:root {
  --ink: #363636;
  --muted: #6d6d6d;
  --line: #dddddd;
  --soft: #f6f6f6;
  --paper: #ffffff;
  --link: #3273dc;
  --max: 980px;
  color-scheme: light;
  font-family: "Noto Sans", sans-serif;
  font-synthesis: none;
  scroll-behavior: smooth;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { color: var(--ink); background: var(--paper); font-size: 16px; line-height: 1.6; }
img, video { display: block; width: 100%; }
img { height: auto; }
video { background: #151515; }
figure, h1, h2, h3, p { margin: 0; }
h1, h2, h3 { font-family: "Noto Sans", sans-serif; }
a { color: var(--link); }

.skip-link {
  position: fixed;
  top: -80px;
  left: 16px;
  z-index: 100;
  padding: 10px 14px;
  color: #fff;
  background: #333;
}
.skip-link:focus { top: 12px; }
.section-shell { width: min(var(--max), calc(100% - 48px)); margin: 0 auto; }
.narrow { max-width: 820px; }

.hero { padding: 70px 0 58px; text-align: center; }
.hero h1 {
  max-width: 940px;
  margin: 0 auto;
  font-family: "Google Sans", sans-serif;
  font-size: clamp(34px, 5vw, 48px);
  font-weight: 600;
  letter-spacing: normal;
  line-height: 1.125;
  text-wrap: balance;
}
.hero h1 span { margin-right: .12em; font-size: .82em; }
.authors { margin-top: 24px; font-size: 19px; }
.authors a { text-decoration: none; }
.authors a:hover { text-decoration: underline; }
.affiliation { margin-top: 4px; color: var(--muted); font-size: 15px; }
.hero-actions { display: flex; justify-content: center; gap: 10px; margin-top: 22px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 0 18px;
  border: 0;
  border-radius: 999px;
  color: #fff;
  background: #363636;
  font-size: 16px;
  font-weight: 400;
  text-decoration: none;
  transition: background-color .16s ease, transform .16s ease;
}
.button:hover { background: #111; transform: translateY(-1px); }
.button-icon { width: 17px; height: 17px; flex: 0 0 auto; }
.supplementary-video { margin-top: 34px; scroll-margin-top: 24px; }
.supplementary-video video { aspect-ratio: 16 / 9; object-fit: contain; border-radius: 6px; }
.lead {
  max-width: 760px;
  margin: 28px auto 0;
  color: #505050;
  font-size: 16px;
  line-height: 1.5;
  text-wrap: balance;
}

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px;
  margin-top: 52px;
  text-align: left;
}
.comparison-card { min-width: 0; }
.media-heading { display: flex; align-items: center; justify-content: center; gap: 12px; margin-bottom: 12px; }
.media-heading > div { display: flex; align-items: baseline; gap: 9px; }
.media-heading h2 { font-size: 18px; font-weight: 600; letter-spacing: normal; }
.media-index { display: none; }
.condition-chip {
  padding: 3px 9px;
  border: 1px solid #d1d1d1;
  border-radius: 999px;
  color: #555;
  background: #f7f7f7;
  font-size: 11px;
  font-weight: 700;
}
.condition-chip.neutral { color: #777; }
.condition-chip.feel-chip { color: #8a303a; border-color: #ce9aa4; background: #fbf1f3; }
.comparison-grid, .execution-comparison { position: relative; }
.comparison-grid::before, .execution-comparison::before { content: ""; position: absolute; top: 0; bottom: 0; left: 50%; width: 1px; background: #c8c8c8; }
.comparison-card video { aspect-ratio: 16 / 9; object-fit: cover; border-radius: 6px; }
figcaption { margin-top: 9px; color: var(--muted); font-size: 13px; line-height: 1.5; }

.paper-section { padding: 70px 0; border-top: 1px solid #ececec; scroll-margin-top: 24px; }
.section-heading { margin-bottom: 30px; text-align: center; }
.section-heading > div { display: contents; }
.section-number { display: none; }
.section-heading h2 { font-size: 32px; font-weight: 600; letter-spacing: normal; line-height: 1.2; }
.section-summary { max-width: 760px; margin: 13px auto 0; color: var(--muted); }
.abstract-copy { color: #464646; font-size: 16px; line-height: 1.6; text-align: justify; }

