@font-face {
  font-family: "Noto Sans";
  font-style: normal;
  font-weight: 400 650;
  font-display: swap;
  src: url("assets/fonts/noto-sans-latin-wght.woff2") format("woff2");
}

:root {
  --ink: #282b2a;
  --muted: #6b716e;
  --line: #e4e7e5;
  --accent: #286454;
  --body: "Noto Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 32px; }
body { margin: 0; background: #fff; color: var(--ink); font-family: var(--body); line-height: 1.7; -webkit-font-smoothing: antialiased; }
button, select { font: inherit; }
button, summary { cursor: pointer; }
button, a, select { -webkit-tap-highlight-color: transparent; }
a { color: inherit; }
button:focus-visible, a:focus-visible, select:focus-visible, summary:focus-visible, [tabindex]:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
button:disabled { cursor: default; opacity: .55; }
img, video { max-width: 100%; display: block; }
figure { margin: 0; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { line-height: 1.25; font-weight: 600; }
h2 { font-size: 2.1rem; letter-spacing: -.8px; margin-bottom: 0; }
h3 { font-size: 1.4rem; letter-spacing: -.35px; }
p { margin-bottom: 20px; }
strong { font-weight: 600; }
.muted, .mono { color: var(--muted); }
.accent { color: var(--accent); }
.mono, .caption, figcaption { font-size: .83rem; }
.eyebrow { font-size: .8rem; color: var(--muted); margin-bottom: 8px; }
.caption, figcaption { color: var(--muted); line-height: 1.65; }
figcaption { margin: 18px auto 0; text-align: center; max-width: 860px; }
.skip-link { position: fixed; top: -100px; left: 20px; padding: 12px; background: white; z-index: 100; }
.skip-link:focus { top: 10px; }
[hidden] { display: none !important; }

/* Full-viewport motion, with a quiet title and navigation over the footage. */
.hero { height: 100svh; min-height: 580px; position: relative; isolation: isolate; overflow: hidden; background: #202322; color: #fff; }
.hero-viewport, .hero-shade { position: absolute; inset: 0; }
.hero-viewport { z-index: -2; }
.hero-video { width: 100%; height: 100%; object-fit: cover; object-position: center; filter: blur(2px); }
.hero-shade { z-index: -1; background: linear-gradient(180deg, #10171375 0%, #10171342 38%, #10171305 66%, #101713a8 100%); pointer-events: none; }
.hero-top { display: flex; justify-content: space-between; align-items: center; gap: 30px; padding: 28px 42px; }
.wordmark { text-decoration: none; font-size: 1.12rem; font-weight: 650; letter-spacing: -.4px; }
.toc { display: flex; flex-wrap: wrap; gap: 26px; }
.toc a { text-decoration: none; font-size: .83rem; color: #ffffffe0; padding: 3px 0; border-bottom: 1px solid transparent; }
.toc a:hover, .toc a.active { color: white; border-bottom-color: white; }
.hero-content { position: absolute; top: 17%; left: 24px; right: 24px; text-align: center; text-shadow: 0 2px 25px #0003; }
.hero h1 { font-size: clamp(4.5rem, 8.1vw, 7.8rem); letter-spacing: -4.5px; line-height: 1.08; margin: 0 0 20px; font-weight: 650; }
.hero-subtitle { font-size: clamp(1.35rem, 2.2vw, 2rem); line-height: 1.4; font-weight: 400; margin: 0 auto 20px; }
.hero-authors { display: flex; justify-content: center; flex-wrap: wrap; gap: 6px 20px; font-size: 1.05rem; line-height: 1.6; margin: 0 0 8px; }
.hero-authors > span { white-space: nowrap; }
.hero-credits sup { font-size: .7em; line-height: 0; vertical-align: super; }
.hero-affiliations { font-size: .95rem; line-height: 1.6; color: #ffffffd9; margin: 0; }
.hero-resources { display: flex; justify-content: center; flex-wrap: wrap; gap: 10px; margin: 22px auto 0; }
