:root {
  --catalog-paper: #f7f7f5;
  --catalog-panel: #ffffff;
  --catalog-ink: #151515;
  --catalog-muted: #62676f;
  --catalog-line: #d7d8d5;
  --catalog-accent: #2b6bff;
  --catalog-max: 1240px;
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: light;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--catalog-paper);
  color: var(--catalog-ink);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

button,
input,
select {
  color: inherit;
  font: inherit;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
}

.catalog-shell {
  width: min(calc(100% - 48px), var(--catalog-max));
  margin-inline: auto;
}

.catalog-header {
  position: relative;
  z-index: 30;
  border-bottom: 1px solid var(--catalog-line);
  background: rgba(247, 247, 245, 0.96);
}

.catalog-header__row {
  display: grid;
  grid-template-columns: 178px minmax(0, 1fr) auto;
  align-items: center;
  min-height: 76px;
  gap: 32px;
}

.catalog-brand {
  width: 162px;
}

.catalog-brand img {
  width: 100%;
  height: auto;
}

.catalog-nav {
  display: flex;
  align-items: center;
  gap: 30px;
}

.catalog-nav a {
  position: relative;
  padding-block: 25px;
  font-size: 14px;
  white-space: nowrap;
}

.catalog-nav a::after {
  position: absolute;
  right: 0;
  bottom: 18px;
  left: 0;
  height: 1px;
  background: currentColor;
  content: "";
  opacity: 0;
}

.catalog-nav a:hover::after,
.catalog-nav a.is-current::after {
  opacity: 1;
}

.catalog-header__actions {
  display: flex;
  align-items: center;
  gap: 22px;
}

.catalog-account {
  min-width: 44px;
  text-align: center;
  font-size: 14px;
}

.catalog-workbench {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  border: 1px solid var(--catalog-ink);
  border-radius: 4px;
  background: var(--catalog-ink);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
}

.catalog-menu,
.catalog-mobile-nav {
  display: none;
}

.catalog-hero {
  padding: 76px 0 64px;
  border-bottom: 1px solid var(--catalog-line);
}

.catalog-hero__eyebrow {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 14px;
  color: var(--catalog-muted);
  font-size: 13px;
}

.catalog-hero__eyebrow a {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.catalog-hero h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(38px, 5vw, 68px);
  font-weight: 500;
  line-height: 1.12;
  letter-spacing: 0;
}

.catalog-hero__intro {
  max-width: 720px;
  margin: 22px 0 0;
  color: var(--catalog-muted);
  font-size: 17px;
}

.catalog-main {
  padding-block: 72px 96px;
}

.catalog-section-heading {
  display: block;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--catalog-ink);
}

.catalog-section-heading p,
.catalog-results-heading > div > p {
  margin: 0 0 5px;
  color: var(--catalog-muted);
  font-size: 13px;
}

.catalog-section-heading h2,
.catalog-results-heading h2 {
  margin: 0;
  font-size: 30px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0;
}

.catalog-entrances {
  margin: 54px 0 76px;
}

.catalog-entrance-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.catalog-entrance-grid > a {
  min-height: 230px;
  padding: 28px 24px 24px;
  border-right: 1px solid var(--catalog-line);
  border-bottom: 1px solid var(--catalog-line);
  background: transparent;
  transition: background-color 150ms ease, color 150ms ease;
}

.catalog-entrance-grid > a:first-child {
  border-left: 1px solid var(--catalog-line);
}

.catalog-entrance-grid > a:hover {
  background: var(--catalog-panel);
}

.catalog-entrance__count {
  display: block;
  min-height: 28px;
  color: var(--catalog-accent);
  font-size: 18px;
  font-weight: 700;
}

.catalog-entrance-grid h3 {
  margin: 20px 0 8px;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0;
}

.catalog-entrance-grid p {
  min-height: 54px;
  margin: 0;
  color: var(--catalog-muted);
  font-size: 14px;
}

.catalog-entrance-grid strong {
  display: inline-block;
  margin-top: 30px;
  border-bottom: 1px solid currentColor;
  font-size: 14px;
}

.catalog-search {
  padding-bottom: 28px;
  border-bottom: 1px solid var(--catalog-line);
}

.catalog-search > label {
  display: block;
  margin-bottom: 10px;
  color: var(--catalog-muted);
  font-size: 13px;
}

