:root {
  --bg: #fcfcfb;
  --ink: #1b1f27;
  --ink-2: #444a55;
  --ink-3: #6b717c;
  --rule: #e3e3df;
  --rule-2: #d2d2cc;
  --soft: #f4f4f1;
  --accent: #1f3a68;
  --accent-soft: #eef2f8;
  --ours: #fbf3ee;
  --green: #2e7d4f;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "IBM Plex Sans", -apple-system, "Segoe UI", "Helvetica Neue", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 64px; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
img { display: block; max-width: 100%; height: auto; }
sup, sub { line-height: 0; }

.wrap { max-width: 860px; margin: 0 auto; padding: 0 24px; }
.wrap.wide { max-width: 1120px; }

/* ---------- nav ---------- */
nav.top {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: saturate(1.4) blur(8px);
  -webkit-backdrop-filter: saturate(1.4) blur(8px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s;
}
nav.top.scrolled { border-bottom-color: var(--rule); }
nav.top .wrap { max-width: 1120px; display: flex; align-items: center; justify-content: space-between; height: 52px; }
.brand { font-family: var(--serif); font-weight: 700; font-size: 1.1rem; color: var(--ink); letter-spacing: .01em; }
.brand:hover { text-decoration: none; }
.links-nav { display: flex; gap: 26px; }
.links-nav a { color: var(--ink-3); font-size: .9rem; padding: 14px 0; }
.links-nav a:hover, .links-nav a.on { color: var(--ink); text-decoration: none; }
.links-nav a.on { box-shadow: inset 0 -2px 0 var(--accent); }

/* ---------- header ---------- */
.head { text-align: center; padding: 56px 0 40px; }
.head .wrap { max-width: 1000px; }
.venue {
  display: inline-block; margin: 0 0 22px;
  font-size: .8rem; font-weight: 600; letter-spacing: .14em; text-transform: uppercase;
  color: var(--accent); line-height: 1.6;
  padding: 3px 12px; border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent); border-radius: 3px;
}
h1 {
  font-family: var(--serif); font-weight: 600;
  font-size: clamp(1.75rem, 1.1rem + 2.6vw, 2.75rem);
  line-height: 1.22; letter-spacing: -.01em;
  margin: 0 auto 28px; max-width: 22em; text-wrap: balance;
}
.authors { font-size: 1.06rem; margin: 0 0 8px; display: flex; flex-wrap: wrap; justify-content: center; column-gap: 22px; row-gap: 2px; }
.authors span { white-space: nowrap; color: var(--ink); }
.authors sup { font-size: .68em; color: var(--ink-3); margin-left: 1px; }
.affils { font-size: .92rem; color: var(--ink-2); margin: 0 0 6px; display: flex; flex-wrap: wrap; justify-content: center; column-gap: 20px; }
.affils sup { font-size: .7em; margin-right: 2px; }
.notes { font-size: .82rem; color: var(--ink-3); margin: 0 0 28px; }

.btns { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  height: 40px; padding: 0 18px; border-radius: 999px;
  background: var(--ink); color: #fafaf8;
  font-size: .92rem; font-weight: 500;
  transition: background .15s;
}
.btn svg { width: 17px; height: 17px; }
.btn:hover { background: #333a47; text-decoration: none; }
.btn.ghost { background: transparent; color: var(--ink); box-shadow: inset 0 0 0 1px var(--rule-2); }
.btn.ghost:hover { background: var(--soft); }
.btn.soon { background: var(--soft); color: var(--ink-3); cursor: default; box-shadow: inset 0 0 0 1px var(--rule); }
.btn.soon small { font-size: .72rem; color: var(--ink-3); border-left: 1px solid var(--rule-2); padding-left: 8px; margin-left: 2px; }

/* ---------- sections ---------- */
main section { padding: 44px 0; }
main section + section { border-top: 1px solid var(--rule); }
main section.teaser { padding-top: 8px; }
main section.teaser + section { border-top: 0; }
h2 {
  font-family: var(--serif); font-weight: 600;
  font-size: 1.8rem; line-height: 1.25;
  margin: 0 0 18px; text-align: center;
}
h3 { font-family: var(--serif); font-weight: 600; font-size: 1.22rem; margin: 34px 0 10px; color: var(--ink); }
p { margin: 0 0 16px; color: var(--ink-2); }
p b, li b { color: var(--ink); font-weight: 600; }
.muted { color: var(--ink-3); font-size: .92rem; }
.abstract { text-align: justify; hyphens: auto; color: var(--ink-2); }

/* ---------- figures ---------- */
figure { margin: 28px 0 8px; }
.frame { background: #fff; border: 1px solid var(--rule); border-radius: 6px; padding: 14px; cursor: zoom-in; }
figcaption { font-size: .9rem; line-height: 1.6; color: var(--ink-3); margin: 12px auto 0; max-width: 860px; padding: 0 2px; }
figcaption b { color: var(--ink); }

