User:Juanjpro/hydra.css

.spoiler { width: calc(100% - 350px); display: inline-block; }

/* blinking keyframes */

.blinking { display: inline-block; width: 500px; height: 267px; background: #000000; animation: blinkin 3s infinite; -webkit-animation: blinkin 3s infinite; -moz-animation: blinkin 3s infinite; }

@keyframes blinkin { 0%  {opacity: 100;} 80% {opacity: 1000;} 90% {opacity: 0;} 100% {opacity: 100;} }

@-webkit-keyframes blinkin { 0%  {opacity: 100;} 80% {opacity: 100;} 90% {opacity: 0;} 100% {opacity: 100;} }

@-moz-keyframes blinkin { 0%  {opacity: 100;} 80% {opacity: 100;} 90% {opacity: 0;} 100% {opacity: 100;} }