:root {
  --paper: oklch(0.975 0.006 95);
  --sheet: oklch(0.995 0.002 95);
  --ink: oklch(0.24 0.035 255);
  --ink-2: oklch(0.44 0.025 255);
  --rule: oklch(0.87 0.01 255);
  --blue: oklch(0.42 0.11 255);
  --hl: oklch(0.91 0.15 108);
  --hl-soft: oklch(0.955 0.08 108);
  --night: oklch(0.25 0.045 255);
  --night-2: oklch(0.85 0.015 255);
  --night-rule: oklch(0.58 0.03 255);
  --go: oklch(0.62 0.15 150);
  --serif: "Newsreader", Georgia, serif;
  --sans: "Hanken Grotesk", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --edge: clamp(20px, 5vw, 64px);
  --ease: cubic-bezier(.65, 0, .25, 1);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 17px/1.6 var(--sans);
  text-wrap: pretty; -webkit-font-smoothing: antialiased; overflow-x: clip; }
a { color: var(--blue); text-underline-offset: 3px; }
a:hover { color: var(--ink); }
::selection { background: var(--hl); color: var(--ink); }
:focus-visible { outline: 2px solid var(--blue); outline-offset: 3px; }
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 var(--edge); }
.mono { font: 500 12.5px/1.4 var(--mono); letter-spacing: .05em; text-transform: uppercase; color: var(--ink-2); margin: 0; }

/* progress + nav */
.progress { position: fixed; top: 0; left: 0; right: 0; height: 3px; background: var(--hl);
  transform-origin: 0 50%; transform: scaleX(0); z-index: 30; }
.nav { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid transparent;
  background: color-mix(in oklch, var(--paper) 90%, transparent); backdrop-filter: blur(10px);
  transition: border-color .3s; }
.nav.scrolled { border-bottom-color: var(--rule); }
.nav-in { display: flex; align-items: center; gap: 28px; height: 68px; }
.brand { font: 400 21px/1 var(--serif); color: var(--ink); text-decoration: none; margin-right: auto; white-space: nowrap; }
.brand em { font-style: italic; }
.brand:hover { color: var(--ink); }
.nav .link { font: 500 15px/1 var(--sans); color: var(--ink-2); text-decoration: none; white-space: nowrap; }
.nav .link:hover { color: var(--ink); }
@media (max-width: 760px) { .nav .link { display: none; } }
@media (max-width: 420px) { .nav-in { gap: 14px; } .brand { font-size: 18px; } }
@media (max-width: 360px) { .brand { font-size: 16px; } .nav .btn-sm { padding: 0 12px; font-size: 13px; } }

/* buttons */
.btn { display: inline-flex; align-items: center; gap: 10px; height: 48px; padding: 0 22px;
  border-radius: 4px; border: 1.5px solid var(--ink); font: 600 15px/1 var(--sans);
  text-decoration: none; cursor: pointer; white-space: nowrap;
  transition: background .2s, color .2s, border-color .2s, transform .2s; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--ink); color: var(--paper); }
.btn-primary:hover { background: var(--blue); border-color: var(--blue); color: var(--paper); }
.btn-ghost { background: transparent; color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: var(--paper); }
.btn-sm { height: 40px; padding: 0 16px; font-size: 14px; }
.btn[disabled] { opacity: .35; cursor: not-allowed; }
.btn-hl { background: var(--hl); color: var(--ink); border-color: var(--hl); }
.btn-hl:hover { background: var(--paper); border-color: var(--paper); color: var(--ink); }
.arrow-link { font: 600 15px/1 var(--sans); color: var(--ink); text-decoration: none; display: inline-flex; gap: 8px; align-items: center; }
.arrow-link span { transition: transform .25s var(--ease); }
.arrow-link:hover { color: var(--blue); }
.arrow-link:hover span { transform: translateX(4px); }

/* highlighter */
.hl { background: linear-gradient(var(--hl), var(--hl)) no-repeat 0 88% / 0% .36em;
  -webkit-box-decoration-break: clone; box-decoration-break: clone;
  transition: background-size 1.1s var(--ease) .25s; }
.hl.on { background-size: 100% .36em; }

/* sections */
.sec { display: grid; grid-template-columns: 200px minmax(0, 1fr); gap: 24px 48px;
  padding-block: clamp(64px, 9vw, 112px); border-top: 1px solid var(--rule); }
.sec-label { position: sticky; top: 100px; align-self: start; display: grid; gap: 6px; }
.sec-label .num { font: 500 13px/1 var(--mono); color: var(--blue); }
.title { font: 400 clamp(34px, 4.2vw, 54px)/1.06 var(--serif); letter-spacing: -.015em; margin: 0; max-width: 18ch; }
.title em { font-style: italic; }
.intro { max-width: 58ch; color: var(--ink-2); margin: 20px 0 0; font-size: 17.5px; }
@media (max-width: 860px) { .sec { grid-template-columns: 1fr; } .sec-label { position: static; } }

/* reveal */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .7s ease, transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .08s; } .reveal.d2 { transition-delay: .16s; } .reveal.d3 { transition-delay: .24s; }

/* footer */
footer { padding: 36px 0 44px; font-size: 14px; color: var(--ink-2); }
footer .frow { display: flex; gap: 12px 28px; flex-wrap: wrap; justify-content: space-between; border-top: 1px solid var(--rule); padding-top: 24px; }
footer .links { display: flex; gap: 24px; flex-wrap: wrap; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .hl { transition: none; }
  .reveal { opacity: 1; transform: none; }
  .hl { background-size: 100% .36em; }
}