:root{color-scheme:dark;--bg:#10151d;--panel:#171e28;--ink:#edece5;--muted:#a3adba;--line:#303946;--gold:#f2cb91}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}button,select{font:inherit}button{cursor:pointer;color:inherit}button:focus-visible,select:focus-visible{outline:2px solid var(--gold);outline-offset:5px}button:disabled{opacity:.4;cursor:default}.shell{max-width:1440px;margin:auto;padding:32px 48px 22px}header{display:flex;align-items:center;justify-content:space-between}.wordmark{font-size:22px;letter-spacing:-1px;font-weight:650;display:flex;gap:10px;align-items:center}.symbol{font-size:29px;color:var(--gold);font-weight:300}.edition{text-transform:uppercase;font-size:10px;letter-spacing:2px;color:var(--muted)}main{display:grid;grid-template-columns:minmax(0,1fr) 290px;gap:48px;align-items:center;min-height:calc(100svh - 140px)}.intro{position:absolute;top:24px;left:0;pointer-events:none}.eyebrow{font-size:10px;letter-spacing:2.4px;text-transform:uppercase;color:var(--gold);margin-bottom:13px}h1{font-family:Georgia,serif;font-weight:400;font-size:clamp(32px,3.3vw,48px);letter-spacing:-1.7px;margin:0;line-height:1.08}.universe{position:relative;min-width:0}.stage{position:relative;width:100%;aspect-ratio:1;max-width:780px;margin-inline:auto;touch-action:none;user-select:none;border-radius:50%;isolation:isolate}.stage canvas{width:100%;height:100%;display:block;pointer-events:none}.planet-layer{position:absolute;inset:0;pointer-events:none}.planet{position:absolute;width:44px;height:44px;margin:-22px;border:0;background:none;border-radius:50%;display:grid;place-items:center;pointer-events:auto;touch-action:none;z-index:3}.planet::after{content:"";width:var(--size);height:var(--size);background:var(--color);border-radius:50%;box-shadow:0 0 18px color-mix(in srgb,var(--color),transparent 65%),inset -3px -3px 5px #0003}.planet:focus-visible::before{content:"";position:absolute;inset:3px;border:1px solid var(--gold);border-radius:50%}.stage-hint{text-align:center;color:var(--muted);font-size:12px;margin:-8px 0 18px}.stage-hint span{color:#d5d9dd}.sidebar{padding-top:32px}.subtitle{font-family:Georgia,serif;font-size:26px;font-weight:400;letter-spacing:-.5px;margin:0 0 14px}.description{font-size:13px;color:var(--muted);line-height:1.75;margin:0 0 28px}.primary{width:100%;background:var(--gold);color:#29221a;border:1px solid var(--gold);border-radius:100px;padding:15px 12px;font-weight:600;font-size:13px;transition:background .2s}.primary:hover{background:#ffe0b2}.sound-note{text-align:center;font-size:10px;color:var(--muted);margin:10px 0 29px;min-height:15px}.divider{height:1px;background:var(--line);margin:24px 0}.label{font-size:10px;text-transform:uppercase;letter-spacing:1.8px;color:var(--muted);margin-bottom:12px;display:block}.presets{display:flex;gap:7px;flex-wrap:wrap}.pill{border:1px solid var(--line);border-radius:100px;background:transparent;padding:9px 11px;font-size:11px}.pill[aria-pressed=true]{border-color:#baaa8c;background:#f2cb9110;color:var(--gold)}.tools{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:24px 0 10px}.tool{background:#1c2430;border:1px solid var(--line);border-radius:9px;min-height:44px;font-size:12px}.tool:hover,.pill:hover{border-color:#8d98a7}.text-actions{display:flex;justify-content:space-between;margin-top:18px}.text-button{background:none;border:0;color:var(--muted);font-size:11px;padding:8px 0;text-decoration:underline;text-underline-offset:4px}.text-button:hover{color:var(--ink)}.stat{display:flex;justify-content:space-between;align-items:center;font-size:11px;color:var(--muted);margin-top:25px}.live-note{color:var(--gold);font-variant-numeric:tabular-nums}.guide{font-size:11px;line-height:1.8;color:var(--muted)}.guide p{margin:6px 0}.guide b{font-weight:500;color:#d5d9dd}.volume{width:100%;accent-color:var(--gold);margin:8px 0 0}footer{display:flex;justify-content:space-between;font-size:10px;color:#7e8a99;letter-spacing:.2px;border-top:1px solid var(--line);padding-top:17px}.status{position:absolute;bottom:15%;left:50%;transform:translateX(-50%);font-size:11px;color:var(--muted);text-align:center;pointer-events:none;white-space:nowrap}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media(min-width:1450px){main{min-height:820px}}@media(max-width:900px){.shell{padding:25px 28px}main{gap:22px;grid-template-columns:minmax(0,1fr) 250px}.intro{top:0}h1{font-size:34px}.edition{font-size:9px;letter-spacing:1.2px}.sidebar{padding-top:20px}.stage{min-height:360px}.intro{position:relative;margin-top:25px}.stage-hint{margin-top:0}}
@media(max-width:650px){.shell{padding:20px 20px 24px}main{display:flex;flex-direction:column;gap:5px;min-height:0}.universe{width:100%}.intro{text-align:center;margin-top:32px}.eyebrow{font-size:9px;margin-bottom:10px}h1{font-size:37px}.stage{width:calc(100% + 20px);margin-left:-10px;min-height:0;max-height:none}.stage-hint{font-size:11px;margin:-3px 0 19px}.sidebar{width:100%;padding:0 5px 25px;max-width:430px}.subtitle,.description{display:none}.sound-note{margin-bottom:22px}.divider{margin:20px 0}.presets{display:grid;grid-template-columns:repeat(3,1fr)}.pill{padding:11px 5px}.tools{margin-top:20px}.guide{display:grid;grid-template-columns:1fr 1fr;gap:12px}.guide p{margin:0}footer{font-size:9px;gap:20px;line-height:1.6}.stat{margin-top:18px}.status{bottom:12%}.edition{max-width:110px;text-align:right;line-height:1.6}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}
.line-label{position:absolute;top:3%;left:calc(50% + 8px);font-size:9px;letter-spacing:1.2px;color:#a3adba80;pointer-events:none}.outcome{font-size:11px;line-height:1.6;color:var(--muted);min-height:34px;margin-top:12px}.explanation{margin-top:22px;font-size:11px;line-height:1.7;color:var(--muted)}.explanation summary{cursor:pointer;color:#d5d9dd;min-height:34px;display:list-item}.explanation p{margin:10px 0}.planet[hidden]{display:none}.planet.is-aimed::before{content:"";position:absolute;inset:1px;border:1px dashed var(--gold);border-radius:50%}.planet-layer{overflow:visible}.stage{overflow:hidden;border-radius:20px}.status{bottom:8%;white-space:normal;width:85%;line-height:1.5}.intro{z-index:2}h1{font-size:clamp(30px,3vw,43px)}.line-label{top:5%}@media(max-width:650px){h1{font-size:34px;letter-spacing:-1.4px}.intro{margin-top:28px}.stage-hint{max-width:300px;margin:0 auto 20px;line-height:1.8}.line-label{top:2%}.status{bottom:4%;font-size:10px}.outcome{min-height:18px}.explanation{margin-top:18px}.sidebar{padding-bottom:22px}}
.sound-tools{display:flex;justify-content:center;align-items:center;gap:13px;margin:-21px 0 24px}.sound-tools .text-button{padding:8px 4px;min-height:36px;color:var(--gold)}.signal{color:var(--gold);font-size:16px;opacity:.25;letter-spacing:2px}.sound-note{line-height:1.6;min-height:30px;margin-top:10px}

