.blink_me { 
  animation: blinker 1s linear infinite; 
} 
 
@keyframes blinker { 
  50% { 
    opacity: 0; 
  } 
} 
.special-card {
  /* create a custom class so you 
     do not run into specificity issues 
     against bootstraps styles
     which tends to work better than using !important 
     (future you will thank you later)*/
  
    background-color: rgba(245, 245, 245, 1);
    opacity: .4;
  }