:root {
  --tutorial-nav-width: 292px;
  --tutorial-nav-bg: #ffffff;
  --tutorial-nav-ink: #1f2933;
  --tutorial-nav-muted: #667085;
  --tutorial-nav-accent: #0b6e8a;
  --tutorial-nav-border: #d8dee4;
  --tutorial-nav-soft: #eef7f9;
  --tutorial-nav-shadow: 0 12px 32px rgba(15, 23, 42, 0.14);
}

html {
  scroll-padding-top: 24px;
}

body.tutorial-enhanced {
  padding-left: var(--tutorial-nav-width);
}

body.tutorial-enhanced h2,
body.tutorial-enhanced h3 {
  scroll-margin-top: 24px;
}

body.tutorial-enhanced nav#toc,
body.tutorial-enhanced nav.toc,
body.tutorial-enhanced .container > .toc,
body.tutorial-enhanced nav.sidebar,
body.tutorial-enhanced aside.toc {
  display: none;
}

body.tutorial-enhanced .layout {
  display: block;
  max-width: 980px;
  margin: 0 auto;
}

header.cover,
header.title-block,
header.title,
header.book-header,
.container > .cover,
main > .hero {
  margin: 0 0 40px;
  padding: 60px 28px;
  color: #ffffff;
  text-align: center;
  background: linear-gradient(135deg, #0b6e8a 0%, #0d4757 100%);
  border: 0;
  border-radius: 0;
  box-shadow: none;
}

header.cover h1,
header.title-block h1,
header.title h1,
header.book-header h1,
.container > .cover h1,
main > .hero h1 {
  margin: 0;
  padding: 0;
  color: #ffffff;
  border: 0;
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 750;
  line-height: 1.24;
  letter-spacing: 0;
}

header.cover .subtitle,
header.title-block .subtitle,
header.title .subtitle,
header.title .sub,
header.book-header .subtitle,
.container > .cover .subtitle,
main > .hero .subtitle {
  margin: 14px auto 0;
  max-width: 860px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 17px;
  line-height: 1.6;
}

header.cover .meta,
header.title-block .meta,
header.title .meta,
header.book-header .meta,
header.book-header .credit,
.container > .cover .meta,
main > .hero .meta {
  display: block;
  margin: 24px auto 0;
  max-width: 900px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 14px;
  line-height: 1.75;
  opacity: 1;
}

header.cover a,
header.cover code,
header.cover strong,
header.title-block a,
header.title-block code,
header.title-block strong,
header.title a,
header.title code,
header.title strong,
header.book-header a,
header.book-header code,
header.book-header strong,
.container > .cover a,
.container > .cover code,
.container > .cover strong,
main > .hero a,
main > .hero code,
main > .hero strong {
  color: inherit;
}

header.cover code,
header.title-block code,
header.title code,
header.book-header code,
.container > .cover code,
main > .hero code {
  background: rgba(255, 255, 255, 0.15);
}

header.cover .course-id,
header.title .eyebrow,
header.book-header .label,
main > .hero .tag {
  display: none;
}

main > .intro-note {
  margin: -16px 0 36px;
  padding: 16px 20px;
  color: inherit;
  background: rgba(11, 110, 138, 0.08);
  border-left: 4px solid var(--tutorial-nav-accent);
  border-radius: 0 6px 6px 0;
}

main > .intro-note p {
  margin: 0;
}

.tutorial-left-nav {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 1000;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  width: var(--tutorial-nav-width);
  min-width: 0;
  color: var(--tutorial-nav-ink);
  background: rgba(255, 255, 255, 0.98);
  border-right: 1px solid var(--tutorial-nav-border);
  box-shadow: 1px 0 14px rgba(15, 23, 42, 0.06);
}

.tutorial-site-nav,
.tutorial-page-nav {
  min-width: 0;
  background: transparent;
}

.tutorial-site-nav {
  padding: 14px 14px 12px;
  border-bottom: 1px solid var(--tutorial-nav-border);
}

.tutorial-left-nav a {
  text-decoration: none;
  border-bottom: 0;
}

.tutorial-nav-section-title,
.tutorial-page-nav-title {
  margin: 0 0 10px;
  color: var(--tutorial-nav-accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.tutorial-page-nav-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.tutorial-page-nav-item {
  margin: 0;
  padding: 0;
}

.tutorial-chapter-select {
  display: block;
  width: 100%;
  min-width: 0;
  height: 36px;
  padding: 0 34px 0 10px;
  color: var(--tutorial-nav-ink);
  background: #ffffff;
  border: 1px solid var(--tutorial-nav-border);
  border-radius: 6px;
  font: inherit;
  font-size: 13px;
  font-weight: 650;
  line-height: 36px;
  cursor: pointer;
  appearance: auto;
}

