:root {
  --bg: #f7f9fb;
  --paper: #ffffff;
  --paper-soft: #eef6f8;
  --ink: #17202a;
  --muted: #5d6875;
  --line: #d8e1ea;
  --line-strong: #b9c7d6;
  --primary: #1f7a8c;
  --primary-dark: #135c6b;
  --accent: #b85c24;
  --accent-soft: #fff3df;
  --success: #177245;
  --code-bg: #f8fbfd;
  --code-head: #e8f1f5;
  --code-text: #182331;
  --shadow: 0 16px 40px rgba(23, 32, 42, 0.08);
  --radius: 8px;
  --content-width: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(180deg, #ffffff 0, var(--bg) 20rem),
    var(--bg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

a {
  color: var(--primary-dark);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

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

img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.25rem 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 28px rgba(23, 32, 42, 0.08);
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -10rem;
  z-index: 20;
  padding: 0.55rem 0.8rem;
  color: #ffffff;
  background: var(--primary-dark);
  border-radius: 6px;
}

.skip-link:focus {
  top: 1rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(100%, var(--content-width));
  margin: 0 auto;
  padding: 0.85rem 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 0;
  color: var(--ink);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  flex: 0 0 auto;
  width: 2.35rem;
  height: 2.35rem;
  place-items: center;
  color: #ffffff;
  background: var(--primary);
  border-radius: 50%;
  font-weight: 800;
}

.brand-title {
  display: block;
  overflow: hidden;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.2;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand-subtitle {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.25;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 0.45rem;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 2.35rem;
  padding: 0.35rem 0.7rem;
  color: var(--ink);
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 650;
  text-decoration: none;
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--primary-dark);
  background: var(--paper-soft);
  border-color: #cae1e7;
}

.content {
  width: min(100%, var(--content-width));
  margin: 0 auto;
  padding: 2.5rem 1rem 4rem;
}

.content > h1:first-child,
.tutorial-index > h1:first-child {
  max-width: 780px;
  margin: 0 0 0.85rem;
  font-size: clamp(2rem, 4vw, 3.7rem);
  line-height: 1.05;
}

.content > p {
  max-width: 760px;
}

.lead,
.tutorial-description,
.summary {
  max-width: 780px;
  color: var(--muted);
  font-size: 1.08rem;
}

h1,
h2,
h3 {
  color: var(--ink);
  line-height: 1.2;
}

h2 {
  margin-top: 2.5rem;
  font-size: 1.55rem;
}

h3 {
  margin-top: 1.75rem;
  font-size: 1.18rem;
}

hr {
  height: 1px;
  margin: 2rem 0;
  background: var(--line);
  border: 0;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #ffffff;
}

.footer-inner {
  width: min(100%, var(--content-width));
  margin: 0 auto;
  padding: 1.25rem 1rem;
  color: var(--muted);
  font-size: 0.92rem;
}

/* Home and shared cards */
.home-actions,
.tutorial-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 1.35rem 0;
}

.primary-action,
.secondary-action,
.action-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.55rem;
  padding: 0.55rem 0.9rem;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 750;
  text-decoration: none;
}

.primary-action,
.action-link {
  color: #ffffff;
  background: var(--primary-dark);
  border: 1px solid var(--primary-dark);
}

.primary-action:hover,
.action-link:hover {
  color: #ffffff;
  background: var(--primary);
}

.secondary-action {
  color: var(--primary-dark);
  background: #ffffff;
  border: 1px solid var(--line-strong);
}

.secondary-action:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.feature-grid,
.help-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.9rem;
  margin: 1.25rem 0 2rem;
}

.feature-card,
.help-card {
  display: block;
  padding: 1rem;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 24px rgba(23, 32, 42, 0.05);
}

.feature-card {
  text-decoration: none;
}

.feature-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
}

.feature-card h3,
.help-card h2 {
  margin: 0 0 0.45rem;
  font-size: 1.08rem;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.5;
}

