@font-face{font-family:Archivo;src:url(/fonts/Archivo.woff2)format("woff2");font-weight:100 900;font-stretch:62% 125%;font-display:swap}@font-face{font-family:IBM Plex Sans;src:url(/fonts/IBMPlexSans.woff2)format("woff2");font-weight:100 700;font-stretch:75% 100%;font-display:swap}:root{--black:#111;--steel:#e9ecee;--zinc:#9aa5ad;--yellow:#ffc400;--charcoal:#1b1f21;--slate:#657078;--color-bg-page:var(--black);--color-bg-surface:var(--charcoal);--color-bg-inverse:var(--steel);--color-text-primary:var(--steel);--color-text-secondary:var(--zinc);--color-text-inverse:var(--black);--color-accent-solid:var(--yellow);--color-text-on-accent:var(--black);--color-border:var(--slate);--color-separator:#363b3f;--color-focus:var(--yellow);--color-error:#ffb8ad;--text-sm:.875rem;--text-body:1rem;--text-lg:1.125rem;--text-title:1.5rem;--radius:8px;--gutter:clamp(1rem,4vw,3rem);--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;color:var(--color-text-primary);background:var(--color-bg-page);font-synthesis-weight:none;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-family:IBM Plex Sans,Arial,sans-serif}*{box-sizing:border-box}body{min-width:320px;font-size:var(--text-body);margin:0;line-height:1.55}a{color:inherit;text-underline-offset:4px;text-decoration-thickness:from-font}button,input,select,textarea{font:inherit}button,a,input,select,summary{touch-action:manipulation;-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default;opacity:.55}img,svg{max-width:100%}img{display:block}h1,h2,h3,p{margin:0}h1,h2,h3{text-wrap:balance}h1,h2{letter-spacing:-.035em;font-family:Archivo,Arial,sans-serif;font-weight:900;font-stretch:115%;line-height:1.1}h1{font-size:clamp(2.25rem,4.3vw,3.5rem)}h2{font-size:clamp(1.5rem,2.6vw,2rem)}h3{font-size:var(--text-lg);font-weight:600;line-height:1.35}p{text-wrap:pretty}:focus-visible{outline:3px solid var(--color-focus);outline-offset:4px}main:focus,section[tabindex="-1"]:focus{outline:none}::selection{background:var(--color-accent-solid);color:var(--color-text-on-accent)}.sr-only{clip:rect(0,0,0,0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.skip-link{inset-inline-start:16px;background:var(--color-accent-solid);color:var(--color-text-on-accent);z-index:100;padding:12px 20px;position:fixed;top:-100px}.skip-link:focus{top:12px}.icon{vertical-align:middle;flex-shrink:0;width:20px;height:20px}.muted{color:var(--color-text-secondary)}.small{font-size:var(--text-sm)}.button{border-radius:var(--radius);text-align:center;border:1px solid #0000;justify-content:center;align-items:center;gap:12px;min-height:48px;padding:12px 20px;font-size:1rem;font-weight:600;line-height:1.4;text-decoration:none;display:inline-flex}.primary{background:var(--color-accent-solid);color:var(--color-text-on-accent)}.secondary{border-color:var(--color-border);color:var(--color-text-primary);background:0 0}.text-button{min-width:44px;min-height:44px;color:inherit;font-size:var(--text-sm);text-underline-offset:4px;background:0 0;border:0;justify-content:center;align-items:center;gap:8px;padding:8px;font-weight:500;text-decoration:underline;display:inline-flex}.text-link{align-items:center;min-height:44px;font-weight:500;text-decoration:underline;display:inline-flex}.site-header{padding-inline:max(var(--gutter),env(safe-area-inset-left));padding-top:env(safe-area-inset-top);border-bottom:1px solid var(--color-separator)}.header-inner{align-items:center;gap:40px;max-width:1200px;min-height:96px;margin-inline:auto;display:flex}.brand{flex-shrink:0;align-items:center;gap:12px;min-height:44px;text-decoration:none;display:flex}.brand img{width:48px;height:48px}.brand span{text-transform:uppercase;letter-spacing:-.035em;font-family:Archivo,Arial,sans-serif;font-size:18px;font-weight:900;font-stretch:120%;line-height:1.05}.header-inner