:root {
  --line: 2rem;
  --paper: #fcfbf6;
  --paper-past: #f4efe2;
  --rule: #d9e4f0;
  --margin: #eba5a1;
  --ink: #2e2e33;
  --ink-soft: #5c5b63;
  --pen: #2160d6;
  --pen-dark: #184db3;
  --serif: ui-serif, "New York", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, system-ui, "Segoe UI", Roboto, sans-serif;
  --gutter: 4.5rem;
  --left: max(var(--gutter), calc((100vw - 64rem) / 2));
  color-scheme: light;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 1.25rem/var(--line) var(--serif); font-kerning: normal;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}
img { display: block; max-width: 100%; height: auto; }
a { color: var(--pen); text-decoration-thickness: 1px; text-underline-offset: .2em; }
a:hover { color: var(--pen-dark); text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--pen); outline-offset: 3px; border-radius: 4px; }
p, ul, ol, dl, h1, h2, h3, table, figure { margin: 0; }
.skip { position: absolute; left: -999px; top: 0; }
.skip:focus { left: 1rem; top: 1rem; background: var(--paper); padding: .5rem 1rem; z-index: 2; }

/* A sheet is a ruled page with the red margin line. Every line box inside is a multiple of --line, so the
   text sits on the ruling. */
.sheet {
  position: relative;
  padding: calc(var(--line) * 2) 1.5rem calc(var(--line) * 2) var(--left);
  background-image: repeating-linear-gradient(to bottom, transparent 0, transparent calc(var(--line) - 1px),
                    var(--rule) calc(var(--line) - 1px), var(--rule) var(--line));
}
.sheet::before {
  content: ""; position: absolute; top: 0; bottom: 0; left: calc(var(--left) - 1.25rem);
  border-left: 1px solid var(--margin); z-index: 1; pointer-events: none;
}
.sheet > * { max-width: 40rem; }
.sheet > h1 { max-width: none; }
.sheet + .sheet { padding-top: 0; }
.sheet p + p, .sheet p + .actions, .sheet .actions + p { margin-top: var(--line); }

h1, h2, h3 { font-family: var(--serif); color: var(--ink); text-wrap: balance; }
/* Big writing takes two lines of the page: the h1 covers the ruling with its own, twice as wide, so no rule
   runs through the middle of the letters. */
h1 {
  font-size: clamp(2.375rem, 6vw, 3.75rem); line-height: calc(var(--line) * 2); font-weight: 600;
  letter-spacing: -.015em; margin-bottom: var(--line); position: relative;
  background: var(--paper) repeating-linear-gradient(to bottom, transparent 0, transparent calc(var(--line) * 2 - 1px),
              var(--rule) calc(var(--line) * 2 - 1px), var(--rule) calc(var(--line) * 2));
  max-width: none; margin-left: calc(-1 * var(--left)); margin-right: -1.5rem;
  padding-left: var(--left); padding-right: 1.5rem;
}
h2 { font-size: 1.75rem; line-height: var(--line); font-weight: 600; margin-bottom: var(--line); }
h3 { font-size: 1.375rem; line-height: var(--line); font-weight: 600; }
.lead { font-size: 1.375rem; }
.soft { color: var(--ink-soft); }
kbd {
  font: 600 .95rem/1 var(--sans); display: inline-block; min-width: 1.6em; padding: .2em .4em; margin: 0 .08em;
  text-align: center; color: var(--ink); background: #fff; border: 1px solid #d3d0c6; border-bottom-width: 2px;
  border-radius: 6px; vertical-align: .08em;
}

/* Header and footer sit outside the ruling, like the top and bottom of a page. */
.site-header { display: flex; align-items: center; gap: 1rem; padding: 1rem 1.5rem 1rem calc(var(--left) - 2.75rem);
  font-family: var(--sans); font-size: 1.0625rem; }
.logo { display: inline-flex; align-items: center; gap: .6rem; color: var(--ink); text-decoration: none;
  font: 600 1.375rem/1 var(--serif); }
.logo img { width: 32px; height: 32px; }
.site-header nav { margin-left: auto; display: flex; gap: 1.25rem; }
.site-header nav a { color: var(--ink-soft); text-decoration: none; }
.site-header nav a:hover, .site-header nav a[aria-current] { color: var(--ink); text-decoration: underline; }

