:root {
  --bg: #f4f6fb;
  --paper: #ffffff;
  --line: #e6ebf2;
  --text: #111827;
  --muted: #667085;
  --link: #117cee;
  --shadow: 0 18px 48px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Noto Sans SC", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(17, 124, 238, 0.08), transparent 24%),
    linear-gradient(180deg, #f7faff 0%, var(--bg) 100%);
  line-height: 1.8;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  display: block;
  border-radius: 14px;
}

.doc-shell {
  max-width: 1440px;
  margin: 0 auto;
  padding: 28px 20px 48px;
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 24px;
}

.doc-sidebar {
  position: relative;
}

.sidebar-sticky {
  position: sticky;
  top: 20px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.sidebar-kicker,
.toc {
  margin: 0;
}

.sidebar-kicker {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.doc-sidebar h2 {
  margin: 8px 0 14px;
  font-size: 1.25rem;
  line-height: 1.4;
}

.toc {
  display: grid;
  gap: 10px;
}

.toc a {
  padding: 10px 12px;
  border-radius: 12px;
  color: #344054;
  background: #f8fbff;
}

.toc a:hover {
  text-decoration: none;
  background: #eaf4ff;
}

.doc-main {
  min-width: 0;
}

.single-page {
  grid-template-columns: 1fr;
  max-width: 980px;
}

.doc-paper {
  padding: 42px 54px;
  border: 1px solid var(--line);
  border-radius: 32px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.doc-meta-card {
  margin: 18px 0 24px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #f8fbff;
}

.doc-meta-card p {
  margin: 6px 0;
}

.doc-paper h1 {
  margin: 0 0 20px;
  font-size: clamp(2rem, 3vw, 2.8rem);
  line-height: 1.18;
}

.doc-paper h2 {
  margin-top: 42px;
  margin-bottom: 16px;
  font-size: 1.7rem;
  line-height: 1.35;
}

.doc-paper h3 {
  margin-top: 28px;
  margin-bottom: 12px;
  font-size: 1.18rem;
  line-height: 1.5;
}

.doc-paper h4 {
  margin-top: 22px;
  margin-bottom: 10px;
  font-size: 1rem;
}

.doc-paper p {
  margin: 10px 0;
  font-size: 1rem;
}

.doc-list,
.link-list {
  margin: 12px 0;
  padding-left: 22px;
}

.doc-list li,
.link-list li {
  margin: 8px 0;
}

.image-block {
  margin: 18px 0 20px;
}

.image-row {
  display: grid;
  gap: 18px;
  margin: 18px 0 20px;
  align-items: start;
}

.image-row.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.image-row.two-small {
  grid-template-columns: 253px 278px;
}

.hl-blue-white {
  display: inline-block;
  padding: 4px 8px;
  color: #fff;
  background: rgb(17, 124, 238);
  border-radius: 6px;
}

.hl-gray {
  background: #fafafa;
}

.hl-blue,
.blue-text {
  color: #117cee;
}

.hl-soft-blue {
  padding: 2px 6px;
  background: #d9dffc;
  border-radius: 6px;
}

.strong-red,
.red-text {
  color: rgb(223, 42, 63);
  font-weight: 700;
}

.hl-yellow-red {
  color: #df2a3f;
  background: #fce75a;
  padding: 1px 3px;
}

.hl-yellow-black {
  color: #111;
  background: rgb(251, 222, 40);
  padding: 1px 6px;
  border-radius: 4px;
}

.hl-green {
  background: rgb(116, 182, 2);
  color: white;
  padding: 2px 6px;
  border-radius: 4px;
}

.hl-green-dark {
  color: #74b602;
  background: #000000;
  padding: 2px 8px;
  border-radius: 6px;
}

.purple-text {
  color: #601bde;
}

.blue-strong {
  color: rgb(17, 124, 238);
  font-weight: 700;
}

.orange-text {
  color: rgb(255, 111, 4);
}

.deep-red-text {
  color: rgb(173, 26, 43);
}

.warm-orange-text {
  color: rgb(243, 143, 57);
}

.pink-text {
  color: rgb(228, 73, 91);
}

.gold-text {
  color: rgb(236, 170, 4);
}

.orange-strong {
  color: #ed740c;
  font-weight: 700;
}

.hl-cyan {
  background: #cef5f7;
  padding: 2px 6px;
  border-radius: 4px;
}

.gray-italic {
  color: #8a8f8d;
  font-style: italic;
}

.code-block {
  margin: 14px 0 22px;
  padding: 18px 20px;
  overflow-x: auto;
  border-radius: 18px;
  border: 1px solid #d9e6f7;
  background: #0f172a;
  color: #e5eefc;
  line-height: 1.7;
}

.code-block code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  white-space: pre-wrap;
  word-break: break-word;
}

.doc-rule {
  margin: 28px 0;
  border: 0;
  border-top: 1px dashed #cfd8e3;
}

@media (max-width: 1100px) {
  .doc-shell {
    grid-template-columns: 1fr;
  }

  .sidebar-sticky {
    position: static;
  }
}

@media (max-width: 800px) {
  .doc-paper {
    padding: 24px 18px;
    border-radius: 22px;
  }

  .image-row.two,
  .image-row.two-small {
    grid-template-columns: 1fr;
  }

  .doc-shell {
    padding: 16px;
  }
}