:root {
  --bg: #F6F8FA;
  --surface: #FFFFFF;
  --surface-2: #EDF2F7;
  --ink: #16232E;
  --ink-muted: #4A5A68;
  --ink-faint: #7C8B99;
  --border: rgba(22, 35, 46, 0.11);
  --border-strong: rgba(22, 35, 46, 0.20);
  --accent: #205E7A;
  --accent-strong: #164A61;
  --accent-soft: #E3EEF3;
  --good: #157A63;
  --good-soft: #E3F3EE;
  --good-border: rgba(21, 122, 99, 0.28);
  --shadow: 0 1px 2px rgba(22, 35, 46, 0.06), 0 8px 24px rgba(22, 35, 46, 0.05);
  --font-display: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;
  --font-body: 'Public Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #070B19;
    --surface: #0F172A;
    --surface-2: #131F35;
    --ink: #E7EDF3;
    --ink-muted: #9FB0C3;
    --ink-faint: #6B7C90;
    --border: rgba(231, 237, 243, 0.12);
    --border-strong: rgba(231, 237, 243, 0.22);
    --accent: #4F9BC2;
    --accent-strong: #7CC2E5;
    --accent-soft: #142433;
    --good: #4FCDA9;
    --good-soft: #0E2621;
    --good-border: rgba(79, 205, 169, 0.30);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 12px 32px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-strong); }
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand img {
  width: 34px;
  height: 34px;
  display: block;
}

.brand-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.14em;
  color: var(--ink);
}

nav.site-nav {
  display: flex;
  gap: 4px;
}

nav.site-nav a {
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink-muted);
  padding: 8px 14px;
  border-radius: 8px;
  transition: color 0.15s, background 0.15s;
}

nav.site-nav a:hover {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

nav.site-nav a.active {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: 8px;
  padding-left: 10px;
  border-left: 1px solid var(--border);
}

.lang-switch a {
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-decoration: none;
  color: var(--ink-faint);
  padding: 6px 8px;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
}

.lang-switch a:hover {
  color: var(--accent-strong);
}

.lang-switch a.active {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
}

.eyebrow {
  font-family: var(--font-display);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 14px;
}

h1 {
  font-weight: 700;
  font-size: clamp(28px, 4.5vw, 40px);
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 14px;
  text-wrap: balance;
}

h2 {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

.dek {
  color: var(--ink-muted);
  font-size: 17px;
  max-width: 60ch;
  margin: 0 0 8px;
}

section {
  padding: 44px 0;
  border-top: 1px solid var(--border);
}

section:first-of-type,
.hero {
  border-top: none;
}

.hero {
  padding: 56px 0 32px;
}

p { max-width: 68ch; color: var(--ink-muted); }
.lede { color: var(--ink); font-size: 17px; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 8px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
  box-shadow: var(--shadow);
}

.feature-card .icon-dot {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  margin-bottom: 12px;
}

.feature-card h3 {
  font-size: 15.5px;
  margin: 0 0 6px;
  color: var(--ink);
}

.feature-card p {
  font-size: 14px;
  margin: 0;
  color: var(--ink-muted);
}

.callout {
  background: var(--good-soft);
  border: 1px solid var(--good-border);
  border-radius: 12px;
  padding: 18px 20px;
  margin: 20px 0;
}

.callout .callout-label {
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--good);
  display: block;
  margin-bottom: 6px;
}

.callout p {
  color: var(--ink);
  margin: 0;
  max-width: none;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 4px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-display);
  font-size: 12px;
  color: var(--ink-muted);
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 6px 11px;
  border-radius: 8px;
}

.tag-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  flex: none;
}

.status-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.08em;
  font-weight: 600;
  color: var(--good);
  background: var(--good-soft);
  border: 1px solid var(--good-border);
  padding: 5px 10px 5px 8px;
  border-radius: 999px;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--good);
  flex: none;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px 20px;
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
}

.summary-grid li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 14.5px;
  color: var(--ink-muted);
}

.summary-grid li::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--good);
  margin-top: 7px;
  flex: none;
}

.summary-grid strong { color: var(--ink); font-weight: 600; }

.section-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 12px;
}

.section-num {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-strong);
  flex: none;
}

section ul {
  margin: 0 0 14px;
  padding-left: 0;
  list-style: none;
  max-width: 68ch;
}

section ul li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 9px;
  color: var(--ink-muted);
  font-size: 15.5px;
}

section ul li::before {
  content: "\2013";
  position: absolute;
  left: 0;
  color: var(--ink-faint);
}

.not-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 16px;
  margin: 16px 0 4px;
}

.not-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14.5px;
  color: var(--ink-muted);
  padding: 10px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.not-item::before {
  content: "\2715";
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-faint);
  flex: none;
}

.contact-card {
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--shadow);
}

.contact-card .label {
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 6px;
}

.contact-card .value {
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
  margin: 0;
}

strong { color: var(--ink); font-weight: 600; }

.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 24px;
}

.site-footer-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 28px 24px 48px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 12px;
  color: var(--ink-faint);
}

.site-footer-inner a { color: var(--ink-faint); }
.site-footer-inner a:hover { color: var(--accent-strong); }

nav.toc {
  margin: 24px 0 12px;
}

nav.toc p {
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 10px;
}

.toc ol {
  columns: 2;
  column-gap: 24px;
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: toc-counter;
}

.toc li {
  counter-increment: toc-counter;
  break-inside: avoid;
  margin-bottom: 8px;
}

.toc a {
  display: flex;
  gap: 8px;
  font-size: 14px;
  color: var(--ink-muted);
  text-decoration: none;
  padding: 3px 0;
}

.toc a:hover { color: var(--accent-strong); }

.toc a::before {
  content: counter(toc-counter, decimal-leading-zero);
  font-family: var(--font-display);
  font-size: 12px;
  color: var(--ink-faint);
  flex: none;
}

@media (max-width: 620px) {
  .card-grid, .not-list, .summary-grid { grid-template-columns: 1fr; }
  .toc ol { columns: 1; }
}