.back-link{font-size:11px;color:var(--muted)}.gravity-intro{display:flex;justify-content:space-between;align-items:center;gap:30px;margin:28px 0 38px}.gravity-intro h1{font-size:clamp(32px,3.8vw,49px)}.gravity-intro .lead{margin-bottom:0}.intro-equation{display:flex;flex-direction:column;align-items:center;justify-content:center;width:230px;height:210px;background:#fff2cb;border-radius:50%;transform:rotate(8deg);flex-shrink:0}.intro-equation>span{font-size:40px;color:#cd923a}.intro-equation strong{font-size:22px;line-height:1.3;color:#9e7434}.intro-equation small{font-size:10px;margin-top:10px}.orbit-lab{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:20px}.orbit-stage{position:relative;min-width:0;border:1px solid #dce5fc;border-radius:24px;background:#edf2ff;overflow:hidden}.stage-heading{display:flex;justify-content:space-between;align-items:center;padding:22px 25px;font-size:10px;letter-spacing:1px;font-weight:600}.stage-heading i{display:inline-block;width:6px;height:6px;border-radius:50%;background:#3157ed;margin-right:8px}.stage-heading>span:last-child{font-size:12px;letter-spacing:0;color:var(--muted)}#orbit-canvas{display:block;width:100%;height:440px}.stage-overlay{display:flex;align-items:center;justify-content:space-between;gap:15px;position:absolute;top:64px;left:24px;right:24px;pointer-events:none}.orbit-label{font-size:11px;background:#fff;border-radius:20px;padding:7px 12px;color:var(--blue);font-weight:700}.scale-note{font-size:9px;color:var(--muted)}.zoom-controls{position:absolute;bottom:91px;right:20px;display:flex;gap:6px}.zoom-controls button{width:32px;height:32px;border:1px solid var(--line);border-radius:9px;background:#fff;font-size:18px}.playback{display:flex;align-items:center;gap:10px;border-top:1px solid #dce5fc;padding:17px 22px;background:#f5f7ff}.playback button{font-size:11px;border:1px solid var(--line);border-radius:20px;background:#fff;padding:10px 14px;cursor:pointer}.playback .play-button{background:var(--blue);color:#fff;border-color:var(--blue);min-width:90px}.playback label{margin-left:auto;font-size:10px;color:var(--muted);white-space:nowrap}.playback select{font:inherit;color:#23335b;background:#fff;border:1px solid var(--line);border-radius:7px;padding:6px}.orbit-controls{border:1px solid var(--line);border-radius:24px;background:#fff;padding:25px}.control-title{display:flex;gap:10px;align-items:center}.control-title h2{font-size:15px}.step-label{display:grid;place-items:center;width:27px;height:27px;border-radius:9px;background:var(--blue);font-size:11px;color:#fff}.control-note{font-size:10px;color:var(--muted);line-height:1.8;margin:15px 0 25px}.slider-label{display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:12px;font-weight:700;margin-top:24px}.slider-label output{font-size:11px;color:var(--blue);font-weight:600}.orbit-controls input[type=range]{display:block;width:100%;margin:16px 0 7px;accent-color:var(--blue);cursor:pointer}.range-ends{display:flex;justify-content:space-between;font-size:9px;color:var(--muted)}.speed-hint{font-size:10px;line-height:1.9;background:#f5f7fb;padding:12px;border-radius:10px;margin:18px 0}.display-options{display:flex;flex-wrap:wrap;gap:12px;font-size:10px;padding-top:12px}.display-options label{display:flex;align-items:center;gap:4px}.display-options input{accent-color:var(--blue)}.vector-key{display:flex;gap:16px;font-size:10px;margin-top:15px}.vector-key span:first-child{color:#3157ed}.vector-key span:last-child{color:#cf713e}.orbit-readings{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));background:#fff;border:1px