body { background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab); background-size: 400% 400%; animation: gradient 15s ease infinite; height: 100vh; } @keyframes gradient { 0% { background-position: 0% 50%; } 50% { background-position: 100% 50%; } 100% { background-position: 0% 50%; } }