*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #1a1b26;
  --bg-light: #24283b;
  --bg-lighter: #292e42;
  --border: #3b4261;
  --text: #c0caf5;
  --text-dim: #737aa2;
  --accent-ruby: #f7768e;
  --accent-crystal: #bb9af7;
  --accent-elixir: #a855f7;
  --accent-go: #73daca;
  --accent-kotlin: #ff79c6;
  --accent-python: #7aa2f7;
  --accent-rust: #ff9e64;
  --accent-swift: #f0805e;
  --accent-typescript: #e0af68;
  --accent: var(--accent-ruby);
  --tree-hover: #292e42;
  --tree-active: #3b4261;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* --------- Landing page --------- */

body.landing {
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.landing-main {
  max-width: 46rem;
  text-align: center;
}

/* Keep prose readable even though the hub is wide enough for a 3-up card row. */
.landing-main .blurb,
.landing-main .overview,
.landing-main .reading {
  max-width: 40rem;
  margin-left: auto;
  margin-right: auto;
}

.logo {
  width: 128px;
  height: 128px;
  margin-bottom: 1.25rem;
}

.landing-main h1 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

.landing-main .tagline {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-bottom: 2rem;
}

.landing-main .blurb {
  color: var(--text);
  font-size: 0.95rem;
  line-height: 1.55;
  margin-bottom: 2rem;
}

.landing-nav {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.landing-nav a {
  display: inline-block;
  padding: 0.55rem 1rem;
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  text-decoration: none;
  font-size: 0.9rem;
  transition: background 0.15s, border-color 0.15s;
}

.landing-nav a:hover {
  background: var(--bg-light);
  border-color: var(--accent);
}

.overview {
  text-align: left;
  color: var(--text);
  font-size: 0.9rem;
  line-height: 1.55;
  margin-bottom: 2rem;
}

.overview p {
  margin-bottom: 0.9rem;
}

.overview code {
  font-size: 0.85em;
}

.reading {
  list-style: none;
  padding: 0;
  color: var(--text-dim);
  font-size: 0.85rem;
}

.reading li {
  margin-bottom: 0.35rem;
}

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

.footnote {
  color: var(--text-dim);
  font-size: 0.8rem;
}

.footnote a {
  color: var(--text-dim);
}

.footnote a:hover {
  color: var(--text);
}

/* --------- Browse page --------- */

header {
  padding: 1.25rem 1.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
}

header h1 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--accent);
}

header h1 a {
  color: inherit;
  text-decoration: none;
}

.tagline {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 0.15rem;
}

/* Language tabs */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  padding: 0 1.5rem;
  flex-wrap: wrap;
}

.tab {
  background: none;
  border: none;
  color: var(--text-dim);
  padding: 0.6rem 1.25rem;
  font-size: 0.85rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.tab:hover {
  color: var(--text);
}

.tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab[data-lang="blog"].active { color: var(--accent-ruby); border-bottom-color: var(--accent-ruby); }
.tab[data-lang="ruby"].active { color: var(--accent-ruby); border-bottom-color: var(--accent-ruby); }
.tab[data-lang="crystal"].active { color: var(--accent-crystal); border-bottom-color: var(--accent-crystal); }
.tab[data-lang="elixir"].active { color: var(--accent-elixir); border-bottom-color: var(--accent-elixir); }
.tab[data-lang="go"].active { color: var(--accent-go); border-bottom-color: var(--accent-go); }
.tab[data-lang="kotlin"].active { color: var(--accent-kotlin); border-bottom-color: var(--accent-kotlin); }
.tab[data-lang="python"].active { color: var(--accent-python); border-bottom-color: var(--accent-python); }
.tab[data-lang="rust"].active { color: var(--accent-rust); border-bottom-color: var(--accent-rust); }
.tab[data-lang="swift"].active { color: var(--accent-swift); border-bottom-color: var(--accent-swift); }
.tab[data-lang="typescript"].active { color: var(--accent-typescript); border-bottom-color: var(--accent-typescript); }

/* Main layout */
main {
  flex: 1;
  overflow: hidden;
}

.panels {
  display: flex;
  height: calc(100vh - 8rem);
}

/* File tree */
.file-tree {
  width: 260px;
  min-width: 200px;
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 0.5rem 0;
}