.help-card dl {
  margin: 0;
}

.help-card dt {
  margin-top: 0.85rem;
  font-weight: 800;
}

.help-card dt:first-child {
  margin-top: 0;
}

.help-card dd {
  margin: 0.2rem 0 0;
  color: var(--muted);
}

/* Tutorial index */
.tutorial-index {
  display: grid;
  gap: 2rem;
}

.tutorial-section {
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

.section-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.section-heading h2 {
  margin: 0;
}

.section-count {
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 650;
  white-space: nowrap;
}

.tutorial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 0.9rem;
}

.tutorial-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.75rem;
  min-height: 100%;
  padding: 1rem;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 24px rgba(23, 32, 42, 0.05);
  text-decoration: none;
}

.tutorial-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
  transform: translateY(-1px);
}

.tutorial-number {
  display: grid;
  width: 2.15rem;
  height: 2.15rem;
  place-items: center;
  color: var(--primary-dark);
  background: var(--paper-soft);
  border: 1px solid #cae1e7;
  border-radius: 50%;
  font-size: 0.86rem;
  font-weight: 800;
}

.tutorial-card h3 {
  margin: 0;
  font-size: 1.02rem;
}

.tutorial-card p {
  margin: 0.35rem 0 0;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.45;
}

/* Tutorial pages */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  align-items: center;
  margin-bottom: 1.25rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.breadcrumb a {
  font-weight: 700;
  text-decoration: none;
}

.breadcrumb-separator {
  color: var(--line-strong);
}

.tutorial-heading {
  max-width: 820px;
  margin-bottom: 2rem;
}

.eyebrow {
  margin: 0 0 0.5rem;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.tutorial-heading h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.45rem);
  line-height: 1.05;
}

.tutorial-progress {
  max-width: 520px;
  margin-top: 1.2rem;
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.35rem;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 750;
}

.progress-track {
  height: 0.55rem;
  overflow: hidden;
  background: #dfe8ef;
  border-radius: 999px;
}

.progress-track span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: inherit;
}

.tutorial-shell {
  display: grid;
  grid-template-columns: minmax(180px, 240px) minmax(0, 1fr);
  gap: 2rem;
  align-items: start;
}

.tutorial-sidebar {
  position: sticky;
  top: 5.7rem;
}

.toc {
  padding: 0.95rem;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.toc[hidden] {
  display: none;
}

.toc-title {
  margin: 0 0 0.65rem;
  color: var(--ink);
  font-size: 0.84rem;
  font-weight: 800;
  text-transform: uppercase;
}

.toc ol {
  display: grid;
  gap: 0.35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.toc a {
  display: block;
  padding: 0.4rem 0.5rem;
  color: var(--muted);
  border-radius: 6px;
  font-size: 0.9rem;
  line-height: 1.3;
  text-decoration: none;
}

.toc a:hover {
  color: var(--primary-dark);
  background: var(--paper-soft);
}

.sidebar-help {
  display: grid;
  gap: 0.45rem;
  margin-top: 0.8rem;
}

.sidebar-help a {
  display: block;
  padding: 0.55rem 0.7rem;
  color: var(--primary-dark);
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: 0.88rem;
  font-weight: 750;
  text-decoration: none;
}

.sidebar-help a:hover {
  border-color: var(--primary);
}

.tutorial-body {
  min-width: 0;
  padding: 1.25rem 1.4rem;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(23, 32, 42, 0.05);
}

.tutorial-body > h1:first-child {
  display: none;
}

.tutorial-body h2 {
  margin-top: 2.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
  scroll-margin-top: 6.5rem;
}

.tutorial-body h2:first-child,
.tutorial-body > h1:first-child + h2 {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.tutorial-body p,
.tutorial-body li {
  max-width: 78ch;
}