.hero-resource { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 7px 18px; border: 1px solid #ffffff80; border-radius: 999px; background: #ffffffed; color: var(--ink); font-size: .95rem; font-weight: 500; line-height: 1.4; text-decoration: none; text-shadow: none; box-shadow: 0 2px 12px #00000012; }
.hero-resource svg { width: 20px; height: 20px; flex: none; }
.hero-resource small { display: block; font-size: .65rem; font-weight: 400; line-height: 1.2; color: var(--muted); }
a.hero-resource:hover { background: #fff; border-color: #fff; }
.hero-bottom { position: absolute; left: 42px; right: 42px; bottom: 30px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: end; gap: 24px; }
.hero-caption { font-size: .8rem; line-height: 1.8; }
.hero-caption > span { color: #ffffffa8; font-size: .72rem; }
.hero-scroll { text-decoration: none; text-align: center; font-size: .8rem; }
.hero-scroll span { display: block; font-size: 1.4rem; line-height: 1.6; }
#hero-toggle { justify-self: end; align-self: end; color: #fff; font-size: .78rem; padding: 7px 15px; background: #ffffff0d; border: 1px solid #ffffff66; border-radius: 30px; }
#hero-toggle:hover { background: #ffffff24; }
.hero-viewport > .hero-media-error { position: absolute; inset: 0; border: 0; border-radius: 0; background: #202322; color: #d5dad7; padding-top: 40vh; }
.hero a:focus-visible, .hero button:focus-visible { outline-color: white; }

/* Research sections use centered headings, readable copy, and wide figures. */
.container { width: min(1100px, calc(100% - 64px)); margin: 0 auto; }
.section { padding: 64px 0; border-bottom: 1px solid var(--line); }
.section:last-child { border-bottom: 0; }
.section-heading { text-align: center; margin-bottom: 24px; }
.section-intro { font-size: 1.05rem; line-height: 1.85; max-width: 900px; margin: 0 auto 32px; }
.section-intro { color: #525955; }
.centered { text-align: center; }
.abstract-section { padding: 72px 0; }
.abstract-copy { font-size: 1rem; line-height: 1.6; max-width: 840px; margin: 0 auto; text-align: justify; hyphens: auto; }
.abstract-copy p:last-child { margin-bottom: 0; }
.method-part > h2 { text-align: center; margin: 0 0 24px; }
.method-part + .method-part { margin-top: 60px; }
.design-example { max-width: 1040px; margin: 28px auto 32px; }
.design-example-block { display: grid; grid-template-columns: minmax(0, 3fr) minmax(0, 7fr); border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.design-example h3 { font-size: 1rem; text-align: center; margin: 0 0 14px; }
.design-input, .design-output { min-width: 0; padding: 20px; }
.design-input { border-right: 1px solid var(--line); }
.design-input > img { width: 100%; height: 190px; object-fit: contain; }
.design-tasks { margin: 16px 0 0; font-size: .86rem; line-height: 1.6; }
.design-tasks > div + div { margin-top: 12px; }
.design-tasks dt { font-weight: 600; margin-bottom: 4px; }
.design-tasks dd { margin: 0; color: var(--muted); }
.design-output { display: flex; flex-direction: column; background: #f0f3f0; }
.design-output model-viewer { flex: 1; min-height: 300px; }
model-viewer { display: block; width: 100%; height: 340px; background: #f0f3f0; border-radius: 5px; --poster-color: #f0f3f0; }
.model-status { position: absolute; bottom: 14px; left: 14px; right: 14px; padding: 9px 12px; margin: 0; background: #fffffff0; border-radius: 4px; color: var(--muted); font-size: .8rem; text-align: center; }
.model-status[hidden] { display: none; }
.model-controls { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 4px 16px; margin-top: 10px; }
.model-controls .caption, .model-controls .text-button { font-size: .78rem; }
