.credits-box {
  position: relative;
  top: 20vh;
  max-width: 700px;
  margin: auto;
  padding: 40px;
  border: 2px solid #444;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(8px);
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.2);

  height: 500px;       /* fixed height */
  overflow-y: auto;    /* scroll inside */
  overflow-x: hidden;  /* hide horizontal scroll just in case */
}