:root{color-scheme:light;--ink:#123b43;--sea:#256a72;--paper:#f7f2e7;--muted:#51676a;--coral:#a4432c;--line:#becbc4;--soft:#e8eee6;font-family:Georgia,'Times New Roman',serif;color:var(--ink);background:var(--paper)}
*{box-sizing:border-box}body{margin:0;background:radial-gradient(ellipse at 95% 0%,#e0e9dd 0,transparent 45%),var(--paper);min-width:280px}a{color:inherit;text-underline-offset:4px}button,select{font:inherit;color:inherit}button{cursor:pointer;min-height:44px;border:1px solid var(--line);border-radius:7px;background:var(--paper);padding:.65rem .9rem;touch-action:manipulation}button:hover{background:#e1eae1}button:disabled{opacity:.45;cursor:default}button:focus-visible,a:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--coral);outline-offset:3px}button[aria-pressed=true]{background:var(--ink);color:var(--paper);border-color:var(--ink)}[hidden]{display:none!important}
.site-header,.site-footer{max-width:850px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:22px 26px;font:12px/1.4 ui-sans-serif,system-ui,sans-serif;letter-spacing:.06em}.brand{display:flex;gap:10px;align-items:center;text-decoration:none;font-weight:750;letter-spacing:.2em}.game-shell{max-width:660px;margin:10px auto 50px;padding:0 26px}.heading{display:flex;align-items:center;justify-content:space-between;margin:20px 0 27px}.eyebrow{margin:0 0 8px;font:600 10px/1.4 ui-sans-serif,system-ui,sans-serif;letter-spacing:.17em;color:var(--muted)}h1{font-weight:400;font-size:clamp(38px,8vw,58px);letter-spacing:-.035em;line-height:1;margin:0 0 12px}.genre{font:14px/1.4 ui-sans-serif,system-ui,sans-serif;margin:0;color:var(--muted)}.survey-seal{border:1px solid var(--line);border-radius:50%;height:82px;width:82px;display:grid;align-content:center;text-align:center;font:12px/1.5 ui-monospace,monospace;color:var(--sea)}
.chart-panel{background:#fffdf6;border:1px solid var(--line);border-radius:13px;padding:23px;box-shadow:0 12px 30px #183b4310;position:relative}.chart-panel:before{content:'';position:absolute;top:-1px;left:24px;right:24px;height:3px;background:var(--sea);border-radius:0 0 3px 3px}.chart-top{display:flex;justify-content:space-between;align-items:center;gap:14px}.chart-top h2{margin:0;font-size:26px;font-weight:400;line-height:1.2}.chart-picker{font:11px/1.4 ui-sans-serif,system-ui,sans-serif;color:var(--muted);display:grid;gap:4px;max-width:47%}select{min-height:44px;width:100%;max-width:230px;background:var(--paper);border:1px solid var(--line);border-radius:7px;padding:7px 9px;font:12px/1.3 ui-sans-serif,system-ui,sans-serif}.chart-stats{display:flex;justify-content:space-between;gap:8px;font:11px/1.5 ui-monospace,monospace;letter-spacing:.02em;color:var(--muted);border-bottom:1px solid var(--line);padding:18px 0 10px}.map-frame{padding:14px 0 12px;max-width:490px;margin:auto}#board{--size:5;display:grid;grid-template-columns:26px repeat(var(--size),minmax(0,1fr));gap:3px}.corner,.total{display:grid;place-items:center;font:600 14px/1 ui-monospace,monospace;min-width:0}.corner{font-size:10px;color:var(--sea)}.column-total{height:27px}.total.met{color:var(--sea);text-decoration:underline;text-underline-offset:4px}.total.over{color:var(--coral);text-decoration:line-through}.cell{padding:0;min-height:0;aspect-ratio:1;border:1px solid #bbcec7;background:#f1f4ec;border-radius:3px;position:relative;display:grid;place-items:center;overflow:visible;min-width:0}.cell:hover{background:#dce8df}.cell-icon{font-family:ui-sans-serif,system-ui,sans-serif;font-size:clamp(16px,4vw,24px);line-height:1;pointer-events:none}.cell[data-mark="1"]{background:var(--ink);border-color:var(--ink);color:#fffdf6}.cell[data-mark="-1"]{background:#e7f0ec;color:#256a72}.cell[data-mark="0"]{color:#80948c}.cell.given:after{content:'';position:absolute;right:3px;bottom:3px;width:4px;height:4px;border-radius:50%;background:currentColor}.cell.given{outline:1px solid #79998c;outline-offset:-4px}.cell.highlight{box-shadow:inset 0 0 0 3px #c16343}.cell:focus-visible{z-index:1;outline:3px solid var(--coral);outline-offset:1px}