nav{align-items:center;gap:12px;margin-inline:auto;display:flex}.header-inner nav a{min-height:48px;color:var(--color-text-secondary);white-space:nowrap;justify-content:center;align-items:center;padding:12px 16px;font-weight:500;text-decoration:none;display:flex}.header-inner nav a[aria-current]{color:var(--color-text-primary);text-decoration:underline;-webkit-text-decoration-color:var(--color-accent-solid);text-decoration-color:var(--color-accent-solid);text-underline-offset:10px;text-decoration-thickness:3px}.progress-link{min-height:44px;color:var(--color-text-secondary);font-size:var(--text-sm);font-variant-numeric:tabular-nums;align-items:center;gap:8px;text-decoration:none;display:flex}.progress-link svg{color:var(--color-accent-solid)}.main{width:100%;max-width:1296px;padding-inline:var(--gutter);min-height:65vh;margin-inline:auto}.site-footer{max-width:1296px;padding:24px var(--gutter) calc(32px + env(safe-area-inset-bottom));font-size:var(--text-sm);border-top:1px solid var(--color-separator);justify-content:space-between;align-items:center;gap:24px;margin:80px auto 0;display:flex}.site-footer>span{flex-wrap:wrap;gap:12px;display:flex}.site-footer>div{flex-wrap:wrap;align-items:center;gap:24px;display:flex}.site-footer a{align-items:center;min-height:44px;display:flex}.home-hero{grid-template-columns:1.1fr 1fr;align-items:center;gap:56px;padding-block:64px 56px;display:grid}.hero-copy h1{text-transform:uppercase;letter-spacing:-.045em;font-size:clamp(3rem,5.5vw,5rem);font-stretch:120%;line-height:1.04}.hero-copy>p:first-of-type{font-size:var(--text-lg);color:var(--color-text-secondary);max-width:40ch;margin-block:24px 32px;line-height:1.65}.hero-action{gap:32px;min-height:56px;padding-inline:24px}.hero-note{color:var(--color-text-secondary);font-size:var(--text-sm);margin-top:16px}.hero-puzzle{border:1px solid var(--color-separator);border-radius:16px;min-width:0;position:relative;overflow:hidden}.hero-figure{justify-content:center;height:340px;display:flex;position:relative;overflow:hidden}.hero-figure img{width:480px;max-width:none;height:640px;position:absolute;top:-20px}.daily-caption{background:var(--color-bg-surface);justify-content:space-between;align-items:center;gap:24px;padding:24px 28px;display:flex}.daily-caption h2{letter-spacing:-.02em;margin-block:4px;font-family:IBM Plex Sans,sans-serif;font-size:1.5rem;font-weight:600}.daily-caption p{font-size:var(--text-sm);color:var(--color-text-secondary)}.daily-caption>div>span{font-size:var(--text-sm)}.type-stamp{color:var(--color-text-secondary);font-family:Archivo,sans-serif;font-size:2.5rem;font-weight:900}.welcome-strip{border-block:1px solid var(--color-separator);justify-content:space-between;align-items:center;gap:32px;padding-block:32px;display:flex}.welcome-strip p{color:var(--color-text-secondary)}.welcome-strip strong{color:var(--color-text-primary);font-weight:500}.progress-summary{color:var(--color-text-secondary);gap:40px;display:flex}.progress-summary>span{min-width:70px;font-size:var(--text-sm);flex-direction:column;gap:4px;display:flex}.progress-summary strong{font-variant-numeric:tabular-nums;font-family:Archivo,sans-serif;font-size:2rem;font-weight:800;line-height:1.2}.type-section{padding-block:64px}.section-heading{justify-content:space-between;align-items:center;gap:24px;margin-bottom:32px;display:flex}.section-heading p{color:var(--color-text-secondary);margin-top:12px}.type-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;display:grid}.type-card{border-bottom:1px solid var(--color-separator);grid-template-columns:64px 1fr 20px;align-items:start;gap:18px;padding:24px 0;text-decoration:none;display:grid}.type-card .type-mark{width:64px;height:64px;color:var(--color-text-primary)}.type-code{color:var(--color-text-secondary);font-size:var(--text-sm)}.type-card h3{margin-block:4px 8px}.type-card p{font-size:var(--text-sm);color:var(--color-text-secondary);max-width:24ch}.type-card>.icon{color:var(--color-text-secondary);align-self:center}.youtube-section{background:var(--color-bg-inverse);color:var(--color-text-inverse);border-radius:16px;align-items:center;gap:24px;padding:32px;display:flex}.youtube-section>.icon{flex-shrink:0;width:40px;height:40px}.youtube-section h2{font-size:1.5rem}.youtube-section p{margin-top:8px}.youtube-section .button{color:var(--color-text-inverse);border-color:var(--color-text-inverse);flex-shrink:0;margin-inline-start:auto}.youtube-section :focus-visible{outline-color:var(--color-text-inverse)}.page-heading{padding-block:64px 48px}.page-heading>p,.page-heading>div>p{color:var(--color-text-secondary);max-width:58ch;font-size:var(--text-lg);margin-top:20px}.browse-layout{grid-template-columns:260px 1fr;gap:56px;display:grid}.type-nav{flex-direction:column;align-self:start;gap:8px;display:flex}.type-nav a{min-height:72px;color:var(--color-text-secondary);border-radius:8px;align-items:center;gap:16px;padding:12px 16px;text-decoration:none;display:flex}.type-nav .type-mark{flex-shrink:0;width:36px;height:36px}.type-nav small{font-size:var(--text-sm);display:block}.type-nav a[aria-current]{background:var(--color-bg-surface);color:var(--color-text-primary);box-shadow:inset 3px 0 var(--color-accent-solid)}.browse-results{min-width:0}.browse-results .section-heading{margin-bottom:16px}.browse-results>.muted{max-width:60ch;margin-bottom:24px}.segmented{background:var(--color-bg-surface);border:1px solid var(--color-border);border-radius:12px;gap:4px;padding:4px;display:flex}.segmented a{min-height:44px;color:var(--color-text-secondary);border-radius:8px;justify-content:center;align-items:center;padding:8px 16px;text-decoration:none;display:flex}.segmented a[aria-current]{background:var(--color-bg-inverse);color:var(--color-text-inverse);font-weight:600}.puzzle-list{margin:0;padding:0;list-style:none}.puzzle-list li{border-bottom:1px solid var(--color-separator)}.puzzle-row{border-radius:8px;grid-template-columns:64px 1fr 106px 20px;align-items:center;gap:24px;min-height:96px;padding:22px 12px;text-decoration:none;display:grid}.puzzle-number{font-variant-numeric:tabular-nums;color:var(--color-text-secondary)}.puzzle-row-title{flex-direction:column;gap:4px;min-width:0;display:flex}.puzzle-row-title strong{font-size:var(--text-lg);font-weight:500}.puzzle-row-title>span{color:var(--color-text-secondary);font-size:var(--text-sm)}.row-level{margin-inline-start:16px}.row-status{color:var(--color-text-secondary);font-size:var(--text-sm);justify-content:flex-end;align-items:center;gap:8px;display:flex}.row-status.solved{color:var(--color-text-primary)}.row-status.solved .icon{color:var(--color-accent-solid)}.puzzle-row>.icon{color:var(--color-text-secondary)}.archive-heading{justify-content:space-between;align-items:center;gap:48px;display:flex}.archive-progress{min-width:240px;font-size:var(--text-sm);color:var(--color-text-secondary);flex-direction:column;gap:8px;display:flex}.archive-progress strong{color:var(--color-text-primary);font-variant-numeric:tabular-nums;font-family:Archivo,sans-serif;font-size:3rem;font-weight:900;line-height:1.1}.archive-progress strong>span{color:var(--color-text-secondary);font-size:1.5rem}progress{background:var(--color-separator);border:0;border-radius:3px;width:100%;height:6px;margin-block:4px}progress::-webkit-progress-bar{background:var(--color-separator);border-radius:3px}progress::-webkit-progress-value{background:var(--color-accent-solid);border-radius:3px}progress::-moz-progress-bar{background:var(--color-accent-solid)}.filters{border-block:1px