fff);border:1px solid rgba(17,19,24,.08)}.step-graphic>span{max-width:150px;color:#575b63;font-size:12px;font-weight:800}.double-graphic{gap:12px}.graphic-arrow{font-size:28px!important;color:var(--blue)!important}.face-diagram{flex:0 0 auto;width:112px;height:112px;display:grid;grid-template-columns:repeat(3,1fr);gap:5px;padding:7px;border-radius:12px;background:var(--ink);box-shadow:0 12px 20px rgba(17,19,24,.16)}.face-diagram i{display:block;border-radius:4px;background:#dadddf;box-shadow:inset 0 2px 0 rgba(255,255,255,.55),inset 0 -3px 0 rgba(0,0,0,.12)}.face-diagram .st-white{background:#fff}.face-diagram .st-yellow{background:var(--yellow)}.face-complete-white i{background:#fff}.two-layers i:nth-child(-n+3){background:#dadddf}.two-layers i:nth-child(n+4){background:var(--red)}.yellow-cross i:nth-child(2),.yellow-cross i:nth-child(4),.yellow-cross i:nth-child(5),.yellow-cross i:nth-child(6),.yellow-cross i:nth-child(8){background:var(--yellow)}.corner-positions i:nth-child(1){background:var(--red)}.corner-positions i:nth-child(3){background:var(--blue)}.corner-positions i:nth-child(7){background:var(--orange)}.corner-positions i:nth-child(9){background:var(--green)}.corner-positions i:nth-child(5){background:var(--yellow)}.face-complete-yellow i{background:var(--yellow)}
.step-question{margin:0 0 8px!important;color:var(--ink)!important;font-size:13px;font-weight:950}.micro-steps{position:relative;z-index:1;list-style:none;counter-reset:micro;margin:0 0 20px;padding:0;display:grid;gap:9px}.micro-steps li{counter-increment:micro;display:grid;grid-template-columns:26px 1fr;gap:10px;align-items:start;color:#4f535c;font-size:14px;line-height:1.6}.micro-steps li::before{content:counter(micro);display:grid;place-items:center;width:24px;height:24px;border-radius:8px;background:var(--accent);color:var(--ink);font-size:11px;font-weight:950}.algorithm-box{position:relative;z-index:1;margin-top:auto;padding:14px 16px;border-radius:14px;background:var(--ink);color:#fff}.algorithm-box>span{display:block;margin-bottom:7px;color:#aeb2bc;font-size:10px;font-weight:800}.algorithm-box code{padding:0;background:transparent;box-shadow:none;font-size:16px}.algorithm-pair{position:relative;z-index:1;display:grid;grid-template-columns:1fr 1fr;gap:8px}.algorithm-pair>div{min-width:0;padding:12px;border-radius:13px;background:var(--ink);color:#fff}.algorithm-pair span{display:block;margin-bottom:6px;color:#b8bbc3;font-size:10px}.algorithm-pair code{display:block;padding:0;background:transparent;box-shadow:none;font-size:12px;white-space:normal}.success-check{position:relative;z-index:1;display:block;margin-top:16px;padding:11px 13px;border-radius:12px;background:#dff8ec;color:#116441;font-size:12px;font-weight:850;line-height:1.6}.strong-check{background:linear-gradient(90deg,#dff8ec,#fff5bd);font-size:14px}.warning-note{position:relative;z-index:1;margin-top:12px!important;padding:11px 13px;border-radius:12px;background:#fff1d6;color:#764a00!important;font-size:12px!important;font-weight:750;line-height:1.6}
.graphic-progression{gap:8px;flex-wrap:wrap}.tiny-state{display:grid;place-items:center;width:55px;height:55px;border:6px solid var(--ink);border-radius:9px;background:#dadddf;color:var(--yellow);font-size:30px;font-weight:950;text-shadow:0 1px 0 #000}.graphic-progression>span{font-size:20px;color:var(--blue)}.solved-graphic{gap:30px}.solved-cube{position:relative;width:130px;height:112px;transform:rotate(-3deg)}.solved-cube i{position:absolute;width:78px;height:78px;border:5px solid var(--ink);background-size:33.33% 33.33%;box-shadow:inset 0 0 0 2px