/* ============================================================
 * Keel — mdbook theme
 * Drop this into your mdbook `theme/` directory as `css/general.css`
 * overrides, OR load it via `additional-css` in book.toml:
 *
 *   [output.html]
 *   additional-css = ["brand/keel-docs.css"]
 *   preferred-dark-theme = "keel"
 *   default-theme      = "keel"
 *
 * Then register the theme in theme/index.hbs if you want the toggle.
 * ============================================================ */

/* ---------- Fonts ------------------------------------------------ */
@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,500;9..144,600;9..144,700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ---------- Palette & tokens ------------------------------------ */
:root {
  --keel-onyx:  #0B0D10;
  --keel-onyx-2:#13161B;
  --keel-onyx-3:#1E232A;
  --keel-ash:   #3A4048;
  --keel-fog:   #9BA3AE;
  --keel-ivory: #F2EFE6;
  --keel-mist:  #D8D4C7;
  --keel-paper: #FAF8F1;
  --keel-amber: #FFB84A;
  --keel-burnt: #D2691A;

  --keel-font-display: 'Fraunces', ui-serif, Georgia, serif;
  --keel-font-body:    'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --keel-font-mono:    'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* ---------- Dark theme (default: "keel") ------------------------ */
.keel,
.navy,            /* alias mdbook's navy to keel */
.ayu,
html.keel body,
html.navy body {
  --bg:                var(--keel-onyx);
  --fg:                var(--keel-ivory);
  --sidebar-bg:        var(--keel-onyx-2);
  --sidebar-fg:        var(--keel-mist);
  --sidebar-non-existant: #2a2f37;
  --sidebar-active:    var(--keel-amber);
  --sidebar-spacer:    var(--keel-onyx-3);

  --scrollbar:         var(--keel-ash);

  --icons:             var(--keel-fog);
  --icons-hover:       var(--keel-amber);

  --links:             var(--keel-amber);

  --inline-code-color: var(--keel-amber);

  --theme-popup-bg:        var(--keel-onyx-2);
  --theme-popup-border:    var(--keel-onyx-3);
  --theme-hover:           var(--keel-onyx-3);

  --quote-bg:              var(--keel-onyx-2);
  --quote-border:          var(--keel-amber);

  --table-border-color:    var(--keel-onyx-3);
  --table-header-bg:       var(--keel-onyx-2);
  --table-alternate-bg:    #0f1217;

  --searchbar-border-color: var(--keel-onyx-3);
  --searchbar-bg:          var(--keel-onyx-2);
  --searchbar-fg:          var(--keel-ivory);
  --searchbar-shadow-color:#000;
  --searchresults-header-fg: var(--keel-fog);
  --searchresults-border-color: var(--keel-onyx-3);
  --searchresults-li-bg:   var(--keel-onyx-2);
  --search-mark-bg:        var(--keel-amber);

  --color-scheme: dark;
}

/* ---------- Light theme: "keel-light" --------------------------- */
.keel-light,
.light,
.rust {
  --bg:                var(--keel-paper);
  --fg:                var(--keel-onyx);
  --sidebar-bg:        var(--keel-ivory);
  --sidebar-fg:        var(--keel-onyx);
  --sidebar-non-existant: var(--keel-fog);
  --sidebar-active:    var(--keel-burnt);
  --sidebar-spacer:    var(--keel-mist);

  --scrollbar:         var(--keel-mist);

  --icons:             var(--keel-ash);
  --icons-hover:       var(--keel-burnt);

  --links:             var(--keel-burnt);

  --inline-code-color: var(--keel-burnt);

  --theme-popup-bg:        #fff;
  --theme-popup-border:    var(--keel-mist);
  --theme-hover:           var(--keel-ivory);

  --quote-bg:              var(--keel-ivory);
  --quote-border:          var(--keel-burnt);

  --table-border-color:    var(--keel-mist);
  --table-header-bg:       var(--keel-ivory);
  --table-alternate-bg:    #f6f2e6;

  --searchbar-border-color: var(--keel-mist);
  --searchbar-bg:          #fff;
  --searchbar-fg:          var(--keel-onyx);
  --searchbar-shadow-color:rgba(0,0,0,0.08);
  --searchresults-header-fg: var(--keel-ash);
  --searchresults-border-color: var(--keel-mist);
  --searchresults-li-bg:   var(--keel-ivory);
  --search-mark-bg:        var(--keel-amber);

  --color-scheme: light;
}

/* ---------- Global type ---------------------------------------- */
html { font-family: var(--keel-font-body); font-feature-settings: "ss01", "cv11"; }
body { font-family: var(--keel-font-body); line-height: 1.6; }

