:root {
  --md-primary-fg-color: #0b2545;
  --md-primary-fg-color--light: #174873;
  --md-primary-fg-color--dark: #071a31;
  --md-accent-fg-color: #b85c38;
  --book-ink: #112031;
  --book-muted: #5f6c78;
  --book-paper: #fbfaf5;
  --book-panel: #f1efe6;
  --book-line: #d8d4c8;
  --book-blue: #0b5f8a;
  --book-amber: #c47b2d;
  --book-coral: #b85c38;
}

[data-md-color-scheme="slate"] {
  --md-hue: 212;
  --md-primary-fg-color: #081b31;
  --md-accent-fg-color: #e3a35d;
  --book-ink: #edf3f7;
  --book-muted: #aab8c4;
  --book-paper: #101a26;
  --book-panel: #172534;
  --book-line: #304151;
  --book-blue: #5eb8db;
  --book-amber: #e3a35d;
  --book-coral: #e48367;
}

html {
  scroll-behavior: smooth;
}

body,
input {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

.md-header {
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: none;
}

.md-tabs {
  background: #0b2545;
}

.md-typeset {
  color: var(--book-ink);
  font-size: 0.82rem;
  line-height: 1.82;
}

.md-typeset h1,
.md-typeset h2,
.md-typeset h3 {
  color: var(--book-ink);
  font-weight: 760;
  letter-spacing: -0.02em;
}

.md-typeset h1 {
  font-size: clamp(1.9rem, 4vw, 2.65rem);
  line-height: 1.18;
  margin-bottom: 1.15rem;
}

.md-typeset h2 {
  border-top: 1px solid var(--book-line);
  font-size: 1.45rem;
  margin-top: 3rem;
  padding-top: 1.1rem;
}

.md-typeset h3 {
  font-size: 1.08rem;
}

.md-typeset a {
  text-underline-offset: 0.18em;
}

.md-typeset img {
  border: 1px solid var(--book-line);
  display: block;
  margin: 1.25rem auto 0.6rem;
}

.md-typeset code {
  border-radius: 2px;
}

.md-typeset pre > code {
  font-size: 0.72rem;
  line-height: 1.65;
}

.md-typeset table:not([class]) {
  border: 1px solid var(--book-line);
  box-shadow: none;
}

.md-typeset table:not([class]) th {
  background: var(--book-panel);
  color: var(--book-ink);
}

.md-typeset blockquote {
  border-left-color: var(--book-amber);
  color: var(--book-muted);
}

.arithmatex {
  overflow-x: auto;
  padding-block: 0.2rem;
}

.book-hero {
  background: #0b2545;
  border-left: 6px solid var(--book-amber);
  color: #f8f5eb;
  margin: 0 0 1.4rem;
  padding: clamp(2rem, 6vw, 4.4rem) clamp(1.4rem, 5vw, 4rem);
  position: relative;
}

.book-hero::after {
  border-bottom: 1px solid rgba(255, 255, 255, 0.17);
  border-top: 1px solid rgba(255, 255, 255, 0.17);
  content: "";
  height: 0.55rem;
  position: absolute;
  right: 0;
  top: 2.2rem;
  width: 22%;
}

.book-hero__eyebrow {
  color: #e9b872;
  font-size: 0.68rem;
  font-weight: 720;
  letter-spacing: 0.12em;
  margin-bottom: 1.15rem;
  text-transform: uppercase;
}

.md-typeset .book-hero h1 {
  color: #f8f5eb;
  font-size: clamp(2.05rem, 6.4vw, 4.2rem);
  line-height: 1.06;
  margin: 0;
  max-width: 14ch;
}

.md-typeset .book-hero h1 span {
  color: #78c4df;
}

.book-hero__lead {
  color: #d9e3ea;
  font-size: clamp(0.88rem, 1.8vw, 1.08rem);
  line-height: 1.85;
  margin: 1.6rem 0 0;
  max-width: 45rem;
}

.book-hero__actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.8rem;
}

.md-typeset .book-hero .md-button {
  border-color: #f8f5eb;
  color: #f8f5eb;
}

.md-typeset .book-hero .md-button--primary {
  background: #f8f5eb;
  border-color: #f8f5eb;
  color: #0b2545;
}

.md-typeset .book-hero .md-button:hover,
.md-typeset .book-hero .md-button--primary:hover {
  background: #e9b872;
  border-color: #e9b872;
  color: #071a31;
}

.md-typeset .book-text-link {
  color: #f8f5eb;
  font-weight: 700;
  margin-left: 0.35rem;
}

.book-stats {
  background: var(--book-panel);
  border: 1px solid var(--book-line);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-bottom: 3rem;
}

.book-stats > div {
  align-items: baseline;
  border-right: 1px solid var(--book-line);
  display: flex;
  gap: 0.5rem;
  padding: 1rem 1.2rem;
}

.book-stats > div:last-child {
  border-right: 0;
}

.book-stats strong {
  color: var(--book-blue);
  font-size: 1.55rem;
  line-height: 1;
}

