:root {
  color-scheme: light dark;

  --color-background: #f5f3ee;
  --color-surface: #ffffff;
  --color-text: #1f1f24;
  --color-text-muted: #5c5c66;
  --color-border: #dcd8d0;
  --color-accent: #b8560f;
  --color-accent-contrast: #ffffff;
  --color-accent-tint: #f8e9dc;
  --color-focus: #1d4ed8;
  --color-error: #a4262c;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;

  --radius: 0.75rem;
  --tap-target: 2.75rem;
  --header-height: 3.5rem;
  --bottom-navigation-height: 3.75rem;
  --sidebar-width: 14rem;
  --content-max-width: 64rem;
  --text-measure: 72ch;
  --story-measure: 68ch;

  --font-family:
    system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial,
    sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-background: #17171b;
    --color-surface: #232329;
    --color-text: #ececf1;
    --color-text-muted: #a6a6b3;
    --color-border: #37373f;
    --color-accent: #f0a05a;
    --color-accent-contrast: #1f1f24;
    --color-accent-tint: #3a2a1c;
    --color-focus: #8ab4f8;
    --color-error: #f2a8a4;
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    'header'
    'main'
    'navigation';
  font-family: var(--font-family);
  font-size: 1rem;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-background);
  overflow-wrap: anywhere;
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

a {
  color: var(--color-accent);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.app-header {
  grid-area: header;
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  height: var(--header-height);
  padding: 0 var(--space-4);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.app-title {
  display: inline-flex;
  align-items: center;
  min-height: var(--tap-target);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  white-space: nowrap;
}

.node-badge {
  margin: 0;
  padding: var(--space-1) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.node-badge:has(#node-name:empty) {
  visibility: hidden;
}

.app-navigation {
  grid-area: navigation;
  position: sticky;
  bottom: 0;
  z-index: 1;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.app-navigation ul {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
}

.app-navigation li {
  flex: 1 1 0;
  min-width: 0;
}

.app-navigation a {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  min-width: var(--tap-target);
  min-height: var(--bottom-navigation-height);
  padding: var(--space-2);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
}

.app-navigation a[aria-current='page'] {
  color: var(--color-accent);
}

.app-main {
  grid-area: main;
  width: 100%;
  min-width: 0;
  max-width: var(--content-max-width);
  padding: var(--space-4);
}

.view-title {
  margin: 0 0 var(--space-4);
  font-size: 1.5rem;
  line-height: 1.25;
}

.card-list {
  display: grid;
  gap: var(--space-4);
  margin: 0;
  padding: 0;
  list-style: none;
}

.card {
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

a.card {
  display: block;
  min-height: var(--tap-target);
  color: inherit;
  text-decoration: none;
}

.species-name {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.3;
}

.species-latin-name {
  margin: var(--space-1) 0 var(--space-3);
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.species-description {
  max-width: var(--text-measure);
  margin: 0 0 var(--space-4);
}

.animal-name {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.3;
}

.animal-meta {
  display: flex;
  flex-wrap: wrap;
  column-gap: var(--space-3);
  row-gap: var(--space-1);
  margin: var(--space-1) 0 var(--space-3);
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.animal-price {
  margin: 0;
  font-weight: 600;
}

.back-link {
  display: inline-flex;
  align-items: center;
  min-height: var(--tap-target);
  margin-bottom: var(--space-2);
  color: var(--color-text-muted);
  text-decoration: none;
}

.animal-facts {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: var(--space-4);
  row-gap: var(--space-2);
  max-width: var(--text-measure);
  margin: 0 0 var(--space-6);
  font-size: 0.9375rem;
}

.animal-facts dt {
  margin: 0;
  color: var(--color-text-muted);
}

.animal-facts dd {
  margin: 0;
}

/*
 * The background story is the reading-comfort surface of this view: at
 * least 17px so it stays comfortable on a phone, a relaxed line height, and
 * a measure kept to roughly 65 to 70 characters on wide screens so a line
 * of text never grows too long to track by eye.
 */
.animal-story {
  max-width: var(--story-measure);
}

.animal-story p {
  margin: 0 0 var(--space-5);
  font-size: 1.0625rem;
  line-height: 1.6;
}

.animal-story p:last-child {
  margin-bottom: 0;
}

.species-filter {
  display: flex;
  flex-wrap: nowrap;
  gap: var(--space-2);
  margin: 0 0 var(--space-4);
  padding-bottom: var(--space-1);
  overflow-x: auto;
}

.chip {
  display: inline-flex;
  flex: none;
  align-items: center;
  justify-content: center;
  min-height: var(--tap-target);
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-surface);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  white-space: nowrap;
  text-decoration: none;
}

.chip[aria-current='page'] {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-accent-contrast);
}

.status {
  max-width: var(--text-measure);
  margin: 0;
  color: var(--color-text-muted);
}

.status-error {
  padding: var(--space-4);
  border: 1px solid var(--color-error);
  border-radius: var(--radius);
  color: var(--color-text);
}

.status-headline {
  margin: 0;
  font-weight: 600;
  color: var(--color-error);
}

.status-detail {
  margin: var(--space-2) 0 var(--space-4);
  color: var(--color-text-muted);
}

.not-found p {
  max-width: var(--text-measure);
  margin: 0 0 var(--space-4);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: var(--tap-target);
  min-height: var(--tap-target);
  padding: var(--space-2) var(--space-5);
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-weight: 600;
  color: var(--color-accent-contrast);
  background: var(--color-accent);
  text-decoration: none;
  cursor: pointer;
}

@media (hover: hover) {
  .app-navigation a:hover {
    color: var(--color-accent);
  }

  .button:hover {
    filter: brightness(1.1);
  }

  .chip:not([aria-current='page']):hover {
    border-color: var(--color-accent);
  }

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

  .back-link:hover {
    color: var(--color-accent);
  }
}

@media (min-width: 768px) {
  body {
    grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
    grid-template-rows: auto 1fr;
    grid-template-areas:
      'header header'
      'navigation main';
  }

  .app-header {
    padding: 0 var(--space-6);
  }

  .app-navigation {
    top: var(--header-height);
    bottom: auto;
    align-self: start;
    height: calc(100vh - var(--header-height));
    height: calc(100dvh - var(--header-height));
    padding: var(--space-4) var(--space-3);
    border-top: 0;
    border-right: 1px solid var(--color-border);
  }

  .app-navigation ul {
    flex-direction: column;
    gap: var(--space-1);
  }

  .app-navigation a {
    flex-direction: row;
    justify-content: flex-start;
    gap: var(--space-3);
    min-height: var(--tap-target);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius);
    font-size: 1rem;
  }

  .app-navigation a[aria-current='page'] {
    background: var(--color-accent-tint);
  }

  .app-main {
    padding: var(--space-6) var(--space-8);
  }

  .view-title {
    font-size: 1.75rem;
  }

  .card-list {
    grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr));
    gap: var(--space-5);
  }

  .card {
    padding: var(--space-5);
  }
}