solid var(--color-separator);gap:24px;padding-block:24px;display:flex}.filters .filter-field{max-width:320px;font-size:var(--text-sm);color:var(--color-text-secondary);flex-direction:column;flex:1;gap:8px;display:flex}select{background:var(--color-bg-surface);border:1px solid var(--color-border);width:100%;min-height:48px;color:var(--color-text-primary);border-radius:8px;padding:10px 14px;font-size:1rem}.result-count{font-size:var(--text-sm);color:var(--color-text-secondary);margin-block:24px 8px}.empty{max-width:65ch;padding-block:80px}.empty p{color:var(--color-text-secondary);margin-block:20px 24px}.about{max-width:720px;margin-inline:auto;padding-bottom:24px}.about .page-heading img{margin-bottom:32px}.about section{margin-bottom:48px}.about section h2{margin-bottom:20px}.about section p{max-width:65ch;font-size:var(--text-lg);margin-bottom:20px}.contact-link{overflow-wrap:anywhere;align-items:center;min-height:48px;margin-bottom:24px;display:flex}.storage-note{color:var(--color-error);font-size:var(--text-sm);padding:16px 0}.puzzle-heading{justify-content:space-between;align-items:flex-end;gap:24px;padding-block:24px 28px;display:flex}.puzzle-heading h1{margin-top:8px;font-size:clamp(1.75rem,3.5vw,2.5rem)}.back-link{min-height:44px;font-size:var(--text-sm);color:var(--color-text-secondary);align-items:center;display:inline-flex}.puzzle-meta{color:var(--color-text-secondary);font-size:var(--text-sm);font-variant-numeric:tabular-nums;flex-direction:column;align-items:flex-end;gap:4px;display:flex}.puzzle-meta>span:first-child{color:var(--color-text-primary)}.meta-divider{color:var(--color-text-secondary);padding-inline:10px}.play-layout{grid-template-columns:minmax(0,1.3fr) minmax(340px,1fr);align-items:start;gap:48px;display:grid}.figure-panel{border:1px solid var(--color-separator);border-radius:16px;min-width:0;overflow:hidden}.figure-toolbar{border-bottom:1px solid var(--color-separator);font-size:var(--text-sm);color:var(--color-text-secondary);justify-content:space-between;align-items:center;gap:16px;padding:8px 16px;display:flex}.figure-toolbar .text-button{color:var(--color-text-primary);flex-shrink:0}.figure-stage{background:var(--color-bg-page);justify-content:center;align-items:center;min-width:0;display:flex}.puzzle-figure{object-fit:contain;outline-offset:-1px;outline:1px solid #ffffff1a;width:100%;height:auto;max-height:640px}.figure-F1 .figure-stage{background:#fff}.figure-F1 .puzzle-figure{max-width:360px;max-height:640px}.instructions{border-top:1px solid var(--color-separator);color:var(--color-text-secondary);font-size:var(--text-sm);padding:8px 20px}.instructions summary{cursor:pointer;min-height:44px;color:var(--color-text-primary);align-content:center}.instructions p{max-width:65ch;padding-block:8px 16px}.diagram-description{white-space:normal;overflow-wrap:anywhere}.play-panel{min-width:0;padding-top:4px}.puzzle-level{font-size:var(--text-sm);color:var(--color-text-secondary);margin-bottom:12px;display:block}.question-section h2{letter-spacing:-.025em;text-wrap:pretty;font-family:IBM Plex Sans,sans-serif;font-size:clamp(1.375rem,2vw,1.75rem);font-weight:500;line-height:1.35}.mode-control{justify-content:space-between;align-items:center;gap:12px;margin-top:24px;display:flex}.challenge-toggle{cursor:pointer;min-height:44px;font-size:var(--text-sm);align-items:center;gap:10px;display:flex;position:relative}.challenge-toggle input{opacity:0;width:40px;height:24px;margin:0;position:absolute;inset-inline-start:0}.switch{pointer-events:none;border:1px solid