:root {
  --ink: #172033;
  --muted: #5d677a;
  --line: #d9dee8;
  --paper: #ffffff;
  --canvas: #f4f6f9;
  --blue: #1769e0;
  --green: #14805e;
  --amber: #a45a08;
  --soft-blue: #eef5ff;
  --soft-green: #edf8f4;
  --soft-amber: #fff7e8;
  --code: #111827;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  max-width: 1180px;
  margin: 0 auto;
  padding: 54px 64px 96px 330px;
  background: var(--canvas);
  color: var(--ink);
  font-family: Inter, "SF Pro Text", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.72;
  letter-spacing: 0;
}

body > :not(nav) {
  max-width: 850px;
  margin-right: auto;
  margin-left: auto;
}

nav#TOC {
  position: fixed;
  top: 0;
  bottom: 0;
  left: max(20px, calc((100vw - 1180px) / 2));
  width: 270px;
  padding: 32px 24px;
  overflow-y: auto;
  border-right: 1px solid var(--line);
  background: #ffffff;
}

nav#TOC::before {
  display: block;
  margin-bottom: 18px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  content: "petaV3 AI Proposal · v2.1";
}

nav#TOC ul {
  margin: 0;
  padding-left: 0;
  list-style: none;
}

nav#TOC ul ul {
  padding-left: 14px;
}

nav#TOC li {
  margin: 5px 0;
}

nav#TOC a {
  color: #465064;
  font-size: 12px;
  line-height: 1.4;
  text-decoration: none;
}

nav#TOC a:hover {
  color: var(--blue);
}

h1 {
  margin: -54px -36px 36px;
  padding: 58px 36px 34px;
  border-bottom: 4px solid var(--blue);
  background: var(--paper);
  color: #111827;
  font-size: 34px;
  line-height: 1.22;
  letter-spacing: 0;
}

h2 {
  margin-top: 58px;
  padding-top: 12px;
  border-top: 2px solid var(--ink);
  color: #131b2c;
  font-size: 24px;
  line-height: 1.3;
  letter-spacing: 0;
}

h3 {
  margin-top: 34px;
  color: #1e293b;
  font-size: 18px;
  line-height: 1.35;
  letter-spacing: 0;
}

h4 {
  margin-top: 26px;
  color: var(--blue);
  font-size: 15px;
  line-height: 1.4;
  letter-spacing: 0;
}

p {
  margin: 12px auto;
}

blockquote {
  margin: 20px 0;
  padding: 14px 18px;
  border-left: 4px solid var(--amber);
  background: var(--soft-amber);
  color: #5a3a11;
}

blockquote p {
  margin: 0;
}

strong {
  color: #111827;
}

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

ul,
ol {
  padding-left: 24px;
}

li {
  margin: 6px 0;
}

table {
  display: table;
  width: 100%;
  margin: 22px 0 30px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-collapse: separate;
  border-spacing: 0;
  border-radius: 6px;
  background: var(--paper);
  font-size: 13px;
  line-height: 1.5;
}

thead th {
  padding: 11px 12px;
  border-right: 1px solid #2f405a;
  background: #243249;
  color: #ffffff;
  font-weight: 700;
  text-align: left;
  vertical-align: top;
}

thead th:last-child {
  border-right: 0;
}

tbody td {
  padding: 10px 12px;
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
  vertical-align: top;
}

tbody td:last-child {
  border-right: 0;
}

tbody tr:nth-child(even) {
  background: #f8fafc;
}

code {
  padding: 2px 5px;
  border-radius: 4px;
  background: #edf1f7;
  color: #24425f;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.9em;
}

pre {
  margin: 24px 0;
  padding: 20px;
  overflow-x: auto;
  border-left: 4px solid var(--green);
  border-radius: 4px;
  background: var(--code);
  color: #e5edf8;
  font-size: 12px;
  line-height: 1.55;
}

pre code {
  padding: 0;
  background: transparent;
  color: inherit;
}

hr {
  margin: 44px 0;
  border: 0;
  border-top: 1px solid var(--line);
}

@media (max-width: 920px) {
  body {
    width: 100%;
    padding: 0 20px 64px;
  }

  body > :not(nav) {
    max-width: 100%;
  }

  nav#TOC {
    position: static;
    width: 100%;
    max-height: 340px;
    margin-bottom: 24px;
    padding: 22px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    background: transparent;
  }

  h1 {
    margin: 0 -20px 28px;
    padding: 36px 20px 26px;
    font-size: 28px;
  }

  h2 {
    font-size: 21px;
  }

  table {
    display: block;
    overflow-x: auto;
    white-space: normal;
  }
}

@media print {
  @page {
    size: A4;
    margin: 16mm 14mm;
  }

  body {
    max-width: none;
    padding: 0;
    background: #ffffff;
    color: #000000;
    font-size: 10pt;
  }

  body > :not(nav) {
    max-width: none;
  }

  nav#TOC {
    display: none;
  }

  h1 {
    margin: 0 0 20mm;
    padding: 14mm 0 8mm;
    font-size: 24pt;
  }

  h2 {
    break-before: page;
    margin-top: 0;
    padding-top: 0;
    font-size: 16pt;
  }

  h3,
  h4 {
    break-after: avoid;
  }

  table,
  pre,
  blockquote {
    break-inside: avoid;
  }

  a {
    color: #000000;
    text-decoration: none;
  }
}