/* notes_source — visual style modelled on the upstream hugo-book theme. */

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&family=Roboto+Mono&display=swap');

:root {
  --gray-100: #f8f9fa;
  --gray-200: #e9ecef;
  --gray-500: #adb5bd;
  --color-link: #0055bb;
  --color-visited-link: #8440f1;
  --body-background: #fff;
  --body-font-color: #000;
  --sidebar-w: 16rem;
  --toc-w: 16rem;
  --content-max: 80rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --gray-100: rgba(255, 255, 255, 0.1);
    --gray-200: rgba(255, 255, 255, 0.2);
    --gray-500: rgba(255, 255, 255, 0.5);
    --color-link: #84b2ff;
    --color-visited-link: #b88dff;
    --body-background: #000;
    --body-font-color: #fff;
  }
  img:not(.logo):not(.no-invert) { filter: brightness(0.9); }
}

* { box-sizing: border-box; }
html { font-size: 16px; scroll-behavior: smooth; }
html, body { margin: 0; padding: 0; }
body {
  min-width: 20rem;
  color: var(--body-font-color);
  background: var(--body-background);
  font-family: Roboto, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-weight: 400;
  letter-spacing: 0.33px;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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

/* Centered three-column container ------------------------------------- */
.container {
  max-width: var(--content-max);
  margin: 0 auto;
  display: flex;
  align-items: flex-start;
  min-height: 100vh;
}

/* Sidebar -------------------------------------------------------------- */
.sidebar {
  flex: 0 0 var(--sidebar-w);
  font-size: 0.875rem;
}
.sidebar-inner {
  width: var(--sidebar-w);
  padding: 1rem;
  background: var(--body-background);
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-x: hidden;
  overflow-y: auto;
}
@media (min-width: 80rem) {
  .sidebar-inner { padding: 2rem 1rem; }
}

.site-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: inherit;
  font-weight: 700;
  margin-bottom: 1rem;
}
.site-title:hover { color: inherit; }
.site-title .logo {
  height: 1.5em;
  width: 1.5em;
  margin-inline-end: 0.5rem;
}

.menu ul { list-style: none; padding: 0; margin: 0; }
.menu ul li { margin: 1em 0; position: relative; }
.menu ul a, .menu ul .section-label {
  display: block;
  color: inherit;
  word-wrap: break-word;
}
.menu ul a:hover { opacity: 0.5; }
.menu ul a.active { color: var(--color-link); }
.menu ul .section-title { font-weight: 700; }
.menu ul .section-label { color: var(--gray-500); cursor: default; }
.menu ul ul { padding-inline-start: 1rem; }
.menu > ul > li { margin: 1em 0; }
.menu > ul > li > a,
.menu > ul > li > .section-label { font-weight: 700; }

/* Main content -------------------------------------------------------- */
.content {
  min-width: 20rem;
  flex-grow: 1;
  padding: 1rem;
}
@media (min-width: 80rem) {
  .content { padding: 2rem 1rem; }
}

.page-cover {
  display: block;
  width: 100%;
  height: auto;
  margin: 0 0 1.5rem;
}

.page-header h1 {
  font-size: 2em;
  font-weight: 400;
  margin: 0 0 0.5rem;
  line-height: 1;
}
.page-meta {
  color: var(--gray-500);
  font-size: 0.875rem;
  margin: 0 0 2rem;
}
.page-meta .sep { margin: 0 0.4rem; }

.page-body { min-width: 0; line-height: 1.6; }
.page-body > :first-child { margin-top: 0; }

/* Markdown content ---------------------------------------------------- */
.page-body h1,
.page-body h2,
.page-body h3,
.page-body h4,
.page-body h5,
.page-body h6 {
  font-weight: 400;
  line-height: 1;
  margin-top: 1.5em;
  margin-bottom: 1rem;
}
.page-body h4, .page-body h5, .page-body h6 { font-weight: 700; }
.page-body h5 { font-size: 0.875em; }
.page-body h6 { font-size: 0.75em; }