.fleet-key{display:flex;gap:15px;align-items:center;padding:10px 0 15px;border-bottom:1px solid var(--line)}.fleet-key h3{font:600 11px/1.4 ui-sans-serif,system-ui,sans-serif;letter-spacing:.1em;text-transform:uppercase;margin:0}#fleet{display:flex;flex-wrap:wrap;gap:8px 15px}.fleet-item{display:flex;gap:6px;align-items:center;font:11px/1.4 ui-monospace,monospace;white-space:nowrap}.fleet-shape{display:flex;gap:1px}.fleet-shape i{display:block;background:var(--ink);width:8px;height:8px;border-radius:1px}.mark-tools{display:grid;grid-template-columns:1fr 1fr 1fr;gap:6px;margin-top:17px}.mark-tools button,.game-actions button{font:600 12px/1.4 ui-sans-serif,system-ui,sans-serif}.mark-tools span{margin-right:5px}.keyboard-help{font:11px/1.5 ui-sans-serif,system-ui,sans-serif;color:var(--muted);margin:11px 0 14px}.game-actions{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:6px}.game-actions button{padding:.6rem .25rem;background:transparent}.feedback{font:13px/1.6 ui-sans-serif,system-ui,sans-serif;min-height:0;margin:16px 0 0}.feedback:empty{display:none}.victory{margin-top:18px;background:#e5eddf;border:1px solid #a7bba9;border-radius:8px;padding:15px;display:flex;gap:12px;align-items:center;justify-content:space-between}.victory h3{font-size:23px;font-weight:400;margin:0 0 5px}.victory p{font:12px/1.5 ui-sans-serif,system-ui,sans-serif;margin:0}.victory button{background:var(--ink);color:var(--paper);font:600 12px/1.4 ui-sans-serif,system-ui,sans-serif;white-space:nowrap}.rule-note{font:12px/1.7 ui-sans-serif,system-ui,sans-serif;color:var(--muted);margin:18px 10px 0}.site-footer{border-top:1px solid var(--line);color:var(--muted);font-size:10px;gap:15px;flex-wrap:wrap}.site-footer nav{display:flex;gap:20px}.notice{border:1px solid #c18d64;background:#fff3df;border-radius:8px;padding:15px;margin-bottom:18px;font:13px/1.6 ui-sans-serif,system-ui,sans-serif}.notice p{margin:0 0 10px}.notice-actions{display:flex;gap:8px;flex-wrap:wrap}.notice button{font-size:12px}details{margin-top:10px}summary{cursor:pointer;min-height:30px}pre{white-space:pre-wrap;overflow-wrap:anywhere;font:12px/1.6 ui-monospace,monospace}dialog{max-width:420px;width:calc(100% - 32px);border:1px solid var(--line);border-radius:12px;padding:24px;background:var(--paper);color:var(--ink)}dialog::backdrop{background:#123b4388}dialog h2{font-size:26px;font-weight:400;margin:0 0 13px}dialog p{font:14px/1.7 ui-sans-serif,system-ui,sans-serif}.dialog-actions{display:flex;gap:9px;justify-content:flex-end;margin-top:20px}.dialog-actions button{font:600 13px/1.4 ui-sans-serif,system-ui,sans-serif}.dialog-actions button[value=confirm]{background:var(--ink);color:var(--paper)}
.article{max-width:660px;padding:0 26px;margin:40px auto 60px}.article h1{font-size:43px;line-height:1.12;margin-bottom:26px}.article h2{font-size:25px;font-weight:400;margin-top:30px}.article p,.article li{font:15px/1.8 ui-sans-serif,system-ui,sans-serif}.article li{margin:10px 0}.article .callout{background:#e5eddf;border-left:3px solid var(--sea);padding:12px 18px}.article code{font:13px/1.6 ui-monospace,monospace;overflow-wrap:anywhere}.article .notice{margin-top:18px}.article button{font:600 13px/1.4 ui-sans-serif,system-ui,sans-serif}
@media(max-width:480px){.site-header,.site-footer{padding:18px 16px}.game-shell{padding:0 12px;margin-bottom:35px}.heading{margin:17px 4px 23px}.survey-seal{width:64px;height:64px;font-size:10px}.chart-panel{padding:14px 11px}.chart-top{display:block}.chart-top h2{font-size:24px}.chart-picker{margin-top:13px;display:flex;align-items:center;gap:10px;max-width:100%}.chart-picker select{max-width:none;flex:1}.chart-stats{padding-top:14px}.map-frame{padding-top:10px}#board{grid-template-columns:20px repeat(var(--size),minmax(0,1fr));gap:2px}.total{font-size:12px}.fleet-key{gap:10px;align-items:flex-start}#fleet{gap:7px 10px}.fleet-item{font-size:10px}.fleet-shape i{width:7px;height:7px}.keyboard-help{font-size:10px}.victory{display:block;padding:13px}.victory button{margin-top:12px;width:100%}.rule-note{margin-left:4px;margin-right:4px}.article{padding:0 18px;margin-top:25px}.article h1{font-size:36px}}
@media(prefers-reduced-motion:no-preference){.cell{transition:background .1s,color .1s}.victory{animation:surface .2s ease-out}@keyframes surface{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:none}}}