.highlights {
  list-style: none; margin: 28px auto 0; padding: 0; max-width: 960px;
  display: grid; grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule);
}
.highlights li { padding: 18px 20px; text-align: center; font-size: .93rem; color: var(--ink-2); line-height: 1.5; }
.highlights li + li { border-left: 1px solid var(--rule); }
.highlights b { display: block; font-family: var(--serif); font-size: 1.85rem; font-weight: 600; color: var(--accent); margin-bottom: 4px; font-variant-numeric: tabular-nums; }

/* ---------- lists ---------- */
.findings { padding-left: 1.3em; margin: 0 0 8px; }
.findings li { margin-bottom: 10px; color: var(--ink-2); padding-left: 4px; }
.bullets { padding-left: 1.2em; margin: 24px 0 0; }
.bullets li { margin-bottom: 10px; color: var(--ink-2); }

.note { background: var(--accent-soft); border-radius: 6px; padding: 20px 24px 6px; margin-top: 28px; }
.note-k { font-size: .78rem; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }
.note p { font-size: .96rem; }

/* ---------- math ---------- */
.eq { margin: 6px 0 22px; overflow-x: auto; overflow-y: hidden; padding: 4px 0; }
.eq .katex-display { margin: 0; }
.eq .katex { font-size: 1.12em; }
.eq.sm .katex { font-size: 1.02em; }
.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; margin: 8px 0 10px; }
.cols > div { border-top: 2px solid var(--ink); padding-top: 4px; min-width: 0; }
.cols h3 { margin-top: 10px; font-size: 1.08rem; }
.cols p { font-size: .95rem; }

/* ---------- tables ---------- */
.tbl { overflow-x: auto; margin: 26px 0 8px; -webkit-overflow-scrolling: touch; }
table { width: 100%; border-collapse: collapse; font-size: .9rem; font-variant-numeric: tabular-nums; }
caption { caption-side: top; text-align: left; font-size: .88rem; line-height: 1.55; color: var(--ink-3); padding-bottom: 10px; }
caption b { color: var(--ink); }
thead tr:first-child th { border-top: 1.5px solid var(--ink); }
thead tr:last-child th { border-bottom: 1px solid var(--ink); }
th { font-weight: 600; padding: 7px 10px; text-align: center; white-space: nowrap; color: var(--ink); }
thead tr:first-child th[colspan] { border-bottom: 1px solid var(--rule-2); }
td { padding: 6px 10px; text-align: center; white-space: nowrap; color: var(--ink-2); }
th.l, td.l { text-align: left; }
tbody tr:last-child td { border-bottom: 1.5px solid var(--ink); }
td.avg { background: var(--soft); }
tr.grp td { font-size: .76rem; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-3); padding-top: 12px; border-top: 1px solid var(--rule-2); background: transparent; }
tr.sep td { border-top: 1px dashed var(--rule-2); }
tr.ours td { background: var(--ours); color: var(--ink); }
tr.ours td.avg { background: #f6e8df; }
td b { color: var(--ink); }
.gain { font-size: .76em; color: var(--green); font-weight: 500; margin-left: 2px; }

/* ---------- bibtex ---------- */
.bib { position: relative; background: var(--soft); border: 1px solid var(--rule); border-radius: 6px; }
.bib pre { margin: 0; padding: 18px 20px; overflow-x: auto; font: 13.5px/1.6 ui-monospace, "SF Mono", Menlo, Consolas, monospace; color: var(--ink); }
#copy {
  position: absolute; top: 10px; right: 10px;
  font: 500 .78rem var(--sans); color: var(--ink-2);
  background: #fff; border: 1px solid var(--rule-2); border-radius: 4px; padding: 4px 10px; cursor: pointer;
}
#copy:hover { color: var(--ink); }
#copy.done { color: var(--green); border-color: var(--green); }

footer { border-top: 1px solid var(--rule); padding: 28px 0 48px; text-align: center; }
footer p { font-size: .85rem; color: var(--ink-3); margin: 0; }

/* ---------- lightbox ---------- */
.lb { position: fixed; inset: 0; z-index: 50; background: rgba(20, 22, 28, .86); display: none; align-items: center; justify-content: center; padding: 3vw; cursor: zoom-out; }
.lb.on { display: flex; }
.lb img { max-width: 100%; max-height: 100%; background: #fff; border-radius: 4px; padding: 10px; }