.book-stats span {
  color: var(--book-muted);
  font-size: 0.67rem;
}

.learning-chain {
  counter-reset: chain;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  margin: 1.4rem 0 3rem;
}

.learning-chain > div {
  border-left: 1px solid var(--book-line);
  min-height: 8rem;
  padding: 0.9rem 1rem;
}

.learning-chain > div:last-child {
  border-right: 1px solid var(--book-line);
}

.learning-chain span {
  color: var(--book-coral);
  display: block;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  margin-bottom: 0.8rem;
}

.learning-chain strong {
  display: block;
  font-size: 0.82rem;
}

.learning-chain p {
  color: var(--book-muted);
  font-size: 0.67rem;
  line-height: 1.65;
  margin-bottom: 0;
}

.route-grid {
  display: grid;
  gap: 0.85rem;
  grid-template-columns: repeat(2, 1fr);
  margin: 1.4rem 0 3rem;
}

.md-typeset .route-card {
  background: var(--book-paper);
  border: 1px solid var(--book-line);
  color: var(--book-ink);
  display: block;
  min-height: 12.5rem;
  padding: 1.35rem;
  text-decoration: none;
  transition: border-color 160ms ease, transform 160ms ease;
}

.md-typeset .route-card:hover {
  border-color: var(--book-blue);
  transform: translateY(-2px);
}

.route-card__tag {
  color: var(--book-coral);
  font-size: 0.62rem;
  font-weight: 760;
  letter-spacing: 0.08em;
}

.md-typeset .route-card h3 {
  margin: 0.55rem 0 0.6rem;
}

.route-card p {
  color: var(--book-muted);
  font-size: 0.73rem;
  min-height: 3.7rem;
}

.route-card strong {
  color: var(--book-blue);
  font-size: 0.7rem;
}

.part-list {
  border-top: 1px solid var(--book-line);
  margin: 1.4rem 0 3rem;
}

.part-list section {
  align-items: start;
  border-bottom: 1px solid var(--book-line);
  display: grid;
  gap: 1rem;
  grid-template-columns: 4.5rem 1.2fr 2fr auto;
  padding: 1.1rem 0;
}

.part-list span {
  color: var(--book-coral);
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.md-typeset .part-list h3,
.part-list p {
  margin: 0;
}

.part-list p {
  color: var(--book-muted);
  font-size: 0.7rem;
}

.part-list a {
  font-size: 0.68rem;
  font-weight: 700;
  white-space: nowrap;
}

.closing-callout {
  background: var(--book-panel);
  border-left: 5px solid var(--book-blue);
  margin-top: 3.5rem;
  padding: 1.8rem 2rem;
}

.closing-callout p {
  color: var(--book-coral);
  font-size: 0.68rem;
  font-weight: 760;
  letter-spacing: 0.06em;
  margin: 0;
}

.md-typeset .closing-callout h2 {
  border: 0;
  margin: 0.4rem 0 1.2rem;
  padding: 0;
}

.md-typeset .md-button {
  border-radius: 2px;
}

@media screen and (min-width: 76.25em) {
  .md-grid {
    max-width: 90rem;
  }

  .md-content__inner {
    margin-left: 1.2rem;
    margin-right: 1.2rem;
  }
}

@media screen and (max-width: 59.984375em) {
  .book-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .book-stats > div:nth-child(2) {
    border-right: 0;
  }

  .book-stats > div:nth-child(-n + 2) {
    border-bottom: 1px solid var(--book-line);
  }

  .learning-chain {
    grid-template-columns: repeat(2, 1fr);
  }

  .learning-chain > div {
    border-bottom: 1px solid var(--book-line);
  }

  .learning-chain > div:nth-child(even) {
    border-right: 1px solid var(--book-line);
  }

  .part-list section {
    grid-template-columns: 4rem 1fr;
  }

  .part-list p,
  .part-list a {
    grid-column: 2;
  }
}

@media screen and (max-width: 44.984375em) {
  .book-hero {
    margin-inline: -0.8rem;
    padding: 2.2rem 1.25rem;
  }

  .book-hero::after {
    display: none;
  }

  .book-hero__actions {
    align-items: stretch;
    flex-direction: column;
  }

  .md-typeset .book-hero .md-button,
  .md-typeset .book-text-link {
    margin: 0;
    text-align: center;
  }

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

  .learning-chain {
    grid-template-columns: 1fr;
  }

  .learning-chain > div,
  .learning-chain > div:nth-child(even),
  .learning-chain > div:last-child {
    border-left: 1px solid var(--book-line);
    border-right: 1px solid var(--book-line);
    min-height: auto;
  }

  .part-list section {
    display: block;
  }

  .part-list h3 {
    margin-top: 0.25rem !important;
  }

  .part-list p {
    margin: 0.45rem 0 0.55rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .md-typeset .route-card {
    transition: none;
  }
}