*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  color: rgb(23 23 23);
  background: white;
  font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100dvh;
  margin: 0;
}

main {
  width: 100%;
  max-width: 64rem;
  margin-inline: auto;
  padding: 3rem 1.25rem 6rem;
}

a {
  color: inherit;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 4px;
}

h1,
h2,
p {
  margin: 0;
}

h1,
h2 {
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

button,
input {
  font: inherit;
}

[hidden] {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.page-intro,
.detail-site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
}

.page-intro {
  margin-bottom: 3.5rem;
}

.intro-copy {
  max-width: 48rem;
}

.intro-copy h1,
.entry-detail-header h1 {
  font-size: 1.875rem;
  font-weight: 500;
  line-height: 2.25rem;
  letter-spacing: -0.025em;
}

.intro-copy p {
  max-width: 42rem;
  margin-top: 1rem;
  color: rgb(82 82 82);
  font-size: 0.875rem;
  line-height: 1.5rem;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  font-size: 0.875rem;
  line-height: 1.5rem;
}

.site-nav a {
  color: rgb(115 115 115);
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: rgb(23 23 23);
}

.site-nav a[aria-current="page"] {
  font-weight: 500;
}

.filters-section {
  display: block;
}

.filters {
  min-width: 0;
}

.filters > summary {
  display: inline-flex;
  min-height: 2.25rem;
  align-items: center;
  gap: 0.625rem;
  padding: 0.375rem 0.75rem;
  border: 1px solid rgb(212 212 212);
  color: rgb(64 64 64);
  cursor: pointer;
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1rem;
  list-style: none;
}

.filters > summary::-webkit-details-marker {
  display: none;
}

.filters > summary:hover {
  border-color: rgb(23 23 23);
  color: rgb(23 23 23);
}

.filters > summary svg {
  width: 0.75rem;
  height: 0.75rem;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-width: 1.4;
}

.filters[open] .filter-icon-vertical {
  display: none;
}

.filter-panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 1rem;
  padding: 1.25rem;
  border: 1px solid rgb(229 229 229);
}

.filter-panel fieldset {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.filter-panel legend {
  margin-bottom: 0.75rem;
  color: rgb(23 23 23);
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1rem;
}

.filter-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.filter-option {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 2rem;
  padding: 0.25rem 0.625rem;
  border: 1px solid rgb(229 229 229);
  color: rgb(82 82 82);
  cursor: pointer;
  font-size: 0.75rem;
  line-height: 1rem;
}

.filter-option:hover,
.filter-option:has(input:checked) {
  border-color: rgb(23 23 23);
  color: rgb(23 23 23);
}

.filter-option input {
  width: 0.875rem;
  height: 0.875rem;
  margin: 0;
  accent-color: rgb(23 23 23);
}

.filter-count {
  color: rgb(163 163 163);
  font-variant-numeric: tabular-nums;
}

.clear-filters {
  justify-self: start;
  padding: 0;
  border: 0;
  color: rgb(82 82 82);
  background: transparent;
  cursor: pointer;
  font-size: 0.75rem;
  line-height: 1rem;
  text-decoration: underline;
  text-decoration-color: rgb(212 212 212);
  text-underline-offset: 0.25rem;
}

.clear-filters:hover {
  color: rgb(23 23 23);
  text-decoration-color: rgb(82 82 82);
}

.clear-filters:disabled {
  color: rgb(163 163 163);
  cursor: default;
  text-decoration: none;
}

.timeline-section {
  margin-top: 3rem;
}

.timeline-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.timeline-list > li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  padding-block: 1.5rem;
  border-top: 1px solid rgb(229 229 229);
}

.timeline-list > li:last-child {
  border-bottom: 1px solid rgb(229 229 229);
}

.timeline-list time,
.detail-date {
  color: rgb(115 115 115);
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
  line-height: 1.25rem;
}

.entry-meta {
  color: rgb(115 115 115);
  font-size: 0.875rem;
  line-height: 1.25rem;
}

.timeline-list h2 {
  margin-top: 0.5rem;
  font-size: 1.125rem;
  font-weight: 500;
  line-height: 1.375;
}

.timeline-list h2 a {
  text-decoration: none;
}

.timeline-list h2 a:hover {
  color: rgb(82 82 82);
}

.entry-summary {
  max-width: 42rem;
  margin-top: 0.75rem;
  color: rgb(64 64 64);
  font-size: 0.875rem;
  line-height: 1.5rem;
}