var(--color-border);background:var(--color-bg-surface);border-radius:11px;flex-shrink:0;width:38px;height:22px;position:relative}.switch:after{content:"";top:3px;background:var(--color-text-secondary);border-radius:50%;width:14px;height:14px;position:absolute;inset-inline-start:3px}.challenge-toggle input:checked+.switch{background:var(--color-accent-solid);border-color:var(--color-accent-solid)}.challenge-toggle input:checked+.switch:after{background:var(--color-text-on-accent);inset-inline-start:19px}.challenge-toggle input:focus-visible+.switch{outline:3px solid var(--color-focus);outline-offset:4px}.mode-value{font-variant-numeric:tabular-nums;color:var(--color-text-secondary);font-size:var(--text-sm);white-space:nowrap;align-items:center;gap:8px;display:flex}.mode-value .icon{width:16px;height:16px}.mode-description{font-size:var(--text-sm);color:var(--color-text-secondary);min-height:44px;margin-top:4px}.answer-dock{margin-top:24px}fieldset{border:0;min-width:0;margin:0 0 16px;padding:0}legend{font-size:var(--text-sm);margin-bottom:12px;padding:0;font-weight:500}.options{grid-auto-columns:minmax(0,1fr);grid-auto-flow:column;gap:12px;display:grid}.option{cursor:pointer;min-width:0;display:block;position:relative}.option input{opacity:0;cursor:pointer;width:100%;height:100%;margin:0;position:absolute;inset:0}.option-content{border:1px solid var(--color-border);background:var(--color-bg-surface);min-height:56px;color:var(--color-text-primary);border-radius:8px;justify-content:center;align-items:center;gap:8px;padding:10px 8px;display:flex}.option-content strong{font-weight:600;font-size:var(--text-lg)}.option-content>.icon{width:16px;height:16px;display:none}.option input:checked+.option-content{background:var(--color-accent-solid);border-color:var(--color-accent-solid);color:var(--color-text-on-accent)}.option input:checked+.option-content>.icon{display:block}.option input:focus-visible+.option-content{outline:3px solid var(--color-focus);outline-offset:4px}.value-options{grid-auto-flow:initial;grid-template-columns:1fr 1fr;gap:12px}.value-options .option-content{justify-content:flex-start;padding-inline:12px}.value-options .option-content>strong{font-size:var(--text-sm);min-width:20px;font-weight:500}.value-options .option-content>span{font-variant-numeric:tabular-nums;font-size:var(--text-lg);letter-spacing:.04em}.value-options .option-content>.icon{margin-inline-start:auto}.numeric-label{align-items:center;gap:16px;display:flex}.numeric-label input{border:1px solid var(--color-border);background:var(--color-bg-surface);width:100%;min-width:0;height:56px;color:var(--color-text-primary);font-variant-numeric:tabular-nums;border-radius:8px;padding:12px 16px;font-size:1.25rem}.numeric-label>span{color:var(--color-text-secondary)}.dock-actions{grid-template-columns:1fr 1.2fr;gap:12px;display:grid}.dock-actions .button{font-size:var(--text-sm);gap:8px;padding-inline:12px}.hint-button{border-color:var(--color-border);color:var(--color-text-primary);background:0 0}.hint-count{font-variant-numeric:tabular-nums;color:var(--color-text-secondary);margin-inline-start:4px}.answer-message{color:var(--color-text-primary);font-size:var(--text-sm);min-height:0;margin-top:12px}.answer-message:empty{display:none}.answer-message.is-error{color:var(--color-error)}.keyboard-guide{color:var(--color-text-secondary);flex-wrap:wrap;align-items:center;gap:4px;margin-top:20px;font-size:.75rem;display:flex}.keyboard-guide>span{margin-inline-start:8px}kbd{font:inherit;border:1px solid var(--color-separator);border-radius:4px;padding:0 4px;line-height:1.6;display:inline-block}.hint-panel{border:1px solid var(--color-separator);border-radius:12px;min-height:232px;margin-top:32px;padding:24px}.hint-heading{justify-content:space-between;align-items:center;gap:12px;margin-bottom:12px;display:flex}.hint-heading