#viewport {
  grid-row: 2 / 3;
  position: relative;
  overflow: hidden;
  background: var(--bg);
}

#canvas3d {
  display: block;
  width: 100%;
  height: 100%;
}

/* Empty-state hint */
.viewport-hint {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  pointer-events: none;
  transition: opacity 0.3s;
}

.viewport-hint .icon {
  font-size: 48px;
  margin-bottom: 8px;
  opacity: 0.18;
}

.viewport-hint p {
  font-size: 13px;
  color: var(--text-hint);
}

.viewport-hint .sub-hint {
  margin-top: 4px;
  font-size: 11px;
  color: var(--text-hint);
  opacity: 0.6;
}

/* ── Desktop: floor panel top-right, view panel bottom-right ─────────────── */

.floor-controls-wrap {
  position: absolute;
  top: 10px;
  right: 10px;
}

.view-controls-wrap {
  position: absolute;
  bottom: 10px;
  right: 10px;
}

.floor-control {
  background: var(--surface);
  border: 1px solid var(--border-md);
  border-radius: var(--radius);
  padding: 8px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 150px;
}

.floor-control-label {
  font-size: 9px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-hint);
  padding-bottom: 2px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2px;
}

.floor-btns {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.floor-step {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 7px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  background: transparent;
  font-size: 11px;
  font-family: var(--font);
  color: var(--text-muted);
  cursor: pointer;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
  text-align: left;
  width: 100%;
}

.floor-step:hover {
  background: var(--bg);
  border-color: var(--border);
}

.floor-step.active {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}

.floor-step .pips {
  display: flex;
  flex-direction: column;
  gap: 1.5px;
  flex-shrink: 0;
}

.floor-step .pips span {
  display: block;
  width: 14px;
  height: 3px;
  border-radius: 1px;
  background: currentColor;
  opacity: 0.3;
}

.floor-step .pips span.on {
  opacity: 1;
}

.view-controls {
  background: var(--surface);
  border: 1px solid var(--border-md);
  border-radius: var(--radius);
  padding: 8px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 150px;
}

.view-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 7px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  background: transparent;
  font-size: 11px;
  font-family: var(--font);
  color: var(--text-muted);
  cursor: pointer;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
  text-align: left;
  width: 100%;
}

.view-btn:hover {
  background: var(--text);
  border-color: var(--text);
  color: #fff;
}

.view-btn-divider {
  width: 100%;
  height: 1px;
  background: var(--border);
  margin: 2px 0;
}

/* ── Loader ──────────────────────────────────────────────────────────────── */

#loader {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 220px;
  padding: 16px 20px;
  background: rgb(255, 255, 255);
  backdrop-filter: blur(6px);
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  text-align: center;
  font-family: 'Inter', sans-serif;
  z-index: 999;
  pointer-events: none;
}

#loader.hidden {
  display: none;
}

.loader-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

#loader-text {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
}

/* ── Mobile ──────────────────────────────────────────────────────────────── */

@media (max-width: 640px) {

  /* Floor: compact pill anchored top-right */
  .floor-controls-wrap {
    top: 6px;
    right: 6px;
    bottom: auto;
    left: auto;
  }

  .floor-control {
    flex-direction: row;
    align-items: center;
    gap: 2px;
    padding: 4px 8px;
    border-radius: 20px;
    min-width: 0;
  }

  .floor-control .floor-control-label {
    display: none;
  }

  .floor-btns {
    flex-direction: row;
    gap: 2px;
  }

  /* Pips hidden on mobile */
  .floor-step .pips {
    display: none;
  }

  /* Show the short label via data-short attr, hide full text */
  .floor-step .floor-lbl {
    display: none;
  }

  .floor-step::after {
    content: attr(data-short);
  }

  .floor-step {
    padding: 3px 8px;
    border-radius: 12px;
    width: auto;
    font-size: 10px;
  }

  /* View: pinned bottom bar, full width, horizontally scrollable */
  .view-controls-wrap {
    bottom: 0;
    left: 0;
    right: 0;
    top: auto;
  }

  .view-controls {
    flex-direction: row;
    align-items: center;
    flex-wrap: nowrap;
    gap: 4px;
    padding: 8px 12px;
    border-radius: 0;
    border-left: none;
    border-right: none;
    border-bottom: none;
    min-width: 0;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    background: #ffffff00;
  }

  .view-controls::-webkit-scrollbar {
    display: none;
  }

  /* Hide the section label in the horizontal bar */
  .view-controls .floor-control-label {
    display: none;
  }

  .view-btn {
    flex-shrink: 0;
    padding: 5px 11px;
    border-radius: 16px;
    border: 1px solid var(--border);
    background: var(--bg);
    font-size: 11px;
    width: auto;
    white-space: nowrap;
  }

  .view-btn:hover,
  .view-btn:active {
    background: var(--text);
    border-color: var(--text);
    color: #fff;
  }

  .view-btn-divider {
    flex-shrink: 0;
    width: 1px;
    height: 18px;
    background: var(--border);
    margin: 0 2px;
  }
}