.design-example > figcaption { max-width: 940px; text-align: left; }
.design-metrics { max-width: 940px; margin: 0 auto; font-size: 1rem; line-height: 1.75; color: #525955; }
.design-metrics > p { margin-bottom: 14px; }
.design-metrics > p > strong { color: var(--ink); }
.design-figure { max-width: 1040px; margin: 36px auto 0; }
.design-figure img { width: 100%; height: auto; }
.metric-definitions { list-style: none; margin: 0; padding: 0; }
.metric-definitions li { position: relative; padding-left: 20px; }
.metric-definitions li + li { margin-top: 8px; }
.metric-definitions li::before { content: "-"; position: absolute; left: 0; color: var(--ink); }
.metric-definitions strong { color: var(--ink); }
.method-figure { max-width: 920px; margin: 36px auto 0; }
.method-figure img { width: 100%; height: auto; }
.evidence-note { color: var(--muted); font-size: .8rem; line-height: 1.75; margin: 26px auto 0; max-width: 940px; }

/* Shared video cards and reference-case controls. */
.chip { flex: 1; min-width: 0; border: 1px solid transparent; border-radius: 6px; background: transparent; color: #626864; padding: 8px 16px; min-height: 40px; font-size: .88rem; }
.chip.active { background: #fff; color: var(--accent); border-color: #dce3de; box-shadow: 0 1px 3px #18251d0a; font-weight: 600; }
.chip:hover:not(.active) { background: #e8ece9; color: var(--ink); }
.two-video-grid, .baseline-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 36px 28px; }
.text-button { color: var(--accent); background: none; border: 0; padding: 6px 0; font-size: .87rem; text-decoration: none; }
.text-button:hover { text-decoration: underline; text-underline-offset: 4px; }
.loading-message { color: var(--muted); }
.load-error { padding: 18px; background: #f6f2ed; color: #7b4426; font-size: .9rem; }
.video-card { min-width: 0; }
.video-card-header { position: relative; display: flex; justify-content: center; align-items: baseline; flex-wrap: wrap; gap: 8px 12px; font-size: 1.08rem; font-weight: 500; margin-bottom: 10px; }
.video-card.featured .video-card-header > span:first-child { color: var(--accent); font-weight: 600; }
.video-tag { font-size: .76rem; font-weight: 400; color: var(--muted); }
.video-frame { position: relative; aspect-ratio: 16/9; background: #f1f3f1; border-radius: 5px; overflow: hidden; }
.video-frame video { width: 100%; height: 100%; object-fit: contain; }

/* Paired execution, references, and baseline comparisons share one video layout. */
.robot-tabs { display: flex; justify-content: center; gap: 4px; width: 440px; max-width: 100%; padding: 4px; margin: 0 auto 24px; background: #f2f4f2; border: 1px solid #e7ebe7; border-radius: 10px; }
.refinement-row + .refinement-row { margin-top: 36px; padding-top: 36px; border-top: 1px solid var(--line); }
.case-heading h3 { font-size: 1.25rem; text-align: center; margin-bottom: 14px; }
.task-prompt { font-size: .94rem; color: var(--muted); max-width: 850px; text-align: center; margin: 0 auto 20px; }
.playback-toolbar { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-top: 12px; }
.playback-buttons { display: flex; gap: 4px; flex-shrink: 0; }
.small-button { padding: 7px 12px; min-height: 36px; font-size: .8rem; border: 1px solid transparent; border-radius: 6px; background: transparent; color: #626864; }
.small-button[data-action="play"], .small-button[data-action="pause"] { background: #f2f4f2; color: var(--ink); }
.small-button:hover { background: #e8ece9; color: var(--ink); }
.playback-toolbar > .caption { text-align: right; font-size: .76rem; }
.playback-status { font-size: .84rem; color: var(--accent); margin: 10px 0 0; }
