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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  background: #0d1117;
  color: #e6edf3;
  overflow: hidden;
  height: 100vh;
  width: 100vw;
}

/* ── Scene container ─────────────────────────────────────── */

#scene-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* ── HUD (bottom controls) ───────────────────────────────── */

#hud {
  display: flex;
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: rgba(13, 17, 23, 0.8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid #30363d;
  border-radius: 12px;
  z-index: 15;
}

#hud button, #hud select {
  font-family: inherit;
  font-size: 0.8rem;
  padding: 6px 14px;
  border: 1px solid #30363d;
  border-radius: 6px;
  background: #21262d;
  color: #e6edf3;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  white-space: nowrap;
}

#hud button:hover, #hud select:hover {
  background: #30363d;
  border-color: #58a6ff;
}

#hud select {
  appearance: auto;
}

#counter-label {
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 0.8rem;
  color: #8b949e;
  min-width: 3.5em;
  text-align: center;
}

/* ── Back link (always visible) ──────────────────────────── */

#header {
  position: fixed;
  top: 12px;
  left: 16px;
  z-index: 10;
  display: flex;
  gap: 6px;
}

#header a {
  color: #58a6ff;
  text-decoration: none;
  font-size: 0.85rem;
  padding: 4px 10px;
  background: rgba(13, 17, 23, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid #30363d;
  border-radius: 6px;
}

#header a:hover {
  color: #79c0ff;
  border-color: #58a6ff;
}

/* ── Gene display overlay ────────────────────────────────── */

#gene-overlay {
  display: block;
  position: fixed;
  top: 16px;
  right: 16px;
  background: rgba(13, 17, 23, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid #30363d;
  border-radius: 8px;
  padding: 10px 14px;
  z-index: 15;
  max-width: 280px;
  pointer-events: none;
}

#gene-overlay h3 {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #58a6ff;
  margin-bottom: 6px;
}

#gene-display {
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 0.7rem;
  color: #8b949e;
  line-height: 1.6;
  word-break: break-all;
}

#collect-prompt {
  font-size: 0.7rem;
  text-align: center;
  margin-top: 6px;
  color: #8b949e;
}

#specimen-counter {
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 0.7rem;
  text-align: center;
  margin-top: 4px;
  color: #8b949e;
}