:root{color-scheme:light;--paper:#f4efe6;--card:#fffdf8;--ink:#2a2f3a;--muted:#6f6878;--line:#e2dccd;--green:#1f6b4b;--amber:#c27f22;--gold:#e7c25a;--night:#1d2340;--re-bg:var(--card);--re-ink:var(--ink);--re-muted:var(--muted);--re-line:var(--line);--re-accent:var(--green)}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:system-ui,sans-serif}[hidden]{display:none!important}button,select{font:inherit;color:inherit;min-height:44px;border:1px solid var(--line);border-radius:9px;background:var(--card);padding:8px 12px}button{cursor:pointer;touch-action:manipulation}button:disabled{opacity:.5;cursor:default}button:focus-visible,a:focus-visible,select:focus-visible{outline:3px solid var(--amber);outline-offset:3px}a{color:var(--green)}
.shell{max-width:1280px;margin:auto;padding:24px 32px 10px}header{display:flex;gap:12px;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);padding-bottom:16px}.brand{display:inline-flex;align-items:center;min-height:44px;font-size:16px;font-weight:800;letter-spacing:2px;text-decoration:none;color:var(--ink)}.brand span{color:var(--amber)}.utilities{display:flex;gap:6px;flex-wrap:wrap}.utilities button{font-size:13px}.heading{margin:30px 0 22px}.eyebrow{font-size:12px;letter-spacing:2px;color:var(--green);font-weight:800}h1{font-size:clamp(36px,6vw,60px);letter-spacing:-2px;margin:0;line-height:1.1}h1 span{color:var(--green)}.howto{color:var(--muted);line-height:1.5}.layout{max-width:1140px;margin:auto}.lab{position:relative;border:1px solid var(--line);border-radius:20px;background:var(--card);padding:20px;box-shadow:0 12px 40px #3a2f1a08}
.game-area{scroll-margin-top:76px;width:min(100%,480px);margin:auto}.toolbar{display:flex;align-items:end;gap:10px}.toolbar label{flex:1;font-size:13px;font-weight:700}.toolbar select{display:block;width:100%;margin-top:5px}.hud{display:grid;grid-template-columns:repeat(4,1fr);margin:16px 0;padding:10px 0;border-block:1px solid var(--line);text-align:center}.hud small{font-size:12px;color:var(--muted)}.hud strong{display:block;font-size:22px;font-variant-numeric:tabular-nums;margin-top:4px}
/* The board is always square and sized by its width, so a new puzzle or size never shifts the page.
   Each lamp button fills its whole grid cell (at least 44px at 7×7 on a 390px screen); the lamp is drawn inside. */
.field{position:relative;border-radius:16px;background:radial-gradient(circle at 50% 40%,#2c3560,var(--night) 75%);padding:8px;box-shadow:inset 0 0 0 3px #b98a3e,inset 0 0 0 5px #5c4524}.board{--n:5;display:grid;grid-template-columns:repeat(var(--n),1fr);aspect-ratio:1;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none;touch-action:manipulation}
.cell{position:relative;min-width:0;min-height:0;padding:0;border:0;border-radius:50%;background:none}
.cell::before{content:"";position:absolute;inset:9%;border-radius:50%;background:radial-gradient(circle at 38% 32%,#5d6380,#353a52 60%,#262a3d);box-shadow:inset 0 -3px 0 #0005,0 2px 3px #0006;transition:background .15s,box-shadow .15s}
.cell[data-on="true"]::before{background:radial-gradient(circle at 42% 36%,#fff3c4,#ffc54d 38%,#e88a1c 78%,#b8620f);box-shadow:inset 0 -3px 0 #a3530c66,0 0 14px #ffb53f99,0 0 3px #ffd77a}
/* A carved rune on each lamp: decorative shapes only, no letters or digits. */
.cell::after{content:"";position:absolute;left:50%;top:50%;width:30%;height:30%;transform:translate(-50%,-50%);background:#ffffff26;pointer-events:none}
.cell[data-on="true"]::after{background:#8a3f0a59}
.cell[data-rune="0"]::after{border-radius:50%;background:none;border:2px solid #ffffff30}.cell[data-on="true"][data-rune="0"]::after{border-color:#8a3f0a66}
.cell[data-rune="1"]::after{width:24%;height:24%;transform:translate(-50%,-50%) rotate(45deg)}
.cell[data-rune="2"]::after{clip-path:polygon(50% 0,100% 100%,0 100%)}
.cell[data-rune="3"]::after{clip-path:polygon(40% 0,60% 0,60% 40%,100% 40%,100% 60%,60% 60%,60% 100%,40% 100%,40% 60%,0 60%,0 40%,40% 40%)}
.cell[data-rune="4"]::after{width:14%;height:34%;border-radius:4px}
.cell[data-rune="5"]::after{clip-path:polygon(50% 0,100% 50%,50% 100%,0 50%,50% 50%)}
.cell[data-hint="true"]::before{outline:3px solid #9ef0d8;outline-offset:2px}
.cell:hover::before{filter:brightness(1.12)}.cell:focus-visible{outline:none}.cell:focus-visible::before{outline:3px solid var(--gold);outline-offset:3px}
body[data-phase="won"] .cell::before{animation:glow .7s ease-out}@keyframes glow{40%{filter:brightness(1.6)}}
.paused-note{position:absolute;inset:0;display:grid;place-content:center;gap:12px;text-align:center;border-radius:16px;background:var(--night);color:white;font-size:24px;font-weight:800}.paused-note p{margin:0}.paused-note button{background:var(--gold);color:var(--ink)}body[data-phase="paused"] .board{visibility:hidden}
.tools{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:14px}.tools button{font-size:14px}.tools a{display:inline-flex;align-items:center;min-height:44px;font-size:14px;margin-left:auto}.small,.instructions{font-size:13px;color:var(--muted);line-height:1.65}#status{font-size:14px;line-height:1.5;min-height:42px;margin-bottom:4px}.small{margin:0}.instructions{margin:14px 4px}
@media(max-width:600px){.shell{padding:12px 12px 4px}header{position:sticky;top:0;z-index:3;background:var(--paper);padding:6px 0 12px;gap:6px}.utilities{flex-wrap:nowrap}.lab{padding:12px}.heading{margin:16px 0 12px}.howto{font-size:14px;margin:8px 0}.eyebrow{letter-spacing:1px}.brand{font-size:12px;letter-spacing:1px}.utilities button{padding:6px 8px}.hud{margin:10px 0;padding:8px 0}.hud strong{font-size:18px;margin-top:2px}.field{padding:6px}.tools a{margin-left:0}}
.game-help-links{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:8px;margin:12px 4px}.game-help-links button,.game-help-links a{display:inline-flex;align-items:center;min-height:44px;font-size:13px}.game-help-links button{border:0;background:none;color:var(--green);padding:0}#help-panel{width:min(520px,calc(100% - 24px));max-height:calc(100dvh - 32px);padding:0;border:1px solid var(--line);border-radius:16px;background:var(--card);color:var(--ink)}#help-panel::backdrop{background:#17271fd9}#help-panel[open]{display:flex;flex-direction:column}.help-body{overflow:auto;padding:20px;line-height:1.65}.help-body h2{margin-top:0}.help-actions{padding:12px 20px;border-top:1px solid var(--line)}.help-actions button{width:100%}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}.cell::before{transition:none}body[data-phase="won"] .cell::before{animation:none}}