:root {
  --bg: #0b1117;
  --surface: #161b22;
  --border: #21262d;
  --text: #e6edf3;
  --muted: #7d8590;
  --accent: #58a6ff;
  --topbar-h: 44px;
  --radius: 6px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; background: var(--bg); color: var(--text); font-family: system-ui, sans-serif; overflow: hidden; }

#app { display: flex; flex-direction: column; height: 100%; }

#topbar {
  height: var(--topbar-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: .75rem; padding: 0 1rem;
  flex-shrink: 0;
  user-select: none; -webkit-user-select: none; -webkit-touch-callout: none;
}
#title { font-weight: 700; font-size: .95rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 220px; }
#meta  { font-size: .78rem; color: var(--muted); flex: 1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tb-btn { background: var(--border); border: none; color: var(--text); border-radius: var(--radius); padding: .35rem .75rem; font-size: .78rem; cursor: pointer; white-space: nowrap; flex-shrink: 0; }
.tb-btn:hover { background: #2d333b; }

#viewport-wrap { flex: 1; position: relative; background: #000; touch-action: none; user-select: none; overflow: hidden; }
#canvas {
  /* Centrado + aspect-ratio preservado. Antes width/height 100% lo estiraba
     y los cortes salían ovalados en pantallas widescreen. */
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  margin: auto;
  max-width: 100%; max-height: 100%;
  width: auto; height: auto;
  image-rendering: pixelated;  /* sin filtro al upscale — más fiel al CT */
  display: block;
}

#overlay {
  position: absolute; top: .5rem; right: .75rem; pointer-events: none;
  display: flex; flex-direction: column; align-items: flex-end; gap: .25rem;
  font-size: .72rem; color: #facc15; font-variant-numeric: tabular-nums;
  text-shadow: 0 1px 2px rgba(0,0,0,.85);
}

#loading {
  position: absolute; inset: 0;
  background: rgba(0,0,0,.7);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  z-index: 10; padding: 1rem;
}
.spinner {
  width: 32px; height: 32px; border-radius: 50%;
  border: 3px solid var(--border); border-top-color: var(--accent);
  animation: spin .8s linear infinite; margin-bottom: 1rem;
}
@keyframes spin { to { transform: rotate(360deg); } }
#loading-text { font-size: .92rem; font-weight: 600; margin-bottom: .8rem; }
#loading-bar-wrap { width: min(360px, 80vw); height: 6px; background: var(--border); border-radius: 3px; overflow: hidden; margin-bottom: .55rem; }
#loading-bar { height: 100%; width: 0%; background: var(--accent); border-radius: 3px; transition: width .15s linear; }
#loading-detail { font-size: .78rem; color: var(--muted); font-variant-numeric: tabular-nums; text-align: center; }

#slice-bar {
  padding: .5rem 1rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}
#slice-input { width: 100%; accent-color: var(--accent); }
#slice-input:disabled { opacity: .35; }

/* Forbidden / error screens use the same dark theme */
.error-card {
  background: var(--surface); border-radius: 16px; padding: 2rem;
  max-width: 24rem; text-align: center;
}

@media (max-width: 768px) {
  #topbar { padding: 0 .6rem; gap: .4rem; }
  #title { max-width: 110px; font-size: .85rem; }
  #meta { display: none; }
}