/* ---------- responsive ---------- */
@media (max-width: 760px) {
  body { font-size: 16px; }
  .links-nav { gap: 16px; }
  .links-nav a:nth-child(2), .links-nav a:nth-child(5) { display: none; }
  .head { padding: 36px 0 28px; }
  .authors { column-gap: 14px; font-size: 1rem; }
  .affils { font-size: .85rem; flex-direction: column; }
  h2 { font-size: 1.5rem; }
  .highlights { grid-template-columns: 1fr; }
  .highlights li + li { border-left: 0; border-top: 1px solid var(--rule); }
  .cols { grid-template-columns: 1fr; gap: 8px; }
  .frame { padding: 6px; }
  .abstract { text-align: left; }
  main section { padding: 34px 0; }
}
@media (max-width: 420px) {
  .links-nav a:nth-child(1) { display: none; }
}

/* ================= refinements: motion & polish ================= */
:root { --ease: cubic-bezier(.16, 1, .3, 1); --red: #b23a2a; --blue: #1f4f8f; }
.progress { position: absolute; left: 0; bottom: -1px; height: 2px; width: 100%; background: var(--accent); transform: scaleX(0); transform-origin: left; }
::selection { background: #f3d9cf; }

h1 .hl {
  background: linear-gradient(transparent 62%, #f3d2c6 62%, #f3d2c6 92%, transparent 92%) no-repeat 0 0 / 0% 100%;
  animation: hl 1.1s .5s var(--ease) forwards; padding: 0 .06em;
}
@keyframes hl { to { background-size: 100% 100%; } }

.js .rv { opacity: 0; transform: translateY(14px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.js .rv.in { opacity: 1; transform: none; }

.frame { transition: border-color .25s, box-shadow .25s; }
.frame:hover { border-color: var(--rule-2); box-shadow: 0 6px 22px -14px rgba(27, 31, 39, .35); }
tbody tr:not(.grp) { transition: background-color .15s; }
tbody tr:not(.grp):not(.ours):hover td { background: #f7f7f4; }
.highlights b { transition: color .3s; }
.note { position: relative; }

/* ================= credit lens ================= */
.lens { margin: 34px 0 0; background: #fff; border: 1px solid var(--rule); border-radius: 8px; overflow: hidden; }
.lens-top { display: flex; flex-wrap: wrap; gap: 14px 20px; align-items: center; justify-content: space-between; padding: 16px 22px; border-bottom: 1px solid var(--rule); }
.lens-k { margin: 0; font-size: .74rem; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--red); }
.lens-t { margin: 2px 0 0; font-family: var(--serif); font-size: 1.08rem; color: var(--ink); line-height: 1.4; }
.seg { display: inline-flex; padding: 3px; background: var(--soft); border: 1px solid var(--rule); border-radius: 999px; }
.seg button { font: 500 .84rem var(--sans); padding: 6px 14px; border: 0; border-radius: 999px; background: transparent; color: var(--ink-3); cursor: pointer; transition: background .25s, color .25s, box-shadow .25s; }
.seg button[aria-pressed="true"] { background: #fff; color: var(--ink); box-shadow: 0 1px 3px rgba(27, 31, 39, .14); }

.lens-q { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 26px; align-items: center; padding: 20px 22px; border-bottom: 1px solid var(--rule); background: #fdfdfc; }
.clocks { display: flex; gap: 18px; }
.clock { width: 84px; text-align: center; font-size: .74rem; color: var(--ink-2); line-height: 1.3; }
.clock svg { width: 84px; height: 84px; display: block; margin-bottom: 4px; }
.clock .cf { fill: #d8402f; }
.clock .cd { fill: #fff; }
.clock .ticks line { stroke: #2a2a2a; stroke-width: 1.2; }
.clock .hh, .clock .mh { stroke: #1b1f27; stroke-linecap: round; transform-origin: 40px 40px; transition: transform 1.6s var(--ease); }
.clock .hh { stroke-width: 3.4; }
.clock .mh { stroke-width: 2; transform: rotate(-360deg); }
.clock .cc { fill: #1b1f27; }
.lens.in .clock .mh { transform: rotate(0deg); }
.qa .q { margin: 0 0 10px; font-size: .95rem; color: var(--ink); line-height: 1.6; }
.qa .q b { color: var(--ink); }
.pred { margin: 0; display: flex; flex-wrap: wrap; gap: 8px; font-size: .84rem; }
.pred span { padding: 3px 10px; border-radius: 4px; background: var(--soft); color: var(--ink-2); }
.pred .ok { background: #e7f3ec; color: var(--green); font-weight: 500; }

.lens-bar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; padding: 12px 22px 0; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chips button, .replay { font: 500 .78rem var(--sans); color: var(--ink-3); background: transparent; border: 1px solid var(--rule); border-radius: 999px; padding: 4px 12px; cursor: pointer; transition: all .2s; }
.chips button:hover, .replay:hover { color: var(--ink); border-color: var(--rule-2); }
.chips button[aria-pressed="true"] { color: var(--ink); border-color: var(--ink); }
.replay { display: inline-flex; align-items: center; gap: 6px; }
.replay svg { width: 13px; height: 13px; }

