.bande-passante {
  background-color: red;
  color: white;
  font-weight: bold;
  overflow: hidden;
  white-space: nowrap;
  position: relative;
  height: 40px;
  display: flex;
  align-items: center;
  font-family: sans-serif;
  font-size: 16px;
}

.texte-bande {
  display: inline-block;
  padding-left: 100%;
  animation: defilement 90s linear infinite; /* <- tu peux changer 15s ici */
}

@keyframes defilement {
  0% {
    transform: translateX(0%);
  }
  100% {
    transform: translateX(-100%);
  }
}