@import"https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Nunito:wght@700;800;900&display=swap";:root{--yellow:#ffd500;--blue:#003daa;--red:#c41e3a;--green:#009b48;--dark:#111;--line:#ebebeb;--muted:#777;font-family:Inter,Arial,sans-serif;color:var(--dark);background:#f5f5f5}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{margin:0;overflow-x:hidden}button,input{font:inherit}button{cursor:pointer;touch-action:manipulation}input{min-width:0}a{color:inherit;text-decoration:none}h1,h2,h3,p{margin-top:0}h1,h2,h3,.brand{font-family:Nunito,Inter,sans-serif}.topbar{height:64px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 48px;position:sticky;top:0;z-index:10}.topbar nav,.topbar>div{display:flex;align-items:center;gap:12px}.topbar nav>a:not(.button){color:#666;font-size:14px;font-weight:600;margin-right:8px}.brand{display:flex;align-items:center;gap:9px;font-size:20px;font-weight:900;white-space:nowrap}.cube-logo{display:grid;grid-template-columns:repeat(3,8px);gap:1px;border:2px solid rgba(0,0,0,.15);border-radius:4px;overflow:hidden;padding:1px}.cube-logo i{height:8px}.cube-logo i:nth-child(1){background:var(--red)}.cube-logo i:nth-child(2){background:var(--yellow)}.cube-logo i:nth-child(3){background:#ff5800}.cube-logo i:nth-child(4){background:var(--green)}.cube-logo i:nth-child(5){background:var(--blue)}.cube-logo i:nth-child(6){background:#fff}.cube-logo i:nth-child(n+7){display:none}.button{border:0;background:var(--yellow);color:#111;padding:10px 17px;border-radius:9px;font-weight:800;font-size:14px;display:inline-block;text-align:center}.button:hover{filter:brightness(.96)}.button:disabled{cursor:wait;opacity:.65}.button--outline{background:#fff;border:2px solid #111;padding:8px 15px}.button--dark{background:#111;color:#fff}.button--muted{background:#f2f2f2}.button--large{padding:14px 27px;font-size:16px;border-radius:12px}.landing{background:#fff}.hero{max-width:1110px;margin:auto;padding:80px 48px 65px;display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:50px}.eyebrow{display:inline-block;background:var(--yellow);padding:5px 14px;border-radius:20px;font-size:13px;font-weight:800;margin-bottom:19px}.hero h1{font-size:54px;line-height:1.04;letter-spacing:-1.8px;margin-bottom:20px}.hero h1 em{color:var(--red);font-style:normal}.hero h1 strong{color:var(--blue)}.hero p{color:#555;font-size:18px;line-height:1.6;max-width:470px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:34px}.hero-cube-wrap{position:relative;width:min(318px,100%);margin:auto}.hero-cube{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px;transform:rotate(-8deg);overflow:hidden;border:3px solid #111;border-radius:16px;box-shadow:8px 8px 0 var(--yellow)}.hero-cube i{aspect-ratio:1;height:auto;position:relative}.hero-cube i:after{content:"";position:absolute;top:19px;right:19px;bottom:19px;left:19px;border:2px solid #ffffff52;background:#ffffff1f;border-radius:8px}.hero-cube .red{background:var(--red)}.hero-cube .yellow{background:var(--yellow)}.hero-cube .blue{background:var(--blue)}.hero-cube .green{background:var(--green)}.hero-cube .orange{background:#ff5800}.cube-note{position:absolute;padding:8px 13px;border:2px solid #111;border-radius:11px;color:#fff;font-size:13px}.cube-note--top{background:var(--blue);top:-18px;right:-25px}.cube-note--bottom{background:var(--green);bottom:-18px;left:-25px}.stat-banner{background:#111;color:#fff;display:flex;justify-content:center;gap:72px;padding:29px 40px;flex-wrap:wrap}.stat-banner div{min-width:110px;text-align:center}.stat-banner b{font:900 41px/1 Nunito;color:var(--yellow);display:block}.stat-banner div:nth-child(2) b{color:#4780e4}.stat-banner div:nth-child(3) b{color:#ef4965}.stat-banner div:nth-child(4) b{color:#2fc778}.stat-banner span{color:#fff9;font-size:14px}.marketing-section{max-width:1110px;margin:auto;padding:70px 48px}.marketing-section h2,.how h2,.cta h2{font-size:36px;text-align:center;letter-spacing:-1px}.