.btn {
  display: inline-flex; align-items: center; gap: .6rem; height: calc(var(--line) * 1.75); padding: 0 1.4rem;
  margin: calc(var(--line) * .125) 0; border-radius: 999px; background: var(--pen); color: #fff;
  font: 600 1.125rem/1 var(--sans); text-decoration: none; box-shadow: 0 1px 0 rgba(0, 0, 0, .08);
}
.btn:hover { background: var(--pen-dark); color: #fff; text-decoration: none; }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 0 1.25rem; }

/* The screenshot band: past-page paper, no ruling. */
.shot { background: var(--paper-past); padding: calc(var(--line) * 2) 1rem; border-block: 1px solid #e6dfcd; }
.shot picture { display: block; max-width: 1022px; margin: 0 auto; }
.shot img { width: 100%; border-radius: 10px;
  box-shadow: 0 1px 2px rgba(60, 45, 20, .12), 0 12px 32px rgba(60, 45, 20, .16), 0 40px 80px -24px rgba(60, 45, 20, .22); }
.shot figcaption { max-width: 40rem; margin: var(--line) auto 0; text-align: center; color: var(--ink-soft);
  font-size: 1.125rem; }

/* Features: a short to-do list, each one ticked off. */
.features { list-style: none; padding: 0; display: grid; gap: var(--line) 3rem; }
.sheet > .features { max-width: 64rem; }
.features li { position: relative; }
.features h3 { margin-bottom: 0; }
.check { position: absolute; left: calc(-1 * var(--gutter) + 1.6rem); top: .3rem; width: 1.5rem; height: 1.5rem;
  fill: none; stroke-linecap: round; stroke-linejoin: round; }
.check rect { stroke: var(--pen); stroke-width: 1.4; fill: #fff; }
.check path { stroke: var(--pen); stroke-width: 2.6; }
@media (min-width: 900px) { .features { grid-template-columns: 1fr 1fr; } }

.price { font-size: 1.375rem; }
.faq h3 { margin-top: var(--line); }
.faq h3:first-of-type { margin-top: 0; }
.more { margin-top: var(--line); }

/* Prose pages */
.dated { color: var(--ink-soft); }
.prose h2 { margin: var(--line) 0 0; }
.prose h2 + p { margin-top: 0; }
.contact { font-size: 1.375rem; }
table.keys { border-collapse: collapse; width: 100%; max-width: 32rem; }
table.keys th, table.keys td { padding: 0; height: var(--line); vertical-align: middle; text-align: left; }
table.keys th { width: 8.5rem; white-space: nowrap; font-weight: 400; }

.site-footer { font-family: var(--sans); font-size: 1.0625rem; line-height: 1.6; color: var(--ink-soft);
  padding: 2rem 1.5rem 3rem var(--left); border-top: 3px double var(--margin); }
.site-footer p { margin: 0 0 .5rem; }
.site-footer a { color: var(--ink); }
.site-footer nav { display: flex; flex-wrap: wrap; gap: .25rem 1.5rem; margin-bottom: .75rem; }

@media (max-width: 640px) {
  :root { --gutter: 3rem; }
  body { font-size: 1.1875rem; }
  .sheet { padding-right: 1.25rem; }
  .sheet::before { left: 1.75rem; }
  .check { left: -2.75rem; width: 1.25rem; height: 1.25rem; top: .4rem; }
  h1 { font-size: 1.875rem; line-height: var(--line); background: none; }
  h2 { font-size: 1.5rem; }
  .lead, .price, .contact { font-size: 1.25rem; }
  .site-header { padding-left: 1rem; padding-right: 1rem; }
  .site-header nav { gap: 1rem; }
  .site-header .nav-features { display: none; }
  .shot { padding: var(--line) .75rem; }
  .site-footer { padding-left: 1.25rem; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }