style.css

*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    border: none;
    outline: none;
    font-family: 'Roboto Mono', monospace;
}

body {
    background-color: #121317;
}

.container{
    background-color: #202229;
    width: 60vmin;
    padding: 2.5em 2em;
    position: absolute;
    transform: translate(-50%,-50%);
    top: 50%;
    left: 50%;
    font-size: 3vmin;
    border-radius: 10px;
}

#output-color {
    position: relative;
    height: 30vmin;
    width: 30vmin;
    border:0.5em solid #f5f5f5;
    border-radius: 50%;
    margin: auto;
    display: grid;
    place-items: center;
}

#output-color span{
    display: block;
    width: calc( 100% - 20px);
    height: calc( 100% - 20px);
    border-radius: 50%;
}

.show-color{
    animation: pop 0.8s;
}

@keyframes pop{
    0%{
        transform: scale(0);
    }
    100%{
        transform: scale(1);
    }
}

input[type="text"]{
    width: 100%;
    background-color: transparent;
    border: 2.5px dashed #f5f5f5;
    font-size: 1.3em;
    padding:0.8em 0;
    margin: 1em 0;
    border-radius: 8px;
    color: #f5f5f5;
    text-align: center;
}

input[type="text"]::-moz-selection{
    background: transparent;
}

input[type="text"]::selection{
    background: transparent;
}

.btns {
    display: flex;
    justify-content: space-around;
}

.btns button {
    font-size: 1em;
    padding: 0.8em 1.7em;
    border-radius: 7px;
    font-weight: 600;
    cursor: pointer;
}

#gen-btn{
    background-color: #18f98f;
    color: #202229;
}

#copy-btn{
    border: 3px solid #18f98f;
    background-color: transparent;
    color: #18f98f;
}

.custom-alert{
    background-color: rgba(255,255,255,0.3);
    font-size: 2.5vmin;
    padding: 1em 1.5em;
    position: fixed;
    top: 10px;
    right: 10px;
    color: #f5f5f5;
    transition: 0.5s;
    transform: translateX(calc(100% + 10px));
}