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}.feature{border:2px solid var(--line);border-top-width:4px;border-radius:16px;padding:24px}.feature span{display:block;width:12px;height:12px;border-radius:50%;margin-bottom:14px}.feature h3{font-size:18px;margin-bottom:10px}.feature p{color:#666;font-size:14px;line-height:1.6;margin:0}.feature.yellow{border-top-color:var(--yellow)}.feature.yellow span{background:var(--yellow)}.feature.blue{border-top-color:var(--blue)}.feature.blue span{background:var(--blue)}.feature.red{border-top-color:var(--red)}.feature.red span{background:var(--red)}.feature.green{border-top-color:var(--green)}.feature.green span{background:var(--green)}.how{background:#f9f9f9;padding:70px 48px}.steps{display:flex;max-width:800px;gap:16px;margin:48px auto 0}.steps article{background:#fff;border:2px solid var(--line);border-radius:16px;padding:28px 20px;text-align:center;flex:1}.steps b{font:900 48px/1 Nunito;color:var(--yellow)}.steps article:nth-child(2) b{color:var(--blue)}.steps article:nth-child(3) b{color:var(--red)}.steps h3{margin:10px 0 7px}.steps p{margin:0;color:#777;font-size:14px}.cta{background:#111;color:#fff;padding:70px 20px;text-align:center}.cta h2{color:var(--yellow);margin-bottom:14px}.cta p{color:#ffffffb0;margin-bottom:28px}footer{background:#0a0a0a;color:#fff8;padding:25px 48px;font-size:13px;text-align:center}.auth-page{min-height:100vh;display:grid;place-items:center;padding:24px;background:#f5f5f5}.auth-card{width:min(860px,100%);min-height:520px;background:#fff;border:2px solid var(--line);border-radius:20px;overflow:hidden;display:grid;grid-template-columns:1fr 1fr;box-shadow:0 20px 60px #00000012}.auth-aside{background:#111;color:#fff;padding:44px;display:flex;flex-direction:column;gap:38px}.auth-aside h1{font-size:30px;line-height:1.2;color:var(--yellow);margin:0 0 14px}.auth-aside p{color:#ffffffa0;line-height:1.65}.auth-aside .brand{color:#fff}.auth-form{padding:44px;display:flex;flex-direction:column;gap:15px}.auth-tabs,.segmented{display:flex;padding:4px;gap:4px;background:#f5f5f5;border-radius:10px}.auth-tabs button,.segmented button{flex:1;border:0;background:transparent;padding:9px;border-radius:8px;color:#888;font-weight:600}.auth-tabs button.active,.segmented button.active{color:#111;background:#fff;box-shadow:0 2px 8px #00000012}.auth-form h2{margin:6px 0 0;font-size:26px}.auth-form label{font-size:13px;font-weight:700;color:#444}.auth-form input,.catalog-controls input{width:100%;border:2px solid var(--line);border-radius:10px;padding:12px 14px;outline:none;margin-top:6px;background:#fafafa}.auth-form input:focus,.catalog-controls input:focus{border-color:var(--blue)}.password-field{position:relative}.password-field input{padding-right:76px}.password-field button{position:absolute;right:7px;top:12px;color:var(--blue);border:0;background:transparent;font-size:12px;font-weight:700}.auth-submit{margin-top:5px;padding:14px}.auth-form p{text-align:center;color:#888;font-size:13px;margin:0}.text-button,.back-link{color:var(--blue);border:0;background:transparent;padding:0;font-size:13px;font-weight:700}.auth-form .back-link{text-align:center;margin-top:4px}.app-shell{min-height:100vh;display:flex}.sidebar{width:220px;flex-shrink:0;background:#111;color:#fff;padding:24px 