/* Six proposals for a colophon: how the site is made and what it weighs, on Tau's own tokens. */
:root, :root[data-theme] {
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --page: #fcfcfb; --ground: #f1f0ed; --raised: #ffffff; --ink: #0b0b0b; --ink2: #52514e; --ink3: #6c6b69; --faded: #97958d;
  --line: rgb(11 11 11 / 10%); --line-strong: rgb(11 11 11 / 20%);
  --glass: rgb(255 255 255 / 78%); --accent: #6250d6;
  --e1: 0 3px 6px -2px rgb(0 0 0 / .02), 0 1px 1px rgb(0 0 0 / .04);
  --e2: 0 0 0 .5px rgb(0 0 0 / .06), 0 6px 18px rgb(0 0 0 / .05), 0 3px 9px rgb(0 0 0 / .06), 0 1px 1px rgb(0 0 0 / .04);
  --e3: 0 0 0 .5px rgb(0 0 0 / .06), 0 24px 64px rgb(0 0 0 / .16), 0 8px 24px rgb(0 0 0 / .10), 0 1px 1px rgb(0 0 0 / .04);
  --m: clamp(16px, 2.8vw, 40px);
  --statement: clamp(38px, 6.4vw, 96px);
  --tau-ease: linear(0, 0.0234 0.39%, 0.0740 1.28%, 0.1420 2.54%, 0.2210 4.15%, 0.3058 6.06%, 0.3921 8.27%, 0.4764 10.75%, 0.5561 13.48%, 0.6294 16.47%, 0.6951 19.70%, 0.7528 23.17%, 0.8025 26.86%, 0.8443 30.78%, 0.8791 34.91%, 0.9074 39.26%, 0.9301 43.81%, 0.9481 48.56%, 0.9621 53.52%, 0.9728 58.67%, 0.9810 64.02%, 0.9870 69.55%, 0.9915 75.28%, 0.9948 81.19%, 0.9972 87.28%, 0.9988 93.55%, 1);
}
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) {
  color-scheme: dark; --page: #0d0d0d; --ground: #161615; --raised: #1f1f1e; --ink: #f0efec; --ink2: #c3c2b7; --ink3: #8f8e89; --faded: #5f5e5a;
  --line: rgb(255 255 255 / 10%); --line-strong: rgb(255 255 255 / 20%); --glass: rgb(40 40 40 / 75%);
  --e2: 0 0 0 .5px rgb(255 255 255 / 8%), 0 6px 18px rgb(0 0 0 / .4), 0 1px 1px rgb(0 0 0 / .3);
  --e3: 0 0 0 .5px rgb(255 255 255 / 9%), 0 24px 64px rgb(0 0 0 / .6), 0 8px 24px rgb(0 0 0 / .4); } }
:root[data-theme="dark"] {
  color-scheme: dark; --page: #0d0d0d; --ground: #161615; --raised: #1f1f1e; --ink: #f0efec; --ink2: #c3c2b7; --ink3: #8f8e89; --faded: #5f5e5a;
  --line: rgb(255 255 255 / 10%); --line-strong: rgb(255 255 255 / 20%); --glass: rgb(40 40 40 / 75%);
  --e2: 0 0 0 .5px rgb(255 255 255 / 8%), 0 6px 18px rgb(0 0 0 / .4), 0 1px 1px rgb(0 0 0 / .3);
  --e3: 0 0 0 .5px rgb(255 255 255 / 9%), 0 24px 64px rgb(0 0 0 / .6), 0 8px 24px rgb(0 0 0 / .4); }
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--page); color: var(--ink); }
body { font: 400 15px/24px var(--font); letter-spacing: -0.011em; -webkit-font-smoothing: antialiased; font-feature-settings: "ss01", "cv01", "cv11"; }
a { color: inherit; text-decoration: none; }
[hidden] { display: none !important; }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; } }