.catalog-search__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
}

.catalog-search input {
  width: 100%;
  min-height: 54px;
  padding: 0 16px;
  border: 1px solid var(--catalog-ink);
  border-radius: 0;
  background: var(--catalog-panel);
  outline: none;
}

.catalog-search input:focus {
  border-color: var(--catalog-accent);
  box-shadow: 0 0 0 2px rgba(43, 107, 255, 0.18);
}

.catalog-search button,
.catalog-empty button {
  min-width: 86px;
  min-height: 54px;
  border: 1px solid var(--catalog-ink);
  border-radius: 0;
  background: var(--catalog-ink);
  color: #fff;
  cursor: pointer;
}

.catalog-filter-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 230px;
  align-items: end;
  gap: 28px;
  padding: 24px 0 30px;
}

.catalog-type-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.catalog-type-tabs button {
  min-height: 40px;
  padding: 0 15px;
  border: 1px solid var(--catalog-line);
  border-radius: 3px;
  background: transparent;
  cursor: pointer;
}

.catalog-type-tabs button:hover,
.catalog-type-tabs button[aria-pressed="true"] {
  border-color: var(--catalog-ink);
  background: var(--catalog-ink);
  color: #fff;
}

.catalog-topic {
  display: grid;
  gap: 8px;
  color: var(--catalog-muted);
  font-size: 13px;
}

.catalog-topic select {
  width: 100%;
  min-height: 44px;
  padding: 0 38px 0 12px;
  border: 1px solid var(--catalog-line);
  border-radius: 0;
  background: var(--catalog-panel);
}

.catalog-results-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  padding: 30px 0 20px;
  border-top: 1px solid var(--catalog-ink);
}

.catalog-result-count {
  margin: 0;
  color: var(--catalog-muted);
  font-size: 14px;
}

.resource-catalog-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-auto-rows: auto;
  align-items: start;
  gap: 18px;
}

.resource-card {
  display: flex;
  min-width: 0;
  min-height: 100%;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--catalog-line);
  background: var(--catalog-panel);
}

.resource-card__media {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border-bottom: 1px solid var(--catalog-line);
  background: #eef0f3;
}

.resource-card__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: opacity 150ms ease;
}

.resource-card:hover .resource-card__media img {
  opacity: 0.88;
}

.resource-card--initial_structure .resource-card__media img {
  object-fit: contain;
  background: #fff;
}

.resource-card__body {
  display: flex;
  min-height: 280px;
  flex: 1;
  flex-direction: column;
  padding: 22px;
}

.resource-card--course .resource-card__body,
.resource-card--open_resource .resource-card__body {
  min-height: 320px;
}

.resource-card__meta {
  display: flex;
  min-height: 24px;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 12px;
  color: var(--catalog-muted);
  font-size: 12px;
}

.resource-card__type {
  color: var(--catalog-accent);
  font-weight: 700;
}

.resource-card h3 {
  margin: 18px 0 10px;
  overflow-wrap: anywhere;
  font-size: 21px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0;
}

.resource-card__summary {
  display: -webkit-box;
  margin: 0;
  overflow: hidden;
  color: var(--catalog-muted);
  font-size: 14px;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

.resource-card__facts {
  display: grid;
  gap: 7px;
  margin: 18px 0 0;
  color: var(--catalog-muted);
  font-size: 13px;
}

.resource-card__facts span {
  display: block;
  overflow-wrap: anywhere;
}

.resource-card__cta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: auto;
  padding-top: 24px;
  color: var(--catalog-ink);
  font-size: 14px;
  font-weight: 700;
}

.resource-card__cta::after {
  color: var(--catalog-accent);
  content: "↗";
  font-size: 18px;
}

.resource-card__cta:hover {
  color: var(--catalog-accent);
}

.catalog-empty {
  padding: 54px 24px;
  border: 1px solid var(--catalog-line);
  text-align: center;
}

.catalog-empty h3 {
  margin: 0;
  font-size: 22px;
}

.catalog-empty p {
  margin: 10px 0 24px;
  color: var(--catalog-muted);
}

.catalog-pagination {
  display: flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 32px;
}

.catalog-pagination button,
.catalog-pagination span {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--catalog-line);
  background: var(--catalog-panel);
}

