styles.css

html {
    background-color: #181818; 
    /* background-size: 100%; */
    border-image: linear-gradient(to right, #3a86ff 25%, #8338ec 25%, #ff006e 50%, #fb5607 50%, #ffbe0b 75%, #0aff99 75%) 100;
    border-width: 1px;
    border-style: solid;
    padding-bottom: 111px;
    margin-top: 2px;
    overflow-x:hidden;
}

#side-menu {
    width: 20%;
    margin-left: 10%;
    margin-top: 4%;
    float: left;
    background-color: #202020;
    border-radius: 20px;
    height: 500px;
    border-image: linear-gradient(to right, #3a86ff 25%, #8338ec 25%, #ff006e 50%, #fb5607 50%, #ffbe0b 75%, #0aff99 75%) 50;
    border-width: 1px;
    border-style: solid;
}

h5 {
    font-family: 'Source Sans Pro', sans-serif;
    color: #d8e2dc;
    font-size: 20px;
    margin: 0px -24%;
}

#clear-button{
    margin-left: 34%;
    margin-top: 7%;
}

button {
    background-color: #394656;
    border-color: #283618;
    border-width: 1px;
    font-size: 17px;
    color: #d8e2dc;
    border-radius: 10px;
    padding: 5px 10px 5px 10px;
}

button:disabled {
    background-color: #adb5bd;
}

button:hover {
    border-radius: 100px;
}


input[type="color"] {
	display: block;
	width: 20%;
	height: 7%;
    border-radius: 2px;
    margin-left: 40%;
}

.title {
    font-family: 'Gluten', cursive;
    /* color: #d8e2dc; */
    font-size: 50px;
    margin: 0px auto;
    background-image: linear-gradient(to right, #3a86ff, #8338ec, #ff006e, #fb5607, #ffbe0b, #0aff99);
    -webkit-background-clip: text;
    -moz-background-clip: text;
    background-clip: text;
    color: transparent;
}

.grid-size {
    margin-left: 50%;
    margin-top: 4%;
}

.grid-button {
    margin-top: 7%;
    position: relative;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);    
}

#container {
    display: grid;
    width: 30%;
    grid-template-rows: repeat(var(--grid-rows));
    grid-template-columns: repeat(var(--grid-cols), 1fr);
    margin-left: 50%;
    margin-top: 6%;
    margin-bottom: 0px;
}
  
.grid-item {
    padding: 45%;
    border: 0.5px solid #343a40;
    text-align: center;
}