solid var(--line);border-radius:18px;margin-top:20px;padding:23px}.orbit-readings>div{padding:0 22px;border-right:1px solid var(--line)}.orbit-readings>div:last-child{border:0}.orbit-readings>div>span{display:block;font-size:10px;color:var(--muted);margin-bottom:8px}.orbit-readings strong{font-size:27px;font-weight:600}.orbit-readings small{font-size:11px;font-weight:500;color:var(--muted)}.orbit-status{min-height:2em;font-size:11px;color:var(--muted);line-height:1.8;margin:13px 4px}.orbit-experiments{margin:48px 0 30px}.preset-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.preset{font:inherit;text-align:left;color:inherit;border:1px solid var(--line);border-radius:17px;background:#fff;padding:22px 19px;cursor:pointer;display:flex;flex-direction:column;align-items:start;gap:10px;transition:transform .15s}.preset:hover{transform:translateY(-3px)}.preset.active{outline:2px solid var(--blue);outline-offset:-2px;background:#edf2ff}.preset-icon{font-size:32px;color:var(--blue);height:42px}.ellipse-icon{transform:scaleX(1.5);transform-origin:left}.preset strong{font-size:13px}.preset>span:not(.preset-icon){font-size:10px;line-height:1.8;color:var(--muted)}.preset small{font-size:10px;margin-top:auto;color:var(--blue);padding-top:10px}.orbit-discovery{display:grid;grid-template-columns:1.5fr 1fr;gap:35px;background:#fff7df;border-radius:22px;padding:34px 38px;margin:0 0 50px}.orbit-discovery .eyebrow{margin-bottom:12px}.orbit-discovery h2{font-size:21px}.orbit-discovery p{font-size:12px;color:#6d6554;line-height:2;margin:12px 0 0}.orbit-units{border-left:1px solid #e9dfc5;padding-left:30px}.orbit-units strong{font-size:12px}.orbit-units p{font-size:11px}.gravity-main button:focus-visible,.gravity-main input:focus-visible,.gravity-main select:focus-visible{outline:3px solid var(--blue);outline-offset:4px}.gravity-main button:disabled{opacity:.5;cursor:default}@media(max-width:950px){.orbit-lab{grid-template-columns:minmax(0,1fr) 270px}.orbit-controls{padding:20px}.orbit-readings>div{padding:0 12px}.intro-equation{width:180px;height:180px}.preset-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.playback{flex-wrap:wrap;padding:14px}.playback label{margin-left:0}.orbit-discovery{gap:22px;padding:28px}.orbit-discovery h2{font-size:18px}}@media(max-width:700px){.gravity-intro{margin:18px 0 28px}.gravity-intro h1{font-size:32px}.gravity-intro .eyebrow{font-size:9px}.intro-equation{display:none}.back-link{font-size:9px}.orbit-lab{grid-template-columns:1fr;gap:15px}#orbit-canvas{height:340px}.stage-heading{padding:20px;font-size:9px}.stage-overlay{left:18px;right:18px}.playback{gap:8px}.playback button{padding:10px 12px}.playback label{margin-left:auto;font-size:9px}.orbit-controls{padding:23px}.control-note{margin-bottom:15px}.slider-label{margin-top:22px}.orbit-readings{grid-template-columns:repeat(2,minmax(0,1fr));padding:6px 15px}.orbit-readings>div{padding:16px 10px}.orbit-readings>div:nth-child(2){border:0}.orbit-readings>div:nth-child(-n+2){border-bottom:1px solid var(--line)}.orbit-readings strong{font-size:25px}.orbit-status{font-size:10px}.orbit-experiments{margin-top:32px}.preset-grid{gap:10px}.preset{padding:18px 14px}.preset strong{font-size:12px}.orbit-discovery{grid-template-columns:1fr;padding:24px;gap:22px;margin-bottom:35px}.orbit-discovery h2{font-size:18px}.orbit-discovery p{font-size:11px}.orbit-units{border-left:0;border-top:1px solid #e9dfc5;padding:20px 0 0}.zoom-controls{bottom:90px}}