.rp-grid {
  display: grid;
  gap: 4px;
  background: #1a2022;
  padding: 4px;
  border-radius: 12px;
  margin: 0 auto;
  max-width: 540px;
}
.rp-tile {
  aspect-ratio: 1 / 1;
  background: #2e3638;
  border: none;
  padding: 0;
  position: relative;
  cursor: pointer;
  border-radius: 4px;
  touch-action: manipulation;
  overflow: hidden;
  transition: background .15s ease;
}
.rp-tile:hover { background: #3a4346; }
.rp-tile__svg {
  width: 100%;
  height: 100%;
  display: block;
  transition: transform .25s ease;
}
.rp-tile.is-fixed { cursor: default; background: #181e20; }
.rp-tile.is-connected { background: #2a3b2a; }
.rp-tile.is-start { background: #3a2a1a; }
.rp-tile.is-end   { background: #1a2a3a; }

.rp-tile__badge {
  position: absolute;
  top: 4px; left: 4px;
  font-size: 1.1rem;
  pointer-events: none;
  filter: drop-shadow(0 1px 2px #000);
}

.rp-car {
  position: absolute;
  font-size: 1.8rem;
  pointer-events: none;
  transition: all .25s linear;
  z-index: 2;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,.6));
}

.rp-controls {
  display: flex;
  justify-content: center;
  margin-top: 1rem;
}