.lens-text { padding: 14px 22px 20px; font-size: .9rem; line-height: 2.3; color: var(--ink); }
.lens-text .t {
  display: inline-block; line-height: 1.5; padding: 1px 5px; margin: 0 1px 3px 0; border-radius: 3px;
  background: #f1f1ee; color: var(--ink-2); cursor: default;
  transition: background-color .55s var(--ease), color .55s var(--ease), opacity .3s, transform .2s var(--ease), box-shadow .2s;
}
.lens-text .t.nl { color: var(--ink-3); }
.lens-text .t:hover { transform: translateY(-2px); box-shadow: 0 3px 10px -4px rgba(27, 31, 39, .45); }
.lens-text.f-hi .t:not(.hi), .lens-text.f-lo .t:not(.lo) { opacity: .16; }
.lens-text .nlbr { display: block; height: 0; }

.lens-foot { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px 24px; padding: 14px 22px 16px; border-top: 1px solid var(--rule); background: #fdfdfc; }
.legend { display: flex; align-items: center; gap: 12px; flex: 1 1 420px; min-width: 0; }
.lg-end { font-family: var(--serif); font-size: .74rem; font-weight: 600; line-height: 1.15; color: var(--blue); text-align: center; white-space: nowrap; }
.lg-end.r { color: var(--red); }
.lg-bar { position: relative; flex: 1; height: 10px; border-radius: 2px; margin-bottom: 16px;
  background: linear-gradient(90deg, #17407a 0%, #4f86c6 20%, #c7dbef 40%, #f7f5f0 50%, #f4c6b3 62%, #e07b5f 80%, #a8281f 100%); }
.lg-ticks span { position: absolute; top: 13px; transform: translateX(-50%); font-size: .68rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.lg-ticks span::before { content: ""; position: absolute; left: 50%; top: -4px; width: 1px; height: 3px; background: var(--ink-3); }
.lg-mark { position: absolute; top: -5px; left: 50%; width: 2px; height: 20px; background: var(--ink); border-radius: 1px; opacity: 0; transform: translateX(-50%); transition: left .35s var(--ease), opacity .2s; }
.lg-mark.on { opacity: 1; }
.lens-read { margin: 0; font-size: .84rem; color: var(--ink-3); min-width: 230px; text-align: right; font-variant-numeric: tabular-nums; }
.lens-read b { color: var(--ink); }
.lens-cap { font-size: .9rem; line-height: 1.6; color: var(--ink-3); margin: 12px auto 0; max-width: 860px; }
.lens-cap b { color: var(--ink); }
.sw { display: inline-block; width: .8em; height: .8em; border-radius: 2px; vertical-align: -.05em; margin-right: 4px; }
.sw.r { background: #c4452f; } .sw.b { background: #2c63a8; }

.cases { margin-top: 26px; }
.cases-nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px; border-bottom: 1px solid var(--rule); margin-bottom: 14px; }
.cases-nav button { font: 500 .88rem var(--sans); padding: 8px 14px; border: 0; background: transparent; color: var(--ink-3); cursor: pointer; position: relative; }
.cases-nav button::after { content: ""; position: absolute; left: 10px; right: 10px; bottom: -1px; height: 2px; background: var(--accent); transform: scaleX(0); transition: transform .35s var(--ease); }
.cases-nav button[aria-selected="true"] { color: var(--ink); }
.cases-nav button[aria-selected="true"]::after { transform: scaleX(1); }
.case-stage { display: grid; }
.case-stage figure { grid-area: 1 / 1; margin: 0; opacity: 0; visibility: hidden; transform: translateY(6px); transition: opacity .45s var(--ease), transform .45s var(--ease), visibility 0s .45s; }
.case-stage figure.on { opacity: 1; visibility: visible; transform: none; transition-delay: 0s; }

@media (max-width: 760px) {
  .lens-top, .lens-q, .lens-bar, .lens-text, .lens-foot { padding-left: 14px; padding-right: 14px; }
  .lens-q { grid-template-columns: 1fr; gap: 14px; }
  .clocks { justify-content: center; }
  .lens-text { font-size: .84rem; }
  .lens-read { text-align: left; min-width: 0; }
  .legend { flex-basis: 100%; }
}
@media (prefers-reduced-motion: reduce) {
  .js .rv { opacity: 1; transform: none; transition: none; }
  h1 .hl { animation: none; background-size: 100% 100%; }
  .lens-text .t, .clock .hh, .clock .mh { transition: none; }
}