.overview-figure img { width: 100%; height: auto; }
.overview-figure figcaption { text-align: center; }
.overview-interactive { position: relative; isolation: isolate; }
.overview-phase {
  position: absolute;
  top: 0;
  height: 97.991071%;
  width: 31.145833%;
  color: #7d2e3a;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}
.overview-phase-a { left: .3125%; }
.overview-phase-b { left: 34.375%; }
.overview-phase-c { left: 68.4375%; }
/* Match the image's existing frame: x=6/660/1314, y=34, 598×405. */
.overview-phase-frame {
  position: absolute;
  top: 7.744875%;
  left: 0;
  width: 100%;
  height: 92.255125%;
  fill: currentColor;
  fill-opacity: .035;
  stroke: currentColor;
  stroke-width: 5;
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease;
}
.overview-phase-cue {
  position: absolute;
  top: 7.744875%;
  right: 0;
  display: grid;
  place-items: center;
  width: clamp(18px, 2.3vw, 26px);
  aspect-ratio: 1;
  border: 1px solid #e3e3e3;
  border-radius: 50%;
  color: #626262;
  background: #fff;
  box-shadow: 0 2px 6px rgba(0, 0, 0, .07);
  transform: translate(28%, -36%);
  transition: color .18s ease, background-color .18s ease, border-color .18s ease;
}
.overview-phase-cue svg {
  width: 61%;
  height: 61%;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform .18s ease;
}
.overview-phase:is(:hover, :focus-visible) { outline: 0; z-index: 1; }
.overview-phase:is(:hover, :focus-visible) .overview-phase-frame { opacity: 1; }
.overview-phase:is(:hover, :focus-visible) .overview-phase-cue {
  color: #fff;
  background: #7d2e3a;
  border-color: #7d2e3a;
}
.overview-phase:is(:hover, :focus-visible) .overview-phase-cue svg { transform: translate(1px, -1px); }
@media (prefers-reduced-motion: reduce) {
  .overview-phase-frame, .overview-phase-cue, .overview-phase-cue svg { transition: none; }
}

.stage-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin-top: 30px;
}
.stage-link {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-width: 0;
  min-height: 82px;
  padding: 20px 18px;
  border: 1px solid transparent;
  border-radius: 10px;
  color: var(--ink);
  background: #f5f5f5;
  text-decoration: none;
  transition: transform .18s ease, background-color .18s ease, border-color .18s ease, box-shadow .18s ease;
}
.stage-link:hover, .stage-link:focus-visible {
  transform: translateY(-3px);
  border-color: #6f2933;
  color: #fff;
  background: #6f2933;
  box-shadow: 0 5px 14px rgba(75, 25, 35, .18);
}
.stage-link:hover > span, .stage-link:focus-visible > span { color: #6f2933; background: #fff; }
.stage-link > span {
  display: grid;
  place-items: center;
  flex: 0 0 30px;
  height: 30px;
  border-radius: 50%;
  color: #fff;
  background: #555;
  font-size: 13px;
  font-weight: 800;
}
.stage-strip h3 { font-size: 18px; font-weight: 600; line-height: 1.35; }

.method-block { padding: 36px 0 44px; text-align: center; scroll-margin-top: 24px; }
#overview { padding-bottom: 36px; }
#method { padding-top: 36px; border-top: 0; }
#method .method-block:first-child { padding-top: 0; }
.method-block + .method-block { border-top: 1px solid var(--line); }
.method-copy { max-width: 760px; margin: 0 auto 24px; }
.method-copy h2 { font-size: 32px; font-weight: 600; letter-spacing: normal; line-height: 1.2; }
.method-copy > p { max-width: 690px; margin: 13px auto 0; color: var(--muted); }
#data-collection { padding-bottom: 28px; }
#data-collection .method-copy { margin-bottom: 0; }
.method-figure { cursor: zoom-in; }
.method-figure img { width: 100%; height: auto; }
.model-diagram-scroll { overflow-x: auto; border-radius: 6px; background: #ffffff; }
.flow-diagram { display: block; width: 100%; height: auto; }
@media (min-width: 1200px) {
  .model-figure { width: calc(100% + 120px); margin-inline: -60px; }
}
.model-figure figcaption { max-width: 790px; margin: 12px auto 0; }
.force-model-demo { width: min(820px, 100%); margin: 34px auto 0; scroll-margin-top: 24px; }
.force-model-demo h4 { margin: 0 0 10px; font-size: 20px; font-weight: 600; }
.media-summary { margin: 0 auto 18px; color: var(--muted); font-size: 14px; }
.force-model-demo video { aspect-ratio: 16 / 9; border-radius: 6px; object-fit: contain; }
.force-model-demo figcaption { text-align: center; }
.formula-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1.2fr;
  align-items: center;
  gap: 9px;
  max-width: 660px;
  margin: 20px auto 0;
  color: #555;
  font-size: 12px;
  text-align: center;
}
.formula-row span, .formula-row strong {
  min-height: 52px;
  display: grid;
  place-items: center;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
}
.formula-row strong { background: var(--soft); }
.equation-card {
  display: inline-flex;
  align-items: center;
  gap: 18px;
  margin-top: 20px;
  padding: 12px 18px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--soft);
}
.equation-card span { color: var(--muted); font-size: 12px; font-weight: 700; text-transform: uppercase; }
.equation-card strong { font-size: 21px; font-weight: 600; }
.capture-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin: 0 0 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--line);
}
.capture-grid figure { min-width: 0; }
.capture-grid h3 { margin: 0 0 12px; text-align: center; font-size: 14px; font-weight: 500; }
.capture-grid video { aspect-ratio: 16 / 9; object-fit: cover; border-radius: 5px; }

