:root {
  --ink: #12172B;
  --panel: #1B2242;
  --surface: #F4F6F4;
  --surface-2: #FFFFFF;
  --business: #2FB6A6;
  --business-dim: #1F8577;
  --private: #F2A33B;
  --line: rgba(18, 23, 43, 0.12);
  --line-dark: rgba(244, 246, 244, 0.14);
  --ink-soft: rgba(18, 23, 43, 0.62);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, "Inter", "Segoe UI", Arial, sans-serif;
  background: var(--surface);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3 {
  font-family: Georgia, "Zilla Slab", serif;
  font-weight: 600;
  letter-spacing: -0.01em;
}

a {
  color: var(--business-dim);
}

/* ---------- HEADER ---------- */
.doc-header {
  background: var(--ink);
  color: #F4F6F4;
  padding: 56px 28px 44px;
  text-align: center;
}

.doc-header .logo {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 18px;
}

.logo-mark {
  width: 20px;
  height: 20px;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--business) 0%, var(--private) 100%);
  display: inline-block;
}

.doc-header h1 {
  font-size: 32px;
  line-height: 1.2;
  max-width: 620px;
  margin: 0 auto;
}

.doc-header p {
  margin-top: 10px;
  font-size: 15px;
  color: rgba(244, 246, 244, 0.62);
}

/* ---------- TOC ---------- */
.toc {
  max-width: 760px;
  margin: -28px auto 0;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px 28px;
  box-shadow: 0 20px 50px rgba(18, 23, 43, 0.10);
  position: relative;
}

.toc-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--business-dim);
  margin-bottom: 12px;
  display: block;
}

.toc ol {
  list-style: none;
  display: grid;
  gap: 8px;
}

.toc a {
  display: flex;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
  font-size: 14.5px;
  font-weight: 500;
}

.toc a:hover {
  color: var(--business-dim);
}

.toc .num {
  color: var(--business-dim);
  font-family: "IBM Plex Mono", Consolas, monospace;
  font-size: 12.5px;
  flex-shrink: 0;
}

/* ---------- CONTENT ---------- */
.content {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 28px 90px;
}

.part {
  padding-top: 12px;
  margin-bottom: 60px;
  scroll-margin-top: 24px;
}

.part+.part {
  border-top: 1px solid var(--line);
  padding-top: 48px;
}

.part-eyebrow {
  font-family: "IBM Plex Mono", Consolas, monospace;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--business-dim);
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.part-eyebrow .n {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--business);
  color: #08211d;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
}

.part h2 {
  font-size: 25px;
  margin-bottom: 10px;
}

.part>p.intro {
  color: var(--ink-soft);
  font-size: 15.5px;
  max-width: 600px;
  margin-bottom: 30px;
}

.sub {
  margin-top: 30px;
  scroll-margin-top: 24px;
}

.sub h3 {
  font-size: 17px;
  margin-bottom: 12px;
  color: var(--ink);
}

.sub ul,
.sub ol {
  padding-left: 22px;
  display: grid;
  gap: 9px;
}

.sub ul li,
.sub ol li {
  font-size: 15px;
  color: var(--ink);
}

.sub ol {
  counter-reset: step;
}

.sub ol li {
  list-style: none;
  counter-increment: step;
  position: relative;
  padding-left: 4px;
}

.sub ol li::before {
  content: counter(step);
  position: absolute;
  left: -26px;
  top: 1px;
  width: 18px;
  height: 18px;
  border-radius: 5px;
  background: var(--panel);
  color: #F4F6F4;
  font-family: "IBM Plex Mono", Consolas, monospace;
  font-size: 10.5px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sub ul li::marker {
  color: var(--business-dim);
}

code,
.mono {
  font-family: "IBM Plex Mono", Consolas, monospace;
  font-size: 13px;
  background: var(--panel);
  color: #9fe8db;
  padding: 2px 7px;
  border-radius: 5px;
  word-break: break-all;
}

.note {
  margin-top: 22px;
  display: flex;
  gap: 12px;
  background: rgba(242, 163, 59, 0.08);
  border: 1px solid rgba(242, 163, 59, 0.28);
  border-radius: 10px;
  padding: 14px 16px;
  font-size: 14px;
  color: var(--ink);
}

.note svg {
  flex-shrink: 0;
  margin-top: 2px;
}

.note strong {
  color: var(--private);
  display: block;
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 3px;
  font-family: "IBM Plex Mono", Consolas, monospace;
  font-weight: 600;
}

/* ---------- FOOTER ---------- */
footer {
  background: var(--ink);
  color: rgba(244, 246, 244, 0.5);
  text-align: center;
  padding: 32px 28px;
  font-size: 13px;
}

footer strong {
  color: rgba(244, 246, 244, 0.8);
}

@media (max-width: 640px) {
  .doc-header h1 {
    font-size: 26px;
  }

  .toc {
    margin-left: 16px;
    margin-right: 16px;
    padding: 18px 18px;
  }

  .content {
    padding: 40px 20px 70px;
  }
}