.small { margin: 0; font-size: 13px; line-height: 20px; color: var(--ink3); }
.mono { font-family: ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: 0; }
.kick { font: 500 11px/16px ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink3); text-transform: uppercase; letter-spacing: .04em; }
.glass { background: var(--glass); -webkit-backdrop-filter: blur(20px); backdrop-filter: blur(20px); box-shadow: 0 0 0 .5px var(--line), var(--e2); }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; height: 34px; padding: 0 14px; border: 0; border-radius: 9999px; background: color-mix(in srgb, var(--ink) 7%, transparent); color: var(--ink); font: 500 13px/1 var(--font); cursor: pointer; white-space: nowrap; }
.btn[aria-pressed="true"] { background: var(--ink); color: var(--page); }
a:focus-visible, button:focus-visible, [tabindex]:focus-visible, input:focus-visible { outline: 1.5px solid var(--accent); outline-offset: 3px; }
body { overflow-x: clip; }

/* the bar, as on the site */
.bar { position: fixed; z-index: 50; top: calc(12px + env(safe-area-inset-top, 0px)); left: 50%; transform: translateX(-50%); display: flex; align-items: center; gap: 4px; height: 48px; padding: 0 4px 0 14px;
  border-radius: 9999px; background: var(--glass); -webkit-backdrop-filter: blur(20px); backdrop-filter: blur(20px); box-shadow: 0 0 0 .5px var(--line), var(--e2); font-size: 13px; white-space: nowrap; }
.bar b { font-weight: 550; font-size: 14px; margin-right: 12px; }
.bar span { height: 32px; display: inline-flex; align-items: center; padding: 0 10px; border-radius: 9999px; color: var(--ink2); }
.bar i { font-style: normal; margin-left: 8px; height: 36px; padding: 0 16px; display: flex; align-items: center; border-radius: 9999px; background: var(--ink); color: var(--page); }
@media (max-width: 720px) { .bar span { display: none; } }

.co { padding: 148px var(--m) 0; }
.co-h { margin: 0; font: 450 clamp(60px, 10vw, 156px)/.9 var(--font); letter-spacing: -0.048em; }
.co-lede { max-width: 33em; margin: 32px 0 0; font-size: clamp(17px, 1.45vw, 21px); line-height: 1.48; letter-spacing: -0.014em; color: var(--ink2); }
.bud { padding: clamp(56px, 7vw, 96px) 0 200px; }
.sec-h { margin: 0 0 22px; font: 450 clamp(26px, 2.6vw, 38px)/1.08 var(--font); letter-spacing: -0.026em; }
.src { display: block; margin-top: 4px; font: 400 11px/15px ui-monospace, "SF Mono", Menlo, monospace; color: var(--faded); }

/* the switcher, a rail on the right edge */
.pick { position: fixed; z-index: 90; right: 10px; top: 50%; transform: translateY(-50%); -webkit-user-select: none; user-select: none; }
.pick-rail { display: flex; flex-direction: column; gap: 2px; padding: 4px; border-radius: 9999px; }
.pick-rail button { width: 30px; height: 30px; padding: 0; border: 0; border-radius: 50%; background: none; font: 500 12px/1 var(--font); color: var(--ink3); cursor: pointer; }
.pick-rail button[aria-pressed="true"] { background: var(--ink); color: var(--page); }
.pick-note { position: absolute; right: calc(100% + 10px); top: 50%; width: min(300px, calc(100vw - 72px)); margin: 0; padding: 12px 14px; border-radius: 12px; transform: translateY(-50%); font-size: 13px; line-height: 19px; color: var(--ink2);
  opacity: 0; pointer-events: none; transition: opacity .3s var(--tau-ease); background: color-mix(in srgb, var(--page) 94%, transparent); }
.pick-note b { display: block; margin-bottom: 2px; font-weight: 600; color: var(--ink); }
.pick.is-note .pick-note { opacity: 1; }
@media (max-width: 720px) {
  .pick { top: auto; bottom: calc(24px + env(safe-area-inset-bottom, 0px)); transform: none; right: 6px; }
  .pick-rail button { width: 26px; height: 26px; font-size: 11px; }
  .pick-note { top: auto; bottom: 0; transform: none; }
}