.tree-item {
  display: flex;
  align-items: center;
  padding: 0.2rem 0.75rem;
  cursor: pointer;
  font-size: 0.8rem;
  color: var(--text-dim);
  white-space: nowrap;
  user-select: none;
}

.tree-item:hover {
  background: var(--tree-hover);
  color: var(--text);
}

.tree-item.active {
  background: var(--tree-active);
  color: var(--text);
}

.tree-item.dir {
  color: var(--text);
  font-weight: 500;
}

.tree-icon {
  width: 1rem;
  margin-right: 0.35rem;
  text-align: center;
  font-size: 0.7rem;
  flex-shrink: 0;
}

.tree-item.dir .tree-icon::before { content: "\25B6"; }
.tree-item.dir.open .tree-icon::before { content: "\25BC"; }
.tree-item.file .tree-icon::before { content: ""; }

.tree-children {
  display: none;
}

.tree-children.open {
  display: block;
}

/* Code panel */
.code-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.code-header {
  padding: 0.5rem 1rem;
  font-size: 0.8rem;
  color: var(--text-dim);
  background: var(--bg-light);
  border-bottom: 1px solid var(--border);
  font-family: "SF Mono", "Fira Code", "Cascadia Code", monospace;
}

.code-content {
  flex: 1;
  overflow: auto;
  padding: 1rem;
  background: var(--bg);
  font-family: "SF Mono", "Fira Code", "Cascadia Code", monospace;
  font-size: 0.8rem;
  line-height: 1.5;
  tab-size: 2;
  white-space: pre;
  color: var(--text);
}

.code-content.hljs {
  background: var(--bg);
}

footer {
  padding: 0.5rem 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
}

footer a {
  color: var(--text-dim);
  text-decoration: none;
  margin-right: 1rem;
}

footer a:hover {
  color: var(--text);
}

.loading {
  padding: 2rem;
  text-align: center;
  color: var(--text-dim);
}

/* --------- Doc / prose page (demo) --------- */

.doc-main {
  max-width: 52rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
  line-height: 1.6;
}

.doc-main h2 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--accent);
  margin: 2.5rem 0 0.85rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

.doc-main h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

.doc-main h3 {
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text);
  margin: 1.6rem 0 0.5rem;
}

.doc-main .lead {
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 1.5rem;
}

.doc-main p {
  color: var(--text);
  margin-bottom: 1rem;
}

.doc-main ul {
  margin: 0 0 1rem 1.25rem;
  color: var(--text);
}

.doc-main li {
  margin-bottom: 0.4rem;
}

.doc-main a {
  color: var(--accent-python);
  text-decoration: none;
}

.doc-main a:hover {
  text-decoration: underline;
}

.doc-main code {
  font-family: "SF Mono", "Fira Code", "Cascadia Code", monospace;
  font-size: 0.85em;
  background: var(--bg-lighter);
  padding: 0.1rem 0.35rem;
  border-radius: 0.25rem;
  color: var(--accent-go);
}

.doc-main pre {
  background: var(--bg-light);
  border: 1px solid var(--border);
  border-radius: 0.4rem;
  padding: 0.9rem 1.1rem;
  overflow-x: auto;
  margin: 0 0 1.25rem;
  font-size: 0.82rem;
  line-height: 1.55;
}

.doc-main pre code {
  background: none;
  padding: 0;
  color: var(--text);
  font-size: inherit;
}

.doc-main .note {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.doc-main table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 1.5rem;
  font-size: 0.88rem;
}

.doc-main th, .doc-main td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

.doc-main th {
  color: var(--accent);
  font-weight: 600;
}

.doc-main .pill {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.15rem 0.55rem;
  border: 1px solid var(--border);
  border-radius: 1rem;
  color: var(--text-dim);
  margin: 0 0.35rem 0.35rem 0;
}

.doc-main .run-live {
  background: var(--bg-light);
  border: 1px solid var(--accent-typescript);
  border-radius: 0.5rem;
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
}
.doc-main .run-live a {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent-typescript);
}
.doc-main .run-live small {
  color: var(--text-dim);
  display: inline-block;
  margin-top: 0.5rem;
}