/* ---------- video ---------- */
.h2-meta { font-family: var(--sans); font-size: .82rem; font-weight: 400; color: var(--ink-3); letter-spacing: .02em; margin-left: 12px; vertical-align: .2em; }
.vid { display: grid; grid-template-columns: minmax(0, 1fr) 248px; gap: 22px; align-items: start; }
.vid-player { border: 1px solid var(--rule); border-radius: 6px; overflow: hidden; background: #f6f4ee; aspect-ratio: 16 / 9; box-shadow: 0 24px 60px -40px rgba(27, 31, 39, .45); }
.vid-player video { display: block; width: 100%; height: 100%; object-fit: contain; background: #f6f4ee; }
.chapters { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--rule); counter-reset: ch; }
.chapters button { display: grid; grid-template-columns: 44px 1fr; width: 100%; text-align: left; border: 0; background: transparent; cursor: pointer; font: 400 .86rem/1.35 var(--sans); color: var(--ink-2); padding: 7px 10px 7px 14px; margin-left: -1px; border-left: 2px solid transparent; transition: color .2s, background .2s, border-color .2s; }
.chapters button span { font-variant-numeric: tabular-nums; color: var(--ink-3); font-size: .8rem; padding-top: 1px; }
.chapters button:hover { background: var(--soft); color: var(--ink); }
.chapters button.on { border-left-color: #b23a2a; color: var(--ink); font-weight: 500; background: var(--ours); }
.chapters button.on span { color: #b23a2a; }
@media (max-width: 900px) {
  .vid { grid-template-columns: 1fr; }
  .chapters { border-left: 0; border-top: 1px solid var(--rule); display: grid; grid-template-columns: 1fr 1fr; padding-top: 6px; }
  .chapters button { border-left: 0; margin-left: 0; padding: 6px 8px; }
}
@media (max-width: 600px) { .h2-meta { display: block; margin: 6px 0 0; } }

/* ================= effect visuals (restrained, reveal-once) ================= */
.fx { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr); gap: 0; margin: 28px 0 6px; background: #fff; border: 1px solid var(--rule); border-radius: 8px; overflow: hidden; }
.fx-main { padding: 18px 24px 16px; border-right: 1px solid var(--rule); min-width: 0; }
.fx-side { display: grid; grid-template-rows: auto auto; background: #fdfdfc; min-width: 0; }
.fx-box { padding: 18px 22px 14px; min-width: 0; }
.fx-box + .fx-box { border-top: 1px solid var(--rule); }
.fx-head { display: flex; flex-wrap: wrap; gap: 10px 18px; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.fx-k { margin: 0; font-size: .72rem; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--red); }
.fx-t { margin: 2px 0 0; font-family: var(--serif); font-size: 1.08rem; color: var(--ink); line-height: 1.4; }
.fx-box .fx-k { color: var(--ink-3); margin-bottom: 10px; }
.fx-note { margin: 8px 0 0; font-size: .78rem; color: var(--ink-3); line-height: 1.45; }
.fx-leg { margin: 6px 0 0; font-size: .78rem; color: var(--ink-3); }
.lg-o, .lg-r { display: inline-block; width: 9px; height: 9px; border-radius: 50%; vertical-align: -.02em; margin-right: 3px; }
.lg-o { background: #fff; border: 1.5px solid #8b919b; }
.lg-r { background: var(--red); }

/* dumbbell */
.db { position: relative; padding: 6px 0 22px; }
.db-row { display: grid; grid-template-columns: 128px minmax(0, 1fr) 62px; align-items: center; gap: 12px; height: 44px; }
.db-lab { font-size: .84rem; color: var(--ink-2); line-height: 1.2; }
.db-lab small { display: block; font-size: .72rem; color: var(--ink-3); }
.db-tr { position: relative; height: 100%; }
.db-tr::before { content: ""; position: absolute; left: 0; right: 0; top: 50%; border-top: 1px dotted var(--rule-2); }
.db-ln, .db-pt { position: absolute; left: 0; top: 0; width: 100%; height: 100%; transition: transform 1.1s var(--ease); will-change: transform; pointer-events: none; }
.db-ln { transform-origin: 0 50%; }
.db-ln::after { content: ""; position: absolute; left: 0; right: 0; top: calc(50% - 1.5px); height: 3px; background: color-mix(in oklch, var(--red) 34%, #fff); border-radius: 2px; }
.db-pt::after { content: ""; position: absolute; left: -6px; top: calc(50% - 6px); width: 12px; height: 12px; border-radius: 50%; box-sizing: border-box; }
.db-pt.o::after { background: #fff; border: 1.5px solid #8b919b; }
.db-pt.r::after { background: var(--red); box-shadow: 0 0 0 3px #fff; }
.db-v { position: absolute; top: calc(50% - 22px); left: 0; transform: translateX(-50%); font-size: .7rem; color: var(--ink-3); font-variant-numeric: tabular-nums; white-space: nowrap; }
.db-pt.r .db-v { color: var(--ink); font-weight: 600; }
.db-g { font-family: var(--serif); font-size: 1.02rem; font-weight: 600; color: var(--green); text-align: right; font-variant-numeric: tabular-nums; }
.db-g.neg { color: var(--ink-3); }
.db-ax { position: absolute; left: 140px; right: 74px; bottom: 0; height: 18px; }
.db-ax span { position: absolute; top: 2px; transform: translateX(-50%); font-size: .68rem; color: var(--ink-3); font-variant-numeric: tabular-nums; transition: opacity .3s; }
.db-grid { position: absolute; left: 140px; right: 74px; top: 6px; bottom: 22px; pointer-events: none; }
.db-grid i { position: absolute; top: 0; bottom: 0; border-left: 1px solid #f0f0ec; }

