/* piR2 — clean light template */
:root{
  --bg:#ffffff;
  --bg-alt:#f7f8fa;
  --panel:#ffffff;
  --ink:#111418;        /* headings */
  --text:#2b3038;       /* body */
  --dim:#333b45;        /* secondary */
  --faint:#9aa3ae;      /* tertiary */
  --line:#e9ecf1;
  --line2:#dde2e9;
  --accent:#0e9e8f;     /* brand teal */
  --accent-d:#0a7d72;
  --accent-soft:#e7f6f3;
  --fast:#2f6df0;       /* proprioception (method only) */
  --slow:#e0568f;       /* vision/language (method only) */
  --good:#0e9e8f; --bad:#c2452f;
  --mono:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,monospace;
  --sans:'Inter',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  --maxw:1000px;
  --shadow:0 1px 2px rgba(16,24,40,.04),0 6px 24px rgba(16,24,40,.06);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);
  font-size:17px;line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
a:hover{color:var(--accent-d)}
h1,h2,h3{color:var(--ink);line-height:1.12;letter-spacing:-.022em;font-weight:700;margin:0}
h2{font-size:clamp(23px,3.0vw,32px)}
h3{font-size:19px;letter-spacing:-.01em}
section{padding:58px 0;border-top:1px solid var(--line)}
section.alt{background:var(--bg-alt);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.rollblock .gv{max-width:920px;margin:0 auto 22px}
.rollblock .gv .lab{font-family:var(--mono);font-size:17px;font-weight:600;color:var(--dim);margin-bottom:8px}
.rollblock .gv.ours .lab{color:var(--accent);font-weight:700}
.rollblock .gv video{width:100%;display:block;border:1px solid var(--line);border-radius:10px;background:#000}
.rollblock .gv.ours video{border:2px solid var(--accent)}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.eyebrow{font-family:var(--mono);font-size:13px;letter-spacing:.16em;text-transform:uppercase;color:var(--accent);margin:0 0 14px;font-weight:700}
.lead{color:var(--dim);font-size:18px;max-width:740px;margin:14px 0 0}
.mono{font-family:var(--mono)}
.center{text-align:center}
.jump{text-decoration:none;border-bottom:1px dotted currentColor;font-weight:600}
.jump:hover{opacity:.65}
.center .lead{margin-left:auto;margin-right:auto}

/* nav */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:22px;height:60px}
.nav .brand{font-weight:800;letter-spacing:-.03em;color:var(--ink);font-size:18px}
.nav .brand b{color:var(--accent)}
.nav .links{margin-left:auto;display:flex;gap:24px;font-size:14.5px}
.nav .links a{color:var(--dim);font-weight:500}
.nav .links a:hover{color:var(--ink)}
.nav-actions{margin-left:22px;display:flex;gap:8px}
.navbtn{font-size:13.5px;font-weight:600;padding:7px 14px;border-radius:8px;border:1px solid var(--line2);color:var(--ink);background:#fff;transition:.15s}
.navbtn:hover{border-color:var(--accent);color:var(--accent)}
@media(max-width:760px){.nav .links{display:none}}