/* ---------------------------------------------------------------- 1 the book */
.bk { max-width: 620px; margin: 0 auto; text-align: center; }
.bk-orn { display: block; width: 44px; height: 44px; margin: 0 auto 40px; color: var(--ink); }
.bk h3 { margin: 56px 0 12px; font: 500 11px/16px var(--font); letter-spacing: .16em; text-transform: uppercase; color: var(--ink3); }
.bk h3:first-of-type { margin-top: 0; }
.bk p { margin: 0 auto; max-width: 30em; font: 400 clamp(18px, 1.5vw, 21px)/1.6 var(--font); letter-spacing: -0.012em; color: var(--ink); text-wrap: pretty; }
.bk p + p { margin-top: 12px; }
.bk .live { padding: 0 .2em; border-radius: 4px; background: color-mix(in srgb, var(--accent) 12%, transparent); font-variant-numeric: tabular-nums; }
.bk .end { margin-top: 64px; font-size: 13px; color: var(--ink3); }

/* ---------------------------------------------------------------- 2 the specimen sheet */
.sp-bar { display: flex; flex-wrap: wrap; gap: 6px 18px; align-items: center; margin-bottom: 40px; }
.sp-bar .grp { display: flex; gap: 4px; }
.sp-grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 56px 56px; margin-right: 34px; }
.sw { display: grid; grid-template-columns: repeat(auto-fill, minmax(118px, 1fr)); gap: 10px; }
.sw-c { padding: 0; border: 0; background: none; text-align: left; cursor: pointer; font: inherit; color: inherit; }
.sw-chip { height: 76px; border-radius: 10px; box-shadow: inset 0 0 0 .5px var(--line-strong); }
.sw-c b { display: block; margin-top: 8px; font: 500 12px/16px var(--font); }
.sw-c span { display: block; font: 400 11px/15px ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink3); }
.sw-c.is-copied span { color: var(--accent); }
.ty-row { display: grid; grid-template-columns: 96px minmax(0, 1fr); align-items: baseline; gap: 16px; padding: 12px 0; border-top: .5px solid var(--line-strong); }
.ty-row .mono { font-size: 11px; color: var(--ink3); }
.ty-row div { overflow: hidden; white-space: nowrap; text-overflow: clip; }
.shapes { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; }
.shape div { height: 64px; background: var(--ground); box-shadow: inset 0 0 0 .5px var(--line-strong); }
.shape b { display: block; margin-top: 8px; font: 500 12px/16px var(--font); }
.shape span { display: block; font: 400 11px/15px ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink3); }
.elev { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; padding: 20px; border-radius: 14px; background: var(--ground); }
.elev div { height: 84px; border-radius: 12px; background: var(--raised); display: grid; place-items: center; font: 500 12px/1 ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink3); }
.tok-list { margin: 0; padding: 0; list-style: none; }
.tok-list li { display: flex; justify-content: space-between; gap: 12px; padding: 7px 0; border-top: .5px solid var(--line-strong); font-size: 13px; }
.tok-list li span:first-child { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 12px; color: var(--ink3); }
@media (max-width: 900px) { .sp-grid { grid-template-columns: 1fr; margin-right: 0; } .shapes { grid-template-columns: repeat(3, minmax(0, 1fr)); } }

