:root {
  color-scheme: light dark;

  --bg: #f4f5f7;
  --card: #ffffff;
  --fg: #16181d;
  --muted: #6b7280;
  --line: #e5e7eb;
  --line-soft: #eef0f3;
  --accent: #2563eb;
  --accent-soft: #eff4ff;
  --note-bg: #fbfbfc;
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 8px 24px rgba(16, 24, 40, .06);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --card: #171a20;
    --fg: #e9eaec;
    --muted: #9aa1ac;
    --line: #2a2e37;
    --line-soft: #23262d;
    --accent: #7ea6ff;
    --accent-soft: #1b2333;
    --note-bg: #1c1f26;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .28);
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  padding: clamp(1.5rem, 5vw, 4rem) 1.125rem clamp(3rem, 8vw, 6rem);
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  font-size: 16.5px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 40rem;
  margin: 0 auto;
}

.card {
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: clamp(1.5rem, 4vw, 2.75rem);
}

/* --- typography --- */

.eyebrow {
  display: block;
  font-size: .8125rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: .5rem;
}

h1 {
  font-size: clamp(1.5rem, 4.5vw, 1.875rem);
  line-height: 1.35;
  font-weight: 700;
  letter-spacing: -.01em;
  margin: 0 0 .625rem;
}

.lede {
  color: var(--muted);
  margin: 0;
}

h2 {
  font-size: 1.0625rem;
  font-weight: 650;
  margin: 2.25rem 0 .875rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line-soft);
}

h2:first-of-type { border-top: 0; padding-top: 0; }

p { margin: 0 0 1rem; }

a {
  color: var(--accent);
  text-decoration-color: color-mix(in srgb, var(--accent) 35%, transparent);
  text-underline-offset: .2em;
}

a:hover { text-decoration-color: currentColor; }

strong { font-weight: 650; }

/* --- numbered steps --- */

.steps {
  list-style: none;
  counter-reset: step;
  margin: 0;
  padding: 0;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding: 0 0 1.125rem 2.625rem;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: .3125rem;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: .875rem;
  font-weight: 650;
  font-variant-numeric: tabular-nums;
  line-height: 1.75rem;
  text-align: center;
}

/* connector line between step bullets */
.steps li:not(:last-child)::after {
  content: "";
  position: absolute;
  left: .84375rem;
  top: 2.25rem;
  bottom: .25rem;
  width: 1px;
  background: var(--line);
}

.steps li:last-child { padding-bottom: 0; }

/* --- screenshots --- */

figure.shot {
  margin: .875rem 0 .25rem;
}

figure.shot img {
  display: block;
  width: 100%;
  max-width: 544px;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg);
}

/* --- plain bullet lists --- */

.list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.list li {
  position: relative;
  padding-left: 1.25rem;
  margin-bottom: .5rem;
}

.list li::before {
  content: "";
  position: absolute;
  left: .1875rem;
  top: .8125rem;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--muted);
}

.list li:last-child { margin-bottom: 0; }

/* --- callout --- */

.note {
  background: var(--note-bg);
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  padding: 1rem 1.125rem;
  margin: 1.5rem 0 0;
  font-size: .9375rem;
  color: var(--muted);
}

.note p:last-child { margin-bottom: 0; }

.note strong { color: var(--fg); }

/* --- link cards (home page) --- */

.cards {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: grid;
  gap: .75rem;
}

.cards a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.125rem 1.25rem;
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  background: var(--card);
  color: var(--fg);
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: border-color .15s ease, transform .15s ease;
}

.cards a:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, var(--line));
  transform: translateY(-1px);
}

.cards .title { font-weight: 600; }

.cards .desc {
  display: block;
  font-size: .9063rem;
  font-weight: 400;
  color: var(--muted);
  margin-top: .125rem;
}

.cards .chev {
  color: var(--muted);
  flex: none;
}

/* --- footer --- */

.foot {
  margin: 2rem 0 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line-soft);
  font-size: .9375rem;
  color: var(--muted);
}

.back {
  display: inline-block;
  margin-bottom: 1.25rem;
  font-size: .9375rem;
  color: var(--muted);
  text-decoration: none;
}

.back:hover { color: var(--fg); }