:root {
  --paper: #f6f7f9;
  --sheet: #ffffff;
  --ink: #1b1e26;
  --ink-soft: #4a5060;
  --rule: #d7dbe3;
  --magenta: #c4006a;
  --cyan: #0089b8;
  --measure: 34rem;
  --serif: "STIX Two Text", "STIX Two", Georgia, serif;
  --sans: "Public Sans", "Helvetica Neue", Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #15171c; --sheet: #1c1f26; --ink: #e8eaef; --ink-soft: #a4abba;
    --rule: #333846; --magenta: #ff5fae; --cyan: #4cc3ec;
  }
}
:root[data-theme="dark"] {
  --paper: #15171c; --sheet: #1c1f26; --ink: #e8eaef; --ink-soft: #a4abba;
  --rule: #333846; --magenta: #ff5fae; --cyan: #4cc3ec;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 1.125rem/1.6 var(--serif);
  font-feature-settings: "kern", "liga", "onum";
}
a { color: inherit; text-decoration-color: var(--magenta); text-underline-offset: .18em; }
a:hover { color: var(--magenta); }
:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; }
img { max-width: 100%; height: auto; }

.wrap { max-width: 68rem; margin: 0 auto; padding: 0 1rem; }
@media (min-width: 48rem) { .wrap { padding: 0 2rem; } }

/* masthead */
.mast { border-bottom: 1px solid var(--rule); font-family: var(--sans); font-size: .9375rem; }
.mast .wrap { display: flex; align-items: center; gap: 1.5rem; min-height: 3.75rem; flex-wrap: wrap; }
.brand { font: 600 1.25rem/1 var(--serif); text-decoration: none; letter-spacing: -.01em; }
.brand span { color: var(--magenta); }
.mast nav { display: flex; gap: 1.25rem; margin-left: auto; flex-wrap: wrap; }
.mast nav a { text-decoration: none; color: var(--ink-soft); }
.mast nav a:hover { color: var(--ink); }

/* the book-page grid: a wide outer margin for side notes */
.page { display: grid; grid-template-columns: 1fr; gap: 0 3rem; padding: 3rem 0; }
@media (min-width: 60rem) {
  .page { grid-template-columns: minmax(0, var(--measure)) 15rem; justify-content: start; padding-left: 8%; }
}
.page > * { grid-column: 1; }
.note {
  font: .875rem/1.45 var(--sans); color: var(--ink-soft);
  border-left: 2px solid var(--magenta); padding-left: .75rem; margin: 0 0 1.5rem;
}
@media (min-width: 60rem) { .note { grid-column: 2; margin-top: .3rem; } }

h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.15; letter-spacing: -.01em; }
h1 { font-size: clamp(2.25rem, 6vw, 3.75rem); margin: 0 0 1.5rem; }
h2 { font-size: 1.75rem; margin: 3.5rem 0 1rem; }
h3 { font-size: 1.25rem; margin: 2rem 0 .5rem; }
p { margin: 0 0 1em; hyphens: auto; }
.lede { font-size: 1.3125rem; line-height: 1.5; color: var(--ink-soft); hyphens: manual; }
.page p.body { text-align: justify; }
.page p.body + p.body { text-indent: 1.5em; margin-top: -1em; }

/* hero: a chapter opening */
.opening { padding: 4rem 0 2rem; border-bottom: 1px solid var(--rule); }
.folio { font: .875rem/1 var(--sans); color: var(--ink-soft); font-variant-numeric: oldstyle-nums; }
.chapnum { font: 400 clamp(5rem, 16vw, 10rem)/.8 var(--serif); color: var(--magenta); margin: 1rem 0 0; }
.opening h1 { max-width: 22ch; }
.opening .lede { max-width: var(--measure); }
.dropcap::first-letter { float: left; font-size: 3.4em; line-height: .82; padding: .06em .08em 0 0; color: var(--magenta); }

.actions { display: flex; flex-wrap: wrap; gap: .75rem 1.25rem; align-items: center; margin-top: 2rem; font-family: var(--sans); }
.btn {
  display: inline-block; font: 600 1rem/1 var(--sans); text-decoration: none;
  background: var(--ink); color: var(--paper); padding: .9rem 1.4rem; border-radius: 2px;
}
.btn:hover { background: var(--magenta); color: #fff; }
.quiet { font-size: 1rem; }

/* format matrix */
.formats { width: 100%; border-collapse: collapse; font: .9375rem/1.4 var(--sans); margin: 1rem 0 2rem; }
.formats th, .formats td { padding: .55rem .5rem; border-bottom: 1px solid var(--rule); text-align: left; vertical-align: top; }
.formats thead th { font-weight: 600; border-bottom: 2px solid var(--ink); }
.formats td:first-child { font-weight: 600; white-space: nowrap; }
.yes { color: var(--cyan); font-weight: 700; }
.scroll { overflow-x: auto; }

/* pipeline: a real sequence */
.steps { list-style: none; counter-reset: s; padding: 0; margin: 1rem 0 2rem; }
.steps li { counter-increment: s; position: relative; padding: 0 0 1.1rem 2.5rem; }
.steps li::before {
  content: counter(s); position: absolute; left: 0; top: .05rem;
  font: 600 1rem/1.6rem var(--serif); width: 1.6rem; text-align: center;
  color: var(--magenta); border: 1px solid var(--magenta); border-radius: 50%;
}
.steps strong { font-weight: 600; }

ul.plain { padding-left: 1.1rem; margin: 0 0 1.5rem; }
ul.plain li { margin-bottom: .45rem; }

