:root {
  --portal-ink: #172033;
  --portal-muted: #5f6b7a;
  --portal-card: rgba(255, 255, 255, 0.84);
  --portal-line: rgba(23, 32, 51, 0.12);
  --portal-accent: #e45f3f;
  --portal-accent-soft: rgba(228, 95, 63, 0.12);
  --portal-blue: #3157a4;
  --portal-shadow: 0 18px 55px rgba(28, 40, 65, 0.1);
}

[data-md-color-scheme="slate"] {
  --portal-ink: #eef2ff;
  --portal-muted: #aab4c7;
  --portal-card: rgba(20, 27, 43, 0.82);
  --portal-line: rgba(190, 202, 224, 0.16);
  --portal-accent: #ff8b67;
  --portal-accent-soft: rgba(255, 139, 103, 0.14);
  --portal-blue: #9bb9ff;
  --portal-shadow: 0 20px 60px rgba(0, 0, 0, 0.24);
}

.md-grid {
  max-width: 78rem;
}

.md-typeset h1,
.md-typeset h2 {
  color: var(--portal-ink);
  font-weight: 650;
  letter-spacing: -0.025em;
}

.portal-hero {
  position: relative;
  overflow: hidden;
  margin: 1.2rem 0 1rem;
  padding: clamp(2rem, 6vw, 5rem);
  border: 1px solid var(--portal-line);
  border-radius: 1.5rem;
  background:
    radial-gradient(circle at 88% 16%, var(--portal-accent-soft), transparent 34%),
    linear-gradient(135deg, var(--portal-card), transparent);
  box-shadow: var(--portal-shadow);
}

.portal-hero::after {
  position: absolute;
  right: -4rem;
  bottom: -7rem;
  width: 18rem;
  height: 18rem;
  border: 1px solid var(--portal-line);
  border-radius: 50%;
  content: "";
}

.portal-kicker,
.portal-card__eyebrow {
  color: var(--portal-accent);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.portal-hero h1 {
  max-width: 16ch;
  margin: 0.6rem 0 1rem;
  color: var(--portal-ink);
  font-size: clamp(2.1rem, 6vw, 4.8rem);
  line-height: 1.04;
}

.portal-lede {
  max-width: 58ch;
  color: var(--portal-muted);
  font-size: clamp(1rem, 2vw, 1.2rem);
  line-height: 1.8;
}

.portal-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.8rem;
}

.md-typeset .portal-button {
  display: inline-flex;
  align-items: center;
  min-height: 2.8rem;
  padding: 0.65rem 1.1rem;
  border: 1px solid var(--portal-line);
  border-radius: 999px;
  color: var(--portal-ink);
  font-weight: 650;
  text-decoration: none;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.md-typeset .portal-button:hover {
  border-color: var(--portal-accent);
  color: var(--portal-ink);
  transform: translateY(-2px);
}

.md-typeset .portal-button--primary {
  border-color: var(--portal-ink);
  background: var(--portal-ink);
  color: var(--md-default-bg-color);
}

.md-typeset .portal-button--primary:hover {
  border-color: var(--portal-accent);
  background: var(--portal-accent);
  color: #fff;
}

.portal-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
  margin: 1rem 0 2.8rem;
}

.portal-stat {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  padding: 0.95rem 1.1rem;
  border: 1px solid var(--portal-line);
  border-radius: 1rem;
  background: var(--portal-card);
}

.portal-stat strong {
  color: var(--portal-blue);
  font-size: 1.65rem;
  line-height: 1;
}

.portal-stat span {
  color: var(--portal-muted);
  font-size: 0.82rem;
}

.portal-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 1rem 0 2.8rem;
}

.md-typeset a.portal-card {
  display: flex;
  min-height: 13rem;
  flex-direction: column;
  gap: 0.65rem;
  padding: 1.35rem;
  border: 1px solid var(--portal-line);
  border-radius: 1.15rem;
  background: var(--portal-card);
  box-shadow: 0 8px 28px rgba(28, 40, 65, 0.05);
  color: var(--portal-ink);
  text-decoration: none;
  transition: transform 170ms ease, border-color 170ms ease, box-shadow 170ms ease;
}

.md-typeset a.portal-card:hover {
  border-color: var(--portal-accent);
  box-shadow: var(--portal-shadow);
  color: var(--portal-ink);
  transform: translateY(-4px);
}