/* --------- App picker cards (landing hub) --------- */

.app-cards {
  display: grid;
  /* 16rem is the width that makes four cards land 2×2 in the content column
     rather than 3-then-1; narrower viewports still collapse to one. */
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1.5rem;
  text-align: left;
  margin: 2.5rem 0;
}

.app-card {
  display: block;
  padding: 1.2rem 1.3rem 1.3rem;
  /* Tint the card with its app's colour so each section reads clearly on the
     dark page; the plain fill is the fallback where color-mix is unsupported. */
  background: var(--bg-light);
  background: color-mix(in srgb, var(--card-accent, var(--accent)) 14%, var(--bg-light));
  border: 1px solid var(--border);
  border: 1px solid color-mix(in srgb, var(--card-accent, var(--accent)) 45%, var(--border));
  border-top: 3px solid var(--card-accent, var(--accent));
  border-radius: 0.5rem;
  text-decoration: none;
  color: var(--text);
  transition: background 0.15s, transform 0.15s, border-color 0.15s, box-shadow 0.15s;
}

.app-card:hover {
  background: color-mix(in srgb, var(--card-accent, var(--accent)) 24%, var(--bg-light));
  border-color: var(--card-accent, var(--accent));
  transform: translateY(-3px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
}
.app-card.blog     { --card-accent: var(--accent-ruby); }
.app-card.lobsters { --card-accent: var(--accent-rust); }
.app-card.campfire { --card-accent: var(--accent-go); }
.app-card.mastodon { --card-accent: var(--accent-crystal); }

.app-card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--card-accent, var(--accent));
  margin-bottom: 0.25rem;
}

.app-card .role {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--card-accent, var(--accent));
  margin-bottom: 0.6rem;
}

.app-card p {
  font-size: 0.82rem;
  color: var(--text);
  line-height: 1.45;
  margin: 0;
}

.app-card .go {
  display: inline-block;
  margin-top: 0.7rem;
  font-size: 0.8rem;
  color: var(--card-accent, var(--accent));
}

/* --------- Per-app case-study pages (site/apps/) --------- */

body.app-blog     { --card-accent: var(--accent-ruby); }
body.app-lobsters { --card-accent: var(--accent-rust); }
body.app-campfire { --card-accent: var(--accent-go); }
body.app-mastodon { --card-accent: var(--accent-crystal); }

body.doc header h1 a,
body.doc .doc-main h2 { color: var(--card-accent, var(--accent)); }

.status-line {
  font-size: 0.85rem;
  color: var(--text-dim);
  border-left: 3px solid var(--card-accent, var(--accent));
  padding: 0.2rem 0 0.2rem 0.85rem;
  margin: 0 0 1.4rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 1.4rem 0 1.9rem;
}

.cta-row a {
  display: inline-block;
  padding: 0.5rem 0.95rem;
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  text-decoration: none;
  font-size: 0.85rem;
  transition: background 0.15s, border-color 0.15s;
}

.cta-row a:hover { background: var(--bg-light); border-color: var(--card-accent, var(--accent)); }

.cta-row a.primary {
  border-color: var(--card-accent, var(--accent));
  color: var(--card-accent, var(--accent));
  font-weight: 600;
}

/* --------- User guide (docs/guide/*.md, rendered by `roundhouse --site`) --------- */

body.guide .tagline a {
  color: var(--text-dim);
  text-decoration: none;
}
body.guide .tagline a:hover { text-decoration: underline; }

.doc-main ol {
  margin: 0 0 1.25rem 1.5rem;
  line-height: 1.6;
}
.doc-main ol li { margin-bottom: 0.4rem; }

.doc-main h4 {
  font-size: 0.95rem;
  color: var(--text);
  margin: 1.25rem 0 0.5rem;
}

.doc-main hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

/* A flex child's minimum width is its content's: a long unbreakable
   line in a <pre> would push the whole column past the viewport on a
   narrow window. Let the column shrink; the <pre> scrolls on its own. */
.doc-main { min-width: 0; width: 100%; }

/* Wide tables (the coverage page) scroll rather than overflow the column. */
.doc-main table { display: block; overflow-x: auto; }