/* ---------------------------------------------------------------- 3 motion */
.mo { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 40px 56px; margin-right: 34px; }
.mo-stage { position: relative; height: 440px; overflow: hidden; border-radius: 14px; background: var(--ground); touch-action: none; cursor: crosshair; }
.mo-stage canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.mo-puck { position: absolute; left: 0; top: 0; width: 22px; height: 22px; margin: -11px 0 0 -11px; border-radius: 50%; background: var(--ink); box-shadow: var(--e2); pointer-events: none; }
.mo-ghost { position: absolute; left: 0; top: 0; width: 10px; height: 10px; margin: -5px 0 0 -5px; border-radius: 50%; border: 1.5px solid var(--accent); pointer-events: none; }
.mo-hint { position: absolute; left: 16px; top: 14px; margin: 0; }
.mo-presets { display: flex; flex-wrap: wrap; gap: 6px; margin: 16px 0 10px; }
.mo-slider { display: flex; align-items: center; gap: 14px; }
.mo-slider input { flex: 1; accent-color: var(--ink); }
.mo-slider output { min-width: 72px; text-align: right; font: 500 15px/1 ui-monospace, "SF Mono", Menlo, monospace; }
.mo-formula { margin: 22px 0 0; padding: 14px 16px; border-radius: 10px; background: var(--ground); font: 400 13px/20px ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink2); }
.mo-cmp { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 28px; }
.mo-cmp figure { margin: 0; }
.mo-cmp svg { display: block; width: 100%; height: auto; border-radius: 10px; background: var(--ground); }
.mo-cmp figcaption { margin-top: 8px; font-size: 13px; line-height: 19px; color: var(--ink3); }
.mo-cmp figcaption b { display: block; font-weight: 500; color: var(--ink); }
.mo-dots { display: flex; gap: 10px; margin-top: 10px; }
@media (max-width: 900px) { .mo { grid-template-columns: 1fr; margin-right: 0; } .mo-stage { height: 340px; } }

/* ---------------------------------------------------------------- 4 the meter */
.me { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 260px), 1fr)); gap: 12px; margin-right: 34px; }
.me-c { position: relative; min-height: 168px; padding: 18px 18px 16px; border-radius: 14px; background: var(--ground); display: flex; flex-direction: column; }
.me-c .kick { margin-bottom: auto; }
.me-v { margin-top: 18px; font: 450 clamp(40px, 4vw, 60px)/1 var(--font); letter-spacing: -0.04em; font-variant-numeric: tabular-nums; }
.me-v small { margin-left: .15em; font-size: .36em; letter-spacing: 0; color: var(--ink3); }
.me-c p { margin: 8px 0 0; font-size: 13px; line-height: 19px; color: var(--ink2); }
.me-c.is-wide { grid-column: span 2; }
.me-spark { display: block; width: 100%; height: 44px; margin-top: 12px; }
.me-note { margin: 24px 34px 0 0; max-width: 46em; font-size: 14px; line-height: 21px; color: var(--ink3); }
@media (max-width: 720px) { .me { margin-right: 0; } .me-c.is-wide { grid-column: auto; } }

/* ---------------------------------------------------------------- 5 the bill of materials */
.bm-bar { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 24px; }
.bm { width: calc(100% - 34px); border-collapse: collapse; font-size: 14px; }
.bm th { padding: 0 0 10px; text-align: left; font: 500 11px/16px ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink3); text-transform: uppercase; letter-spacing: .04em; cursor: pointer; white-space: nowrap; }
.bm th[aria-sort] { color: var(--ink); }
.bm th.n, .bm td.n { text-align: right; }
.bm th.n, .bm th.k { padding-left: 16px; }
.bm th.b { padding-left: 20px; }
.bm td { padding: 9px 0; border-top: .5px solid var(--line-strong); vertical-align: middle; }
.bm td:first-child { font-weight: 500; }
.bm td.n { font-variant-numeric: tabular-nums; padding-left: 16px; white-space: nowrap; }
.bm td.k { color: var(--ink3); padding-left: 16px; }
.bm td.b { width: 32%; padding-left: 20px; }
.bm .bar2 { height: 8px; border-radius: 4px; background: var(--line); overflow: hidden; }
.bm .bar2 i { display: block; height: 100%; border-radius: 4px; background: var(--ink); }
.bm tr.is-group td { padding-top: 22px; border-top: 0; font: 500 11px/16px ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink3); text-transform: uppercase; letter-spacing: .04em; }
.bm tfoot td { border-top: 1px solid var(--ink); font-weight: 500; }
.bm-note { margin: 22px 34px 0 0; max-width: 48em; font-size: 14px; line-height: 21px; color: var(--ink3); }
@media (max-width: 720px) { .bm { width: 100%; font-size: 13px; } .bm td.k, .bm th.k, .bm td.b, .bm th.b { display: none; } }

