.about-index {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 44px 88px;
}

.about-section {
  margin-top: 56px;
}

.about-section:first-child {
  margin-top: 20px;
}

.about-section__heading {
  position: sticky;
  z-index: 20;
  top: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  flex-wrap: wrap;
  min-height: 34px;
  padding: 14px 0;
  border-top: 1px solid var(--section-heading-rule);
  background: var(--paper);
}

.about-section__heading h2 {
  margin: 0;
  font-family: "Space Grotesk", sans-serif;
  font-size: 24px;
  font-weight: 400;
  line-height: 1.25;
}

.about-section-filters {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
}

.about-section-filter {
  appearance: none;
  cursor: pointer;
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 100px;
  background: transparent;
  color: var(--ink);
  font: 500 12px/1.2 "Space Grotesk", sans-serif;
  transition: background 160ms ease, border-color 160ms ease, color 160ms ease, transform 160ms ease;
}

.about-section-filter:hover,
.about-section-filter:focus-visible {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 13%, transparent);
  transform: translateY(-1px);
}

.about-section-filter:focus-visible {
  outline: 2px solid color-mix(in srgb, var(--accent) 48%, transparent);
  outline-offset: 2px;
}

.about-section-filter[aria-pressed="true"] {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.about-view-switch {
  display: flex;
  flex: 0 0 auto;
  gap: 6px;
  margin-left: 4px;
  padding-left: 10px;
  border-left: 1px solid var(--section-intermediate-rule);
}

.about-reference-search {
  display: flex;
  flex: 0 0 auto;
}

.about-reference-search__input {
  box-sizing: border-box;
  display: none;
  width: 190px;
  height: 26px;
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 100px;
  background: var(--paper);
  color: var(--ink);
  font: 500 12px/1.2 "Space Grotesk", sans-serif;
}

.about-reference-search__input:focus {
  border-color: var(--accent);
  outline: 2px solid color-mix(in srgb, var(--accent) 48%, transparent);
  outline-offset: 2px;
}

.about-reference-search.is-open .about-reference-search__toggle {
  display: none;
}

.about-reference-search.is-open .about-reference-search__input {
  display: block;
}

.patent-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0 18px;
}

.patent-card {
  min-width: 0;
  padding: 17px 0 20px;
  border-top: 1px solid var(--section-intermediate-rule);
}

.patent-card__meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin: 0 0 8px;
  color: var(--soft);
  font: 500 11px/1.2 "Space Grotesk", sans-serif;
}

.patent-card__meta > :last-child {
  text-align: right;
}

.patent-card h3 {
  margin: 0;
  font-family: "Space Grotesk", sans-serif;
  font-size: 22px;
  font-weight: 500;
  line-height: 30px;
  text-wrap: pretty;
}

.patent-card h3 a {
  color: inherit;
  text-decoration: none;
}

.patent-card h3 a:hover {
  color: var(--accent);
}

.patent-card__standfirst {
  margin: var(--standfirst-gap, 6px) 0 0;
  color: var(--soft);
  font-size: 17px;
  line-height: 24px;
}

.book-reference-wall {
  /* Keep the five-column shelf proportional as its columns narrow. */
  --book-cover-height: clamp(220px, calc(30.4vw - 56px), 300px);
  --book-heading-gap: 34px;
  --book-shelf-step: calc(var(--book-cover-height) + var(--book-shelf-gap));
  position: relative;
  isolation: isolate;
  padding-top: var(--book-heading-gap);
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0,
    transparent calc(var(--book-cover-height) + var(--book-heading-gap) - 1px),
    var(--section-intermediate-rule) calc(var(--book-cover-height) + var(--book-heading-gap) - 1px),
    var(--section-intermediate-rule) calc(var(--book-cover-height) + var(--book-heading-gap)),
    transparent calc(var(--book-cover-height) + var(--book-heading-gap)),
    transparent var(--book-shelf-step)
  );
}

.book-reference-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  column-gap: 24px;
  row-gap: var(--book-shelf-gap);
  width: 100%;
}

.book-reference {
  position: relative;
  min-width: 0;
  width: 100%;
  height: var(--book-cover-height);
  display: flex;
  align-items: flex-end;
  justify-content: center;
}