.planet::after{background:transparent;box-shadow:none}

.mass-controls{margin-top:22px;padding:18px 0 0;border-top:1px solid var(--line)}.mass-controls .label{margin:14px 0 3px;display:flex;justify-content:space-between}.mass-controls .label:first-child{margin-top:0}.mass-controls output{color:var(--gold);font-variant-numeric:tabular-nums}.mass-controls input{margin:8px 0 2px;min-height:24px}input:focus-visible{outline:2px solid var(--gold);outline-offset:3px}.line-label{left:calc(50% + 8px)}@media(min-width:901px){main{align-items:start}.universe{position:sticky;top:25px}.sidebar{padding-bottom:35px}}

/* Planet editing follows canvas or keyboard selection. */
.planet-mass{margin-top:20px}.planet-mass[hidden]{display:none}.planet-mass .label{margin:0 0 3px}

/* Moving planets must not become scroll anchors after pointer selection. */
.stage{overflow-anchor:none}.universe{align-self:start}

.note-control{margin-top:16px}.stat{gap:8px;flex-wrap:wrap}.scale-switch{font:inherit;min-height:36px;border:1px solid var(--line);border-radius:20px;background:transparent;color:var(--gold);padding:7px 9px;white-space:nowrap}.scale-switch:hover{border-color:var(--gold)}