rgba(255,255,255,.18)}.solved-cube i::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,transparent 31%,var(--ink) 32% 36%,transparent 37% 64%,var(--ink) 65% 69%,transparent 70%),linear-gradient(0deg,transparent 31%,var(--ink) 32% 36%,transparent 37% 64%,var(--ink) 65% 69%,transparent 70%)}.solved-cube i:nth-child(1){right:28px;top:0;background-color:var(--yellow);transform:skewX(-35deg) scaleY(.62)}.solved-cube i:nth-child(2){right:5px;bottom:0;background-color:var(--red);transform:skewY(-18deg)}.solved-cube i:nth-child(3){left:2px;bottom:0;background-color:var(--blue);transform:skewY(18deg)}
.notation-visuals{display:grid;gap:16px}.turn-demos{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.turn-demos>div{position:relative;min-height:120px;padding:14px;border-radius:17px;background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.2);display:grid;grid-template-columns:55px 1fr;align-items:center;gap:8px}.turn-face{display:grid;place-items:center;width:54px;height:54px;border:4px solid var(--ink);border-radius:9px;background:var(--red);font:bold 18px Arial;direction:ltr;color:#fff;box-shadow:inset 0 0 0 3px rgba(255,255,255,.2)}.turn-demos b{font-size:44px;color:var(--yellow);line-height:1}.turn-demos small{grid-column:1/-1;color:#edf2ff;font-size:11px;line-height:1.4}
@media(max-width:1000px){.parts-grid{grid-template-columns:1fr}.parts-grid article{grid-template-columns:110px 1fr}.basics-section{padding-top:85px}.algorithm-pair{grid-template-columns:1fr}.step-card{min-height:0}}
@media(max-width:650px){.parts-grid article{grid-template-columns:90px 1fr;padding:20px}.part-graphic{transform:scale(.83);transform-origin:center}.hold-cube-tip{grid-template-columns:1fr;text-align:center}.hold-visual{margin:auto}.step-graphic{min-height:130px;margin-top:12px;padding:13px}.face-diagram{width:94px;height:94px}.double-graphic{gap:7px}.graphic-arrow{font-size:20px!important}.micro-steps li{font-size:13px}.turn-demos{grid-template-columns:1fr}.turn-demos>div{min-height:95px;grid-template-columns:55px 55px 1fr}.turn-demos small{grid-column:auto}.solved-cube{transform:scale(.82) rotate(-3deg)}.solved-graphic{gap:10px}}

/* 3D illustrations and interactive motion guide */
.hero-image-stage{isolation:isolate;overflow:visible}.hero-cube-image{position:relative;z-index:2;display:block;width:min(520px,100%);height:auto;filter:drop-shadow(0 32px 28px rgba(17,19,24,.24));transform:rotate(-2deg);animation:heroCubeFloat 5s ease-in-out infinite;transition:transform .45s ease}.hero-image-stage:hover .hero-cube-image{transform:rotate(2deg) scale(1.035)}.image-badge{position:absolute;z-index:4;right:2%;bottom:8%;padding:11px 16px;border:1px solid rgba(17,19,24,.13);border-radius:999px;background:rgba(255,255,255,.88);box-shadow:0 12px 30px rgba(17,19,24,.13);backdrop-filter:blur(10px);font-size:12px;font-weight:900}
.motion-section{margin-top:30px;margin-bottom:15px;padding:54px 64px;display:grid;grid-template-columns:.9fr 1.1fr;gap:70px;align-items:center;border-radius:34px;background:linear-gradient(135deg,#e9efff,#fff 55%,#fff5c7);box-shadow:0 18px 55px rgba(17,19,24,.08);overflow:hidden}.motion-copy h2{max-width:570px;margin:9px 0 16px;font-size:clamp(38px,4vw,62px);line-height:1;letter-spacing:-.04em}.motion-copy>p{max-width:560px;color:#565a63}.move-buttons{display:flex;gap:10px;margin-top:25px;flex-wrap:wrap}.move-button{min-width:95px;padding:11px 16px;display:flex;align-items:center;gap:10px;border:1px solid rgba(17,19,24,.15);border-radius:14px;background:#fff;color:var(--ink);cursor:pointer;box-shadow:0 5px 13px rgba(17,19,24,.05);transition:.2s}.move-button