@media(max-width:520px){.nav-actions{display:none}}

/* hero */
.hero{padding:60px 0 20px;text-align:center}
#teaser{padding-top:18px;border-top:none}
.hero .lead{margin-left:auto;margin-right:auto;text-align:justify;text-align-last:left;hyphens:auto}
.badges{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin-bottom:26px}
.badge{font-family:var(--mono);font-size:12px;padding:5px 12px;border:1px solid var(--line2);border-radius:999px;color:var(--dim)}
.title{font-size:clamp(40px,7vw,72px);letter-spacing:-.04em;margin:0}
.title b{color:var(--accent);font-weight:inherit}
.title .pi{color:var(--ink)}
.brandrow{display:flex;flex-direction:row;align-items:center;justify-content:center;gap:16px}
.hero-wave{display:block;margin:0;width:190px;height:60px;flex:0 0 auto}
.wave-cap{margin:4px 0 0;font-size:12px;color:var(--faint);letter-spacing:.02em}
.wave-cap .wd{display:inline-block;width:9px;height:9px;border-radius:2px;margin:0 4px 0 8px;vertical-align:middle}
.wave-cap .wd:first-child{margin-left:0}
.subtitle{font-size:clamp(22px,3.2vw,32px);color:var(--ink);font-weight:600;margin:10px 0 0}
.authors{color:var(--ink);font-size:17px;font-weight:500;margin:16px 0 0}
.authors a{color:var(--ink);text-decoration:none}
.authors a:hover{color:var(--accent-d)}
.affil{color:var(--dim);font-size:14.5px;margin:1px 0 0}
.authors .mono{color:var(--faint)}
.cta{display:flex;gap:12px;flex-wrap:wrap;justify-content:center;margin-top:18px}
.btn{display:inline-flex;align-items:center;gap:8px;font-size:14px;font-weight:600;
  padding:11px 20px;border-radius:10px;border:1px solid var(--line2);color:var(--ink);background:#fff;transition:.15s}
.btn:hover{border-color:var(--accent);color:var(--accent)}
.btn.primary{background:var(--accent);color:#fff;border-color:var(--accent)}
.btn.primary:hover{background:var(--accent-d);color:#fff}

/* stat row */
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;max-width:660px;margin:26px 0 0}
.stat .n{font-family:var(--mono);font-size:30px;font-weight:700;color:var(--ink)}
.stat .n span{color:var(--accent)}
.stat .l{color:var(--dim);font-size:13px;margin-top:2px}
@media(max-width:680px){.stats{grid-template-columns:repeat(2,1fr)}}

/* panel / cards */
.panel{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:22px;box-shadow:var(--shadow)}
.callout{background:#f1f8f6;border:1px solid #d3e7e1;border-left:4px solid var(--accent);border-radius:12px;padding:18px 22px;font-size:16.5px;line-height:1.65;color:var(--text)}
.overview{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:22px}
@media(max-width:680px){.overview{grid-template-columns:1fr}}
.ov{display:flex;gap:16px;align-items:flex-start;border-radius:14px;padding:22px 24px;font-size:17px;line-height:1.6;color:var(--text);text-decoration:none;transition:.15s}
.ov:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.ov-fast{background:#eaf1ff;border:1px solid #cfe0ff} .ov-acc{background:var(--accent-soft);border:1px solid #bfe7e0}
.ovn{flex:none;width:36px;height:36px;border-radius:50%;background:var(--fast);color:#fff;font:700 18px ui-monospace,monospace;display:flex;align-items:center;justify-content:center}
canvas{display:block;width:100%;border-radius:12px;background:var(--bg-alt)}
.controls{display:flex;align-items:center;gap:22px;flex-wrap:wrap;margin-top:18px;font-family:var(--mono);font-size:13px;color:var(--dim)}
.controls .ctl{display:flex;align-items:center;gap:10px}
.controls input[type=range]{accent-color:var(--accent);width:160px}
.controls .val{color:var(--accent);font-weight:700;min-width:18px;text-align:center}
.btn-sm{font-family:var(--mono);font-size:13px;padding:7px 14px;border-radius:8px;border:1px solid var(--line2);background:#fff;color:var(--ink);cursor:pointer}
.btn-sm:hover{border-color:var(--accent)}
.btn-sm.paused{color:var(--accent);border-color:var(--accent)}
.seg{display:inline-flex;gap:4px;padding:4px;background:var(--bg-alt);border:1px solid var(--line);border-radius:10px;margin-bottom:16px}
.segbtn{font-family:var(--mono);font-size:16px;padding:8px 14px;border:1.5px solid transparent;border-radius:8px;background:transparent;color:var(--dim);cursor:pointer;font-weight:600}
.segbtn.active{background:#fff;color:var(--ink);border-color:currentColor;box-shadow:0 2px 7px rgba(16,24,40,.14)}
.segbtn:hover{color:var(--ink)}
.legend{display:flex;gap:18px;flex-wrap:wrap;margin-top:14px;font-family:var(--mono);font-size:13px;color:var(--dim)}
.legend .k{display:inline-flex;align-items:center;gap:7px}
.dot{width:10px;height:10px;border-radius:3px;display:inline-block}