h3{font-size:1rem}.hint-heading>span{font-size:var(--text-sm);color:var(--color-text-secondary);font-variant-numeric:tabular-nums}.hint-placeholder{color:var(--color-text-secondary);align-items:flex-start;gap:12px;margin-top:32px;display:flex}.hint-placeholder .icon{margin-top:2px}.hint-tabs{gap:12px;margin-bottom:8px;display:flex}.hint-tabs button{min-height:44px;font-size:var(--text-sm);border:1px solid var(--color-border);color:var(--color-text-secondary);background:0 0;border-radius:8px;padding:8px 12px}.hint-tabs button[aria-pressed=true]{color:var(--color-text-primary);border-color:var(--color-text-primary);text-underline-offset:5px;text-decoration:underline}.hint-copy{min-height:50px;font-size:1rem;line-height:1.55}.hint-kind{color:var(--color-text-secondary);margin-top:12px;font-size:.8125rem}.feedback-panel{min-height:88px;margin-top:24px}.feedback-panel p{color:var(--color-text-secondary);margin-top:8px}.feedback-panel h3{letter-spacing:-.02em;font-size:1.5rem}.result-actions{flex-wrap:wrap;align-items:center;gap:24px;margin-top:20px;display:flex}.quiet-note{font-size:var(--text-sm)}.feedback-message{color:var(--color-text-primary)!important}.feedback-panel>.text-button{margin-top:8px;padding-inline:0}.finished-dock{flex-direction:column;gap:16px;display:flex}.finished-dock>span{align-items:center;gap:10px;font-weight:600;display:flex}.finished-dock>span .icon{color:var(--color-accent-solid)}.share-fallback{font-size:var(--text-sm);flex-direction:column;gap:8px;margin-top:16px;display:flex}.share-fallback textarea{border:1px solid var(--color-border);resize:vertical;background:var(--color-bg-surface);width:100%;min-height:160px;color:var(--color-text-primary);border-radius:8px;padding:12px;font-size:1rem}.walkthrough{border-top:1px solid 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p{color:var(--color-text-secondary);max-width:65ch;margin-top:12px;line-height:1.6}.steps .step-conclusion{color:var(--color-text-primary);border-inline-start:3px solid var(--color-accent-solid);padding-inline-start:16px}.walkthrough-end{flex-wrap:wrap;justify-content:space-between;gap:16px;max-width:860px;margin-inline:auto;padding-top:8px;display:flex}.diagram-dialog{border:1px solid var(--color-border);background:var(--color-bg-page);width:min(960px,100% - 32px);max-height:calc(100dvh - 32px);color:var(--color-text-primary);overscroll-behavior:contain;border-radius:16px;padding:0}.diagram-dialog::backdrop{background:#000c}.dialog-bar{border-bottom:1px solid var(--color-separator);justify-content:space-between;align-items:center;gap:16px;padding:12px 20px;display:flex}.dialog-bar h2{font-size:var(--text-lg);letter-spacing:0;font-family:IBM Plex 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a[aria-current]{text-underline-offset:6px}}.library-heading{max-width:820px;padding-bottom:28px}.library-heading h1{text-wrap:balance;font-size:clamp(2.25rem,4.4vw,4rem)}.library-heading p{max-width:52ch}.category-links{flex-wrap:wrap;gap:12px;margin-bottom:48px;display:flex}.category-links a{border:1px solid var(--color-border);min-height:44px;font-size:var(--text-sm);border-radius:24px;align-items:center;padding:10px 16px;text-decoration:none;display:flex}.type-library{gap:56px;display:grid}.category-heading{align-items:baseline;gap:16px;margin-bottom:20px;scroll-margin-top:24px;display:flex}.category-heading h2{margin:0;font-size:1.75rem}.category-heading>span{color:var(--color-text-secondary);font-size:var(--text-sm)}.library-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:24px;display:grid}.library-card{border:1px solid 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