:root {
  color-scheme: dark;
  font-family: system-ui, sans-serif;
}
* { box-sizing: border-box; }
html, body, #app { margin: 0; height: 100%; }
#app { position: relative; background: #111; color: #eee; overflow: hidden; }

.viewer { position: absolute; inset: 0; }
.viewer canvas { display: block; width: 100%; height: 100%; }

.preview {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: contain; background: #111; z-index: 2;
  transition: opacity 0.5s ease;
}
.hidden { display: none !important; }

.progress {
  position: absolute; left: 0; right: 0; bottom: 0; height: 4px; z-index: 3;
  background: rgba(255,255,255,0.1);
}
.progress .bar { height: 100%; width: 0%; background: #4aa3ff; transition: width 0.1s linear; }

.fps {
  position: absolute; top: 8px; left: 8px; z-index: 4;
  font: 12px/1.4 ui-monospace, monospace; padding: 2px 6px;
  background: rgba(0,0,0,0.5); border-radius: 4px; pointer-events: none;
}

.controls {
  position: absolute; top: 8px; right: 8px; z-index: 4;
  display: flex; gap: 6px;
}
.controls button {
  font: 12px/1.4 system-ui, sans-serif; padding: 6px 10px;
  background: rgba(0,0,0,0.55); color: #eee; border: 1px solid #888;
  border-radius: 6px; cursor: pointer;
}
.controls button:hover { background: rgba(0,0,0,0.75); border-color: #4aa3ff; }
.controls button.active { background: #4aa3ff; color: #00264d; border-color: #4aa3ff; }

.dropzone {
  position: absolute; left: 50%; bottom: 24px; transform: translateX(-50%);
  padding: 10px 18px; border: 1px dashed #555; border-radius: 10px;
  background: rgba(0,0,0,0.4); font-size: 13px; cursor: pointer; z-index: 3;
}
.dropzone.drag { border-color: #4aa3ff; background: rgba(74,163,255,0.15); }
.dropzone p { margin: 0; }
.dropzone .status { margin-top: 6px; color: #ff7676; font-size: 12px; min-height: 0; }
.dropzone .status:empty { display: none; }