.entry-authors {
  margin-top: 0.625rem;
  color: rgb(163 163 163);
  font-size: 0.875rem;
  line-height: 1.25rem;
}

.empty-state,
.concepts-empty {
  color: rgb(82 82 82);
  font-size: 0.875rem;
  line-height: 1.5rem;
}

.empty-state {
  padding-block: 2rem;
  border-top: 1px solid rgb(229 229 229);
  border-bottom: 1px solid rgb(229 229 229);
}

.concepts-empty {
  max-width: 42rem;
  padding-block: 2rem;
  border-top: 1px solid rgb(229 229 229);
  border-bottom: 1px solid rgb(229 229 229);
}

.concepts-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.concepts-list > li {
  max-width: 48rem;
  padding-block: 1.5rem;
  border-top: 1px solid rgb(229 229 229);
}

.concepts-list > li:last-child {
  border-bottom: 1px solid rgb(229 229 229);
}

.concepts-list h2 {
  font-size: 1.125rem;
  font-weight: 500;
  line-height: 1.375;
}

.concepts-list h2 a {
  text-decoration: none;
}

.concepts-list article > p {
  max-width: 42rem;
  margin-top: 0.75rem;
  color: rgb(64 64 64);
  font-size: 0.875rem;
  line-height: 1.5rem;
}

.concepts-list .concept-connections {
  margin-top: 0.625rem;
  color: rgb(163 163 163);
}

.concepts-empty h2,
.detail-section h2 {
  color: rgb(23 23 23);
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.5rem;
}

.concepts-empty p {
  margin-top: 0.5rem;
}

.concepts-empty a,
.sources a,
.site-footer a {
  text-decoration-color: rgb(212 212 212);
  text-underline-offset: 0.25rem;
}

.concepts-empty a {
  display: inline-block;
  margin-top: 1rem;
  color: rgb(23 23 23);
  font-weight: 500;
}

.detail-site-header {
  margin-bottom: 3.5rem;
}

.site-name {
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.5rem;
  text-decoration: none;
}

.entry-detail {
  max-width: 48rem;
}

.entry-detail-header {
  margin-bottom: 3.5rem;
}

.entry-detail-header h1 {
  max-width: 42rem;
  margin-top: 0.75rem;
}

.detail-byline {
  margin-top: 1rem;
  color: rgb(64 64 64);
  font-size: 0.875rem;
  line-height: 1.5rem;
}

.concept-definition {
  max-width: 42rem;
  margin-top: 1rem;
  color: rgb(64 64 64);
  font-size: 1rem;
  line-height: 1.75rem;
}

.detail-date {
  margin-top: 0.25rem;
}

.detail-section {
  max-width: 42rem;
  margin-top: 2rem;
}

.detail-section p,
.sources ul {
  margin: 0.5rem 0 0;
  color: rgb(64 64 64);
  font-size: 0.9375rem;
  line-height: 1.75rem;
}

.detail-section p + p {
  margin-top: 0.875rem;
}

.concept-examples ul {
  margin: 0.5rem 0 0;
  padding-left: 1.25rem;
  color: rgb(64 64 64);
  font-size: 0.9375rem;
  line-height: 1.75rem;
}

.concept-examples li + li {
  margin-top: 1rem;
}

.concept-examples p {
  margin-top: 0.125rem;
}

.sources ul {
  padding-left: 1.25rem;
}

.sources li + li {
  margin-top: 0.25rem;
}

.site-footer {
  max-width: 48rem;
  margin-top: 4rem;
  color: rgb(163 163 163);
  font-size: 0.75rem;
  line-height: 1.5rem;
}

.site-footer a:hover,
.sources a:hover,
.concepts-empty a:hover,
.concepts-list h2 a:hover {
  color: rgb(23 23 23);
  text-decoration-color: rgb(82 82 82);
}

::selection {
  color: white;
  background: rgb(23 23 23);
}

@media (min-width: 640px) {
  main {
    padding-inline: 2rem;
  }

  .intro-copy h1,
  .entry-detail-header h1 {
    font-size: 2.25rem;
    line-height: 2.5rem;
  }

  .intro-copy p {
    font-size: 1rem;
    line-height: 1.75rem;
  }

  .filter-panel {
    grid-template-columns: 0.7fr 1.3fr;
  }

  .clear-filters {
    grid-column: 1 / -1;
  }

  .timeline-list > li {
    grid-template-columns: 8rem 1fr;
  }
}

@media (min-width: 1024px) {
  main {
    padding-inline: 2.5rem;
  }
}