.tutorial-chapter-select:hover,
.tutorial-chapter-select:focus,
.tutorial-page-nav a:hover,
.tutorial-page-nav a:focus {
  color: var(--tutorial-nav-accent);
  background: var(--tutorial-nav-soft);
  outline: none;
}

.tutorial-chapter-select:focus {
  border-color: var(--tutorial-nav-accent);
}

.tutorial-page-nav {
  min-height: 0;
  padding: 16px 14px 20px;
  overflow-y: auto;
  scrollbar-width: thin;
}

.tutorial-page-nav a {
  display: block;
  padding: 5px 8px;
  border-left: 2px solid transparent;
  border-radius: 0 4px 4px 0;
  color: var(--tutorial-nav-muted);
  font-size: 12.5px;
  line-height: 1.35;
}

.tutorial-page-nav a.is-current {
  color: var(--tutorial-nav-accent);
  background: var(--tutorial-nav-soft);
  border-left-color: var(--tutorial-nav-accent);
  font-weight: 700;
}

.tutorial-page-nav-h2 a {
  margin-top: 7px;
  color: var(--tutorial-nav-ink);
  font-weight: 750;
}

.tutorial-page-nav-h3 a {
  padding-left: 18px;
  font-size: 12px;
}

.tutorial-toc-toggle,
.tutorial-toc-backdrop {
  display: none;
}

.tutorial-chapter-pager {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  max-width: 980px;
  margin: 24px auto 48px;
  padding: 0 24px;
}

.tutorial-chapter-pager a {
  display: block;
  padding: 16px 18px;
  color: var(--tutorial-nav-ink);
  text-decoration: none;
  background: var(--tutorial-nav-bg);
  border: 1px solid var(--tutorial-nav-border);
  border-radius: 8px;
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.08);
}

.tutorial-chapter-pager a:hover,
.tutorial-chapter-pager a:focus {
  border-color: var(--tutorial-nav-accent);
  outline: none;
}

.tutorial-chapter-pager span {
  display: block;
  margin-bottom: 4px;
  color: var(--tutorial-nav-muted);
  font-size: 12px;
}

.tutorial-chapter-pager strong {
  color: var(--tutorial-nav-accent);
  font-size: 15px;
}

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

.tutorial-pager-next:first-child {
  grid-column: 2;
}

.tutorial-legacy-left-toc .layout {
  display: block;
  max-width: 980px;
}

.tutorial-legacy-left-toc .layout > nav.toc {
  display: none;
}

.tutorial-legacy-left-toc main {
  max-width: 980px;
  margin: 0 auto;
}

@media (max-width: 900px) {
  html {
    scroll-padding-top: 18px;
  }

  body.tutorial-enhanced {
    padding-left: 0;
  }

  body.tutorial-enhanced h2,
  body.tutorial-enhanced h3 {
    scroll-margin-top: 18px;
  }

  .tutorial-left-nav {
    width: min(340px, calc(100vw - 40px));
    transform: translateX(-105%);
    transition: transform 0.22s ease;
    box-shadow: var(--tutorial-nav-shadow);
  }

  body.tutorial-toc-open .tutorial-left-nav {
    transform: translateX(0);
  }

  .tutorial-site-nav {
    padding: 14px 12px 12px;
  }

  header.cover,
  header.title-block,
  header.title,
  header.book-header,
  .container > .cover,
  main > .hero {
    padding: 40px 18px;
  }

  header.cover h1,
  header.title-block h1,
  header.title h1,
  header.book-header h1,
  .container > .cover h1,
  main > .hero h1 {
    font-size: 27px;
  }

  header.cover .subtitle,
  header.title-block .subtitle,
  header.title .subtitle,
  header.title .sub,
  header.book-header .subtitle,
  .container > .cover .subtitle,
  main > .hero .subtitle {
    font-size: 15px;
  }

  .tutorial-page-nav {
    padding: 14px 12px 18px;
  }

  .tutorial-toc-toggle {
    position: fixed;
    left: 14px;
    bottom: 18px;
    z-index: 1050;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 58px;
    min-height: 44px;
    padding: 9px 14px;
    color: #ffffff;
    background: var(--tutorial-nav-accent);
    border: 0;
    border-radius: 999px;
    box-shadow: var(--tutorial-nav-shadow);
    font-size: 14px;
    font-weight: 700;
    cursor: pointer;
  }

  .tutorial-toc-backdrop {
    position: fixed;
    inset: 0;
    z-index: 990;
    width: 100%;
    height: 100%;
    padding: 0;
    background: rgba(15, 23, 42, 0.35);
    border: 0;
    opacity: 0;
    pointer-events: none;
  }

  body.tutorial-toc-open .tutorial-toc-backdrop {
    display: block;
    opacity: 1;
    pointer-events: auto;
  }

  .tutorial-chapter-pager {
    grid-template-columns: 1fr;
    padding: 0 16px;
  }

  .tutorial-pager-next,
  .tutorial-pager-next:first-child {
    grid-column: auto;
    text-align: left;
  }
}