.label[for=volume]{margin:16px 0 0}
/* Fit the instrument on ordinary laptops; smaller/zoomed views keep natural flow. */
@media(min-width:1000px) and (min-height:650px){
 .shell{min-height:100svh;padding:22px 36px 16px;display:flex;flex-direction:column}
 header,footer{flex:none}main{flex:1;min-height:0;padding-top:14px;gap:32px;grid-template-columns:minmax(0,1fr) 300px;align-items:start}
 .universe{position:relative;top:auto}.intro{top:4px;left:0;right:0;text-align:center}
 .stage{max-width:min(100%,calc(100svh - 175px))}.stage-hint{max-width:580px;margin:0 auto;font-size:11px}.line-label{top:82px}
 .sidebar{padding:0}.subtitle,.description,.guide,.divider{display:none}
 .mass-controls{margin-top:14px;padding-top:12px}.mass-controls .label{margin:8px 0 2px}.mass-controls .label:first-child{margin-top:0}
 .sidebar input.volume{min-height:24px;margin:4px 0 0}.planet-mass{margin-top:12px}.note-control{margin-top:10px}
 .tools{margin:14px 0 0}.label[for=volume]{margin:12px 0 0}.text-actions{margin-top:8px}.text-button{min-height:32px;padding:6px 0}
 .stat{margin-top:10px;gap:6px}.scale-switch{min-height:34px;padding:5px 8px}.outcome{margin-top:6px;min-height:32px}
 footer{margin-top:14px}
}

.line-controls{margin-top:14px}.line-controls .label{display:flex;justify-content:space-between;margin:0}.line-controls output{color:var(--gold);font-variant-numeric:tabular-nums}.line-controls input{min-height:24px}.line-controls+.mass-controls{margin-top:10px}
@media(min-width:1000px) and (min-height:650px){.line-controls{margin-top:10px}.line-controls+.mass-controls{margin-top:6px;padding-top:8px}.sidebar .tools{margin-top:10px}.sidebar .planet-mass{margin-top:8px}.sidebar .stat{margin-top:6px}}

.keyboard-hint{font-size:10px;line-height:1.5;text-align:center;color:var(--muted);margin:5px 0 10px}.keyboard-hint[hidden]{display:none}.keyboard-hint kbd{font:inherit;color:var(--gold)}.stage:focus-visible{outline:1px solid var(--gold);outline-offset:3px}.planet.is-selected{box-shadow:0 0 0 1px var(--gold);background:#f2cb9109}.planet.is-selected:focus-visible::before{inset:-4px;border-color:#f2cb9155}

/* Opening the editor must not shift the keyboard-focused sky. */
@media(min-width:901px) and (hover:hover) and (pointer:fine){.universe{position:relative;top:auto}}

.planet.is-offscreen::after{content:"";width:9px;height:9px;background:var(--marker-color);clip-path:polygon(0 0,100% 50%,0 100%);transform:rotate(var(--edge-angle));opacity:.85}.planet.is-offscreen:hover::after,.planet.is-offscreen.is-selected::after{background:var(--gold);opacity:1}

/* Compact keyboard reference. */
.keyboard-hint.sr-only{margin:0}.keys-trigger[hidden]{display:none}.keys-trigger{min-width:44px;text-decoration:none}.keys-trigger:hover,.keys-trigger[aria-expanded=true]{color:var(--gold)}
.keyboard-panel{position:fixed;inset:auto;margin:0;width:292px;max-width:calc(100vw - 32px);max-height:calc(100dvh - 32px);overflow:auto;padding:18px 20px 15px;background:#171e28;color:var(--ink);border:1px solid #37404c;border-radius:12px;box-shadow:0 16px 48px #0005;font-size:11px}.keyboard-panel::backdrop{background:transparent}.keys-heading{display:flex;justify-content:space-between;align-items:center;gap:20px}.keys-heading h2{font:500 14px/1.4 ui-sans-serif,system-ui,sans-serif;margin:0;letter-spacing:.1px}.keys-close{display:grid;place-items:center;width:28px;height:28px;margin:-7px -8px -7px 0;padding:0;border:0;background:none;font-size:19px;font-weight:300;color:var(--muted)}.keys-close:hover{color:var(--ink)}.keyboard-panel p{color:var(--muted);font-size:11px;line-height:1.6;margin:7px 0 17px}.keys-list{margin:0;display:grid;gap:15px}.keys-list>div{display:flex;align-items:center;justify-content:space-between;gap:12px}.keys-list dt{display:flex;align-items:center;gap:4px;white-space:nowrap}.keys-list dt>span{color:#697584;font-size:9px}.keys-list dd{margin:0;color:#cbd0d7;font-size:11px}.keys-list kbd{display:inline-grid;place-items:center;min-width:18px;height:21px;padding:0 4px;border:1px solid #414956;border-radius:4px;background:#1d2530;color:#e0d5bd;font:10px/1 ui-sans-serif,system-ui,sans-serif;box-shadow:0 1px 0 #0004}.keyboard-panel .keys-footnote{font-size:10px;color:#85909e;margin:18px 0 0;padding-top:12px;border-top:1px solid var(--line)}