/* horizontal bars */
.hb-row { display: grid; grid-template-columns: 118px minmax(0, 1fr) 52px; align-items: center; gap: 10px; height: 26px; font-size: .8rem; color: var(--ink-2); }
.hb-row b { font-weight: 600; color: var(--ink); }
.hb-tr { position: relative; height: 9px; background: var(--soft); border-radius: 2px; overflow: hidden; }
.hb-bar { position: absolute; inset: 0; background: #b9bec6; transform-origin: 0 50%; transform: scaleX(0); transition: transform 1.2s var(--ease); border-radius: 2px; }
.hb-row.ours .hb-bar { background: var(--red); }
.hb-v { text-align: right; font-variant-numeric: tabular-nums; color: var(--ink-3); font-size: .78rem; }
.hb-row.ours .hb-v { color: var(--ink); font-weight: 600; }
.hb-v em { font-style: normal; display: block; font-size: .66rem; line-height: 1; color: var(--ink-3); font-weight: 400; }
.hb-v em.up { color: var(--red); }

/* grounding strip */
.gr { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); margin: 22px 0 0; border-top: 1.5px solid var(--ink); border-bottom: 1px solid var(--rule-2); }
.gr-col { padding: 14px 16px 12px; min-width: 0; }
.gr-col + .gr-col { border-left: 1px solid var(--rule); }
.gr-h { margin: 0 0 10px; font-size: .84rem; font-weight: 600; color: var(--ink); line-height: 1.3; }
.gr-h small { display: block; font-weight: 400; font-size: .72rem; color: var(--ink-3); }
.gr-row { display: grid; grid-template-columns: 58px minmax(0, 1fr) 44px; gap: 8px; align-items: center; height: 22px; font-size: .76rem; color: var(--ink-3); }
.gr-row .hb-tr { height: 7px; }
.gr-row.base .hb-bar { background: #c9cdd3; }
.gr-row.rl .hb-bar { background: #8d949e; }
.gr-row.ours { color: var(--ink); font-weight: 600; }
.gr-row.ours .hb-bar { background: var(--red); }
.gr-v { text-align: right; font-variant-numeric: tabular-nums; }
.gr-d { margin: 8px 0 0; font-size: .74rem; color: var(--ink-3); line-height: 1.4; opacity: 0; transform: translateY(4px); transition: opacity .6s var(--ease) 1.3s, transform .6s var(--ease) 1.3s; }
.gr.in .gr-d { opacity: 1; transform: none; }
.gr-d b { color: var(--red); font-weight: 600; }
.gr-cap { font-size: .84rem; color: var(--ink-3); line-height: 1.55; margin: 10px 0 0; }

/* table gains: fade/slide in once the table is revealed */
.js .tbl .gain { display: inline-block; opacity: 0; transform: translateX(-4px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.js .tbl.in .gain { opacity: 1; transform: none; transition-delay: .5s; }
.js .tbl tr.ours td { transition: background-color 1s var(--ease) .3s; }
.js .tbl:not(.in) tr.ours td { background: transparent; }

@media (max-width: 900px) {
  .fx { grid-template-columns: 1fr; }
  .fx-main { border-right: 0; border-bottom: 1px solid var(--rule); }
  .fx-side { grid-template-columns: 1fr 1fr; grid-template-rows: none; }
  .fx-box + .fx-box { border-top: 0; border-left: 1px solid var(--rule); }
}
@media (max-width: 760px) {
  .fx-main { padding: 16px 14px 12px; }
  .fx-side { grid-template-columns: 1fr; }
  .fx-box { padding: 16px 14px 12px; }
  .fx-box + .fx-box { border-left: 0; border-top: 1px solid var(--rule); }
  .db-row { grid-template-columns: 82px minmax(0, 1fr) 50px; gap: 8px; }
  .db-ax, .db-grid { left: 90px; right: 58px; }
  .db-lab { font-size: .78rem; }
  .gr { grid-template-columns: 1fr; }
  .gr-col + .gr-col { border-left: 0; border-top: 1px solid var(--rule); }
}
@media (prefers-reduced-motion: reduce) {
  .db-ln, .db-pt, .hb-bar { transition: none; }
  .gr-d, .js .tbl .gain { transition: none; opacity: 1; transform: none; }
}
.db-v.side-l, .db-v.side-r { top: calc(50% - 9px); }
.db-v.side-l { transform: translateX(calc(-100% - 11px)); }
.db-v.side-r { transform: translateX(11px); }
.hb-cost .hb-row { grid-template-columns: 70px minmax(0, 1fr) 104px; }
.hb-cost .hb-v em { display: inline; font-size: .72rem; margin-right: 6px; }
@media (max-width: 760px) { .db-arr { display: none; } }

