:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--ink:#182338;--muted:#505b6c;--brand:#173f8a;--paper:#f8f5ef;--border:#dfddd5;--gold:#84602a;color:var(--ink);background:var(--paper);font-family:system-ui,-apple-system,Segoe UI,sans-serif}*{box-sizing:border-box}body{margin:0}button,select{font:inherit;color:inherit}button,select,summary{min-height:44px}button{border:1px solid var(--border);cursor:pointer;background:#fff;border-radius:9px;padding:9px 14px}button:hover:not(:disabled){border-color:var(--brand)}button:disabled{cursor:default;color:#606775;background:#f2efe9}button:focus-visible,select:focus-visible,summary:focus-visible{outline-offset:2px;outline:3px solid #2164c4}button[aria-pressed=true]{background:var(--brand);color:#fff;border-color:var(--brand)}[hidden]{display:none!important}.shell{max-width:1160px;padding:24px max(16px, env(safe-area-inset-left)) max(24px, env(safe-area-inset-bottom));margin:auto}.brand{align-items:center;gap:12px;margin-bottom:24px;display:flex}.brand strong{letter-spacing:.15em}.brand p{color:var(--muted);margin:4px 0 0;font-size:.85rem}.monogram{background:var(--brand);color:#fff;border-radius:12px;place-items:center;width:46px;height:46px;font:700 30px Georgia,serif;display:grid}.badge{color:#684819;background:#f8f0e1;border-radius:6px;margin-left:auto;padding:6px 10px;font-size:.78rem}.card{border:1px solid var(--border);background:#fff;border-radius:14px;min-width:0;padding:20px}.course-bar{grid-template-columns:1fr 1fr;gap:12px 20px;display:grid}.course-bar label{gap:6px;min-width:0;font-size:.85rem;font-weight:600;display:grid}select{border:1px solid var(--border);background:#f8f5ef;border-radius:8px;width:100%;min-width:0;max-width:100%;padding:8px}.course-bar p{grid-column:1/-1;margin:0}.meta,footer{color:var(--muted);font-size:.82rem;line-height:1.7}.training-head{grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:10px 24px;padding:24px 0 18px;display:grid}h1{overflow-wrap:anywhere;grid-column:1/-1;margin:0;font-size:clamp(1.35rem,4vw,2rem);line-height:1.4}.head-details{min-width:0;color:var(--muted);flex-wrap:wrap;gap:8px 20px;font-size:.9rem;display:flex}#progress{font-variant-numeric:tabular-nums;white-space:nowrap}.mode-switch{gap:6px;display:flex}.training-layout{grid-template-columns:minmax(0,1.2fr) minmax(0,.9fr);align-items:start;gap:28px;display:grid}.board-panel{min-width:0}.board-controls{justify-content:space-between;align-items:center;margin-bottom:10px;display:flex}.quiet{background:0 0}.board{aspect-ratio:1;touch-action:none;-webkit-user-select:none;user-select:none;border:2px solid #79634c;border-radius:3px;grid-template-rows:repeat(8,minmax(0,1fr));grid-template-columns:repeat(8,minmax(0,1fr));width:100%;display:grid;overflow:hidden}.square{border:0;border-radius:0;place-items:center;min-width:0;min-height:0;padding:0;display:grid;position:relative}.square.light{background:#f0d9b5}.square.dark{background:#b58863}.square.recommended{box-shadow:inset 0 0 0 3px #97730f}.square.selected{box-shadow:inset 0 0 0 4px #173f8a}.square.legal-target:after{content:"";background:#ffffff90;border:3px solid #173f8a;border-radius:50%;width:24%;height:24%;position:absolute}.piece{pointer-events:none;font-family:Segoe UI Symbol,Apple Symbols,"Noto Sans Symbols 2",serif;font-size:clamp(24px,6.5vw,48px);line-height:1}.white-piece{color:#fff;text-shadow:-1px 0 #182338,0 1px #182338,1px 0 #182338,0 -1px #182338}.black-piece{color:#182338}.coordinate{color:#332b21;pointer-events:none;font:600 10px system-ui;position:absolute;bottom:1px;left:3px}.dragging{cursor:grabbing}.board-navigation{grid-template-columns:repeat(4,minmax(0,1fr));gap:6px;margin:12px 0;display:grid}.board-navigation button{padding-inline:4px}.full{width:100%;margin-bottom:8px}.lesson-column{gap:14px;min-width:0;display:grid}h2,h3{margin:0 0 10px;font-size:1rem}h3{font-size:.9rem}p{overflow-wrap:break-word;line-height:1.75}.card p:last-child{margin-bottom:0}.eyebrow{color:var(--gold);letter-spacing:.12em;margin-top:0;font-size:.75rem;font-weight:700}.san{color:var(--brand);margin-bottom:12px;font:600 2.6rem Georgia,serif}.feedback{border-left:4px solid var(--brand)}.feedback[data-kind=error]{background:#fbeef0;border-left-color:#a72b3b}.feedback[data-kind=warning]{background:#faf1e0;border-left-color:#80500d}.feedback[data-kind=success]{background:#eaf5ee;border-left-color:#17613d}summary{cursor:pointer;font-weight:600}.moves{flex-wrap:wrap;gap:4px;display:flex}.moves