12px;display:flex;flex-direction:column;position:sticky;height:100vh;top:0}.sidebar-brand{padding:0 8px 25px;font-size:17px}.side-nav{display:flex;flex-direction:column;gap:4px}.side-nav a,.side-nav button{display:flex;align-items:center;gap:13px;border:0;color:#ffffffa8;padding:11px 12px;background:transparent;border-radius:10px;font-size:14px;text-align:left}.side-nav a.active{background:var(--yellow);color:#111;font-weight:800}.sidebar-user{margin-top:auto;border-top:1px solid #ffffff20;padding:18px 10px 0;display:flex;gap:10px;align-items:center;font-size:13px;color:#fffa;overflow:hidden}.sidebar-user b,.avatar{display:grid;place-items:center;background:var(--yellow);color:#111;border-radius:50%;width:30px;height:30px;font-size:11px;font-weight:900;flex-shrink:0}.workspace{min-width:0;flex:1;background:#f5f5f5}.app-topbar{padding:0 28px}.app-topbar>div{gap:14px}.avatar{width:33px;height:33px}.app-main{padding:32px}.page-container{max-width:1000px;margin:auto}.page-heading,.detail-heading{display:flex;justify-content:space-between;align-items:flex-start;gap:20px;margin-bottom:24px}.page-heading h1,.detail-heading h1{font-size:28px;margin:0 0 7px}.page-heading p,.detail-heading p{color:#888;font-size:14px;margin:0}.catalog-controls{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-bottom:22px}.segmented{width:195px;flex-shrink:0}.catalog-controls input{margin:0;max-width:280px}.algorithm-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;width:100%}.algorithm-card{display:flex;flex-direction:column;width:100%;min-width:0;border:2px solid var(--line);border-top:4px solid var(--yellow);background:#fff;text-align:left;border-radius:16px;padding:17px;transition:.15s}.algorithm-card.pll{border-top-color:var(--blue)}.algorithm-card:hover{transform:translateY(-3px);box-shadow:0 8px 24px #00000014}.cube-diagram{display:block}.algorithm-card .cube-diagram{width:100%;height:130px;margin:8px 0 12px}.algorithm-card h3{font-size:16px;margin:0 0 7px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.algorithm-card code{display:block;width:100%;max-width:100%;color:#555;font-size:11px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;background:#f8f8f8;padding:6px;border-radius:5px;margin-top:auto}.learned-mark{font-size:10px;color:#888;font-weight:800;letter-spacing:.04em;text-transform:uppercase}.learned-mark.learned{color:var(--green)}.empty{background:#fff;border:2px solid var(--line);border-radius:18px;padding:50px 24px;text-align:center;color:#777}.empty h1{color:#111}.detail-heading{margin-bottom:17px}.detail-heading .back-link{margin-bottom:9px;display:block}.detail-progress,.progress-track{height:7px;border-radius:10px;background:#e9e9e9;overflow:hidden}.detail-progress{margin-bottom:26px}.detail-progress i,.progress-track i{display:block;height:100%;background:var(--yellow);border-radius:inherit}.detail-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}.detail-grid>section{display:flex;flex-direction:column;gap:20px}.diagram-card,.formula-card,.tips,.video-card{border:2px solid var(--line);border-radius:20px;background:#fff}.diagram-card{display:flex;flex-direction:column;align-items:center;padding:25px}.diagram-card.oll{border-color:var(--yellow)}.diagram-card.pll{border-color:var(--blue)}.diagram-card .cube-diagram{max-width:100%;height:255px}.diagram-card span{font-size:11px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;background:var(--yellow);padding:5px 10px;border-radius:7px}.diagram-card.pll span{background:var(--blue);color:#fff}.formula-card{background:#111;padding:23px;color:#fff;border:0}.formula-card