/* ================= method walkthrough ================= */
.mw { margin: 30px 0 4px; background: #fff; border: 1px solid var(--rule); border-radius: 8px; overflow: hidden; }
.mw-top { display: flex; gap: 12px; align-items: center; justify-content: space-between; padding: 16px 22px 12px; }
.mw-rail { list-style: none; margin: 0; padding: 0 22px; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 8px; border-bottom: 1px solid var(--rule); }
.mw-rail button { position: relative; width: 100%; display: flex; align-items: center; gap: 8px; text-align: left; border: 0; background: transparent; cursor: pointer; padding: 8px 0 12px; font: 500 .8rem/1.25 var(--sans); color: var(--ink-3); transition: color .3s; }
.mw-rail button span { flex: none; display: inline-grid; place-items: center; width: 20px; height: 20px; border-radius: 50%; border: 1px solid var(--rule-2); font-size: .7rem; font-variant-numeric: tabular-nums; transition: background .3s, color .3s, border-color .3s; }
.mw-rail button i { position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; background: var(--rule); overflow: hidden; }
.mw-rail button i::after { content: ""; position: absolute; inset: 0; background: var(--red); transform: scaleX(0); transform-origin: left; }
.mw-rail button:hover { color: var(--ink); }
.mw-rail button.on, .mw-rail button.done { color: var(--ink); }
.mw-rail button.on span { background: var(--red); border-color: var(--red); color: #fff; }
.mw-rail button.done span { border-color: var(--ink-3); color: var(--ink-2); }
.mw-rail button.done i::after { transform: scaleX(1); background: var(--ink-3); }
.mw-rail button.on i::after { transform: scaleX(1); }
.mw.playing .mw-rail button.on i::after { animation: mwfill 3.4s linear forwards; }
@keyframes mwfill { from { transform: scaleX(0); } to { transform: scaleX(1); } }

.mw-body { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.25fr) minmax(0, 1fr); }
.mw-body > div { padding: 18px 20px; min-width: 0; }
.mw-body > div + div { border-left: 1px solid var(--rule); }
.mw-pic { position: relative; border-radius: 4px; overflow: hidden; border: 1px solid var(--rule); aspect-ratio: 3 / 2; }
.mw-pic svg { display: block; width: 100%; height: 100%; }
.mw-grid { position: absolute; inset: 0; display: grid; grid-template-columns: repeat(12, 1fr); grid-template-rows: repeat(8, 1fr); }
.mw-grid i { background: var(--red); opacity: 0; outline: 1px solid rgba(255, 255, 255, .5); transition: opacity .7s var(--ease); }
.mw[data-step="2"] .mw-pic, .mw[data-step="3"] .mw-pic, .mw[data-step="4"] .mw-pic { opacity: .55; }
.mw-pic { transition: opacity .6s var(--ease); }
.mw-cap { margin: 8px 0 0; font-size: .74rem; color: var(--ink-3); line-height: 1.45; }

.mw-chart { position: relative; height: 196px; padding-top: 22px; }
.mw-ylab { position: absolute; left: 0; top: 0; font-size: .74rem; color: var(--ink-3); }
.mw-cols { position: absolute; left: 0; right: 0; bottom: 0; height: 174px; display: grid; grid-template-columns: repeat(10, minmax(0, 1fr)); gap: 4px; border-bottom: 1px solid var(--ink-3); }
.mw-col { position: relative; border: 0; background: transparent; padding: 0; cursor: pointer; font: inherit; }
.mw-bar { position: absolute; left: 14%; right: 14%; bottom: 0; height: 150px; transform-origin: 50% 100%; transform: scaleY(0); border-radius: 2px 2px 0 0; transition: transform .9s var(--ease), background-color .7s var(--ease); }
.mw-val { position: absolute; left: -6px; right: -6px; bottom: 4px; text-align: center; font-size: .64rem; color: var(--ink-3); font-variant-numeric: tabular-nums; transition: transform .9s var(--ease); white-space: nowrap; }
.mw-tok { position: absolute; left: -4px; right: -4px; top: calc(100% + 4px); text-align: center; font-family: var(--serif); font-size: .8rem; color: var(--ink-2); }
.mw-col.on .mw-tok { color: var(--ink); font-weight: 600; }
.mw-col.on .mw-val { color: var(--ink); font-weight: 600; }
.mw-col.on .mw-bar { box-shadow: 0 0 0 1.5px var(--ink); }
.mw-col:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.mw-ref { position: absolute; left: 0; right: 0; bottom: 0; border-top: 1px dashed var(--ink-3); opacity: 0; transition: transform .9s var(--ease), opacity .4s; pointer-events: none; }
.mw-ref.show { opacity: 1; }
.mw-ref span { position: absolute; right: 0; bottom: 2px; font-size: .64rem; color: var(--ink-3); background: rgba(255, 255, 255, .85); padding: 0 3px; }
.mw-group { margin-top: 34px; opacity: 0; transform: translateY(6px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.mw-group.show { opacity: 1; transform: none; }
.mw-gh { margin: 0 0 6px; font-size: .72rem; color: var(--ink-3); }
.mw-gr { display: grid; grid-template-columns: minmax(0, 1fr) 62px 72px 74px; align-items: center; gap: 8px; height: 22px; font-size: .74rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.mw-gr .hb-tr { height: 6px; }
.mw-gr .hb-bar { background: #b9bec6; }
.mw-gr.me { color: var(--ink); font-weight: 600; }
.mw-gr.me .hb-bar { background: var(--red); }
.mw-gr.bad .hb-bar { background: transparent; }
.mw-ga { text-align: right; }

