* {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
  --bg: #f3f6fb;
  --panel: #ffffff;
  --sidebar: #0f172a;
  --sidebar-text: #d7e5ff;
  --text: #182536;
  --muted: #56657c;
  --border: #d9e2ef;
  --accent: #2563eb;
  --code: #0f172a;
  --code-text: #e2e8f0;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: linear-gradient(180deg, #eef3fa 0%, #f8fbff 100%);
  color: var(--text);
}

.shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 320px 1fr;
}

.sidebar {
  background: var(--sidebar);
  color: var(--sidebar-text);
  padding: 28px 22px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.brand h1 {
  margin: 0 0 10px;
  font-size: 1.8rem;
}

.summary {
  margin: 0 0 22px;
  color: #a9bfdc;
  line-height: 1.5;
}

.eyebrow {
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.72rem;
  font-weight: 700;
  color: #7dd3fc;
}

.nav-group {
  margin-bottom: 20px;
}

.nav-group h3 {
  margin: 16px 0 8px;
  font-size: 0.9rem;
  color: #f8fafc;
}

.nav-link {
  display: block;
  color: #c9d8f0;
  text-decoration: none;
  padding: 8px 10px;
  border-radius: 10px;
  margin-bottom: 4px;
  line-height: 1.35;
}

.nav-link:hover,
.nav-link.active {
  background: rgba(125, 211, 252, 0.14);
  color: #ffffff;
}

.content {
  padding: 28px;
}

.hero,
.markdown-body {
  max-width: 980px;
  margin: 0 auto;
}

.hero {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 28px 30px;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
  margin-bottom: 18px;
}

.hero h2 {
  margin: 0 0 10px;
  font-size: 2rem;
}

.hero p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.markdown-body {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 28px 30px 42px;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3 {
  color: #0f172a;
  scroll-margin-top: 24px;
}

.markdown-body p,
.markdown-body li {
  line-height: 1.7;
}

.markdown-body pre {
  background: var(--code);
  color: var(--code-text);
  padding: 18px;
  border-radius: 16px;
  overflow-x: auto;
}

.markdown-body code {
  font-family: Consolas, "Courier New", monospace;
}

.markdown-body :not(pre) > code {
  background: #e7eefb;
  color: #1d4ed8;
  padding: 2px 6px;
  border-radius: 6px;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border-radius: 16px;
  margin: 20px 0;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--border);
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
}

.markdown-body th {
  background: #eef4ff;
}

.markdown-body blockquote {
  margin: 20px 0;
  padding: 12px 18px;
  border-left: 4px solid var(--accent);
  background: #f7faff;
  border-radius: 0 12px 12px 0;
}

.markdown-body a {
  color: var(--accent);
}

@media (max-width: 980px) {
  .shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    height: auto;
  }

  .content {
    padding: 18px;
  }
}