.result-summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.result-card { padding: 24px 18px; text-align: center; }
.result-card + .result-card { border-left: 1px solid var(--line); }
.result-card span { color: var(--muted); font-size: 13px; font-weight: 700; }
.result-card strong { display: block; margin-top: 8px; color: #333; font-size: 36px; font-weight: 700; letter-spacing: -.03em; }
.result-card p { color: var(--muted); font-size: 13px; }
.result-note { margin: 40px auto 0; text-align: center; scroll-margin-top: 24px; }
.result-note h3 { font-size: 24px; font-weight: 600; letter-spacing: normal; }
.control-cases { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 28px; margin-top: 30px; }
.control-case { min-width: 0; padding: 0 14px; }
.case-inward { --case-color: #9b7a13; }
.case-hold { --case-color: #397757; }
.case-outward { --case-color: #7d2e3a; }
.control-case + .control-case { border-left: 1px solid #e4e4e4; }
.control-case h4 { display: flex; align-items: center; justify-content: center; gap: 7px; margin: 0; font-size: 15px; font-weight: 500; white-space: nowrap; }
.control-case h4 b { color: var(--case-color); font-size: 25px; font-weight: 700; line-height: 1.2; }
.control-case img { margin: 8px auto 0; max-width: 320px; }
.control-action { margin-top: 6px; color: var(--case-color); font-size: 16px; font-weight: 600; }
.control-legend { display: flex; align-items: center; justify-content: center; gap: 8px; margin-top: 13px; color: var(--muted); font-size: 12px; }
.position-key { width: 12px; height: 12px; background: #383838; border-radius: 2px; }
.command-key { width: 12px; height: 12px; margin-left: 12px; border: 1px solid #777777; border-radius: 2px; background: #9298a1; }
.trial-status-definition { margin: 34px auto 20px; color: var(--muted); font-size: 13px; text-align: center; }
.execution-comparison { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 30px; margin-top: 34px; }
.execution-condition { min-width: 0; display: flex; flex-direction: column; }
.execution-heading { display: flex; align-items: center; justify-content: center; gap: 10px; }
.execution-heading h3 { font-size: 18px; font-weight: 600; }
.execution-summary { margin: 9px 0 22px; color: #555; font-size: 12px; text-align: center; }
.trial-grid { flex: 1; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); grid-auto-rows: 1fr; gap: 22px 14px; }
.trial-card { min-width: 0; display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: 5px; overflow: hidden; }
.trial-preview { display: block; position: relative; width: 100%; margin: 0; padding: 0; border: 0; color: #fff; background: #151515; cursor: pointer; }
.trial-preview video { aspect-ratio: 16 / 9; object-fit: contain; }
.trial-play { position: absolute; right: 8px; bottom: 8px; display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; background: rgba(20, 20, 20, .78); font-size: 13px; }
.trial-preview:hover .trial-play { background: #111; }
.trial-preview:focus-visible { outline: 3px solid #86b7fe; outline-offset: -3px; }
.trial-card figcaption { display: flex; align-items: center; justify-content: space-between; gap: 6px; margin: 0; padding: 9px 10px 7px; color: #555; font-size: 12px; }
.trial-card figcaption strong { padding: 2px 6px; border-radius: 3px; color: #444; background: #eeeeee; font-size: 11px; font-weight: 600; }
.status-reliable figcaption strong { color: #fff; background: #286544; }
.status-unreliable { border-color: #b67b84; }
.status-unreliable figcaption strong { color: #fff; background: #943f49; }
.trial-details { margin: 0; padding: 0 10px 10px; color: #666; font-size: 11px; line-height: 1.6; }
.trial-details > div { display: flex; justify-content: space-between; gap: 8px; }
.trial-details dd { margin: 0; color: #444; }
.trial-details .outcome-pass { color: #286544; font-weight: 700; }
.trial-details .outcome-fail { color: #943f49; font-weight: 700; }