.tutorial-body ul,
.tutorial-body ol {
  padding-left: 1.35rem;
}

.tutorial-body li + li {
  margin-top: 0.3rem;
}

.tutorial-body blockquote {
  margin: 1.25rem 0;
  padding: 0.85rem 1rem;
  color: #473515;
  background: var(--accent-soft);
  border-left: 4px solid #e2a93b;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.tutorial-body blockquote p {
  margin: 0.25rem 0;
}

.callout {
  margin: 1.25rem 0;
  padding: 0.9rem 1rem;
  border: 1px solid var(--line);
  border-left-width: 4px;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.callout p:first-child {
  margin-top: 0;
}

.callout p:last-child,
.callout ul:last-child,
.callout ol:last-child {
  margin-bottom: 0;
}

.callout.tip {
  color: #123c46;
  background: #eaf7f8;
  border-color: #9bd3dc;
}

.callout.expected {
  color: #173b24;
  background: #edf8ef;
  border-color: #90cf9d;
}

.callout.warning {
  color: #5d3510;
  background: var(--accent-soft);
  border-color: #e4ad54;
}

.tutorial-body table {
  width: 100%;
  margin: 1.25rem 0;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.tutorial-body th,
.tutorial-body td {
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.tutorial-body th {
  background: var(--paper-soft);
}

.tutorial-pager {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
  margin-top: 1.5rem;
}

.pager-link {
  display: block;
  min-height: 100%;
  padding: 0.95rem 1rem;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
}

.pager-link:hover {
  border-color: var(--primary);
  box-shadow: 0 10px 24px rgba(23, 32, 42, 0.06);
}

.pager-link.next {
  text-align: right;
}

.pager-label {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 750;
  text-transform: uppercase;
}

.pager-title {
  display: block;
  margin-top: 0.25rem;
  font-weight: 800;
}

/* Search */
.search-page {
  max-width: 860px;
  margin-top: 1.4rem;
}

.search-label {
  display: block;
  margin-bottom: 0.4rem;
  color: var(--ink);
  font-weight: 800;
}

.search-input {
  width: 100%;
  min-height: 3rem;
  padding: 0.65rem 0.8rem;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  font: inherit;
}

.search-input:focus {
  outline: 3px solid rgba(31, 122, 140, 0.18);
  border-color: var(--primary);
}

.search-count {
  margin: 0.8rem 0;
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 700;
}

.search-results {
  display: grid;
  gap: 0.75rem;
}

.search-result-card {
  display: block;
  padding: 1rem;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
}

.search-result-card:hover {
  border-color: var(--primary);
  box-shadow: 0 10px 24px rgba(23, 32, 42, 0.06);
}

.search-result-card h2 {
  margin: 0.2rem 0 0.25rem;
  font-size: 1.12rem;
}

.search-result-card p {
  margin: 0;
  color: var(--muted);
}

.result-meta {
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
}

.empty-results {
  padding: 1rem;
  color: var(--muted);
  background: #ffffff;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
}

/* Inline code and code blocks */
.content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.94em;
}

.content p code,
.content li code,
.content dt code,
.content dd code,
.content table code {
  padding: 0.08rem 0.32rem;
  color: #7a3412;
  background: #fff0da;
  border: 1px solid #f1d3a7;
  border-radius: 5px;
}

.content pre {
  margin: 1.2rem 0;
  padding: 1rem;
  overflow-x: auto;
  color: var(--code-text);
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.92rem;
  line-height: 1.55;
  tab-size: 2;
}

.content .highlighter-rouge > .highlight,
.content figure.highlight,
.content div.highlight {
  margin: 1.25rem 0;
  padding: 1rem;
  overflow-x: auto;
  color: var(--code-text);
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.content .highlight pre,
.content .code-frame pre {
  margin: 0;
  padding: 0;
  color: inherit;
  background: transparent;
  border: 0;
  border-radius: 0;
}