b{display:grid;place-items:center;width:34px;height:34px;border-radius:9px;background:#eef1f6;font:900 19px Arial;direction:ltr}.move-button span{font-size:12px;font-weight:850}.move-button:hover,.move-button:focus-visible{transform:translateY(-2px);outline:3px solid rgba(36,107,253,.18);outline-offset:2px}.move-button.is-active{background:var(--ink);color:#fff}.move-button.is-active b{background:var(--yellow);color:var(--ink)}.move-status{width:max-content;max-width:100%;margin-top:16px!important;padding:10px 13px;border-radius:11px;background:#fff;font-size:13px}.move-status strong{direction:ltr;display:inline-block;color:var(--blue);font:900 18px Arial}
.cube-demo{position:relative;min-height:390px;display:grid;place-items:center;perspective:950px}.demo-cube{position:relative;width:150px;height:150px;transform-style:preserve-3d;transform:rotateX(-22deg) rotateY(-32deg);animation:demoCubeIdle 7s ease-in-out infinite}.cube-side{position:absolute;inset:0;padding:7px;display:grid;grid-template-columns:repeat(3,1fr);gap:5px;border:4px solid #0b0d11;border-radius:10px;background:#0b0d11;backface-visibility:visible;box-shadow:inset 0 0 0 1px rgba(255,255,255,.12);transition:filter .2s}.cube-side i{display:block;border-radius:6px;box-shadow:inset 0 4px 0 rgba(255,255,255,.3),inset 0 -5px 0 rgba(0,0,0,.14)}.side-front{transform:translateZ(75px)}.side-front i{background:var(--green)}.side-back{transform:rotateY(180deg) translateZ(75px)}.side-back i{background:var(--blue)}.side-right{transform:rotateY(90deg) translateZ(75px)}.side-right i{background:var(--red)}.side-left{transform:rotateY(-90deg) translateZ(75px)}.side-left i{background:var(--orange)}.side-top{transform:rotateX(90deg) translateZ(75px)}.side-top i{background:var(--yellow)}.side-bottom{transform:rotateX(-90deg) translateZ(75px)}.side-bottom i{background:#fff}.cube-demo[data-move="R"] .side-right,.cube-demo[data-move="U"] .side-top,.cube-demo[data-move="F"] .side-front{filter:brightness(1.18) drop-shadow(0 0 13px rgba(255,255,255,.85))}.cube-demo.is-playing[data-move="R"] .side-right{animation:turnRightFace 1.1s cubic-bezier(.2,.8,.2,1)}.cube-demo.is-playing[data-move="U"] .side-top{animation:turnTopFace 1.1s cubic-bezier(.2,.8,.2,1)}.cube-demo.is-playing[data-move="F"] .side-front{animation:turnFrontFace 1.1s cubic-bezier(.2,.8,.2,1)}.motion-arrow{position:absolute;z-index:5;top:40px;left:50%;translate:-50% 0;display:grid;place-items:center;width:62px;height:62px;border-radius:50%;background:var(--yellow);box-shadow:0 10px 0 var(--ink);font-size:42px;font-weight:950;line-height:1}.cube-demo.is-playing .motion-arrow{animation:arrowTurn 1.1s ease}.replay-button{position:absolute;bottom:18px;padding:11px 17px;border:0;border-radius:12px;background:var(--blue);color:#fff;font-weight:850;cursor:pointer;box-shadow:0 7px 0 #123f9f}.replay-button:hover,.replay-button:focus-visible{translate:0 2px;box-shadow:0 5px 0 #123f9f;outline:3px solid rgba(36,107,253,.18);outline-offset:3px}
.read-guide{margin:-8px 0 38px;padding:18px 24px;display:grid;grid-template-columns:1fr auto 1fr auto 1fr;gap:18px;align-items:center;border:1px solid rgba(17,19,24,.12);border-radius:22px;background:rgba(255,255,255,.66)}.read-guide>div{display:grid;grid-template-columns:50px 1fr;column-gap:13px;align-items:center}.read-guide b{font-size:15px}.read-guide small{grid-column:2;color:#656972}.read-icon{grid-row:1/3;display:grid;place-items:center;width:50px;height:50px;border-radius:14px;font-weight:950}.goal-icon{background:#dfe8ff;color:var(--blue);font-size:28px}.action-icon{background:#fff0b3;color:#674f00;font-size:12px}.check-icon{background:#dff8ec;color:#116441;font-size:27px}.read-arrow{color:var(--blue);font-size:25px;font-weight:950}
.types-image{position:relative;margin:0 0 34px;border-radius:28px;overflow:hidden;background:#fff;box-shadow:0 18px 45px rgba(17,19,24,.09)}.types-image img{display:block;width:100%;height:auto;aspect-ratio:1400/788;object-fit:cover}.types-image figcaption{position:absolute;right:22px;bottom:22px;max-width:420px;padding:15px 19px;display:grid;gap:3px;border-radius:15px;background:rgba(17,19,24,.88);color:#fff;backdrop-filter:blur(10px)}.types-image figcaption strong{font-size:18px}.types-image figcaption span{color:#d9dbe1;font-size:12px;line-height:1.5}.step-card:hover .face-diagram{animation:diagramPop .7s ease}.step-card:hover .graphic-arrow{animation:arrowNudge .8s ease infinite alternate}
@keyframes heroCubeFloat{0%,100%{translate:0 0}50%{translate:0 -15px}}@keyframes demoCubeIdle{0%,100%{transform:rotateX(-22deg) rotateY(-32deg)}50%{transform:rotateX(-17deg) rotateY(-22deg) translateY(-9px)}}@keyframes turnRightFace{0%,15%,100%{transform:rotateY(90deg) translateZ(75px) rotateZ(0)}55%,75%{transform:rotateY(90deg) translateZ(75px) rotateZ(90deg)}}@keyframes turnTopFace{0%,15%,100%{transform:rotateX(90deg) translateZ(75px) rotateZ(0)}55%,75%{transform:rotateX(90deg) translateZ(75px) rotateZ(90deg)}}@keyframes turnFrontFace{0%,15%,100%{transform:translateZ(75px) rotateZ(0)}55%,75%{transform:translateZ(75px) rotateZ(90deg)}}@keyframes arrowTurn{0%{rotate:0}65%{rotate:270deg}100%{rotate:360deg}}@keyframes diagramPop{50%{transform:scale(1.06) rotate(2deg)}}@keyframes arrowNudge{to{translate:-5px 0}}
@media(max-width:1000px){.motion-section{grid-template-columns:1fr;padding:45px;gap:20px}.cube-demo{min-height:360px}.read-guide{grid-template-columns:1fr}.read-arrow{rotate:90deg;justify-self:center}.types-image figcaption{max-width:calc(100% - 44px)}}
@media(max-width:650px){.hero-cube-image{width:min(380px,100%)}.image-badge{right:0;bottom:5%;font-size:10px}.motion-section{width:calc(100% - 20px);padding:35px 22px;border-radius:25px}.motion-copy h2{font-size:40px}.move-buttons{display:grid;grid-template-columns:repeat(3,1fr)}.move-button{min-width:0;padding:9px;display:grid;justify-items:center;gap:4px}.cube-demo{min-height:330px;transform:scale(.88)}.read-guide{padding:16px;margin-bottom:28px}.read-guide>div{grid-template-columns:45px 1fr}.read-icon{width:44px;height:44px}.types-image{border-radius:20px}.types-image img{min-height:260px;object-position:center}.types-image figcaption{right:12px;bottom:12px;max-width:calc(100% - 24px)}}
@media(prefers-reduced-motion:reduce){.hero-cube-image,.demo-cube,.cube-demo.is-playing .cube-side,.cube-demo.is-playing .motion-arrow,.step-card:hover .face-diagram,.step-card:hover .graphic-arrow{animation:none!important}}

/* Photographic puzzle cards */
.types-grid{grid-template-columns:repeat(3,1fr)}.types-grid article{position:relative;padding-top:24px}.type-photo{display:block;width:calc(100% + 48px);max-width:none;height:auto;aspect-ratio:4/3;margin:-24px -24px 6px;object-fit:cover;border-bottom:1px solid rgba(17,19,24,.1);transition:transform .35s ease,filter .35s ease}.types-grid article:hover .type-photo{transform:scale(1.025);filter:saturate(1.06)}.types-grid .difficulty{position:absolute;z-index:3;top:14px;right:14px;box-shadow:0 5px 15px rgba(17,19,24,.13)}
@media(max-width:1000px){.types-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:650px){.types-grid{grid-template-columns:1fr}.type-photo{width:calc(100% + 48px);margin-inline:-24px}}