.catalog-pagination button {
  cursor: pointer;
}

.catalog-pagination button:hover:not(:disabled) {
  border-color: var(--catalog-ink);
}

.catalog-pagination button:disabled {
  cursor: not-allowed;
  opacity: 0.4;
}

.catalog-footer {
  border-top: 1px solid #2f2f2f;
  background: #171717;
  color: #fff;
}

.catalog-footer__grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: 56px;
  padding-block: 64px;
}

.catalog-footer__brand {
  margin: 0;
  font-size: 21px;
  font-weight: 700;
}

.catalog-footer__copy {
  max-width: 330px;
  margin: 12px 0 0;
  color: #b8b8b8;
  font-size: 14px;
}

.catalog-footer__links {
  display: grid;
  align-content: start;
  gap: 9px;
}

.catalog-footer__links p {
  margin: 0 0 10px;
  color: #8f8f8f;
  font-size: 13px;
}

.catalog-footer__links a {
  width: fit-content;
  color: #fff;
  font-size: 14px;
}

.catalog-footer__links a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.catalog-footer__legal {
  padding-block: 20px;
  border-top: 1px solid #333;
  color: #8f8f8f;
  font-size: 12px;
}

@media (max-width: 1023px) {
  .catalog-header__row {
    grid-template-columns: 156px minmax(0, 1fr) auto;
    gap: 18px;
  }

  .catalog-nav {
    gap: 18px;
  }

  .catalog-header__actions {
    gap: 12px;
  }

  .catalog-entrance-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .catalog-entrance-grid > a:nth-child(3) {
    border-left: 1px solid var(--catalog-line);
  }

  .resource-catalog-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .catalog-footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 767px) {
  .catalog-shell {
    width: min(calc(100% - 32px), var(--catalog-max));
  }

  .catalog-header__row {
    grid-template-columns: minmax(0, 1fr) auto;
    min-height: 68px;
  }

  .catalog-brand {
    width: 148px;
  }

  .catalog-nav,
  .catalog-header__actions {
    display: none;
  }

  .catalog-menu {
    display: inline-flex;
    width: 44px;
    height: 44px;
    align-items: center;
    justify-content: center;
    border: 0;
    background: transparent;
  }

  .catalog-menu span,
  .catalog-menu span::before {
    display: block;
    width: 22px;
    height: 1px;
    background: var(--catalog-ink);
    content: "";
  }

  .catalog-menu span::before {
    transform: translateY(-7px);
  }

  .catalog-mobile-nav {
    border-top: 1px solid var(--catalog-line);
    border-bottom: 1px solid var(--catalog-line);
    background: var(--catalog-panel);
  }

  .catalog-mobile-nav.is-open,
  .catalog-mobile-nav.open {
    display: block;
  }

  .catalog-mobile-nav__inner {
    display: grid;
    padding-block: 10px 16px;
  }

  .catalog-mobile-nav a {
    display: flex;
    min-height: 44px;
    align-items: center;
    border-bottom: 1px solid var(--catalog-line);
    font-size: 15px;
  }

  .catalog-hero {
    padding: 52px 0 44px;
  }

  .catalog-hero h1 {
    font-size: 38px;
  }

  .catalog-hero__intro {
    margin-top: 16px;
    font-size: 15px;
  }

  .catalog-main {
    padding-block: 48px 64px;
  }

  .catalog-entrances {
    margin-bottom: 52px;
  }

  .catalog-section-heading {
    align-items: start;
  }

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

  .catalog-entrance-grid > a,
  .catalog-entrance-grid > a:nth-child(3) {
    min-height: auto;
    border-left: 1px solid var(--catalog-line);
  }

  .catalog-entrance-grid p {
    min-height: auto;
  }

  .catalog-entrance-grid strong {
    margin-top: 20px;
  }

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

  .catalog-search button {
    display: none;
  }

  .catalog-filter-row {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .catalog-type-tabs {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .catalog-type-tabs button {
    width: 100%;
  }

  .catalog-results-heading {
    align-items: start;
    flex-direction: column;
  }

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

  .resource-card__body,
  .resource-card--course .resource-card__body,
  .resource-card--open_resource .resource-card__body {
    min-height: auto;
  }

  .resource-card__cta {
    margin-top: 24px;
  }

  .catalog-footer__grid {
    grid-template-columns: 1fr;
    gap: 36px;
    padding-block: 48px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}