.horizontal-wrapper {
  position: relative;
  overflow: hidden;
}

.horizontal-section {
  display: flex;
  gap: 40px;
  align-items: center;        /* vertically center content */
  height: 30vh;              /* full screen height for pinning */
}

.panel {
  flex: 0 0 auto;             /* prevent shrinking */
  width: 300px;               /* fixed width */
  padding: 40px;
  background: #f5f5f5;
  opacity: 0.3;
}