.book-reference:nth-child(5n + 1) {
  justify-content: flex-start;
}

.book-reference:nth-child(5n) {
  justify-content: flex-end;
}

.book-reference__link {
  position: relative;
  width: max-content;
  max-width: 100%;
  height: 100%;
  display: flex;
  align-items: flex-end;
  color: inherit;
  text-decoration: none;
}

.book-reference__cover {
  display: block;
  width: auto;
  max-width: 100%;
  height: auto;
  max-height: 100%;
  object-fit: contain;
  object-position: center bottom;
  border-radius: 3px;
  transition: transform 180ms ease;
}

.book-reference__link:hover .book-reference__cover,
.book-reference__link:focus-visible .book-reference__cover {
  transform: translateY(-2px);
}

.book-reference__link:focus-visible {
  border-radius: 3px;
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.book-reference-list {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--section-intermediate-rule);
  list-style: none;
}

.book-reference-list li {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 25px;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px solid var(--section-intermediate-rule);
}

.book-reference-list__year {
  color: var(--accent);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.35;
  font-variant-numeric: tabular-nums;
}

.book-reference-list__body h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 500;
  line-height: 1.35;
  text-wrap: pretty;
}

.book-reference-list__body h3 a {
  color: inherit;
  text-decoration: none;
}

.book-reference-list__body h3 a:hover {
  color: var(--accent);
}

.book-reference-list__body p {
  margin: 3px 0 0;
  color: var(--soft);
  font-size: 14px;
  line-height: 1.45;
}

.about-section--books .about-section__heading {
  border-bottom: 1px solid var(--section-intermediate-rule);
}

.about-section--books {
  --book-shelf-gap: 48px;
}

.about-section--books .about-section__heading.is-stuck {
  border-bottom-color: transparent;
}

.academic-reference-list {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--section-intermediate-rule);
  list-style: none;
}

.academic-reference-list li {
  padding: 16px 0;
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 25px;
  align-items: start;
  border-bottom: 1px solid var(--section-intermediate-rule);
}

.academic-reference__year {
  color: var(--accent);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.35;
  font-variant-numeric: tabular-nums;
}

.academic-reference__body h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 500;
  line-height: 1.35;
  text-wrap: pretty;
}

.academic-reference__body h3 a {
  color: inherit;
  text-decoration: none;
}

.academic-reference__body h3 a:hover {
  color: var(--accent);
}

.academic-reference__original-title {
  margin: 3px 0 0;
  color: color-mix(in srgb, var(--soft) 84%, transparent);
  font-size: 13px;
  line-height: 1.45;
}

.academic-reference__byline {
  margin: 3px 0 0;
  display: flex;
  align-items: baseline;
  justify-content: flex-start;
  gap: 7px;
  flex-wrap: wrap;
  color: var(--soft);
  font-size: 14px;
  line-height: 1.45;
}

.academic-reference__byline > span {
  min-width: 0;
}

.academic-reference__byline > a {
  color: var(--soft);
  font-size: inherit;
  text-decoration: none;
  white-space: nowrap;
}

.academic-reference__byline > a::before {
  content: "\00b7";
  margin-right: 7px;
}

.academic-reference__byline > a:hover {
  color: var(--ink);
}

.academic-reference-archive-link,
.book-reference-archive-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px 0;
  border-bottom: 1px solid var(--section-intermediate-rule);
  color: var(--ink);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
}

.book-reference-archive-link {
  margin-top: var(--book-shelf-gap);
  border-top: 1px solid var(--section-intermediate-rule);
}

.academic-reference-archive-link::after,
.book-reference-archive-link::after {
  content: "\2192";
  color: var(--accent);
  font-size: 20px;
  font-weight: 400;
  line-height: 1;
  transition: transform 160ms ease;
}

.academic-reference-empty {
  margin: 0;
  padding: 28px 0;
  border-top: 1px solid var(--section-intermediate-rule);
  border-bottom: 1px solid var(--section-intermediate-rule);
  color: var(--soft);
  font-size: 16px;
  line-height: 1.5;
}

