.course-catalog {
  min-height: 100dvh;
  margin: 0;
  background: var(--course-bg);
  color: var(--course-ink);
  font: 16px/1.7 "Avenir Next", Avenir, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.catalog-shell {
  width: min(100% - 40px, 1180px);
  margin: 0 auto;
}

.catalog-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--course-line);
  background: color-mix(in srgb, var(--course-bg) 92%, transparent);
  backdrop-filter: blur(16px);
}

.catalog-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  gap: 20px;
}

.catalog-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--course-ink);
  font-size: 14px;
  font-weight: 760;
  text-decoration: none;
}

.catalog-logo span {
  display: grid;
  width: 29px;
  height: 29px;
  place-items: center;
  border-radius: 8px;
  background: var(--course-accent);
  color: #fff;
  font: 800 11px/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.catalog-nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
}

.catalog-nav a,
.catalog-theme {
  color: var(--course-muted);
  font-size: 13px;
  text-decoration: none;
}

.catalog-nav a:hover,
.catalog-theme:hover {
  color: var(--course-ink);
}

.catalog-theme {
  padding: 7px 10px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
  cursor: pointer;
}

.catalog-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(360px, 0.88fr);
  gap: clamp(48px, 8vw, 100px);
  align-items: center;
  min-height: min(720px, calc(100dvh - 68px));
  padding: 70px 0;
}

.catalog-kicker {
  margin: 0 0 16px;
  color: var(--course-accent);
  font: 750 12px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.catalog-hero h1 {
  max-width: 720px;
  margin: 0;
  color: var(--course-ink);
  font-size: clamp(44px, 6vw, 76px);
  font-weight: 760;
  letter-spacing: -0.055em;
  line-height: 1.03;
}

.catalog-hero-copy > p:not(.catalog-kicker) {
  max-width: 620px;
  margin: 24px 0 0;
  color: var(--course-muted);
  font-size: 18px;
  line-height: 1.75;
}

.catalog-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 30px;
}

.catalog-primary,
.catalog-secondary {
  display: inline-flex;
  align-items: center;
  min-height: 45px;
  padding: 10px 16px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 740;
  text-decoration: none;
}

.catalog-primary {
  border: 1px solid var(--course-accent-strong);
  background: var(--course-accent);
  color: #fff;
}

.catalog-primary:hover {
  background: var(--course-accent-strong);
}

.catalog-secondary {
  border: 1px solid var(--course-line);
  background: var(--course-surface);
  color: var(--course-ink);
}

.catalog-primary:active,
.catalog-secondary:active {
  transform: translateY(1px);
}

.catalog-map {
  position: relative;
  display: grid;
  gap: 9px;
  padding: 20px;
  border: 1px solid var(--course-line);
  border-radius: 18px;
  background: var(--course-surface);
  box-shadow: var(--course-shadow);
}

.catalog-map::before {
  position: absolute;
  top: 48px;
  bottom: 48px;
  left: 39px;
  width: 1px;
  background: var(--course-line);
  content: "";
}

.catalog-map-row {
  position: relative;
  display: grid;
  grid-template-columns: 39px minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  min-height: 68px;
  padding: 10px 11px;
  border-radius: 11px;
  color: var(--course-muted);
  text-decoration: none;
}

.catalog-map-row:hover {
  background: var(--course-surface-muted);
}

.catalog-map-number {
  z-index: 1;
  display: grid;
  width: 39px;
  height: 39px;
  place-items: center;
  border: 1px solid var(--course-line);
  border-radius: 10px;
  background: var(--course-surface);
  color: var(--course-accent);
  font: 800 11px/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.catalog-map-copy strong {
  display: block;
  color: var(--course-ink);
  font-size: 14px;
}

.catalog-map-copy small,
.catalog-map-status {
  color: var(--course-faint);
  font-size: 11px;
}

.catalog-courses {
  padding: 58px 0 90px;
  border-top: 1px solid var(--course-line);
}

.catalog-section-head {
  max-width: 680px;
}

.catalog-section-head h2 {
  margin: 0;
  color: var(--course-ink);
  font-size: clamp(30px, 4vw, 46px);
  letter-spacing: -0.04em;
  line-height: 1.1;
}

.catalog-section-head p {
  margin: 14px 0 0;
  color: var(--course-muted);
}

.catalog-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 26px;
}

.catalog-filter {
  padding: 7px 11px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: var(--course-surface);
  color: var(--course-muted);
  font-size: 12px;
  font-weight: 680;
  cursor: pointer;
}