.cards{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:28px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:var(--shadow)}
.card .tag{font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;font-weight:600}
.card.fast .tag{color:var(--fast)} .card.slow .tag{color:var(--slow)}
.card h3{margin:8px 0 0} .card p{color:var(--dim);font-size:15px;margin:10px 0 0}
@media(max-width:680px){.cards{grid-template-columns:1fr}}
.cards.three{grid-template-columns:repeat(3,1fr)}
@media(max-width:760px){.cards.three{grid-template-columns:1fr}}

/* delay explorer — video-forward */
.explorer{display:grid;grid-template-columns:1fr;gap:20px;margin-top:24px}
.vidwrap{background:#0d1016;border:1px solid var(--line2);border-radius:14px;overflow:hidden;position:relative;aspect-ratio:16/9;display:flex;align-items:center;justify-content:center}
.vidwrap video{width:100%;display:block;transition:opacity .3s ease}
.vidwrap video.switching{opacity:.35}
.vidwrap .ph{color:#8b97a7;font-family:var(--mono);font-size:13px;text-align:center;padding:24px;line-height:1.8}
.explorer-2{display:grid;grid-template-columns:1.4fr 1fr;gap:20px;align-items:start}
@media(max-width:820px){.explorer-2{grid-template-columns:1fr}}
.pgrid{display:block}
.pgrid .vidwrap{max-width:720px;margin:0 auto 18px}
#proprio-canvas{cursor:ew-resize}
.readout{font-family:var(--mono);font-size:14px;color:var(--dim);margin-bottom:12px}
.readout b{color:var(--ink)}