.academic-reference-archive-link:hover,
.book-reference-archive-link:hover {
  color: var(--accent);
}

.academic-reference-archive-link:hover::after,
.book-reference-archive-link:hover::after {
  transform: translateX(3px);
}

.about-filter-transition-shield {
  position: fixed;
  z-index: 1000;
  box-sizing: border-box;
  margin: 0;
  pointer-events: none;
}

@media (prefers-reduced-motion: no-preference) {
  :root {
    view-transition-name: none;
  }

  ::view-transition {
    -webkit-mask-image: linear-gradient(
      to bottom,
      transparent 0,
      transparent var(--about-transition-clip-top, 0px),
      #000 var(--about-transition-clip-top, 0px),
      #000 100%
    );
    mask-image: linear-gradient(
      to bottom,
      transparent 0,
      transparent var(--about-transition-clip-top, 0px),
      #000 var(--about-transition-clip-top, 0px),
      #000 100%
    );
  }

  ::view-transition-group(*) {
    animation-delay: 135ms;
    animation-duration: 520ms;
    animation-fill-mode: both;
    animation-timing-function: cubic-bezier(.22, .8, .22, 1);
  }

  ::view-transition-old(*),
  ::view-transition-new(*) {
    mix-blend-mode: normal;
  }

  ::view-transition-old(*):not(:only-child) {
    opacity: 0;
    animation: none;
  }

  ::view-transition-new(*):not(:only-child) {
    opacity: 1;
    animation: none;
  }

  ::view-transition-old(*):only-child {
    animation: academic-reference-exit 170ms cubic-bezier(.4, 0, .8, .2) both;
  }

  ::view-transition-new(*):only-child {
    animation: academic-reference-enter 230ms cubic-bezier(.16, 1, .3, 1) 510ms both;
  }

  @keyframes academic-reference-exit {
    to {
      opacity: 0;
      transform: translateY(-9px);
    }
  }

  @keyframes academic-reference-enter {
    from {
      opacity: 0;
      transform: translateY(13px);
    }
  }
}

@media (max-width: 760px) {
  .about-index {
    padding-right: 22px;
    padding-left: 22px;
  }

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

  .about-section-filters {
    justify-content: flex-start;
  }

  .academic-reference-list li {
    grid-template-columns: 58px minmax(0, 1fr);
    gap: 17px;
  }

  .academic-reference__byline {
    align-items: flex-start;
    flex-direction: column;
    gap: 3px;
  }

}

@media (max-width: 900px) {
  .about-section--books {
    --book-shelf-gap: 42px;
  }

  .book-reference-wall {
    --book-cover-height: 220px;
    --book-heading-gap: 28px;
  }

  .book-reference-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: 20px;
  }

  .book-reference:nth-child(n) {
    justify-content: center;
  }

  .book-reference:nth-child(3n + 1) {
    justify-content: flex-start;
  }

  .book-reference:nth-child(3n) {
    justify-content: flex-end;
  }
}

@media (max-width: 620px) {
  .about-section__heading {
    display: block;
  }

  .about-section-filters {
    width: 100%;
    margin-top: 8px;
    padding: 2px 0;
    flex-wrap: nowrap;
    justify-content: flex-start;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .about-section-filters::-webkit-scrollbar {
    display: none;
  }

  .about-section-filter {
    flex: 0 0 auto;
  }

  .about-view-switch {
    margin-left: 2px;
    padding-left: 8px;
  }

  .academic-reference-list li,
  .book-reference-list li {
    display: block;
    padding: 14px 0 16px;
  }

  .academic-reference__year,
  .book-reference-list__year {
    display: block;
    margin-bottom: 4px;
    font-size: 13px;
    line-height: 1.2;
  }

  .academic-reference__byline > a::before {
    content: none;
    margin: 0;
  }

  .about-section--books {
    --book-shelf-gap: 36px;
  }

  .book-reference-wall {
    --book-cover-height: 184px;
    --book-heading-gap: 24px;
  }

  .book-reference-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 16px;
  }

  .book-reference:nth-child(n) {
    justify-content: flex-start;
  }

  .book-reference:nth-child(2n) {
    justify-content: flex-end;
  }
}