/* specimen: source beside its result */
.specimen { display: grid; gap: 1rem; margin: 1.5rem 0 2rem; }
@media (min-width: 40rem) { .specimen { grid-template-columns: 1fr 1fr; } }
.specimen figure { margin: 0; background: var(--sheet); border: 1px solid var(--rule); padding: 1rem 1.1rem; }
.specimen figcaption { font: .8125rem/1.3 var(--sans); color: var(--ink-soft); margin-bottom: .6rem; }
.specimen pre { margin: 0; font: .8125rem/1.5 ui-monospace, Menlo, Consolas, monospace; white-space: pre-wrap; word-break: break-word; }
.specimen .set { font-size: 1rem; line-height: 1.5; }
.specimen .eq { text-align: center; font-style: italic; margin: .6rem 0; }
.specimen .eq .n { float: right; font-style: normal; }

/* pricing */
.plans { display: grid; gap: 0; margin: 1.5rem 0 1rem; border-top: 2px solid var(--ink); }
@media (min-width: 48rem) { .plans { grid-template-columns: repeat(3, 1fr); } }
.plan { padding: 1.5rem 1.25rem 1.75rem 0; border-bottom: 1px solid var(--rule); }
@media (min-width: 48rem) {
  .plan { padding: 1.5rem 1.5rem 1.75rem; border-bottom: 0; border-left: 1px solid var(--rule); }
  .plan:first-child { border-left: 0; padding-left: 0; }
}
.plan h3 { margin: 0 0 .25rem; }
.price { font: 400 2.75rem/1 var(--serif); margin: .5rem 0 .25rem; font-variant-numeric: lining-nums; }
.price small { font: .9375rem var(--sans); color: var(--ink-soft); }
.plan ul { font: .9375rem/1.45 var(--sans); padding-left: 1.1rem; margin: 1rem 0 1.25rem; }
.plan ul li { margin-bottom: .4rem; }
.plan .btn { font-size: .9375rem; padding: .75rem 1.1rem; }
.fine { font: .875rem/1.5 var(--sans); color: var(--ink-soft); }

.wide { grid-column: 1 / -1; }

/* footer */
.foot { border-top: 1px solid var(--rule); padding: 2.5rem 0 3rem; font: .875rem/1.6 var(--sans); color: var(--ink-soft); }
.foot .wrap { display: flex; flex-wrap: wrap; gap: 1rem 2.5rem; justify-content: space-between; }
.foot nav { display: flex; flex-wrap: wrap; gap: .5rem 1.25rem; }
.foot a { color: var(--ink-soft); }

/* home hero: the one-button promise */
h1.big { font-size: clamp(3rem, 10vw, 6.5rem); line-height: .95; letter-spacing: -.03em; max-width: none; margin-bottom: 1.25rem; }
.flow { display: grid; gap: 1rem; align-items: center; margin: 2.5rem 0 .5rem; font-family: var(--sans); }
@media (min-width: 52rem) { .flow { grid-template-columns: 1fr auto 1fr; gap: 2rem; } }
.fmt { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: .5rem; }
@media (min-width: 52rem) { .fmt.in { justify-content: flex-end; } }
.fmt li { font-size: .9375rem; padding: .45rem .8rem; border: 1px solid var(--rule); background: var(--sheet); border-radius: 2px; }
.fmt.out li { border-color: var(--cyan); }
.press {
  justify-self: start; font: 600 1.25rem/1 var(--sans); color: #fff; background: var(--magenta);
  padding: 1.1rem 1.8rem; border-radius: 999px; box-shadow: 0 .35rem 0 color-mix(in srgb, var(--magenta) 55%, #000);
}
@media (min-width: 52rem) { .press { justify-self: center; } }
.proof { padding: 3.5rem 0; border-top: 1px solid var(--rule); }
.proof h2 { margin-top: 0; max-width: 24ch; }
.proof p { max-width: var(--measure); color: var(--ink-soft); }
.covers { display: flex; flex-wrap: wrap; gap: 2rem; margin-top: 2rem; }
.covers figure { margin: 0; width: min(11rem, 42vw); }
.covers img { display: block; width: 100%; height: auto; box-shadow: 0 .6rem 1.4rem rgba(20,24,40,.25); }
.covers figcaption { font: .875rem/1.4 var(--sans); color: var(--ink-soft); margin-top: .75rem; }
.manual { background: var(--ink); color: var(--paper); padding: 3.5rem 0; }
.manual h2 { margin-top: 0; color: var(--paper); }
.manual p { max-width: var(--measure); font-size: 1.1875rem; }
.manual .hit { color: #fff; font-weight: 600; border-left: 3px solid var(--magenta); padding-left: 1rem; }
:root[data-theme="dark"] .manual .hit { color: var(--paper); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .manual .hit { color: var(--paper); } }

@media (prefers-reduced-motion: no-preference) {
  .press { animation: pressdown 1.6s ease-in-out .6s 1 both; }
  @keyframes pressdown { 0%, 40%, 100% { transform: none; } 50%, 60% { transform: translateY(.3rem); box-shadow: 0 .05rem 0 color-mix(in srgb, var(--magenta) 55%, #000); } }
  .chapnum { animation: settle .9s cubic-bezier(.2,.7,.2,1) both; }
  @keyframes settle { from { opacity: 0; transform: translateY(-.15em); } to { opacity: 1; transform: none; } }
}