*{box-sizing:border-box}body{color:#121117;font-family:var(--font-figtree), "Figtree", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans CJK JP", system-ui, sans-serif;background:#fff;margin:0}a{color:#121117;text-decoration:none}a:hover{color:#4d4c5c}::selection{color:#121117;background:#ffdf3d}.hero-ghost:hover{color:#fff;background:#121117}.hero-primary:hover{background:#2a2935}.alg-button:not(.is-active):hover{background:#f4f4f8}.hit-row{cursor:pointer;border-bottom:1px solid #dcdce5}.hit-row:hover{background:#f4f4f8}.search-input:focus{outline-offset:-1px;border-color:#121117;outline:2px solid #121117}.player-ghost:hover{border-color:#fff}.player-next:hover{background:#dcdce5}.player-close:hover{color:#fff}.footer-link{color:#dcdce5}.footer-link:hover{color:#fff}.step-cube{width:min(100%,180px);margin:0 auto 20px}.f2l-featured-groups{gap:16px;display:grid}.f2l-group-row{grid-template-columns:repeat(var(--f2l-columns), minmax(0, 1fr));gap:16px;display:grid}.f2l-group{grid-column:span var(--f2l-group-columns);grid-row:span 2;grid-template-columns:subgrid;grid-template-rows:subgrid;row-gap:0;min-width:0;display:grid}.f2l-group>.group-heading{grid-column:1/-1}.group-heading{justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:20px;display:flex}.group-count{color:#6a697c;white-space:nowrap;background:#f4f4f8;border-radius:4px;flex:none;padding:4px 8px;font-size:12px;font-weight:600}.f2l-cases{grid-column:1/-1;grid-template-columns:subgrid;gap:16px;display:grid}.f2l-ad-slot{min-width:0}.f2l-case{flex-direction:column;gap:12px;min-width:0;padding:16px;display:flex}.f2l-case>div{margin:0 auto}.f2l-case>.f2l-algorithms{gap:4px;margin-top:20px;display:grid}:is(.oll-groups,.pll-groups){gap:40px;display:grid}:is(.oll-group,.pll-group) h3{font-family:var(--font-mulish), "Mulish", system-ui, sans-serif;margin:0;font-size:20px;line-height:1.4}:is(.oll-cases,.pll-cases){grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;display:grid}:is(.oll-case,.pll-case){background:#fff;border:1px solid #dcdce5;border-radius:8px;grid-template-columns:164px minmax(0,1fr);align-items:start;gap:16px;min-width:0;padding:20px 16px;display:grid}:is(.oll-case-image,.pll-case-image){margin:0}:is(.oll-case-content,.pll-case-content){min-width:0}:is(.oll-case-heading,.pll-case-heading){flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:4px 12px;margin-bottom:12px;display:flex}:is(.oll-case-heading,.pll-case-heading) h4{margin:0;font-size:15px;font-weight:600}:is(.oll-case-heading,.pll-case-heading)>span{color:#6a697c;white-space:nowrap;font-size:11px}:is(.oll-algorithms,.pll-algorithms){gap:8px;display:grid}:is(.oll-algorithm,.pll-algorithm){overflow-wrap:anywhere;align-items:baseline;gap:10px;width:100%;display:flex}:is(.oll-algorithm-number,.pll-algorithm-number){opacity:.55;flex:none;font-size:11px}:is(.oll-algorithm:focus-visible,.pll-algorithm:focus-visible){outline-offset:3px;outline:2px solid #121117}.oll-case-note{color:#6a697c;margin:12px 0 0;font-size:12px;line-height:1.5}:is(.oll-legend,.pll-legend){border:1px solid #dcdce5;border-radius:8px;flex-wrap:wrap;align-items:center;gap:12px 24px;padding:16px 20px;font-size:14px;display:flex}:is(.oll-legend,.pll-legend)>span{align-items:center;gap:10px;display:inline-flex}:is(.oll-legend,.pll-legend) i{background:#ffdf3d;border:1px solid #121117;flex:none;width:18px;height:18px;display:inline-block}.oll-legend .oll-legend-side{height:6px}.oll-legend .oll-legend-neutral{background:#f4f4f8;border-color:#dcdce5}:is(.oll-source-note,.pll-source-note){color:#6a697c;margin:12px 0 32px;font-size:13px;line-height:1.6}@media (max-width:1100px){:is(.oll-cases,.pll-cases){grid-template-columns:1fr}}@media (max-width:480px){:is(.oll-case,.pll-case){grid-template-columns:1fr;gap:8px}:is(.oll-case-image,.pll-case-image){justify-self:center}}@media (max-width:900px){.grid-hero,.grid-4,.grid-3,.grid-2,.grid-split{grid-template-columns:1fr!important}.hero-art{display:none!important}.section-pad{padding-inline:20px!important}.display-xl{font-size:40px!important}.display-lg{font-size:32px!important}.f2l-group-row{grid-template-columns:repeat(2,minmax(0,1fr))}.f2l-group{grid-column:1/-1}.f2l-ad-slot{display:none}}@media (max-width:600px){.f2l-group-row{grid-template-columns:1fr}.group-heading{flex-direction:column;align-items:flex-start}}body{font-family:var(--font-figtree), "Figtree", system-ui, sans-serif}.home-page{background:#fff;flex-direction:column;min-height:100vh;display:flex}.site-header{z-index:10;background:#fff;border-bottom:1px solid #dcdce5;height:72px;position:relative}.site-header-inner,.home-footer-inner{justify-content:space-between;align-items:center;width:min(100% - 48px,1200px);margin:0 auto;display:flex}.site-header-inner{gap:24px;height:100%;position:relative}.site-header-controls{justify-content:flex-end;align-items:center;gap:12px;display:flex}.site-header-action,.language-switcher-trigger{white-space:nowrap;flex:none;height:36px}.language-switcher{flex:none}.language-switcher-trigger{color:#121117;font:inherit;cursor:pointer;background:#fff;border:1px solid #dcdce5;border-radius:4px;justify-content:center;align-items:center;gap:8px;padding:0 12px;font-size:13px;font-weight:600;line-height:1;display:inline-flex}.language-switcher-trigger:hover,.language-switcher-trigger[aria-expanded=true]{background:#f4f4f8;border-color:#121117}.language-switcher-code{letter-spacing:.065em}.language-switcher-chevron{transition:transform .12s}.language-switcher-trigger[aria-expanded=true] .language-switcher-chevron{transform:rotate(180deg)}.language-switcher-trigger:focus-visible,.language-option:focus-visible{outline-offset:3px;outline:2px solid #121117}.language-panel{top:calc(100% + 12px);z-index:1;color:#121117;background:#fff;border:1px solid #dcdce5;border-radius:8px;width:min(1040px,100vw - 40px);max-height:calc(100dvh - 120px);padding:20px;position:absolute;inset-inline-end:0;overflow-y:auto}.language-panel-heading{justify-content:space-between;align-items:center;gap:16px;margin-bottom:16px;display:flex}.language-panel:focus{outline:none}.language-panel-heading h2{font:inherit;letter-spacing:.065em;text-transform:uppercase;margin:0;font-size:13px;font-weight:600}.language-panel-heading>span{color:#6a697c;font-size:13px}.language-panel-options{grid-template-columns:repeat(4,minmax(0,1fr));gap:4px;display:grid}.language-option{color:#121117;min-width:0;min-height:0;font:inherit;text-align:start;cursor:pointer;background:#fff;border:1px solid #0000;border-radius:8px;align-items:center;gap:10px;padding:10px 12px;display:flex}.language-option:hover{background:#f4f4f8;border-color:#dcdce5}.language-option[aria-pressed=true]{background:#99c5ff;border-color:#121117}.language-option-flag{flex:none;font-size:20px;line-height:1}.language-option-labels{gap:1px;min-width:0;display:grid}.language-option-name{font-family:var(--font-mulish), "Mulish", system-ui, sans-serif;letter-spacing:-.1px;font-size:14px;font-weight:700;line-height:1.35}.language-option-description{color:#4d4c5c;font-size:11px;line-height:1.4}.language-option-check{flex:none;margin-inline-start:auto}.language-panel-hint{color:#6a697c;border-top:1px solid #dcdce5;margin:12px 0 0;padding-top:12px;font-size:13px;line-height:1.5}[dir=rtl] .cube-sticker,[dir=rtl] .alg-button,[dir=rtl] .oll-case-image,[dir=rtl] .pll-case-image,[dir=rtl] .hero-art,[dir=rtl] .home-hero-art{direction:ltr}[dir=rtl] .site-header-action>[aria-hidden=true],[dir=rtl] .home-primary>[aria-hidden=true]{display:inline-block;transform:scaleX(-1)}html:lang(ja),html:lang(zh-CN),html:lang(ko){line-break:strict;word-break:normal}@media (max-width:1100px){.language-panel-options{grid-template-columns:repeat(3,minmax(0,1fr))}}@media (max-width:860px){.language-panel-options{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (max-width:340px){.language-panel{padding:16px}.language-panel-options{grid-template-columns:minmax(0,1fr)}}@media (max-width:620px){.site-header:has(.language-switcher){height:auto;min-height:72px;padding-block:12px}.site-header-inner:has(.language-switcher){flex-wrap:wrap;gap:6px}.site-header-controls{gap:6px}}.brand{color:#121117;font-family:var(--font-mulish), "Mulish", system-ui, sans-serif;letter-spacing:-1.1px;font-size:26px;font-weight:700;line-height:1}.brand-in{color:#99c5ff}.brand-suffix{letter-spacing:-.1px;vertical-align:baseline;margin-inline-start:1px;font-size:14px;font-weight:600}.site-header-action{border:1px solid #121117;border-radius:4px;align-items:center;gap:8px;padding:0 16px;font-size:13px;font-weight:600;line-height:1;display:inline-flex}.site-header-action:hover,.site-header-action:focus-visible{color:#fff;background:#121117}.home-main{background:#f4f4f8}.home-stage{background:#fff;grid-template-columns:minmax(360px,.9fr) minmax(600px,1.1fr);width:min(100%,1440px);margin:0 auto;display:grid}.home-hero{background:#99c5ff;flex-direction:column;justify-content:space-between;min-height:760px;padding:80px clamp(32px,5vw,80px) 56px;display:flex;position:relative;overflow:hidden}.home-hero:after{content:"";opacity:.16;border:3px solid #121117;border-radius:50%;width:190px;height:190px;position:absolute;bottom:-72px;right:-48px}.home-hero-copy{z-index:2;position:relative}.home-eyebrow{color:#4d4c5c;letter-spacing:1.5px;text-transform:uppercase;margin:0 0 14px;font-size:12px;font-weight:600}.home-hero .home-eyebrow{color:#121117}.home-hero h1{max-width:620px;font-family:var(--font-mulish), "Mulish", system-ui, sans-serif;letter-spacing:-2.4px;margin:0;font-size:clamp(46px,5vw,72px);font-weight:700;line-height:1.02}.home-lede{letter-spacing:.18px;max-width:540px;margin:24px 0 0;font-size:18px;line-height:1.55}.home-primary{color:#fff;background:#121117;border-radius:4px;align-items:center;gap:8px;width:fit-content;margin-top:32px;padding:14px 24px;font-size:16px;font-weight:600;display:inline-flex}.home-primary:hover,.home-primary:focus-visible{color:#fff;background:#2a2935}.home-hero-art{z-index:1;width:min(100%,470px);height:270px;margin:32px auto 0;position:relative}.home-hero-card{background:#fff;border:2px solid #121117;border-radius:8px;place-items:center;display:grid;position:absolute;inset:12px 40px 10px 28px;transform:rotate(-3deg)}.home-hero-cube{place-items:center;display:grid}.home-art-label{z-index:3;color:#fff;background:#121117;border-radius:4px;padding:6px 10px;font-size:12px;font-weight:600;position:absolute}.home-art-label--top{top:0;right:12px;transform:rotate(4deg)}.home-art-label--bottom{bottom:2px;left:6px;transform:rotate(-2deg)}.home-art-sun{background:#ffdf3d;border-radius:50%;width:76px;height:76px;position:absolute;bottom:22px;right:0}.home-art-dots{color:#121117;letter-spacing:5px;font-size:22px;line-height:.65;position:absolute;top:26px;left:0;transform:rotate(-8deg)}.home-catalog{background:#fff;padding:64px clamp(32px,5vw,80px)}.home-catalog-heading{max-width:600px;margin-bottom:32px}.home-catalog-heading h2{font-family:var(--font-mulish), "Mulish", system-ui, sans-serif;letter-spacing:-1.5px;margin:0;font-size:clamp(36px,4vw,48px);font-weight:700;line-height:1.08}.home-catalog-heading>p:last-child{color:#4d4c5c;margin:14px 0 0;font-size:16px;line-height:1.5}.topic-list{gap:16px;display:grid}.topic-card{color:#121117;background:#fff;border:1px solid #dcdce5;border-radius:8px;grid-template-columns:minmax(170px,.72fr) minmax(240px,1.28fr);min-height:176px;display:grid;overflow:hidden}.topic-card--active{transition:background-color .16s,border-color .16s,transform .16s}.topic-card--active:hover,.topic-card--active:focus-visible{color:#121117;background:#f4f4f8;border-color:#121117;transform:translateY(-2px)}.topic-card--active:focus-visible{outline-offset:3px;outline:2px solid #121117}.topic-card--soon{cursor:default}.topic-visual{border-inline-end:1px solid #dcdce5;place-items:center;min-height:174px;display:grid;overflow:hidden}.topic-visual--rubik{background:#99c5ff}.topic-visual--origami{background:#ffdf3d}.topic-visual--puzzles{background:#f4f4f8}.topic-icon{color:#121117;width:min(72%,140px);transition:transform .16s}.topic-cube{place-items:center;transition:transform .16s;display:grid}.topic-card--active:hover .topic-icon,.topic-card--active:focus-visible .topic-icon,.topic-card--active:hover .topic-cube,.topic-card--active:focus-visible .topic-cube{transform:rotate(3deg)scale(1.03)}.topic-content{flex-direction:column;justify-content:center;align-items:flex-start;min-width:0;padding:22px 24px;display:flex}.topic-kicker{color:#6a697c;letter-spacing:1.1px;text-transform:uppercase;font-size:11px;font-weight:600}.topic-content strong{font-family:var(--font-mulish), "Mulish", system-ui, sans-serif;letter-spacing:-.5px;margin-top:5px;font-size:28px;line-height:1.15}.topic-description{color:#4d4c5c;margin-top:7px;font-size:14px;line-height:1.45}.topic-action,.topic-status{margin-top:13px;font-size:13px;font-weight:600}.topic-action{text-underline-offset:4px;text-decoration:underline;text-decoration-thickness:1px}.topic-status{color:#fff;letter-spacing:.2px;background:#121117;border-radius:4px;padding:5px 8px}.home-footer{color:#fff;background:#121117}.home-footer-inner{gap:32px;min-height:104px}.home-footer .brand{color:#fff}.home-footer .brand-in{color:#99c5ff}.home-footer p{color:#dcdce5;margin:0;font-size:14px}@media (min-width:1021px){.home-stage{height:calc(100svh - 72px);min-height:0}.home-hero{height:100%;min-height:0;padding-top:clamp(32px,6.5vh,80px);padding-bottom:clamp(28px,5vh,56px)}.home-hero h1{font-size:clamp(48px,min(5vw,7.8vh),72px)}.home-lede{margin-top:clamp(14px,2.5vh,24px)}.home-primary{margin-top:clamp(18px,3.4vh,32px)}.home-hero-art{flex:0 270px;height:auto;min-height:145px;margin-top:clamp(16px,3vh,32px)}.home-catalog{flex-direction:column;height:100%;padding-top:clamp(24px,4.5vh,64px);padding-bottom:clamp(24px,4.5vh,64px);display:flex}.home-catalog-heading{flex:none;margin-bottom:clamp(16px,3vh,32px)}.home-catalog-heading h2{font-size:clamp(34px,min(4vw,5.5vh),48px)}.topic-list{flex:1;grid-template-rows:repeat(3,minmax(0,1fr));gap:clamp(10px,1.5vh,16px);min-height:0}.topic-card,.topic-visual{min-height:0}.topic-content{padding-top:clamp(12px,2vh,22px);padding-bottom:clamp(12px,2vh,22px)}.topic-content strong{font-size:clamp(23px,3.2vh,28px)}}@media (max-width:1020px){.home-stage{grid-template-columns:1fr}.home-hero{min-height:auto;padding-top:64px}.home-hero-copy{max-width:720px}.home-hero-art{align-self:flex-end;margin-inline-end:0}.home-catalog{padding-top:56px;padding-bottom:64px}}@media (max-width:620px){.site-header{height:64px}.site-header-inner,.home-footer-inner{width:min(100% - 40px,1200px)}.site-header-inner{width:calc(100% - 24px)}.site-header .brand{font-size:20px}.site-header .brand-suffix{font-size:11px}.site-header-action,.language-switcher-trigger{gap:4px;padding:0 8px;font-size:12px}.language-switcher-trigger>svg{width:16px;height:16px}.language-switcher-trigger>.language-switcher-chevron{width:12px;height:12px}.home-hero,.home-catalog{padding-inline:20px}.home-hero{padding-top:48px;padding-bottom:40px}.home-hero h1{letter-spacing:-1.7px;font-size:44px}.home-lede{font-size:16px}.home-hero-art{height:220px}.home-hero-card{inset:12px 24px 10px 20px}.home-catalog{padding-top:48px;padding-bottom:48px}.home-catalog-heading h2{font-size:36px}.topic-card{grid-template-columns:116px minmax(0,1fr);min-height:0}.topic-visual{min-height:190px}.topic-icon{width:92px}.topic-content{padding:18px 16px}.topic-content strong{font-size:24px}.home-footer-inner{flex-direction:column;justify-content:center;align-items:flex-start;gap:12px;min-height:120px;padding:24px 0}}@media (max-width:380px){.site-header .brand{font-size:18px}.site-header-action,.language-switcher-trigger{padding-inline:6px;font-size:11px}}@media (prefers-reduced-motion:reduce){.language-switcher-chevron,.topic-card--active,.topic-icon,.topic-cube{transition:none}}