styles.css

@import url('https://fonts.googleapis.com/css2?family=Lobster&display=swap');


*::before,
::after {
    margin: 0;
    padding: 0;
}
body {
    background-color: yellow;
}
header {
    font-size: 30px;
    font-family: 'Lobster', cursive;
    text-align: center;
    padding-left: 200px;
}

.cell {
    background-color: white;
    border: 1px solid black;
    display: inline-block;
}

.grid {
    display: grid;
    width: 550px;
    height: 550px;
    box-shadow: rgba(0, 0, 0, 0.24) 12px 12px 12px;
}

main {
    display: flex;
    align-content: center;
    justify-content: center;
    gap: 50px;
    margin-top: 2em;
}

/*button CSS*/
.btn {
    align-self: center;
    background-color: #fff;
    background-image: none;
    background-position: 0 90%;
    background-repeat: repeat no-repeat;
    background-size: 4px 3px;
    border-radius: 15px 225px 255px 15px 15px 255px 225px 15px;
    border-style: solid;
    border-width: 2px;
    box-shadow: rgba(0, 0, 0, .2) 15px 28px 25px -18px;
    box-sizing: border-box;
    color: #41403e;
    cursor: pointer;
    display: inline-block;
    font-family: Neucha, sans-serif;
    font-size: 1rem;
    line-height: 23px;
    outline: none;
    text-decoration: none;
    transition: all 235ms ease-in-out;
    border-bottom-left-radius: 15px 255px;
    border-bottom-right-radius: 225px 15px;
    border-top-left-radius: 255px 15px;
    border-top-right-radius: 15px 225px;
    user-select: none;
    -webkit-user-select: none;
    touch-action: manipulation;
    border-radius: 20%;
}
  
.btn:hover {
    box-shadow: rgba(0, 0, 0, .3) 2px 8px 8px -5px;
    transform: translate3d(0, 2px, 0);
}
  
.btn:focus {
    box-shadow: rgba(0, 0, 0, .3) 2px 8px 4px -6px;
}


main .left {
    margin-top: 7em;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

#rainbow {
    /* reset */
    -webkit-appearance: none;
    border: 0;
    outline: 0;
    /* styles */
    background: linear-gradient(-45deg, #ffd6d6,#faffb0,#c0ffb6,#d0ddff,#e1bfff);
    animation: gradientBG 4.5s ease infinite;
    color: black;
    transition: .3s;
 }

 @keyframes gradientBG {
	0% {
		background-position: 0% 50%;
	}
	50% {
		background-position: 100% 50%;
	}
	100% {
		background-position: 0% 50%;
	}
}




/* CSS */