.playback-status:empty { display: none; }
.case-explanation { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; margin-top: 20px; }
.case-explanation .mono { font-size: .9rem; font-weight: 600; color: var(--ink); }
.case-explanation .accent { color: var(--accent); }
.case-explanation p { font-size: .92rem; color: #565e58; margin: 8px 0 0; }
#skills { width: min(1320px, calc(100vw - 64px)); position: relative; left: 50%; transform: translateX(-50%); }
#skills > .section-intro { margin-bottom: 24px; }
.comparison-skill > h4 { font-size: 1.08rem; font-weight: 600; text-align: center; margin: 0 0 10px; }
.comparison-skill .task-prompt { font-size: .86rem; margin-bottom: 20px; }
.baseline-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.baseline-grid .video-frame { aspect-ratio: 4/3; }
.baseline-grid .video-card-header { font-size: .94rem; min-height: 32px; align-items: center; padding: 0 32px; }
.video-expand { position: absolute; right: 0; top: 50%; transform: translateY(-50%); display: grid; place-items: center; width: 32px; height: 32px; padding: 0; border-radius: 6px; color: #79827b; }
.video-expand:hover { background: #f2f4f2; color: var(--accent); }
.video-expand svg { width: 16px; height: 16px; }

/* Assembled robot photograph and physical policy recordings. */
.hardware-overview { max-width: 420px; margin: 28px auto; }
.hardware-portrait img { height: auto; width: 100%; }
.hardware-videos { margin-top: 28px; }
.hardware-videos .video-frame { aspect-ratio: 1; }
.hardware-videos video { object-fit: cover; }
.hardware-walk video { object-position: 12.5% 50%; }
.hardware-wave video { object-position: 33.333333% 50%; }
.hardware-videos .task-prompt { font-size: .86rem; margin: 14px 0 0; }
.media-placeholder { min-height: 235px; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding: 24px; border: 1px dashed #c3cbc5; border-radius: 5px; background: #f7f8f7; color: var(--muted); }
.placeholder-play { font-size: 1.8rem; margin-bottom: 10px; }
.placeholder-label { font-size: .75rem; }
.media-placeholder h3 { font-size: 1.2rem; margin: 10px 0; }
.media-placeholder p { font-size: .85rem; margin: 0; }
.video-frame > .media-placeholder { height: 100%; min-height: 0; border: 0; padding: 14px; }
.video-frame > .media-placeholder .placeholder-play { display: none; }

.footer { width: min(1100px, calc(100% - 64px)); margin: auto; padding: 30px 0; border-top: 1px solid var(--line); display: flex; justify-content: space-between; align-items: center; gap: 25px; font-size: .83rem; color: var(--muted); }
.footer p { margin: 0; }
dialog { width: min(1080px, 94vw); max-height: 92svh; overflow: auto; padding: 25px; border: 0; border-radius: 6px; background: #fff; color: var(--ink); }
dialog::backdrop { background: #111713d9; }
.modal-header { display: flex; justify-content: space-between; align-items: center; gap: 20px; margin-bottom: 18px; }
.modal-header h2 { font-size: 1.7rem; margin-top: 4px; }
.icon-button { width: 38px; height: 38px; display: grid; place-items: center; flex-shrink: 0; border: 1px solid var(--line); border-radius: 50%; background: #fff; color: var(--ink); font-size: 1.5rem; }
.modal-media { background: #f1f3f1; border-radius: 4px; overflow: hidden; }
.modal-media video { width: 100%; max-height: 62svh; aspect-ratio: 16/9; object-fit: contain; }
.modal-media + p { font-size: .92rem; color: var(--muted); margin: 18px 0 8px; }
.noscript-note { padding: 16px; text-align: center; font-size: .85rem; background: #edf3ee; }

@media (min-width: 1600px) { .hero-content { top: 19%; } }
