/* Alpaca Engineering — the one stylesheet. Decisions behind it: docs/decisions.md, "Visual design". */

/* Fonts: self-hosted, Latin subset, variable weight. Licenses sit beside the files. */
@font-face {
  font-family: "Source Serif 4";
  src: url("/assets/fonts/source-serif-4-latin-opsz-normal.woff2") format("woff2");
  font-weight: 200 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Sans 3";
  src: url("/assets/fonts/source-sans-3-latin-wght-normal.woff2") format("woff2");
  font-weight: 200 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Sans 3";
  src: url("/assets/fonts/source-sans-3-latin-wght-italic.woff2") format("woff2");
  font-weight: 200 900;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: "Source Code Pro";
  src: url("/assets/fonts/source-code-pro-latin-wght-normal.woff2") format("woff2");
  font-weight: 200 900;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: only light;

  --bg: #faf9f7;
  --band: #f2efeb;
  --surface: #ffffff;
  --rule: #e3dfda;
  --rule-strong: #cfc9c3;
  --text: #1d1b1a;
  --prose: #2e2b29;
  --body: #4a4643;
  --muted: #5f5a56;
  --accent: #9e2e37;
  --accent-hover: #7d222a;

  --serif: "Source Serif 4", Georgia, serif;
  --sans: "Source Sans 3", "Helvetica Neue", Arial, sans-serif;
  --mono: "Source Code Pro", Menlo, Consolas, monospace;

  --content: 1120px;
  --label-column: 280px;
  --gutter: 20px;
}

@media (min-width: 48rem) {
  :root { --gutter: 40px; }
}

/* Base */

*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; }
h1, h2, h3, p, li, dd { text-wrap: pretty; }
img, svg { display: block; max-width: 100%; }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.wrap {
  width: 100%;
  max-width: calc(var(--content) + 2 * var(--gutter));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--gutter);
  padding: 8px 12px;
  background: var(--text);
  color: var(--surface);
}
.skip-link:focus { top: 8px; color: var(--surface); }

.label {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.lead {
  max-width: 44rem;
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--body);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 12px 24px;
  border: 0;
  border-radius: 2px;
  background: var(--accent);
  color: var(--surface);
  font: 500 1rem/1 var(--sans);
  white-space: nowrap;
  cursor: pointer;
}
.button:hover { background: var(--accent-hover); color: var(--surface); }

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 500;
  color: var(--text);
}
.link-arrow .arrow { color: var(--accent); }

@media (min-width: 48rem) {
  .lead { font-size: 1.25rem; }
}

/* Header */

.site-header { border-bottom: 1px solid var(--rule); }

.site-header__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 32px;
  padding-block: 16px;
}

.brand { display: flex; align-items: center; gap: 11px; color: var(--text); }
.brand:hover { color: var(--text); }

/* The mark carries its own oxide field, so it is an image. The wordmark is
   inlined instead, so it takes currentColor and inverts wherever the header does. */
.brand__mark { display: block; width: 30px; height: 30px; border-radius: 1px; }
.brand__wordmark { display: block; }
.brand__wordmark svg { display: block; height: 17px; width: auto; fill: currentColor; }

@media (min-width: 48rem) {
  .brand__mark { width: 34px; height: 34px; }
  .brand__wordmark svg { height: 19px; }
}

.site-nav { display: flex; align-items: center; gap: 28px; font-size: 0.9375rem; }
.site-nav a { color: var(--text); }
.site-nav a:hover,
.site-nav a[aria-current="page"] { color: var(--accent); }

.site-nav__contact {
  padding: 8px 16px;
  border: 1px solid var(--accent);
  border-radius: 2px;
  font-weight: 500;
}
.site-nav .site-nav__contact { color: var(--accent); }
.site-nav .site-nav__contact:hover { color: var(--accent-hover); border-color: var(--accent-hover); }

@media (min-width: 48rem) {
  .site-header__inner { min-height: 80px; }
  .site-nav { gap: 36px; }
}