.catalog-filter[aria-pressed="true"] {
  border-color: color-mix(in srgb, var(--course-accent) 44%, var(--course-line));
  background: var(--course-accent-soft);
  color: var(--course-accent);
}

.catalog-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 14px;
  margin-top: 32px;
}

.catalog-course {
  position: relative;
  display: flex;
  flex-direction: column;
  min-height: 310px;
  padding: 25px;
  overflow: hidden;
  border: 1px solid var(--course-line);
  border-radius: 16px;
  background: var(--course-surface);
  color: var(--course-ink);
  text-decoration: none;
  box-shadow: var(--course-shadow);
  transition: border-color 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

.catalog-course:hover {
  border-color: color-mix(in srgb, var(--course-accent) 35%, var(--course-line));
  transform: translateY(-2px);
  box-shadow: 0 18px 44px rgb(50 42 35 / 0.08);
}

.catalog-course:active {
  transform: translateY(0);
}

.catalog-course[data-size="wide"] {
  grid-column: span 7;
}

.catalog-course[data-size="narrow"] {
  grid-column: span 5;
}

.catalog-course[data-size="full"] {
  grid-column: 1 / -1;
  min-height: 250px;
}

.catalog-course[data-size="half"] {
  grid-column: span 6;
  min-height: 280px;
}

.catalog-course.is-hidden {
  display: none;
}

.catalog-course-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.catalog-course-code {
  color: var(--course-accent);
  font: 750 11px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.catalog-course-kind {
  color: var(--course-faint);
  font-size: 11px;
}

.catalog-course h3 {
  max-width: 680px;
  margin: 43px 0 0;
  font-size: clamp(25px, 3.2vw, 38px);
  letter-spacing: -0.04em;
  line-height: 1.12;
}

.catalog-course p {
  max-width: 610px;
  margin: 12px 0 0;
  color: var(--course-muted);
  font-size: 14px;
}

.catalog-course-bottom {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 22px;
  margin-top: auto;
  padding-top: 35px;
}

.catalog-course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 7px 13px;
  color: var(--course-faint);
  font-size: 11px;
}

.catalog-course-progress {
  min-width: 98px;
  color: var(--course-muted);
  font-size: 11px;
  text-align: right;
}

.catalog-course-track {
  width: 98px;
  height: 4px;
  margin-top: 7px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--course-line);
}

.catalog-course-value {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--course-accent);
}

.catalog-course[data-size="full"]::after {
  position: absolute;
  right: -70px;
  bottom: -120px;
  width: 360px;
  height: 360px;
  border: 1px solid var(--course-line);
  border-radius: 50%;
  box-shadow: 0 0 0 38px var(--course-surface-muted), 0 0 0 39px var(--course-line);
  content: "";
  opacity: 0.58;
}

.catalog-course[data-size="full"] > * {
  position: relative;
  z-index: 1;
}

.catalog-footer {
  padding: 26px 0 42px;
  border-top: 1px solid var(--course-line);
  color: var(--course-faint);
  font-size: 12px;
}

@media (max-width: 900px) {
  .catalog-hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding: 62px 0;
  }

  .catalog-map {
    max-width: 620px;
  }

  .catalog-course[data-size] {
    grid-column: span 6;
  }
}

@media (max-width: 640px) {
  .catalog-shell {
    width: min(100% - 28px, 1180px);
  }

  .catalog-nav-inner {
    min-height: 60px;
  }

  .catalog-nav-links a {
    display: none;
  }

  .catalog-hero {
    gap: 42px;
    padding: 48px 0;
  }

  .catalog-hero h1 {
    font-size: clamp(40px, 13vw, 57px);
  }

  .catalog-hero-copy > p:not(.catalog-kicker) {
    font-size: 16px;
  }

  .catalog-map {
    padding: 13px;
  }

  .catalog-map-status {
    display: none;
  }

  .catalog-courses {
    padding: 45px 0 64px;
  }

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

  .catalog-course[data-size] {
    grid-column: 1;
    min-height: 280px;
    padding: 21px;
  }

  .catalog-course h3 {
    margin-top: 35px;
  }

  .catalog-course[data-size="full"]::after {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .catalog-course {
    transition: none;
  }
}