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

/* ── CSS variables: dark (default) ──────────────────────────────── */
:root {
  --bg:           #0d1117;
  --text:         #e6edf3;
  --text-muted:   #6e7681;
  --toolbar-bg:   rgba(22, 27, 34, 0.92);
  --toolbar-border: rgba(255,255,255,0.1);
  --toolbar-btn:  #8b949e;
  --toolbar-btn-hover-bg: rgba(255,255,255,0.09);
  --toolbar-btn-hover:    #e6edf3;
  --sep-color:    rgba(255,255,255,0.12);
  --grid-dot:     rgba(255,255,255,0.055);
  --node-default-bg:     rgba(22,27,34,0.96);
  --node-default-border: #30363d;
  --node-default-text:   #c9d1d9;
  --logo-color:   #e6edf3;
  --logo-version-color: rgba(255,255,255,0.35);
  --footer-color: rgba(255,255,255,0.28);
  --theme-btn-bg: rgba(22, 27, 34, 0.92);
  --theme-btn-border: rgba(255,255,255,0.1);
}

/* ── CSS variables: light mode ───────────────────────────────────── */
body.light {
  --bg:           #f6f8fa;
  --text:         #24292f;
  --text-muted:   #57606a;
  --toolbar-bg:   rgba(246, 248, 250, 0.92);
  --toolbar-border: rgba(0,0,0,0.1);
  --toolbar-btn:  #57606a;
  --toolbar-btn-hover-bg: rgba(0,0,0,0.06);
  --toolbar-btn-hover:    #24292f;
  --sep-color:    rgba(0,0,0,0.1);
  --grid-dot:     rgba(0,0,0,0.07);
  --node-default-bg:     rgba(255,255,255,0.97);
  --node-default-border: #d0d7de;
  --node-default-text:   #24292f;
  --logo-color:   #24292f;
  --logo-version-color: rgba(0,0,0,0.35);
  --footer-color: rgba(0,0,0,0.3);
  --theme-btn-bg: rgba(246, 248, 250, 0.92);
  --theme-btn-border: rgba(0,0,0,0.1);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  overflow: hidden;
  height: 100vh;
  width: 100vw;
  transition: background 0.25s, color 0.25s;
}

/* ── Dot grid ────────────────────────────────────────────────────── */
#grid-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

/* ── Site header / logo ──────────────────────────────────────────── */
#site-header {
  position: fixed;
  top: 20px;
  left: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
  line-height: 1;
  user-select: none;
}

.logo-letter {
  font-family: 'Arbutus Slab', Calibri, serif; 
  font-size: 3.5rem;
  font-weight: 800;
  color: var(--logo-color);
  letter-spacing: -0.03em;
  line-height: 1;
  transition: color 0.25s;
  
}

.logo-version {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 0.62rem;
  font-weight: 500;
  color: var(--logo-version-color);
  letter-spacing: 0.08em;
  margin-top: 1px;
  margin-left: -1.1rem;
  padding-left: -1.2rem;
  border-bottom: 1px solid var(--logo-version-color);
  padding-top: 2px;
  width: 100%;
  text-align: center;
  transition: color 0.25s, border-color 0.25s;
}

/* ── Viewport ────────────────────────────────────────────────────── */
#viewport {
  position: relative;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  cursor: grab;
  z-index: 1;
}

#viewport.panning { cursor: grabbing; }

/* ── World (pannable/zoomable container) ─────────────────────────── */
#canvas-world {
  position: absolute;
  top: 0;
  left: 0;
  transform-origin: 0 0;
}

#edges-layer {
  position: absolute;
  top: 0;
  left: 0;
  pointer-events: none;
  overflow: visible;
}

#nodes-layer {
  position: absolute;
  top: 0;
  left: 0;
}

/* ── Bottom UI wrapper ───────────────────────────────────────────── */
#bottom-ui {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

#controls-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ── Toolbar pill ────────────────────────────────────────────────── */
#toolbar {
  display: flex;
  gap: 2px;
  align-items: center;
  background: var(--toolbar-bg);
  padding: 6px 12px;
  border-radius: 40px;
  border: 1px solid var(--toolbar-border);
  box-shadow: 0 8px 32px rgba(0,0,0,0.25);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: background 0.25s, border-color 0.25s;
}