button{font-family:Georgia,serif}.moves button[aria-current=true]{border-color:var(--brand);color:var(--brand);background:#eaf0fa;text-decoration:underline}footer{text-align:center;margin-top:28px}a{color:var(--brand)}dialog{border:1px solid var(--border);border-radius:14px;max-width:calc(100% - 32px)}dialog::backdrop{background:#18233899}.promotion-options{gap:6px;margin-block:16px;display:flex}@media (max-width:740px){.training-layout{grid-template-columns:minmax(0,1fr);gap:18px}.board-panel{width:100%;max-width:560px;margin:auto}.lesson-column{width:100%}}@media (max-width:400px){.shell{padding-top:16px}.brand{gap:8px}.badge{max-width:80px}.course-bar,.training-head{grid-template-columns:minmax(0,1fr)}.mode-switch{justify-self:start}.card{padding:16px}}:root{--accent:var(--brand);--line:var(--border)}.site-nav{flex-wrap:wrap;align-items:center;gap:10px 22px;margin-left:auto;font-size:.9rem;display:flex}.site-nav a{color:var(--ink);white-space:nowrap;padding:10px 0;text-decoration:none}.site-nav a[aria-current=page]{color:var(--accent);border-bottom:2px solid}.brand a.monogram{color:#fff;flex-shrink:0;text-decoration:none}.training-brand{flex-wrap:wrap}.home-page .shell{max-width:1160px}.home-brand{border-bottom:1px solid var(--line);padding-bottom:24px}.skip-link{z-index:10;background:#fff;padding:12px;position:absolute;top:-100px;left:16px}.skip-link:focus{top:12px}.home-page a:focus-visible{outline:3px solid var(--accent);outline-offset:5px}.home-hero{grid-template-columns:minmax(0,1.5fr) minmax(0,1fr);align-items:center;gap:clamp(24px,5vw,72px);padding:64px 0 48px;display:grid}.hero-copy h1{letter-spacing:-.055em;overflow-wrap:normal;margin:18px 0 24px;font-size:clamp(2.1rem,5vw,3.8rem);line-height:1.25}.hero-subtitle{color:var(--ink);font-size:clamp(.95rem,2.5vw,1.15rem);line-height:1.8}.hero-description{max-width:30em;color:var(--muted);margin:18px 0 28px;line-height:1.9}.home-cta{background:var(--accent);color:#fff;border-radius:10px;justify-content:space-between;align-items:center;gap:28px;max-width:100%;min-height:50px;padding:15px 22px;font-weight:700;text-decoration:none;display:inline-flex}.home-cta:hover{filter:brightness(.92)}.hero-note{max-width:31em;margin-top:18px;line-height:1.8}.hero-chess{background:#e9eefb;border:1px solid #d5def5;border-radius:20px;min-width:0;padding:32px;position:relative;overflow:hidden}.chess-mark{color:var(--accent);margin-bottom:28px;font-family:Georgia,serif;font-size:7rem;line-height:1}.hero-chess h2{margin:12px 0;font-size:clamp(1.6rem,3vw,2rem);line-height:1.45}.hero-chess>p:not(.eyebrow){color:var(--muted);line-height:1.8}.chess-caption{color:var(--accent);letter-spacing:.08em;padding-top:24px;font-size:.85rem;display:block}.home-section{padding:48px 0;scroll-margin-top:24px}.section-heading{margin-bottom:26px}.section-heading h2{margin:12px 0;font-size:clamp(1.5rem,3vw,2rem)}.section-heading>p:last-child{color:var(--muted);line-height:1.8}.feature-grid,.roadmap-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;display:grid}.feature-card{padding:26px}.feature-index{color:var(--accent);letter-spacing:.12em;font-size:.8rem;font-weight:700}.feature-card h3{margin:22px 0 12px;font-size:1.15rem}.feature-card p,.roadmap p{color:var(--muted);margin-bottom:0;line-height:1.85}.roadmap{border-top:1px solid var(--line)}.roadmap-grid article{border-left:2px solid #ccd4e5;padding:4px 0 4px 20px}.roadmap-grid h3{margin:0;font-size:1rem}.roadmap-grid h3 span{color:var(--muted);margin-top:8px;font-size:.8rem;font-weight:400;display:block}.home-closing{border-top:1px solid var(--line);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:20px;padding:40px 0;display:flex}.home-closing h2{margin:0;font-size:clamp(1.3rem,3vw,1.7rem)}.home-footer{text-align:left;flex-wrap:wrap;justify-content:space-between;gap:20px;margin-top:12px;line-height:1.8;display:flex}.home-footer strong{color:var(--ink);font-size:1rem}.home-footer p{margin:6px 0 0}.home-footer nav{flex-wrap:wrap;gap:12px 20px;display:flex}.home-footer>p{flex-basis:100%;font-size:.8rem}@media (max-width:700px){.home-brand{flex-wrap:wrap;gap:14px}.home-brand .site-nav{flex-basis:100%;margin-left:0}.home-hero{grid-template-columns:minmax(0,1fr);gap:30px;padding-top:32px}.hero-chess{padding:24px}.chess-mark{margin-bottom:16px;font-size:5rem}.feature-grid,.roadmap-grid{grid-template-columns:minmax(0,1fr)}.home-section{padding:32px 0}.training-brand .site-nav{flex-basis:100%;margin-left:0}}