:root{--ink:#101313;--paper:#f2f1ed;--accent:#e84b28;--blue:#2f7cf6;--green:#16a34a;--muted:#9aa3a0;--panel:#151a1a;--line:#2a3131}
*{box-sizing:border-box}
html,body{margin:0}
body.rl{background:#0b0e0e;color:var(--paper);font-family:Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
.rl-top{display:flex;align-items:center;gap:16px;flex-wrap:wrap;padding:12px 18px;border-bottom:1px solid var(--line);background:#0d1111}
.rl-brand{display:flex;align-items:center;gap:8px;color:var(--paper);text-decoration:none;font-weight:700;font-size:14px}
.rl-title{margin:0;font-size:20px;letter-spacing:-.5px}.rl-title b{color:var(--accent)}
.rl-beta{margin-left:8px;font-size:11px;padding:2px 7px;border-radius:999px;background:#2a1a14;color:#ff9a78;vertical-align:middle}
.rl-tabs{display:flex;gap:6px;background:#151a1a;border-radius:999px;padding:4px}
.rl-tabs button{border:0;background:transparent;color:var(--muted);padding:8px 14px;border-radius:999px;font:inherit;font-weight:600;cursor:pointer}
.rl-tabs button.active{background:var(--accent);color:#fff}
.rl-top-actions{margin-left:auto;display:flex;gap:8px;flex-wrap:wrap}
.rl-btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:#151a1a;color:var(--paper);padding:8px 12px;border-radius:10px;font:inherit;font-size:14px;cursor:pointer;text-decoration:none}
.rl-btn:hover{border-color:#4a5555}.rl-btn.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.rl-main{display:grid;grid-template-columns:minmax(0,1fr) 340px;min-height:calc(100vh - 62px)}
.rl-stage{position:relative;min-height:420px;height:calc(100vh - 62px);background:#0d1111}
.rl-stage canvas,#arm3d{position:absolute;inset:0;width:100%;height:100%;touch-action:none;cursor:crosshair}
#arm3d{cursor:grab}#arm3d canvas{display:block}
.rl-hud{position:absolute;left:12px;right:12px;bottom:12px;display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-size:13px;color:#c9cbc6;pointer-events:none}
.rl-hud b{color:var(--accent)}
.rl-hud .warn{background:rgba(255,77,77,.15);color:#ffb3b3;border:1px solid rgba(255,77,77,.35);border-radius:999px;padding:4px 10px}
.rl-panel{background:var(--panel);border-left:1px solid var(--line);padding:18px;overflow:auto;height:calc(100vh - 62px)}
.rl-panel h2{margin:0 0 4px;font-size:18px}.rl-sub{margin:0 0 14px;color:var(--muted);font-size:13px;line-height:1.5}
.rl-seg{display:flex;background:#0d1111;border-radius:12px;padding:4px;margin-bottom:14px}
.rl-seg button{flex:1;border:0;background:transparent;color:var(--muted);padding:8px;border-radius:9px;font:inherit;font-weight:600;cursor:pointer}
.rl-seg button.on{background:#232a2a;color:#fff}
.rl-slider{display:block;margin:10px 0}
.rl-slider span{display:flex;justify-content:space-between;font-size:13px;color:#c9cbc6;margin-bottom:4px}
.rl-slider output{color:#fff;font-variant-numeric:tabular-nums}
.rl-slider input{width:100%;accent-color:var(--accent)}
.rl-row{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.rl-check{display:flex;gap:8px;align-items:center;font-size:13px;color:#c9cbc6;margin:10px 0}
.rl-read{margin:12px 0;padding:10px 12px;border-radius:12px;background:#0d1111;font-size:13px;line-height:1.6;color:#dfe3e1;font-variant-numeric:tabular-nums}
.rl-actions{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0}
.rl-math{margin-top:12px;font-size:13px;color:#c9cbc6;line-height:1.55}
.rl-math summary{cursor:pointer;color:#fff;font-weight:600}
.rl-table{overflow-x:auto}.rl-table table{border-collapse:collapse;width:100%;margin:8px 0}
.rl-table th,.rl-table td{border-bottom:1px solid var(--line);padding:5px 6px;text-align:left}
.rl-fail{position:absolute;inset:0;display:grid;place-items:center;padding:20px;text-align:center;color:#ffb3b3}
.rl-learn{max-width:1100px;margin:0 auto;padding:40px 18px 60px;color:#dfe3e1}
.rl-learn h2{font-size:26px;margin:0 0 16px;color:#fff}
.rl-learn-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px}
.rl-learn-grid section{background:#121717;border:1px solid var(--line);border-radius:18px;padding:18px}
.rl-learn h3{margin:0 0 8px;color:var(--accent);font-size:17px}.rl-learn p{margin:0;line-height:1.6;font-size:15px}
.rl-links{margin-top:20px!important}.rl-learn a{color:#ff9a78}
.rl-autotest{position:fixed;z-index:20;top:8px;left:8px;right:8px;max-height:45vh;overflow:auto;background:#000;color:#9f9;padding:10px;border-radius:10px;font-size:12px;white-space:pre-wrap}
@media(max-width:900px){.rl-main{grid-template-columns:1fr}.rl-stage{height:58vh;min-height:320px}.rl-panel{height:auto;border-left:0;border-top:1px solid var(--line)}.rl-top-actions{margin-left:0}}
.rl-tip{margin:-4px 0 10px;font-size:13px;color:#ffd9c9;background:#2a1a14;border-radius:10px;padding:8px 10px;line-height:1.45}
.rl-seg.small button{padding:6px;font-size:13px}
.rl-hud .ok{background:rgba(22,163,74,.15);color:#b6f0c8;border:1px solid rgba(22,163,74,.35);border-radius:999px;padding:4px 10px}