.content .code-frame,
.content div.highlight.code-frame,
.content figure.highlight.code-frame,
.content .highlighter-rouge > .highlight.code-frame {
  position: relative;
  margin: 1.25rem 0;
  padding: 0;
  overflow: hidden;
  color: var(--code-text);
  background: var(--code-bg);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: 0 10px 28px rgba(23, 32, 42, 0.06);
}

.content .code-frame .code-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  min-height: 2.7rem;
  padding: 0.45rem 0.55rem 0.45rem 0.8rem;
  background: var(--code-head);
  border-bottom: 1px solid var(--line);
}

.content .code-frame .code-language {
  overflow: hidden;
  color: var(--primary-dark);
  font-size: 0.78rem;
  font-weight: 850;
  line-height: 1;
  text-overflow: ellipsis;
  text-transform: uppercase;
  white-space: nowrap;
}

.content .code-frame > pre,
.content .code-frame .highlight > pre {
  padding: 1rem;
  overflow-x: auto;
}

.content .code-frame table.rouge-table {
  display: block;
  width: 100%;
  margin: 0;
  padding: 1rem;
  overflow-x: auto;
  border: 0;
}

.content .code-frame table.rouge-table td,
.content .code-frame table.rouge-table th {
  padding: 0;
  border: 0;
}

.content .code-frame td.rouge-gutter,
.content .code-frame td.gutter,
.content .code-frame td.gl {
  padding-right: 0.8rem;
  color: #7b8794;
  user-select: none;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2rem;
  padding: 0.35rem 0.7rem;
  color: #ffffff;
  background: var(--primary-dark);
  border: 1px solid var(--primary-dark);
  border-radius: 6px;
  cursor: pointer;
  font: inherit;
  font-size: 0.84rem;
  font-weight: 750;
  line-height: 1;
}

.copy-btn:hover {
  background: var(--primary);
}

.copy-btn.copied {
  background: var(--success);
  border-color: var(--success);
}

.copy-btn.copy-error {
  background: #9f2f2f;
  border-color: #9f2f2f;
}

/* Small Rouge palette for readable highlighted code */
.highlight .c,
.highlight .cm,
.highlight .c1 {
  color: #6b7280;
  font-style: italic;
}

.highlight .k,
.highlight .kd,
.highlight .kn,
.highlight .kr {
  color: #8742a0;
  font-weight: 700;
}

.highlight .s,
.highlight .s1,
.highlight .s2,
.highlight .dl {
  color: #9a4d17;
}

.highlight .nf,
.highlight .fm,
.highlight .nb {
  color: #0969da;
}

.highlight .m,
.highlight .mi,
.highlight .mf {
  color: #116329;
}

@media (max-width: 820px) {
  body {
    font-size: 16px;
  }

  .site-header {
    position: static;
  }

  .header-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    justify-content: flex-start;
    width: 100%;
  }

  .brand-subtitle {
    display: none;
  }

  .content {
    padding-top: 1.5rem;
  }

  .tutorial-shell {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .tutorial-sidebar {
    position: static;
  }

  .toc {
    padding: 0.75rem;
  }

  .toc ol {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  }

  .tutorial-body {
    padding: 1rem;
  }

  .tutorial-pager {
    grid-template-columns: 1fr;
  }

  .pager-link.next {
    text-align: left;
  }

  .sidebar-help {
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  }
}

@media (max-width: 520px) {
  .content > h1:first-child,
  .tutorial-index > h1:first-child,
  .tutorial-heading h1 {
    font-size: 2rem;
  }

  .section-heading {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.25rem;
  }

  .tutorial-grid {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .help-grid {
    grid-template-columns: 1fr;
  }

  .tutorial-card {
    grid-template-columns: 1fr;
  }

  .tutorial-number {
    width: 2rem;
    height: 2rem;
  }

  .content .code-frame .code-toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .copy-btn {
    width: 100%;
  }

  .primary-action,
  .secondary-action,
  .action-link {
    width: 100%;
  }
}