/* Home */

.hero { padding-block: 56px 64px; }

.hero__title {
  margin-top: 18px;
  max-width: 920px;
  font-family: var(--serif);
  font-size: clamp(2.25rem, 1.6rem + 2.8vw, 3.625rem);
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: -0.015em;
}

.hero .lead { margin-top: 20px; }

.actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 32px;
  margin-top: 32px;
}

@media (min-width: 48rem) {
  .hero { padding-block: 120px 112px; }
  .hero .lead { margin-top: 28px; }
  .actions { margin-top: 44px; }
}

.section { border-top: 1px solid var(--rule); }

.section__grid {
  display: grid;
  gap: 24px;
  padding-block: 48px 56px;
}

@media (min-width: 48rem) {
  .section__grid { padding-block: 88px 96px; }
}

@media (min-width: 64rem) {
  .section__grid { grid-template-columns: var(--label-column) minmax(0, 1fr); gap: 40px; }
  .section__grid > .label { padding-top: 6px; }
}

.capabilities { display: grid; gap: 36px; }

.capability { border-top: 2px solid var(--text); padding-top: 16px; }
.capability h3 { font-family: var(--serif); font-size: 1.1875rem; font-weight: 600; line-height: 1.3; }
.capability p { margin-top: 8px; color: var(--body); }

@media (min-width: 48rem) {
  .capabilities { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 56px; }
  .capability { padding-top: 20px; }
  .capability h3 { font-size: 1.3125rem; }
  .capability p { margin-top: 12px; line-height: 1.65; }
}

.work-list { margin: 0; padding: 0; list-style: none; border-bottom: 1px solid var(--rule); }
.work-list li { border-top: 1px solid var(--rule); }

.work-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 32px;
  padding-block: 24px;
  color: var(--text);
}
.work-item:hover { color: var(--text); }
.work-item:hover .work-item__title { color: var(--accent); }
.work-item .arrow { display: none; width: 20px; height: 20px; }

.work-item__text { display: flex; flex-direction: column; gap: 8px; }
.work-item__kind {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}
.work-item__title { font-family: var(--serif); font-size: 1.3125rem; font-weight: 500; line-height: 1.3; }
.work-item__summary { max-width: 45rem; font-size: 0.9375rem; line-height: 1.55; color: var(--muted); }

@media (min-width: 48rem) {
  .work-item { padding-block: 32px; }
  .work-item .arrow { display: block; }
  .work-item__text { gap: 10px; }
  .work-item__title { font-size: 1.625rem; }
  .work-item__summary { font-size: 1rem; }
}

.split { display: grid; gap: 16px; }
.statement { font-size: 1.25rem; font-weight: 500; line-height: 1.45; }
.split p:not(.statement) { color: var(--body); line-height: 1.7; }

@media (min-width: 48rem) {
  .split { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 56px; }
  .statement { font-size: 1.5rem; }
}

/* Contact band */

.band { background: var(--band); border-top: 1px solid var(--rule); }

.band__inner {
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding-block: 48px;
}

.band h2 { font-family: var(--serif); font-size: 1.75rem; font-weight: 500; line-height: 1.2; }
.band p { margin-top: 12px; color: var(--body); }

@media (min-width: 48rem) {
  .band__inner { flex-direction: row; align-items: flex-end; justify-content: space-between; gap: 64px; padding-block: 88px; }
  .band h2 { font-size: 2.375rem; line-height: 1.15; letter-spacing: -0.01em; }
  .band p { margin-top: 16px; font-size: 1.125rem; }
}

/* Footer */

.site-footer { border-top: 1px solid var(--rule); }

.site-footer__inner {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-block: 32px 48px;
  font-size: 0.875rem;
  color: var(--muted);
}
.site-footer__inner a { color: var(--muted); }
.site-footer__inner a:hover { color: var(--accent); }

.site-footer__legal { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 12px; }

@media (min-width: 48rem) {
  .site-footer__inner { flex-direction: row; align-items: center; justify-content: space-between; padding-block: 40px 56px; }
}

