/* Tokens are defined on :root and only overridden for dark, so a colour never has its single definition inside
   a media query. markdown.css reads these too. */
:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --text: #1c1d1f;
  --muted: #6b6f76;
  --border: #e2e2df;
  --accent: #1f7a5a;
  --accent-wash: #e8f3ee;
  --accent-muted: #a8cfbf;
  --radius-sm: 6px;
  --radius-lg: 12px;
  --shadow-1: 0 1px 2px rgb(0 0 0 / 6%);
  --shadow-2: 0 6px 20px rgb(0 0 0 / 10%);
  --fast: 140ms;
  --ease: cubic-bezier(0.2, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --surface: #1c1f24;
    --text: #e8e9ea;
    --muted: #9aa0a8;
    --border: #2c3037;
    --accent: #5fd0a4;
    --accent-wash: #1b2b25;
    --accent-muted: #2f5c4b;
    --shadow-1: 0 1px 2px rgb(0 0 0 / 40%);
    --shadow-2: 0 6px 20px rgb(0 0 0 / 45%);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

.hidden {
  display: none !important;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* Masthead */

.masthead {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
  padding: 0.85rem 1.5rem;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.brand {
  font-weight: 640;
  letter-spacing: -0.01em;
}

.masthead nav {
  display: flex;
  gap: 0.35rem;
}

.masthead nav a {
  padding: 0.35rem 0.8rem;
  border-radius: 99px;
  color: var(--muted);
  font-size: 0.88rem;
  text-decoration: none;
  transition: background var(--fast) var(--ease), color var(--fast) var(--ease);
}

.masthead nav a:hover {
  background: var(--accent-wash);
  color: var(--text);
}

.masthead nav a.active {
  background: var(--accent-wash);
  color: var(--accent);
  font-weight: 560;
}

.stamp {
  margin-left: auto;
  color: var(--muted);
  font-size: 0.74rem;
}

main {
  padding: 1.75rem 1.5rem 4rem;
}

/* Notes layout */

.page {
  max-width: 84rem;
  margin: 0 auto;
}

#view-notes.page {
  display: grid;
  grid-template-columns: minmax(14rem, 20rem) 1fr;
  gap: 2rem;
  align-items: start;
}

@media (max-width: 62rem) {
  #view-notes.page {
    grid-template-columns: 1fr;
  }
}

.sidebar {
  position: sticky;
  top: 5rem;
  max-height: calc(100vh - 7rem);
  overflow-y: auto;
  display: grid;
  gap: 0.5rem;
  align-content: start;
}

.search input,
#note-filter {
  width: 100%;
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-size: 0.88rem;
}

#note-filter:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-wash);
}

#note-tree details {
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.3rem;
}

#note-tree summary {
  padding: 0.4rem 0.2rem;
  font-size: 0.82rem;
  font-weight: 560;
  cursor: pointer;
}

#note-tree ul {
  list-style: none;
  margin: 0 0 0.3rem;
  padding: 0 0 0 0.7rem;
  display: grid;
  gap: 0.1rem;
  border-left: 1px solid var(--border);
}

#note-tree a {
  display: block;
  padding: 0.3rem 0.5rem;
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.82rem;
  line-height: 1.35;
  text-decoration: none;
}

#note-tree a:hover {
  background: var(--accent-wash);
}

#note-tree a.selected {
  background: var(--accent-wash);
  box-shadow: inset 2px 0 0 var(--accent);
  color: var(--accent);
}

.reader {
  min-width: 0;
  padding: 1.75rem 2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-2);
}

.reader h1 {
  margin: 0;
  font-size: 1.6rem;
  letter-spacing: -0.015em;
}

.meta {
  margin: 0.35rem 0 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.75rem;
}

/* News */

.news-controls {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
  margin-bottom: 0.75rem;
}

.tracks {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.track {
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 99px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-size: 0.8rem;
  cursor: pointer;
}

.track:hover {
  background: var(--accent-wash);
}

.track.selected {
  border-color: var(--accent);
  background: var(--accent-wash);
  color: var(--accent);
  font-weight: 560;
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--muted);
  font-size: 0.82rem;
  cursor: pointer;
}

.stale-note {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.76rem;
}

.items {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}

.item {
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-1);
}

.item.release {
  box-shadow: inset 3px 0 0 var(--accent), var(--shadow-1);
}

.item-head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.35rem;
  color: var(--muted);
  font-size: 0.72rem;
}

.kind {
  padding: 0.05rem 0.45rem;
  border: 1px solid var(--border);
  border-radius: 99px;
  font-size: 0.66rem;
  text-transform: uppercase;
}

.item.release .kind {
  border-color: var(--accent-muted);
  color: var(--accent);
}

.source {
  font-weight: 560;
  color: var(--text);
}

.title {
  display: block;
  color: var(--text);
  font-size: 1rem;
  font-weight: 560;
  line-height: 1.35;
  text-decoration: none;
}

.title:hover {
  color: var(--accent);
  text-decoration: underline;
}

.summary {
  margin: 0.4rem 0 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.empty {
  color: var(--muted);
}

.diagram {
  margin: 1.25rem 0;
  overflow-x: auto;
  text-align: center;
}

.diagram svg {
  max-width: 100%;
  height: auto;
}

.diagram-error {
  color: #b4342b;
  font-size: 0.8rem;
}

@media (prefers-color-scheme: dark) {
  .diagram-error {
    color: #ff9d94;
  }
}