.uncertainty-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 26px; }
.uncertainty-grid figure { min-width: 0; }
.uncertainty-grid h3 { margin-bottom: 10px; font-size: 18px; font-weight: 600; text-align: center; }
.uncertainty-grid video { aspect-ratio: 16 / 9; object-fit: cover; border-radius: 5px; }
.uncertainty-grid figcaption { text-align: center; }

.figure-dialog {
  width: min(1280px, calc(100% - 40px));
  max-width: none;
  padding: 18px;
  border: 0;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 25px 80px rgba(0, 0, 0, .3);
}
.figure-dialog::backdrop { background: rgba(18, 18, 20, .8); }
.figure-dialog button {
  position: absolute;
  top: 9px;
  right: 11px;
  width: 36px;
  height: 36px;
  border: 0;
  border-radius: 50%;
  color: #fff;
  background: #2f2f2f;
  font-size: 26px;
  line-height: 1;
  cursor: pointer;
}
.figure-dialog img { max-height: 78vh; object-fit: contain; }
.dialog-visual { overflow: auto; max-height: 80vh; }
.dialog-visual svg { display: block; width: 100%; height: 74vh; }
.figure-dialog p { margin-top: 12px; color: var(--muted); font-size: 14px; }
.lightbox-target:focus-visible, .button:focus-visible, .authors a:focus-visible, .stage-link:focus-visible { outline: 3px solid #86b7fe; outline-offset: 4px; }

.trial-dialog { width: min(1040px, calc(100% - 40px)); max-width: none; padding: 18px; border: 0; border-radius: 6px; color: var(--ink); background: #fff; box-shadow: 0 25px 80px rgba(0, 0, 0, .3); }
.trial-dialog::backdrop { background: rgba(18, 18, 20, .8); }
.trial-dialog-heading { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 14px; }
.trial-dialog-heading h2 { font-size: 18px; font-weight: 600; }
.trial-dialog-heading button { flex: 0 0 36px; height: 36px; border: 0; border-radius: 50%; color: #fff; background: #333; font-size: 26px; cursor: pointer; }
.trial-dialog-stage video { width: 100%; max-height: 72vh; aspect-ratio: 16 / 9; object-fit: contain; }
.trial-dialog-outcome { margin-top: 12px; color: #555; font-size: 14px; }

@media (max-width: 820px) {
  .model-diagram-scroll .flow-diagram { min-width: 760px; }
  .dialog-visual .flow-diagram { min-width: 760px; height: auto; }
  .comparison-grid, .capture-grid, .uncertainty-grid { grid-template-columns: 1fr; }
  .stage-strip { grid-template-columns: 1fr; gap: 18px; }
  .result-summary { grid-template-columns: 1fr 1fr; }
  .result-card:last-child { grid-column: 1 / -1; border-top: 1px solid var(--line); }
  .result-card:nth-child(2) { border-left: 1px solid var(--line); }
  .result-card:last-child { border-left: 0; }
  .execution-comparison { grid-template-columns: 1fr; gap: 42px; }
  .comparison-grid::before, .execution-comparison::before { display: none; }
  .comparison-card + .comparison-card, .execution-condition + .execution-condition { padding-top: 26px; border-top: 1px solid #c8c8c8; }
  .control-cases { grid-template-columns: 1fr; gap: 28px; }
  .control-case { padding: 0; }
  .control-case + .control-case { border-left: 0; border-top: 1px solid #e4e4e4; padding: 24px 0 0; }
}

@media (max-width: 600px) {
  .section-shell { width: min(100% - 28px, var(--max)); }
  .hero { padding-top: 46px; }
  .hero h1 { font-size: 36px; }
  .authors { font-size: 17px; }
  .lead { font-size: 16px; }
  .hero-actions { flex-wrap: wrap; gap: 8px; }
  .button { padding: 0 14px; font-size: 14px; }
  .abstract-copy a { overflow-wrap: anywhere; }
  .comparison-grid { margin-top: 42px; }
  .paper-section { padding: 56px 0; }
  .abstract-copy { font-size: 16px; text-align: left; }
  .formula-row { grid-template-columns: 1fr; }
  .formula-row b { transform: rotate(90deg); }
  .result-summary { grid-template-columns: 1fr; }
  .result-card + .result-card, .result-card:nth-child(2) { border-top: 1px solid var(--line); border-left: 0; }
  .result-card:last-child { grid-column: auto; }
}

@media (prefers-reduced-motion: reduce) {
  :root { scroll-behavior: auto; }
  * { transition: none !important; }
}