/* Pages and case studies */

.page-header { padding-block: 48px 40px; }

.page-header h1 {
  max-width: 900px;
  font-family: var(--serif);
  font-size: clamp(2rem, 1.5rem + 2vw, 3rem);
  font-weight: 500;
  line-height: 1.12;
  letter-spacing: -0.012em;
}
.page-header .label + h1 { margin-top: 16px; }
.page-header .lead { margin-top: 20px; }

.facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 24px;
  margin-top: 32px;
  padding-block: 20px;
  border-block: 1px solid var(--rule);
}
.facts dt {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}
.facts dd { margin-top: 6px; }

.page-body { padding-block: 0 64px; }

@media (min-width: 48rem) {
  .page-header { padding-block: 72px 64px; }
  .page-header .label + h1 { margin-top: 20px; }
  .page-header .lead { margin-top: 24px; }
  .facts { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 32px; margin-top: 48px; padding-block: 24px; }
  .page-body { padding-block: 16px 104px; }
}

@media (min-width: 64rem) {
  .page-body > * { margin-left: calc(var(--label-column) + 40px); }
  .page-body--list > * { margin-left: 0; }
}

.prose { max-width: 45rem; font-size: 1.0625rem; line-height: 1.7; color: var(--prose); }
.prose > * + * { margin-top: 1.1em; }
.prose h2 {
  margin-top: 2.2em;
  font-family: var(--serif);
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--text);
}
.prose > h2:first-child { margin-top: 0; }
.prose h2 + * { margin-top: 0.6em; }
.prose ul { padding-left: 1.4em; }
.prose li + li { margin-top: 0.4em; }
.prose a { text-decoration: underline; text-underline-offset: 0.15em; }

.prose figure {
  margin-block: 2em 1.6em;
  padding: 20px;
  border: 1px solid var(--rule);
  background: var(--surface);
}
.prose figcaption { margin-top: 16px; font-size: 0.875rem; line-height: 1.55; color: var(--muted); }

@media (min-width: 48rem) {
  .prose { font-size: 1.125rem; }
  .prose h2 { font-size: 1.625rem; }
  .prose figure { padding: 32px 28px 20px; }
}

/* Diagrams: drawn inline so they use the site's fonts; scroll sideways rather than shrink unreadably. */

.diagram { overflow-x: auto; }
.diagram svg { width: 100%; min-width: 600px; height: auto; }
.diagram__text { font-family: var(--mono); font-size: 12px; fill: var(--text); }
.diagram__sub { fill: var(--muted); font-size: 11px; }
.diagram__note { fill: var(--muted); font-size: 11px; }
.diagram__caption { fill: var(--muted); font-size: 11px; letter-spacing: 0.06em; }
.diagram__box { fill: none; stroke: var(--text); stroke-width: 1.5; }
.diagram__box--accent { stroke: var(--accent); }
.diagram__box--dashed { stroke-dasharray: 4 3; }
.diagram__line { fill: none; stroke: var(--text); stroke-width: 1.5; }

/* Contact form */

.form { display: grid; gap: 20px; max-width: 36rem; }

.field { display: grid; gap: 6px; }
.field label { font-size: 0.9375rem; font-weight: 600; }
.field__optional { font-weight: 400; color: var(--muted); }

.field input,
.field select,
.field textarea {
  width: 100%;
  min-height: 48px;
  padding: 10px 12px;
  border: 1px solid var(--rule-strong);
  border-radius: 2px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
}
.field textarea { min-height: 10rem; resize: vertical; }
.field select {
  appearance: none;
  padding-right: 40px;
  background: var(--surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8' fill='none' stroke='%231d1b1a' stroke-width='1.5'%3E%3Cpath d='M1 1.5l5 5 5-5'/%3E%3C/svg%3E") no-repeat right 14px center;
}
.field input:focus-visible,
.field select:focus-visible,
.field textarea:focus-visible { outline: 2px solid var(--accent); outline-offset: 0; border-color: var(--accent); }

/* The honeypot: off-screen for people, still in the form for bots. */
.field--trap { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }

.form .button { justify-self: start; }
.form-note { margin-top: 28px; color: var(--muted); }