.page-body p { margin: 0 0 1rem; word-wrap: break-word; }
.page-body a { text-decoration: none; }
.page-body a:hover { text-decoration: underline; }
.page-body a:visited { color: var(--color-visited-link); }

.page-body img { max-width: 100%; height: auto; }
.page-body code {
  font-family: "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  padding: 0 0.25rem;
  background: var(--gray-200);
  border-radius: 0.25rem;
  font-size: 0.875em;
}
.page-body pre {
  padding: 1rem;
  background: var(--gray-100);
  border-radius: 0.25rem;
  overflow-x: auto;
}
.page-body pre code { padding: 0; background: none; }
.page-body blockquote {
  font-style: italic;
  margin: 1rem 0;
  padding: 0.5rem 1rem 0.5rem 0.75rem;
  border-inline-start: 0.25rem solid var(--gray-200);
  border-radius: 0.25rem;
}
.page-body blockquote :first-child { margin-top: 0; }
.page-body blockquote :last-child { margin-bottom: 0; }
.page-body table {
  border-collapse: collapse;
  margin: 1rem 0;
  display: block;
  overflow: auto;
}
.page-body table th, .page-body table td {
  padding: 0.5rem 1rem;
  border: 1px solid var(--gray-200);
}
.page-body table tr:nth-child(2n) { background: var(--gray-100); }
.page-body hr { height: 1px; border: none; background: var(--gray-200); margin: 2rem 0; }
.page-body ul, .page-body ol { padding-inline-start: 2rem; word-wrap: break-word; }

/* Table of contents (right) ------------------------------------------- */
.toc {
  flex: 0 0 var(--toc-w);
  font-size: 0.75rem;
}
.toc-inner {
  width: var(--toc-w);
  padding: 1rem;
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-x: hidden;
  overflow-y: auto;
}
@media (min-width: 80rem) {
  .toc-inner { padding: 2rem 1rem; }
}
.toc-title {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--gray-500);
  margin-bottom: 0.5rem;
}
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc ul li { margin: 0.4em 0; }
.toc ul ul { padding-inline-start: 1rem; }
.toc a { color: inherit; }
.toc a:hover { opacity: 0.5; }

/* Section index — children listing */
.children-list {
  margin: 2rem 0;
  list-style: none;
  padding: 0;
}
.children-list li {
  padding: 0.85rem 0;
  border-top: 1px solid var(--gray-200);
}
.children-list li:last-child { border-bottom: 1px solid var(--gray-200); }
.children-list a { display: block; color: inherit; }
.children-list a:hover { opacity: 0.5; }
.children-list .child-title {
  display: block;
  font-weight: 700;
  color: var(--color-link);
}
.children-list .child-meta {
  display: block;
  color: var(--gray-500);
  font-size: 0.85rem;
  margin-top: 0.15rem;
}

/* Mobile menu toggle -------------------------------------------------- */
#menu-toggle-button {
  display: none;
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 20;
  background: var(--body-background);
  border: 1px solid var(--gray-200);
  border-radius: 0.25rem;
  padding: 0.25rem 0.55rem;
  cursor: pointer;
  font-size: 1.2rem;
  color: inherit;
}

@media (max-width: 64rem) {
  .toc { display: none; }
}

@media (max-width: 56rem) {
  .container { display: block; }
  .sidebar { flex: none; }
  .sidebar-inner {
    position: fixed;
    top: 0;
    left: 0;
    width: 16rem;
    height: 100vh;
    transform: translateX(-100%);
    transition: transform 0.18s ease;
    z-index: 15;
    box-shadow: 2px 0 12px rgba(0, 0, 0, 0.1);
  }
  #menu-toggle:checked ~ .container .sidebar-inner { transform: translateX(0); }
  #menu-toggle-button { display: block; }
  .content { padding-top: 3.5rem; }
}