small{color:#fff7;font-weight:700;letter-spacing:.08em}.formula-card>div{display:flex;flex-wrap:wrap;gap:6px;margin-top:14px}.formula-card code{padding:5px 9px;background:#ffffff12;border-radius:6px;color:var(--yellow);font-weight:700;font-size:16px}.master-button{width:100%;margin-top:20px;padding:12px;border:2px solid #ffffff33;color:#fffc;border-radius:10px;background:transparent;font-weight:800}.master-button:hover{background:var(--green);border-color:var(--green);color:#fff}.mastered{color:#66d999;font-weight:800;text-align:center;margin:19px 0 0}.video-card{overflow:hidden;min-height:225px;background:#1a1a1a;aspect-ratio:16 / 9}.video-player{display:block;width:100%;height:100%;min-height:221px;border:0}.video-link,.video-placeholder{height:100%;min-height:221px;padding:36px 20px;display:flex;flex-direction:column;gap:9px;align-items:center;justify-content:center;color:#fff;text-align:center;background:linear-gradient(135deg,#111,#252525)}.video-link span,.video-placeholder span{display:grid;place-items:center;width:58px;height:58px;border-radius:50%;border:2px solid #ffffff66;background:#ffffff1c;font-size:22px}.video-link small,.video-placeholder small{color:#fff8}.tips{padding:22px}.tips h2{font-size:17px;margin:0 0 15px}.tips p{color:#555;font-size:14px;line-height:1.5;margin:9px 0}.profile-card{background:#fff;padding:28px;border:2px solid var(--line);border-radius:20px;display:flex;gap:24px;align-items:flex-start;margin-bottom:24px}.profile-avatar{display:grid;place-items:center;background:linear-gradient(135deg,var(--yellow),#ff5800);border:3px solid #111;height:80px;width:80px;flex-shrink:0;border-radius:50%;font:900 27px Nunito}.profile-name{flex:1}.profile-name h1{margin:0 0 5px;font-size:27px}.profile-name>p{color:#888;font-size:14px}.progress-pairs{display:flex;gap:20px}.progress-pair{min-width:160px}.progress-pair>div:first-child{display:flex;justify-content:space-between;font-size:13px;margin-bottom:6px}.progress-pair span{color:#666}.progress-track i.blue{background:var(--blue)}.overall{background:#111;color:#fff;min-width:120px;text-align:center;padding:17px;border-radius:15px}.overall b{font:900 32px/1 Nunito;color:var(--yellow);display:block}.overall span{color:#fff9;font-size:12px}.profile-columns{display:grid;grid-template-columns:1.2fr .8fr;gap:20px}.panel{background:#fff;border:2px solid var(--line);border-radius:18px;padding:23px}.panel h2{font-size:18px;margin-bottom:16px}.recent{padding:0;margin:0;list-style:none}.recent li{padding:11px 0;display:grid;grid-template-columns:78px 1fr auto;gap:9px;border-bottom:1px solid var(--line);font-size:13px;align-items:center}.recent li:last-child{border:0}.recent li>b{color:var(--blue)}.recent time{color:#999;font-size:11px}.recent .empty-row{display:block;color:#888}.achievement{display:flex;gap:12px;align-items:flex-start;padding:12px 0;color:#aaa;opacity:.6;border-bottom:1px solid var(--line)}.achievement.unlocked{opacity:1;color:#111}.achievement>span{display:flex;flex-direction:column;gap:4px}.achievement small{color:#888}.design-profile-card{align-items:center}.streak-card{background:#111;color:#fff;min-width:132px;padding:16px 22px;border-radius:16px;text-align:center;display:flex;flex-direction:column}.streak-card span{font-size:26px}.streak-card b{color:var(--yellow);font:900 36px/1 Nunito}.streak-card small{color:#fff9;font-size:12px;margin-top:5px}.activity-card{margin-bottom:22px}.activity-days{display:flex;flex-wrap:wrap;align-items:center;gap:8px}.activity-days>span{display:grid;place-items:center;width:36px;height:36px;border:2px