.content h1, .content h2, .content h3, .content h4, .content h5 {
  font-family: var(--keel-font-display);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.15;
}
.content h1 { font-size: 2.5em; margin-top: 0; padding-bottom: 0.4em; border-bottom: 1px solid var(--quote-bg); }
.content h2 { font-size: 1.8em; margin-top: 2.2em; }
.content h3 { font-size: 1.35em; margin-top: 1.8em; }
.content h4 { font-size: 1.12em; margin-top: 1.5em; }

.content a, .content a:visited { color: var(--links); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color 120ms; }
.content a:hover { border-bottom-color: var(--links); }

.content p, .content li { font-size: 1em; }

/* ---------- Sidebar -------------------------------------------- */
.sidebar { font-family: var(--keel-font-body); font-size: 0.9em; }
/* Leave room for the mark bar (::before) so chapter items never scroll under it. */
.sidebar .sidebar-scrollbox { padding: 72px 18px 16px; }
.sidebar .chapter li.chapter-item {
  line-height: 1.5;
  margin: 0.15rem 0;
  padding: 3px 8px;
  border-radius: 4px;
}
.sidebar .chapter li a {
  color: var(--sidebar-fg);
  padding: 2px 0;
  border: none;
}
.sidebar .chapter li a:hover { color: var(--sidebar-active); }
.sidebar .chapter li a.active {
  color: var(--sidebar-active);
  font-weight: 600;
}
.sidebar .chapter li.part-title {
  font-family: var(--keel-font-mono);
  font-size: 0.72em;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--keel-fog);
  margin: 1.8rem 0 0.4rem;
  padding: 0;
}

/* Sidebar Keel mark — sticky header bar at top, opaque so chapter items
   can scroll underneath without showing through. */
.sidebar::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 72px;
  background-color: var(--sidebar-bg);
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 200'><circle cx='100' cy='100' r='92' fill='none' stroke='%23F2EFE6' stroke-width='6'/><path d='M 100 22 L 148 150 L 52 150 Z' fill='%23F2EFE6'/><line x1='100' y1='22' x2='100' y2='178' stroke='%23FFB84A' stroke-width='10'/><path d='M 40 150 Q 100 192 160 150 L 148 150 Q 100 172 52 150 Z' fill='%23F2EFE6'/></svg>");
  background-repeat: no-repeat;
  background-position: center 16px;
  background-size: 40px 40px;
  border-bottom: 1px solid var(--sidebar-spacer);
  z-index: 2;
  pointer-events: none;
}
.keel-light .sidebar::before, .light .sidebar::before, .rust .sidebar::before {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 200'><circle cx='100' cy='100' r='92' fill='none' stroke='%230B0D10' stroke-width='6'/><path d='M 100 22 L 148 150 L 52 150 Z' fill='%230B0D10'/><line x1='100' y1='22' x2='100' y2='178' stroke='%23D2691A' stroke-width='10'/><path d='M 40 150 Q 100 192 160 150 L 148 150 Q 100 172 52 150 Z' fill='%230B0D10'/></svg>");
}

/* ---------- Menu bar ------------------------------------------- */
#menu-bar {
  border-bottom: 1px solid var(--quote-bg);
  background: var(--bg);
}
#menu-bar .left-buttons button,
#menu-bar .right-buttons button { color: var(--icons); }
#menu-bar .menu-title {
  font-family: var(--keel-font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
}

/* ---------- Code ----------------------------------------------- */
code { font-family: var(--keel-font-mono); font-size: 0.92em; }
.content :not(pre) > code {
  background: var(--quote-bg);
  color: var(--inline-code-color);
  padding: 0.15em 0.45em;
  border-radius: 4px;
  font-weight: 500;
}
pre {
  background: var(--quote-bg) !important;
  border: 1px solid var(--quote-bg);
  border-left: 3px solid var(--keel-amber);
  border-radius: 6px;
  padding: 16px 20px;
  font-size: 0.88em;
  line-height: 1.55;
  overflow-x: auto;
}
pre > code { background: transparent !important; padding: 0; color: var(--fg); }

/* Syntax highlighting — keel-flavored */
.hljs-keyword, .hljs-selector-tag, .hljs-built_in { color: var(--keel-amber); font-weight: 500; }
.hljs-string, .hljs-attr, .hljs-symbol, .hljs-bullet { color: #E8C078; }
.hljs-number, .hljs-literal { color: #9CD8C3; }
.hljs-comment, .hljs-quote { color: var(--keel-fog); font-style: italic; }
.hljs-title, .hljs-section, .hljs-function { color: #CBB8FF; }
.hljs-variable, .hljs-name, .hljs-type { color: #A6D6FF; }
.hljs-meta, .hljs-tag { color: var(--keel-burnt); }
.keel-light .hljs-keyword, .light .hljs-keyword, .rust .hljs-keyword { color: var(--keel-burnt); }
.keel-light .hljs-string, .light .hljs-string, .rust .hljs-string { color: #8B5A1F; }
.keel-light .hljs-number, .light .hljs-number, .rust .hljs-number { color: #2F7D5B; }
.keel-light .hljs-comment, .light .hljs-comment, .rust .hljs-comment { color: var(--keel-ash); }