.md-typeset a.portal-card--wide {
  grid-column: 1 / -1;
  min-height: 8.5rem;
  background:
    linear-gradient(110deg, var(--portal-accent-soft), transparent 58%),
    var(--portal-card);
}

.portal-card--featured {
  background:
    linear-gradient(145deg, var(--portal-accent-soft), transparent 68%),
    var(--portal-card) !important;
}

.portal-card strong {
  color: var(--portal-ink);
  font-size: 1.2rem;
  letter-spacing: -0.015em;
}

.portal-card__copy {
  color: var(--portal-muted);
  font-size: 0.88rem;
  line-height: 1.65;
}

.portal-card__meta {
  margin-top: auto;
  color: var(--portal-accent);
  font-size: 0.78rem;
  font-weight: 650;
}

.portal-note {
  margin: 1rem 0 2rem;
  padding: 1.25rem 1.4rem;
  border-left: 4px solid var(--portal-accent);
  border-radius: 0 1rem 1rem 0;
  background: var(--portal-accent-soft);
}

.portal-note strong {
  color: var(--portal-ink);
}

.portal-note p {
  margin: 0.45rem 0 0;
  color: var(--portal-muted);
}

@media screen and (max-width: 900px) {
  .portal-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media screen and (max-width: 600px) {
  .portal-hero {
    padding: 1.5rem;
    border-radius: 1.1rem;
  }

  .portal-stats,
  .portal-grid {
    grid-template-columns: 1fr;
  }

  .portal-stat {
    justify-content: space-between;
  }
}

@media (prefers-reduced-motion: reduce) {
  .md-typeset .portal-button,
  .md-typeset a.portal-card {
    transition: none;
  }
}


.reading-hero {
  margin: 1.2rem 0 1rem;
  padding: 1.25rem 1.5rem 1.45rem;
  border-radius: 1rem;
  background: linear-gradient(90deg, #516ff3 0%, #32c6e7 100%);
  box-shadow: var(--portal-shadow);
  color: #fff;
  text-align: center;
}

.reading-hero__eyebrow {
  margin: 0 0 0.45rem;
  color: rgba(255, 255, 255, 0.86);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.16em;
}

.md-typeset .reading-hero h1 {
  margin: 0;
  color: #fff;
  font-size: clamp(1.55rem, 3.2vw, 2.35rem);
  font-weight: 400;
  letter-spacing: 0;
  line-height: 1.25;
}

.reading-hero__translation {
  margin: 0.45rem 0 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.95rem;
}

.reading-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem;
  margin: 1rem 0 1.4rem;
}

.reading-chip {
  padding: 0.32rem 0.7rem;
  border: 1px solid var(--portal-line);
  border-radius: 999px;
  color: var(--portal-muted);
  font-size: 0.76rem;
}

.bilingual-reading {
  margin: 1rem 0 2.8rem;
}

.reading-pair {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 5vw, 4rem);
  padding: 1.8rem 0;
}

.reading-column p {
  margin: 0;
  color: var(--portal-ink);
  font-size: clamp(1rem, 1.5vw, 1.15rem);
  line-height: 1.85;
}

.reading-column--en p {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.reading-chapter + .reading-chapter {
  margin-top: 2.4rem;
}

.reading-chapter__title {
  padding: 1.5rem 0 0.75rem;
  border-top: 3px solid #516ff3;
}

.reading-chapter__title h2 {
  margin: 0;
  font-size: clamp(1.2rem, 2.2vw, 1.6rem);
  line-height: 1.4;
  letter-spacing: -0.01em;
  scroll-margin-top: 5.25rem;
}

.reading-chapter__title p {
  margin: 0.35rem 0 0;
  color: var(--portal-muted);
  font-size: 1rem;
  line-height: 1.6;
}


.vocab-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 1rem 0 2.5rem;
}

.vocab-card {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--portal-line);
  border-radius: 0.9rem;
  background: var(--portal-card);
}

.vocab-card strong {
  color: var(--portal-ink);
}

.vocab-card span {
  color: var(--portal-muted);
  font-size: 0.84rem;
}

@media screen and (max-width: 700px) {
  .reading-pair,
  .vocab-grid {
    grid-template-columns: 1fr;
  }

  .reading-pair {
    gap: 1.1rem;
    padding: 1.4rem 0;
  }

  .reading-column--zh {
    padding-top: 0;
  }
}