solid #e8e8e8;border-radius:8px;color:#ccc;background:#f0f0f0;font-weight:800}.activity-days>span.active{color:#111;background:var(--yellow);border-color:#e6c000}.activity-legend{color:#888;font-size:12px;margin-left:6px;display:flex;gap:6px;align-items:center}.activity-legend i{width:14px;height:14px;display:inline-block;background:var(--yellow);border-radius:3px}.activity-legend i.muted{background:#f0f0f0;border:1px solid #ddd;margin-left:6px}.achievements-title{font-size:18px;margin-bottom:16px}.achievement-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.achievement-grid .achievement{background:#fafafa;border:2px solid var(--line);border-radius:16px;min-height:104px;padding:18px;font-size:28px}.achievement-grid .achievement.unlocked{background:#fff;border-color:var(--yellow)}.achievement-grid .achievement>span{font-size:14px}.achievement-grid .achievement em{color:var(--green);font-style:normal;font-size:11px;font-weight:800;letter-spacing:.04em;text-transform:uppercase;margin-top:3px}.toast{position:fixed;right:20px;top:20px;z-index:50;color:#fff;padding:13px 17px;border-radius:10px;box-shadow:0 8px 24px #0003;max-width:390px;cursor:pointer;font-size:14px}.toast--notice{background:var(--green)}.toast--error{background:var(--red)}@media(max-width:850px){.hero{grid-template-columns:1fr;padding:55px 25px}.hero-cube-wrap{margin-top:15px}.feature-grid{grid-template-columns:repeat(2,1fr)}.detail-grid,.profile-columns{grid-template-columns:1fr}.algorithm-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.sidebar{width:64px;padding:19px 8px}.sidebar .brand{padding:0 7px 22px}.sidebar .brand:not(.cube-logo),.side-nav span,.sidebar-user span{font-size:0}.sidebar .brand{gap:0}.sidebar .brand .cube-logo{transform:scale(1.1)}.side-nav a,.side-nav button{justify-content:center;padding:12px;font-size:19px}.sidebar-user{padding:18px 8px 0}.app-topbar .brand{display:none}}@media(max-width:620px){.landing-topbar{padding:0 18px}.landing-topbar nav>a:first-child,.landing-topbar .button--outline{display:none}.hero h1{font-size:42px}.hero-cube-wrap{transform:scale(.8);transform-origin:top center;height:265px}.stat-banner{gap:24px}.marketing-section,.how{padding:52px 20px}.feature-grid{grid-template-columns:1fr}.steps{flex-direction:column;margin-top:30px}.auth-page{padding:0}.auth-card{min-height:100vh;border:0;border-radius:0;display:block}.auth-aside{display:none}.auth-form{padding:36px 24px}.app-main{padding:20px 14px}.app-topbar{padding:0 16px}.app-topbar .button{padding:8px 12px}.page-heading{display:block}.page-heading .button{margin-top:14px}.catalog-controls{align-items:stretch;flex-direction:column}.catalog-controls input{max-width:none}.algorithm-grid{grid-template-columns:minmax(0,1fr)}.detail-heading{display:block}.detail-heading>.button{margin-top:15px}.profile-card{flex-wrap:wrap;padding:20px}.progress-pairs{flex-direction:column;gap:12px}.overall{margin-left:auto}.recent li{grid-template-columns:68px 1fr}.recent time{display:none}}@media(max-width:620px){.landing-topbar{padding:0 16px}.landing-topbar nav{gap:0}.landing-topbar nav>a:first-child,.landing-topbar .button--outline{display:none}.landing-topbar .button{min-height:42px;padding:10px 14px}.hero{padding:42px 20px 35px;gap:28px}.eyebrow{margin-bottom:14px;font-size:12px}.hero h1{font-size:clamp(34px,11vw,42px);line-height:1.07;letter-spacing:-1.2px}.hero p{font-size:16px;line-height:1.55}.hero-actions{display:grid;grid-template-columns:1fr;gap:10px;margin-top:25px}.hero-actions .button{width:100%}.hero-cube-wrap{width:min(270px,calc(100% - 