#toolbar button {
  background: transparent;
  border: none;
  color: var(--toolbar-btn);
  padding: 5px 11px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 15px;
  line-height: 1;
  transition: background 0.15s, color 0.15s;
  font-weight: 500;
}

#toolbar button:hover {
  background: var(--toolbar-btn-hover-bg);
  color: var(--toolbar-btn-hover);
}

.tb-sep {
  width: 1px;
  height: 18px;
  background: var(--sep-color);
  margin: 0 4px;
  transition: background 0.25s;
}

#zoom-level {
  color: var(--text-muted);
  font-size: 12px;
  min-width: 42px;
  text-align: center;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  transition: color 0.25s;
}

/* ── Theme toggle button ─────────────────────────────────────────── */
#btn-theme {
  background: var(--toolbar-bg);
  border: 1px solid var(--toolbar-border);
  border-radius: 50%;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 16px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.25);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: background 0.25s, border-color 0.25s, transform 0.2s;
  flex-shrink: 0;
}

#btn-theme:hover {
  transform: scale(1.1);
}

/* ── Footer text ─────────────────────────────────────────────────── */
#footer-text {
  font-size: 11px;
  color: var(--footer-color);
  letter-spacing: 0.04em;
  user-select: none;
  transition: color 0.25s;
}

/* ── Error banner ────────────────────────────────────────────────── */
#error-banner {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2000;
  background: rgba(239,68,68,0.15);
  border: 1px solid #ef4444;
  color: #fca5a5;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 13px;
  display: none;
}

/* ── Canvas nodes ────────────────────────────────────────────────── */
.canvas-node {
  position: absolute;
  border-radius: 10px;
  border: 1.5px solid;
  padding: 14px 18px;
  font-size: 14px;
  line-height: 1.65;
  overflow: hidden;
  transition: box-shadow 0.2s, border-color 0.2s;
  cursor: default;
}

.canvas-node:hover {
  box-shadow: 0 0 0 2px rgba(128,128,128,0.2), 0 8px 28px rgba(0,0,0,0.2);
  z-index: 10;
}

.canvas-node h1 { font-size: 1.6em;  font-weight: 700; line-height: 1.2; }
.canvas-node h2 { font-size: 1.25em; font-weight: 600; line-height: 1.3; }
.canvas-node h3 { font-size: 1.05em; font-weight: 600; line-height: 1.3; }
.canvas-node p  { margin: 4px 0; }

/* Obsidian color palette — dark */
.nc-1 { background: rgba(251,70,76,0.1);   border-color: #fb464c; color: #fca5a8; }
.nc-2 { background: rgba(233,151,63,0.1);  border-color: #e9973f; color: #fdba74; }
.nc-3 { background: rgba(224,172,0,0.1);   border-color: #e0ac00; color: #ca8a04; }
.nc-4 { background: rgba(68,207,110,0.1);  border-color: #44cf6e; color: #16a34a; }
.nc-5 { background: rgba(83,223,221,0.1);  border-color: #53dfdd; color: #0891b2; }
.nc-6 { background: rgba(168,130,255,0.1); border-color: #a882ff; color: #7c3aed; }
.nc-d {
  background:   var(--node-default-bg);
  border-color: var(--node-default-border);
  color:        var(--node-default-text);
}

/* Colored nodes in light mode: keep the tinted bg, darken the text */
body.light .nc-1 { color: #b91c1c; }
body.light .nc-2 { color: #c2410c; }
body.light .nc-3 { color: #92400e; }
body.light .nc-4 { color: #15803d; }
body.light .nc-5 { color: #0e7490; }
body.light .nc-6 { color: #6d28d9; }

/* ── Admonition blocks ───────────────────────────────────────────── */
.adm {
  margin-top: 10px;
  padding: 8px 12px;
  border-radius: 6px;
  border-left: 3px solid;
  font-size: 0.87em;
}

.adm-hint, .adm-tip        { background: rgba(83,223,221,0.07);  border-color: #53dfdd; }
.adm-note, .adm-info       { background: rgba(59,130,246,0.07);  border-color: #3b82f6; }
.adm-warning, .adm-caution { background: rgba(245,158,11,0.07);  border-color: #f59e0b; }
.adm-danger, .adm-error    { background: rgba(239,68,68,0.07);   border-color: #ef4444; }

.adm-title {
  font-weight: 700;
  font-size: 0.8em;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  margin-bottom: 3px;
  opacity: 0.65;
}