@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.hidden {
  display: none !important;
}

.workspace {
  flex: 1;
  display: flex;
  min-height: 0;
  overflow: hidden;
}

.activity-rail {
  width: 2.35rem;
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
  padding: 0.45rem 0.28rem;
  background: #f1f5f9;
  border-color: #cbd5e1;
  border-style: solid;
}

.activity-rail-left {
  border-width: 0 1px 0 0;
}

.activity-rail-right {
  border-width: 0 0 0 1px;
}

.activity-button {
  position: relative;
  width: 1.75rem;
  height: 1.75rem;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: #64748b;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.activity-button:hover,
.activity-button:focus-visible {
  background: #e2e8f0;
  color: #0f172a;
  outline: none;
}

.activity-button.active {
  background: #dbeafe;
  color: #1d4ed8;
  box-shadow: inset 0 0 0 1px rgba(37, 99, 235, 0.16);
}

.activity-rail-spacer {
  flex: 1 1 auto;
  min-height: 0;
}

.activity-button svg,
.activity-button .app-icon {
  width: 1rem;
  height: 1rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}