/* tasks */
.tabs{display:flex;gap:8px;margin:8px 0 22px;flex-wrap:wrap}
.tab{font-family:var(--mono);font-size:13px;padding:8px 16px;border-radius:999px;border:1px solid var(--line2);background:#fff;color:var(--dim);cursor:pointer}
.tab.active{background:var(--ink);color:#fff;border-color:var(--ink)}
.taskgrid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;max-width:820px;margin:0 auto}
.cmpwide{width:min(1120px,94vw);margin-left:50%;transform:translateX(-50%)}
.cmpdesc{max-width:1080px;margin:0 auto 10px;text-align:center;color:var(--dim);font-size:16.5px;font-family:var(--sans)}
.cmplegend{text-align:center;margin:0 0 14px;font:600 14px var(--mono);color:var(--dim)}
.cmplegend .sw{display:inline-block;width:20px;vertical-align:middle;margin:0 6px 0 16px}
.cmpgrid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.cmpgrid .cell{background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow)}
.cmpgrid .cell.ours{border-color:var(--accent)}
.cmpgrid .cell video{width:100%;display:block;background:#fff;cursor:ew-resize}
.cmpgrid .cell .lab{font-family:var(--mono);font-size:13.5px;padding:9px 10px;color:var(--dim);text-align:center}
.cmpgrid .cell.ours .lab{color:var(--accent);font-weight:700}
@media(max-width:640px){.cmpgrid{grid-template-columns:1fr}}
@media(max-width:640px){.tabs .rtbadge{margin-left:0!important}}   /* wrapped tabs: let the badge flow instead of being auto-pushed */
.failgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:18px 0 0}
@media(max-width:760px){.failgrid{grid-template-columns:1fr}}
.teasergrid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;max-width:1000px;margin:0 auto}
.tcell{position:relative;border-radius:12px;overflow:hidden;background:#0d1016;aspect-ratio:1536/1080;border:1px solid var(--line2)}
.tcell video{width:100%;height:100%;object-fit:cover;display:block}
.tlab{position:absolute;left:8px;top:8px;font:600 12px ui-monospace,monospace;color:#fff;background:rgba(0,0,0,.55);padding:3px 8px;border-radius:6px;z-index:2}
.tlab.zoom{left:auto;right:8px;top:8px;background:rgba(14,158,143,.9)}
#teaser-reel{width:100%;height:100%;object-fit:cover;display:block;transition:transform .45s ease}
.reel-sub{position:absolute;left:50%;transform:translateX(-50%);bottom:12px;z-index:2;max-width:calc(100% - 24px);white-space:nowrap;background:rgba(255,255,255,.93);border-radius:11px;padding:10px 20px;text-align:center;color:var(--dim);font:600 18px Inter,sans-serif;box-shadow:0 2px 8px rgba(0,0,0,.18)}
.reel-sub b{color:var(--accent-d);font-weight:800}
@media(max-width:760px){.teasergrid{grid-template-columns:1fr}}
@media(max-width:560px){.taskgrid{grid-template-columns:1fr}}
.vcell{background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow)}
.vcell.ours{border-color:var(--accent)}
.vcell{position:relative}
.vcell video{width:100%;display:block;background:#000}
.taskgrid.uniform .vcell video{aspect-ratio:1536/1080;object-fit:cover}
.taskgrid:not(.uniform) .vcell video{aspect-ratio:1536/1080}
/* outcome shown only near clip end (.show added by JS) */
.vcell.gate.show{border-width:3px}
.vcell.gate.show.res-no{border-color:#ff4d63} .vcell.gate.show.res-ok{border-color:#16cdb5}
.sbadge{position:absolute;top:10px;right:10px;width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;font:700 22px ui-monospace,monospace;color:#fff;box-shadow:0 2px 6px rgba(0,0,0,.3);z-index:2;opacity:0;transition:opacity .25s}
.vcell.show .sbadge{opacity:1}
.sbadge.ok{background:#0e9e8f} .sbadge.no{background:#d8344f}
/* custom fullscreen button (keeps DOM overlays visible in fullscreen) */
.fsbtn{position:absolute;bottom:8px;right:8px;width:30px;height:30px;border-radius:7px;border:0;background:rgba(17,20,24,.6);color:#fff;font-size:15px;cursor:pointer;z-index:3;opacity:0;transition:opacity .15s}
.gvid:hover .fsbtn,.vcell:hover .fsbtn{opacity:1}
.gvid:fullscreen,.vcell:fullscreen{background:#000;width:100vw;height:100vh}
.gvid:fullscreen video,.vcell:fullscreen video{width:100vw;height:100vh;object-fit:fill}
.gvid:fullscreen .grid-badges{inset:0}
.vcell:fullscreen .lab{position:absolute;bottom:14px;left:0;right:0;z-index:3}
/* per-tile badges over a 5x4 rollout grid */
.gvid{position:relative;line-height:0}
.grid-badges{position:absolute;inset:0;display:grid;grid-template-columns:repeat(5,1fr);grid-template-rows:repeat(4,1fr);pointer-events:none;border-radius:10px;overflow:hidden;opacity:0;transition:opacity .3s}
.grid-badges.show{opacity:1}
.gb{display:flex;align-items:flex-start;justify-content:flex-end;padding:4px;box-sizing:border-box}
.gb.ok{background:rgba(14,158,143,0.12)} .gb.no{background:rgba(216,52,79,0.16)}
.gb span{width:24px;height:24px;border-radius:50%;display:flex;align-items:center;justify-content:center;font:700 15px ui-monospace,monospace;color:#fff;box-shadow:0 1px 3px rgba(0,0,0,.4)}
.gb.ok span{background:#0e9e8f} .gb.no span{background:#d8344f}
.vcell .lab{font-family:var(--mono);font-size:13.5px;padding:10px 10px;color:var(--dim);text-align:center}
.vcell.ours .lab{color:var(--accent);font-weight:700}
.taskdesc{color:var(--ink);font-size:16px;margin:0 0 8px;font-weight:700}
.rtbadge{display:inline-block;font:700 12.5px var(--mono);color:var(--accent);background:rgba(14,158,143,.1);border:1px solid rgba(14,158,143,.32);border-radius:999px;padding:4px 11px;letter-spacing:.02em}

