:root {
  --bg: #f4f1ea;
  --paper: #fffdf8;
  --ink: #17212b;
  --muted: #566371;
  --line: #d8d1c4;
  --accent: #155e63;
  --accent-strong: #0b3f44;
  --warm: #c97731;
  --shadow: 0 20px 50px rgba(23, 33, 43, 0.08);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(201, 119, 49, 0.16), transparent 28rem),
    linear-gradient(180deg, #fbf6ed 0%, var(--bg) 100%);
  line-height: 1.7;
}

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

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

img {
  max-width: 100%;
  height: auto;
  border-radius: 14px;
  box-shadow: var(--shadow);
}

code,
pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

code {
  background: #f1ece2;
  border-radius: 6px;
  padding: 0.1rem 0.35rem;
}

pre {
  overflow-x: auto;
  background: #1d2730;
  color: #f5f7fa;
  padding: 1rem 1.1rem;
  border-radius: 14px;
  box-shadow: var(--shadow);
}

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

blockquote {
  margin: 1.5rem 0;
  padding: 0.1rem 1rem;
  border-left: 4px solid var(--warm);
  background: #fcf7ef;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  border: 1px solid var(--line);
  padding: 0.75rem;
  text-align: left;
}

.site-shell {
  display: grid;
  grid-template-columns: 290px minmax(0, 1fr);
  min-height: 100vh;
}

.site-sidebar {
  position: sticky;
  top: 0;
  align-self: start;
  min-height: 100vh;
  padding: 2rem 1.25rem;
  background: rgba(255, 253, 248, 0.78);
  border-right: 1px solid rgba(216, 209, 196, 0.8);
  backdrop-filter: blur(10px);
}

.brand {
  display: flex;
  gap: 0.9rem;
  align-items: center;
  text-decoration: none;
  color: inherit;
  margin-bottom: 2rem;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--warm));
  color: white;
  font-weight: 700;
  letter-spacing: 0.08em;
  font-size: 0.95rem;
}

.brand-copy {
  display: flex;
  flex-direction: column;
}

.brand-copy span {
  color: var(--muted);
  font-size: 0.92rem;
}

.site-nav {
  display: grid;
  gap: 0.55rem;
}

.site-nav a {
  display: block;
  padding: 0.75rem 0.9rem;
  text-decoration: none;
  border-radius: 12px;
  color: var(--ink);
}

.site-nav a[aria-current="page"],
.site-nav a:hover {
  background: #e9f1f1;
  color: var(--accent-strong);
}

.sidebar-note {
  margin-top: 2rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 250, 240, 0.9);
  color: var(--muted);
  font-size: 0.95rem;
}

.site-main {
  padding: 3rem clamp(1.25rem, 3vw, 3rem);
}

.page-header {
  max-width: 64rem;
  margin: 0 auto 2rem;
}

.page-kicker {
  margin: 0 0 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.78rem;
  color: var(--warm);
  font-weight: 700;
}

.page-header h1 {
  margin: 0;
  font-size: clamp(2.4rem, 5vw, 4.6rem);
  line-height: 1.02;
}

.page-lead {
  max-width: 48rem;
  font-size: 1.2rem;
  color: var(--muted);
}

.page-content {
  max-width: 64rem;
  margin: 0 auto;
  padding: clamp(1.25rem, 2vw, 2rem);
  font-size: 1.125rem;
  border-radius: calc(var(--radius) + 4px);
  background: rgba(255, 253, 248, 0.92);
  box-shadow: var(--shadow);
}

.page-content p,
.page-content li,
.page-content blockquote {
  overflow-wrap: break-word;
}

.page-content h1,
.page-content h2,
.page-content h3 {
  line-height: 1.2;
}

.page-content > h1:first-child {
  display: none;
}

.page-content h2 {
  margin-top: 2.6rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--line);
}

.hero-grid,
.card-grid {
  display: grid;
  gap: 1rem;
}

.hero-grid {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  margin: 2rem 0;
}

.card-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin: 1.5rem 0 0;
}

.hero-card,
.resource-card {
  display: block;
  padding: 1.25rem;
  border-radius: var(--radius);
  background: linear-gradient(180deg, #fffdf9, #f5efe4);
  border: 1px solid var(--line);
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow);
}

.hero-card strong,
.resource-card strong {
  display: block;
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}

.hero-card span,
.resource-card span {
  color: var(--muted);
}

.math-block {
  overflow-x: auto;
  padding: 0.1rem 0;
}

.page-content mjx-container {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  font-size: 1.12em !important;
}

.page-content mjx-container[display="true"] {
  display: block;
  margin: 0.4rem 0;
}

.page-content mjx-container[jax="SVG"] > svg {
  max-width: 100%;
  height: auto;
}

.page-content li mjx-container {
  font-size: 1em !important;
}

details {
  margin: 1rem 0;
  padding: 0.1rem 1rem 0.2rem;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fffaf2;
}

summary {
  cursor: pointer;
  font-weight: 700;
  padding: 0.6rem 0;
}

@media (max-width: 920px) {
  .site-shell {
    grid-template-columns: 1fr;
  }

  .site-sidebar {
    position: static;
    min-height: auto;
    border-right: 0;
    border-bottom: 1px solid rgba(216, 209, 196, 0.8);
  }

  .site-main {
    padding-top: 1.5rem;
  }
}