/* ---------------------------------------------------------------- 6 the exploded view */
.ex { display: grid; grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); gap: 32px 48px; margin-right: 34px; align-items: start; }
.ex-view { position: relative; height: 640px; overflow: hidden; border-radius: 16px; background: var(--ground); perspective: 1800px; touch-action: none; cursor: grab; -webkit-user-select: none; user-select: none; }
.ex-view.is-held { cursor: grabbing; }
.ex-rig { position: absolute; left: 50%; top: 50%; width: 560px; height: 350px; margin: -130px 0 0 -280px; transform-style: preserve-3d; }
.ex-l { position: absolute; inset: 0; border-radius: 6px; transform-style: preserve-3d; transition: box-shadow .3s var(--tau-ease), opacity .3s var(--tau-ease); }
.ex-l.is-on { box-shadow: 0 0 0 1.5px var(--accent); }
.ex-tag { position: absolute; left: calc(100% + 18px); top: 0; padding: 4px 9px; border-radius: 6px; background: var(--raised); box-shadow: var(--e1), 0 0 0 .5px var(--line); white-space: nowrap; font: 500 11px/14px var(--font); color: var(--ink2); }
.ex-l.is-on .ex-tag { color: var(--accent); }
.ex-ground { background: var(--page); box-shadow: 0 0 0 .5px var(--line-strong); }
.ex-grid { display: grid; grid-template-columns: repeat(12, 1fr); gap: 8px; padding: 0 20px; }
.ex-grid i { background: color-mix(in srgb, var(--accent) 10%, transparent); box-shadow: inset 0 0 0 .5px color-mix(in srgb, var(--accent) 40%, transparent); }
.ex-type { padding: 64px 22px 0; }
.ex-type b { display: block; max-width: 11em; font: 450 34px/1 var(--font); letter-spacing: -0.04em; color: var(--ink); }
.ex-type span { display: block; max-width: 22em; margin-top: 10px; font-size: 9px; line-height: 13px; color: var(--ink2); }
.ex-pics img { position: absolute; width: 170px; aspect-ratio: 16 / 10; object-fit: cover; object-position: top; border-radius: 2px; box-shadow: 0 0 0 .5px var(--line), var(--e2); }
.ex-parts .p-bar { position: absolute; left: 50%; top: 12px; width: 250px; height: 22px; margin-left: -125px; border-radius: 9999px; background: var(--glass); box-shadow: 0 0 0 .5px var(--line), var(--e2); display: flex; align-items: center; justify-content: space-between; padding: 0 3px 0 10px; font-size: 7px; color: var(--ink2); }
.ex-parts .p-bar em { height: 16px; padding: 0 8px; display: flex; align-items: center; border-radius: 9999px; background: var(--ink); color: var(--page); font-style: normal; }
.ex-parts .p-btn { position: absolute; left: 22px; top: 142px; height: 18px; padding: 0 9px; display: flex; align-items: center; border-radius: 9999px; background: var(--ink); color: var(--page); font-size: 8px; }
.ex-motion svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.ex-side h3 { margin: 0 0 6px; font: 450 28px/1.1 var(--font); letter-spacing: -0.025em; }
.ex-side p { margin: 0 0 16px; font-size: 15px; line-height: 23px; color: var(--ink2); }
.ex-list { margin: 0; padding: 0; list-style: none; }
.ex-list li { display: flex; align-items: baseline; gap: 12px; padding: 9px 0; border-top: .5px solid var(--line-strong); cursor: pointer; color: var(--ink3); }
.ex-list li b { font-weight: 500; color: var(--ink2); }
.ex-list li.is-on b, .ex-list li:is(:hover, [data-hover]) b { color: var(--ink); }
.ex-list li .mono { width: 20px; font-size: 11px; }
.ex-ctl { display: flex; align-items: center; gap: 14px; margin-top: 18px; }
.ex-ctl input { flex: 1; accent-color: var(--ink); }
@media (max-width: 900px) { .ex { grid-template-columns: 1fr; margin-right: 0; } .ex-view { height: 480px; } .ex-rig { transform-origin: 50% 50%; scale: .6; } }