24px));margin-top:8px;transform:none;height:auto}.hero-cube i:after{top:15px;right:15px;bottom:15px;left:15px}.cube-note{padding:6px 9px;font-size:11px}.cube-note--top{right:7px;top:-13px}.cube-note--bottom{bottom:-13px;left:7px}.stat-banner{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px 8px;padding:26px 16px}.stat-banner div{min-width:0}.stat-banner b{font-size:34px}.stat-banner span{font-size:12px}.marketing-section,.how{padding:50px 20px}.marketing-section h2,.how h2,.cta h2{font-size:30px;line-height:1.12}.feature{padding:20px}.steps{gap:12px;margin-top:28px}.steps article{padding:23px 18px}.cta{padding:52px 20px}footer{padding:24px 20px}.auth-page{min-height:100dvh;padding:0}.auth-card{min-height:100dvh;border:0;border-radius:0;display:block}.auth-aside{display:none}.auth-form{padding:32px 24px max(32px,env(safe-area-inset-bottom));gap:15px}.auth-form h2{font-size:24px}.auth-form input{min-height:46px;font-size:16px}.auth-submit{min-height:48px}.app-shell{display:block}.workspace{width:100%}.sidebar{position:fixed;z-index:25;inset:auto 0 0;width:auto;height:calc(68px + env(safe-area-inset-bottom));padding:8px 6px calc(8px + env(safe-area-inset-bottom));border-top:1px solid #ffffff24;flex-direction:row}.sidebar-brand,.sidebar-user{display:none}.side-nav{width:100%;flex-direction:row;justify-content:space-around;gap:2px}.side-nav a,.side-nav button{flex:1 1 20%;min-width:0;min-height:52px;justify-content:center;gap:0;padding:8px 4px;border-radius:9px;font-size:17px}.side-nav span{font-size:0}.app-topbar{height:60px;padding:0 14px}.app-topbar .brand{display:flex;gap:7px;font-size:16px}.app-topbar>div{gap:8px}.app-topbar .button{min-height:40px;padding:8px 10px;font-size:13px}.app-main{padding:18px 14px calc(96px + env(safe-area-inset-bottom))}.page-heading,.detail-heading{gap:14px;margin-bottom:18px}.page-heading h1,.detail-heading h1{font-size:25px}.page-heading p,.detail-heading p{font-size:13px;line-height:1.5}.page-heading .button,.detail-heading>.button{width:100%;min-height:46px;margin-top:12px}.catalog-controls{gap:12px;margin-bottom:16px}.segmented{width:100%}.catalog-controls input{min-height:46px;font-size:16px}.algorithm-grid{gap:12px}.algorithm-card{padding:14px;border-radius:14px}.algorithm-card .cube-diagram{height:auto;aspect-ratio:637 / 563;margin:8px 0 12px}.detail-progress{margin-bottom:20px}.diagram-card,.formula-card,.tips,.video-card{border-radius:16px}.diagram-card{padding:18px}.diagram-card .cube-diagram{width:100%;height:auto;aspect-ratio:637 / 563}.formula-card,.tips{padding:18px}.formula-card code{font-size:14px}.video-card,.video-player,.video-link,.video-placeholder{min-height:0}.video-player{aspect-ratio:16 / 9}.video-link,.video-placeholder{padding:24px 16px}.empty{padding:34px 18px;border-radius:16px}.empty h1{font-size:24px}.profile-card{gap:16px;padding:18px;border-radius:16px}.profile-avatar{width:64px;height:64px;font-size:22px}.profile-name{min-width:0;flex-basis:calc(100% - 80px)}.profile-name h1{font-size:24px;overflow-wrap:anywhere}.progress-pairs{gap:12px}.progress-pair{min-width:0}.streak-card{flex:1 0 100%;width:100%;min-width:0;flex-direction:row;align-items:center;justify-content:center;gap:10px;padding:12px 16px}.streak-card b{font-size:30px}.streak-card small{margin:0}.panel{padding:18px;border-radius:16px}.activity-days{gap:6px}.activity-days>span{width:32px;height:32px}.activity-legend{width:100%;margin:7px 0 0}.achievement-grid{grid-template-columns:1fr;gap:12px}.achievement-grid .achievement{min-height:0;padding:15px}.toast{top:12px;right:14px;left:14px;max-width:none}}