/* matrix */
table.matrix{width:100%;border-collapse:collapse;font-size:14px;margin-top:18px;background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}
table.matrix th,table.matrix td{padding:13px 12px;border-bottom:1px solid var(--line);text-align:center}
table.matrix tr:last-child td{border-bottom:none}
table.matrix th{font-family:var(--mono);font-size:11.5px;color:var(--dim);font-weight:600;text-transform:uppercase;letter-spacing:.04em;background:var(--bg-alt)}
table.matrix td:first-child,table.matrix th:first-child{text-align:left;color:var(--ink)}
table.matrix tr.ours{background:var(--accent-soft)}
table.matrix tr.ours td:first-child{color:var(--accent-d);font-weight:700}
.yes{color:var(--good);font-weight:700}.no{color:var(--faint)}

footer{padding:48px 0;border-top:1px solid var(--line);color:var(--faint);font-size:14px;text-align:center}
.cite{background:var(--bg-alt);border:1px solid var(--line);border-radius:12px;padding:16px 18px;font-family:var(--mono);font-size:12.5px;color:var(--text);white-space:pre-wrap;overflow:auto;text-align:left}
.note{font-family:var(--sans);font-size:15px;color:var(--dim);margin-top:10px;line-height:1.6}

@media(max-width:560px){.hero-wave{width:96px}.brandrow{gap:6px}}

/* mobile: let grid/flex children shrink and wrap long strings */
.explorer-2>*,.explorer>*{min-width:0}
.vidwrap .ph{overflow-wrap:anywhere;word-break:break-word}
.controls input[type=range]{max-width:100%}
@media(max-width:520px){.controls{gap:12px}}

/* mobile: keep wide canvas diagrams legible by scrolling them horizontally
   instead of shrinking to unreadable, and stack the inference-mode toggle */
.hscroll{overflow-x:auto;overflow-y:hidden;-webkit-overflow-scrolling:touch;max-width:100%;border-radius:12px}
.hscroll>canvas{border-radius:12px}
@media(max-width:600px){
  /* give each wide diagram a comfortable render width and scroll it horizontally */
  #vla-canvas,#m1-canvas{min-width:820px}      /* inference pipeline: 4 boxes + labels */
  #m2-canvas{min-width:660px}                  /* latency-adaptive staircase */
  #results-canvas{min-width:660px}             /* results bar chart */
  .hswide{min-width:900px}                      /* proprioception + GT-action plot */
  #flow-seg{flex-direction:column;align-items:stretch;gap:8px}
  #flow-seg .segbtn{width:100%;margin-left:0!important;border:1.5px solid var(--line);border-radius:10px}
  #flow-seg .segbtn.active{border-color:currentColor}
}

/* Comparison/grid videos are encoded much larger than they're displayed (~4x),
   so the browser's software downscale shimmers on motion. Promote each to its own
   GPU layer so scaling is done on the GPU (smoother, less shimmer). */
.vcell video, .rollblock .gv video, .vidwrap video, .taskgrid video, .gv video { transform: translateZ(0); backface-visibility: hidden; }

/* delay/sim plot: draw straight on the white panel (no grey canvas box) */
#delay-canvas{background:transparent}

/* teaser reel phase headline (failures -> ours) */
.reel-phase{font-size:clamp(19px,2.5vw,27px);font-weight:700;letter-spacing:-.01em}