@media (max-width: 1050px) { .baseline-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 26px; } }
@media (max-width: 900px) {
  .hero-top { padding: 24px 28px; gap: 20px; }
  .toc { gap: 16px; }
  .toc a { font-size: .75rem; }
  .hero-bottom { left: 28px; right: 28px; }
  .hero-caption { max-width: 230px; }
  .playback-toolbar { flex-wrap: wrap; gap: 12px; }
  .playback-toolbar > .caption { text-align: left; }
}
@media (max-width: 640px) {
  .hero { min-height: 700px; }
  .hero-top { flex-direction: column; padding: 20px 16px; gap: 10px; }
  .wordmark { font-size: 1rem; }
  .toc { justify-content: center; gap: 5px 15px; max-width: 380px; }
  .toc a { font-size: .7rem; }
  .hero-content { top: 20%; left: 18px; right: 18px; }
  .hero h1 { font-size: clamp(3.3rem, 14vw, 5rem); letter-spacing: -2.5px; margin-bottom: 18px; }
  .hero-subtitle { font-size: 1.08rem; line-height: 1.55; max-width: 350px; }
  .hero-authors { font-size: .88rem; gap: 4px 14px; }
  .hero-affiliations { font-size: .84rem; }
  .hero-resources { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); max-width: 304px; margin-top: 16px; gap: 8px; }
  .hero-resource { padding: 7px 12px; font-size: .9rem; }
  .hero-bottom { left: 22px; right: 22px; bottom: 24px; grid-template-columns: 1fr auto; gap: 22px; }
  .hero-caption { font-size: .72rem; max-width: 220px; }
  .hero-caption > span { font-size: .66rem; }
  .hero-scroll { grid-column: 1 / -1; grid-row: 1; font-size: .75rem; }
  #hero-toggle { font-size: .72rem; padding: 7px 12px; }
  .container, .footer { width: calc(100% - 40px); }
  .section { padding: 52px 0; }
  .section-heading { margin-bottom: 24px; }
  h2 { font-size: 1.8rem; }
  .section-intro { font-size: .97rem; line-height: 1.85; }
  .abstract-copy { text-align: left; }
  .method-part > h2 { margin-bottom: 24px; }
  .method-part + .method-part { margin-top: 48px; }
  .design-example { margin: 30px auto 36px; }
  .design-example-block { grid-template-columns: 1fr; }
  .design-input { border-right: 0; border-bottom: 1px solid var(--line); }
  .design-input > img { height: 200px; }
  .design-output model-viewer { flex: none; min-height: 0; }
  model-viewer { height: 300px; }
  .design-metrics { font-size: .97rem; }
  .method-figure, .design-figure { margin-top: 25px; }
  figcaption { font-size: .77rem; margin-top: 14px; }
  .evidence-note { font-size: .76rem; }
  .two-video-grid, .baseline-grid { grid-template-columns: 1fr; gap: 28px; }
  .chip { flex: 1; min-width: 0; font-size: .78rem; padding: 8px 4px; }
  .robot-tabs { width: 100%; gap: 2px; }
  .small-button { min-height: 44px; }
  .baseline-grid .video-card-header { min-height: 40px; padding: 0 40px; }
  .video-expand { width: 40px; height: 40px; }
  .case-heading h3 { font-size: 1.12rem; }
  .task-prompt { font-size: .88rem; }
  .case-explanation { grid-template-columns: 1fr; gap: 20px; }
  .case-explanation p { font-size: .88rem; }
  #skills { width: 100%; }
  .hardware-overview { margin: 25px auto; }
  .hardware-portrait figcaption { font-size: .75rem; }
  .media-placeholder { min-height: 195px; }
  .footer { align-items: flex-start; font-size: .76rem; }
  .footer p { max-width: 220px; }
  .footer .text-button { white-space: nowrap; font-size: .76rem; }
  dialog { padding: 18px; }
  .modal-header h2 { font-size: 1.4rem; }
}
@media (max-height: 650px) and (min-width: 641px) {
  .hero { min-height: 500px; }
  .hero-content { top: 18%; }
  .hero h1 { font-size: 4.4rem; margin-bottom: 14px; }
  .hero-subtitle { font-size: 1.35rem; margin-bottom: 12px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}