/* ---------- Blockquotes / callouts ------------------------------ */
blockquote {
  background: var(--quote-bg);
  border-left: 3px solid var(--keel-amber);
  border-radius: 0 6px 6px 0;
  padding: 14px 20px;
  margin: 1.5em 0;
  color: var(--fg);
}
blockquote p:last-child { margin-bottom: 0; }

/* Admonition-style callouts — use `> **Note:**`, `> **Warning:**` etc. */
blockquote p:first-child strong:first-child {
  font-family: var(--keel-font-mono);
  font-size: 0.75em;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--keel-amber);
  display: block;
  margin-bottom: 0.4em;
}

/* ---------- Status badges --------------------------------------
   Used inline in docs as <span class="badge badge-soon">Coming soon</span>
   to mark features that are planned or partially implemented. */
.badge {
  display: inline-block;
  font-family: var(--keel-font-mono);
  font-size: 0.72em;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 4px;
  vertical-align: middle;
  margin-left: 0.4em;
}
.badge-soon {
  background: rgba(255, 184, 74, 0.15);
  color: var(--keel-amber);
  border: 1px solid rgba(255, 184, 74, 0.4);
}
.keel-light .badge-soon, .light .badge-soon, .rust .badge-soon {
  background: rgba(210, 105, 26, 0.12);
  color: var(--keel-burnt);
  border: 1px solid rgba(210, 105, 26, 0.35);
}
.badge-partial {
  background: rgba(155, 163, 174, 0.15);
  color: var(--keel-fog);
  border: 1px solid rgba(155, 163, 174, 0.35);
}

/* ---------- Tables --------------------------------------------- */
table {
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 0.95em;
}
table thead tr { background: var(--table-header-bg); }
table th, table td {
  border: 1px solid var(--table-border-color);
  padding: 8px 14px;
}
table th {
  font-family: var(--keel-font-display);
  font-weight: 600;
  text-align: left;
}
table tr:nth-child(even) td { background: var(--table-alternate-bg); }

/* ---------- Search --------------------------------------------- */
#searchbar {
  border: 1px solid var(--searchbar-border-color);
  background: var(--searchbar-bg);
  color: var(--searchbar-fg);
  border-radius: 6px;
  font-family: var(--keel-font-body);
}
#searchbar:focus {
  border-color: var(--keel-amber);
  outline: none;
  box-shadow: 0 0 0 3px rgba(255,184,74,0.18);
}
.searchresults-header { color: var(--searchresults-header-fg); font-family: var(--keel-font-mono); font-size: 0.75em; letter-spacing: 0.1em; text-transform: uppercase; }
mark { background: var(--search-mark-bg); color: var(--keel-onyx); padding: 0 2px; border-radius: 2px; }

/* ---------- Page nav buttons ----------------------------------- */
.nav-chapters {
  color: var(--icons);
  transition: color 160ms;
}
.nav-chapters:hover { color: var(--keel-amber); }

/* ---------- Theme popup ---------------------------------------- */
.theme-popup {
  background: var(--theme-popup-bg);
  border: 1px solid var(--theme-popup-border);
  border-radius: 6px;
  font-family: var(--keel-font-body);
}
.theme-popup .theme:hover { background: var(--theme-hover); }

/* ---------- Footer / print ------------------------------------- */
@media print {
  .sidebar, #menu-bar, .nav-chapters { display: none !important; }
  body { color: #000; background: #fff; }
  pre { border: 1px solid #ccc; border-left: 3px solid #000; }
}

/* ---------- Content width -------------------------------------- */
.content main { max-width: 780px; padding: 0 20px 80px; }

/* ---------- Horizontal rules ----------------------------------- */
hr {
  border: 0;
  border-top: 1px solid var(--quote-bg);
  margin: 2.5em 0;
  position: relative;
  text-align: center;
}
hr::after {
  content: "◆";
  position: absolute;
  top: -0.75em;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg);
  padding: 0 1em;
  color: var(--keel-amber);
  font-size: 0.7em;
}

/* ---------- Keyboard keys -------------------------------------- */
kbd {
  font-family: var(--keel-font-mono);
  font-size: 0.82em;
  background: var(--quote-bg);
  border: 1px solid var(--table-border-color);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0.1em 0.5em;
  color: var(--fg);
}