/*
 * Project page for a NainDev repository, on the NainDev brand system (paper, blue inks, 4 px
 * radius, solid-offset shadows). One stylesheet, no script, no web font: system fonts with
 * the brand faces first, so the page loads fast and works under a strict CSP.
 */

:root {
  --blue: #0047ab;
  --blue-deep: #002b66;
  --blue-soft: #d6e4fa;
  --paper: #edf1f6;
  --surface: #f7f9fc;
  --sunken: #dee6f0;
  --line: #c6d2e3;
  --ink: #1d1d1b;
  --ink-soft: #3d4655;
  --muted: #55627a;
  --green-ink: #2e6b00;
  --green-soft: #e4f5d0;
  --red-ink: #c4001a;
  --font-sans: "Urbanist", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --radius: 4px;
  --shadow: 6px 6px 0 var(--ink);
  --shell: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.12;
  letter-spacing: -0.015em;
}

p {
  margin: 0 0 14px;
}

a {
  color: var(--blue);
}

:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: -999px;
  padding: 10px 14px;
  background: var(--blue);
  color: #fff;
}

.skip:focus {
  left: 12px;
  top: 12px;
  z-index: 30;
}

.shell {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 20px;
}

/* Top bar ------------------------------------------------------------------ */

.top {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 2px solid var(--ink);
  background: var(--surface);
}

.top .shell {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-block: 10px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.mark {
  width: 28px;
  height: 28px;
  padding: 3px;
  border-radius: var(--radius);
  background: var(--blue);
  fill: none;
  stroke: #fff;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.4;
}

.top nav {
  display: flex;
  gap: 4px;
  margin-left: auto;
}

.top nav a {
  padding: 8px 12px;
  color: var(--ink-soft);
  font-size: 0.92rem;
  font-weight: 700;
  text-decoration: none;
}

.top nav a:hover {
  color: var(--blue);
  text-decoration: underline;
}

/* Hero --------------------------------------------------------------------- */

.hero {
  padding: 64px 0 44px;
}

.eyebrow {
  display: block;
  margin-bottom: 12px;
  color: var(--blue);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 18ch;
  margin-bottom: 18px;
  font-size: clamp(2.3rem, 5.4vw, 3.9rem);
  font-weight: 800;
  line-height: 1.04;
}

.lead {
  max-width: 40rem;
  color: var(--ink-soft);
  font-size: 1.2rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 26px 0 22px;
}

.btn {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 10px 20px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  transition: transform 120ms ease, box-shadow 120ms ease;
}

.btn:hover {
  box-shadow: 4px 4px 0 var(--blue);
  transform: translate(-2px, -2px);
}

.btn.primary {
  border-color: var(--blue-deep);
  background: var(--blue);
  color: #fff;
}

.btn.primary:hover {
  box-shadow: 4px 4px 0 var(--red-ink);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.chips li {
  padding: 4px 12px;
  border: 1.5px solid var(--blue);
  border-radius: 999px;
  background: var(--blue-soft);
  color: var(--blue-deep);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
}

/* Sections ----------------------------------------------------------------- */

.section {
  padding: 40px 0;
  border-top: 2px solid var(--line);
}

.section > .shell > h2 {
  margin-bottom: 10px;
  font-size: clamp(1.7rem, 3.2vw, 2.3rem);
  font-weight: 800;
}

.section .intro {
  max-width: 44rem;
  margin-bottom: 26px;
  color: var(--ink-soft);
}

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
}

.card {
  padding: 20px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--surface);
}

.card h3 {
  margin-bottom: 8px;
  font-size: 1.12rem;
}

.card p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.96rem;
}

.card code,
.tag {
  font-family: var(--font-mono);
  font-size: 0.86em;
}

.tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 8px;
  border-radius: 2px;
  background: var(--blue-soft);
  color: var(--blue-deep);
  font-weight: 700;
}

.steps {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
}

.steps li {
  position: relative;
  padding: 18px 18px 18px 64px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.steps li::before {
  position: absolute;
  top: 16px;
  left: 16px;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  content: counter(step);
  counter-increment: step;
  font-family: var(--font-mono);
  font-weight: 700;
}

.steps strong {
  display: block;
}

pre {
  margin: 0 0 16px;
  padding: 16px 18px;
  overflow-x: auto;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--ink);
  box-shadow: 4px 4px 0 var(--blue);
  color: #edf1f6;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  line-height: 1.65;
}

pre .k {
  color: #9cc3ff;
}

pre .c {
  color: #8da0bd;
}

.table-wrap {
  overflow-x: auto;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--surface);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.94rem;
}

th,
td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--sunken);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

tr:last-child td {
  border-bottom: 0;
}

td code {
  font-family: var(--font-mono);
  font-size: 0.88em;
}

.diagram {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--surface);
}

.diagram text {
  fill: var(--ink);
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
}

.diagram .sub {
  fill: var(--muted);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
}

.diagram rect {
  fill: var(--surface);
  stroke: var(--ink);
  stroke-width: 2;
}

.diagram .core rect {
  fill: var(--blue);
}

.diagram .sub-core {
  fill: #c9dcfa;
}

.diagram .dash {
  stroke-dasharray: 6 5;
}

.diagram .core text {
  fill: #fff;
}

.diagram .arrow {
  fill: none;
  stroke: var(--blue);
  stroke-linecap: round;
  stroke-width: 2.2;
}

.note {
  padding: 14px 18px;
  border-left: 6px solid var(--blue);
  background: var(--blue-soft);
  color: var(--blue-deep);
}

.cols {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(auto-fit, minmax(20rem, 1fr));
  align-items: start;
}

/* Grid items default to min-width: auto, so a long code line made a column wider than the phone. */
.cols > *,
.grid > * {
  min-width: 0;
}

.grid + .note,
.table-wrap + .note {
  margin-top: 16px;
}

.diagram + .grid {
  margin-top: 16px;
}

.wf {
  padding: 24px 0;
  border-top: 1px solid var(--line);
}

.wf pre {
  margin: 0;
}

.sub-title {
  margin: 28px 0 12px;
  font-size: 1.15rem;
  font-weight: 800;
}

.sub-title:first-of-type {
  margin-top: 0;
}

.footer {
  padding: 28px 0 56px;
  border-top: 2px solid var(--ink);
  color: var(--muted);
  font-size: 0.9rem;
}

.footer .shell {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  justify-content: space-between;
}

@media (max-width: 40rem) {
  body {
    font-size: 16px;
  }

  .hero {
    padding-top: 40px;
  }

  .top nav a:not(.keep) {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .btn {
    transition: none;
  }
}