.mw-notes { position: relative; display: grid; align-content: start; }
.mw-note { grid-area: 1 / 1; opacity: 0; visibility: hidden; transform: translateY(6px); transition: opacity .5s var(--ease), transform .5s var(--ease), visibility 0s .5s; }
.mw-note.on { opacity: 1; visibility: visible; transform: none; transition-delay: 0s; }
.mw-h { margin: 0 0 6px; font-family: var(--serif); font-weight: 600; font-size: 1rem; color: var(--ink); }
.mw-note p:not(.mw-h) { font-size: .86rem; line-height: 1.55; margin: 0 0 8px; }
.mw-note .eq { margin: 8px 0 0; font-size: .92em; overflow-x: auto; overflow-y: hidden; }
.mw-read { grid-area: 2 / 1; margin: 14px 0 0; padding-top: 10px; border-top: 1px solid var(--rule); font-size: .8rem; line-height: 1.55; color: var(--ink-2); font-variant-numeric: tabular-nums; min-height: 3.2em; }
.mw-read b { color: var(--red); }
.mw-foot { margin: 0; padding: 10px 22px 12px; border-top: 1px solid var(--rule); background: #fdfdfc; font-size: .76rem; color: var(--ink-3); }

@media (max-width: 1000px) {
  .mw-body { grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); }
  .mw-notes { grid-column: 1 / -1; border-left: 0 !important; border-top: 1px solid var(--rule); }
}
@media (max-width: 760px) {
  .mw-top, .mw-foot { padding-left: 14px; padding-right: 14px; }
  .mw-rail { padding: 0 14px; gap: 4px; }
  .mw-rail button { flex-direction: column; align-items: flex-start; gap: 4px; font-size: .68rem; }
  .mw-body { grid-template-columns: 1fr; }
  .mw-body > div { padding: 14px; }
  .mw-body > div + div { border-left: 0; border-top: 1px solid var(--rule); }
  .mw-pic { max-width: 360px; margin: 0 auto; }
  .mw-gr { grid-template-columns: minmax(0, 1fr) 58px 50px 70px; }
}
@media (max-width: 480px) {
  .mw-rail button { font-size: 0; }
  .mw-rail button span { font-size: .7rem; }
  .mw-val { font-size: .56rem; }
}
@media (prefers-reduced-motion: reduce) {
  .mw-bar, .mw-val, .mw-ref, .mw-grid i, .mw-note, .mw-group, .mw-pic { transition: none; }
  .mw.playing .mw-rail button.on i::after { animation: none; }
}
.mv { font-family: var(--serif); font-style: italic; }
.mw-rail button em { font-style: normal; }
.mw-ylab { display: flex; justify-content: space-between; gap: 10px; margin: 0; right: 0; }
.mw-rk { display: inline-flex; align-items: center; gap: 5px; }
.mw-rk s { display: inline-block; width: 16px; border-top: 1px dashed var(--ink-3); }
@media (max-width: 760px) { .mw-tok { font-size: .7rem; } .mw-cols { gap: 2px; } }
@media (max-width: 1000px) { .mw-group:not(.show) { display: none; } .mw-group { margin-top: 30px; } }
.mw-chart { margin-bottom: 24px; }
.mw-group { margin-top: 14px; }
@media (max-width: 1000px) { .mw-group { margin-top: 10px; } }
@media (max-width: 760px) { .mw-tok { font-size: .62rem; left: -1px; right: -1px; white-space: nowrap; overflow: hidden; text-overflow: clip; } }