body {
    margin: 40px auto;
    min-width: 500px;
    max-width: 50%;
    background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
	background-size: 400% 400%;
	animation: gradient 15s ease infinite;
}

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

* {
    box-sizing: border-box;
    border-radius: 20px;
}

.top {
    background-color: lightsalmon;
    color: red;
    text-align: center;
    padding: 20px 30px;
}

.top:after {
    display: table;
    content: "";
    clear: both;
}

#heading {
    margin: 15px; 
    font-size: xx-large;
    font-weight: bolder;
    height: 36px;
}

#heading span {
    color: black;
}

input {
    margin: auto;
    padding: 10px;
    border: inset;
    outline: none;
    border-radius: 20px;
    width: 85%;
    font-size: small;
    float: left;
}

#add-btn {
    background-color: lightgray;
    color: black;
    width: 36px;
    padding: 8px;
    margin-left: 20px;
    float: left;
    text-align: center;
    cursor: pointer;
    transition: 0.3s;
    border-radius: 100%;
    border: 1px solid red;
    font-size: medium;
}


ul {
    margin: 0;
    padding: 5px;
}

ul li {
    position: relative;
    padding: 15px 10px 15px 40px;
    list-style-type: none;
    border-radius: 5px;
    background-color: black;
    color: white;
    font-size: medium;
    font-family: serif;
    transition: 0.1s;

    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

ul li.checked {
    background: royalblue;
    color: black;
}


.delete {
    position: absolute;
    right: 0;
    top: 0;
    padding: 15px 12px 15px 12px;
    color: red;
}

#clr-btn {
    cursor: pointer;
    margin: 25px 40%;
    padding: 3px;
    background-color: gray;
    color: white;
    font-size: x-large;
    font-family: serif;
    font-weight: bold;
    font-style: italic;
    border: ridge;
    border-radius: 20px;
}

#clr-btn:hover {
    background-color: white;
    color: gray;
    text-shadow: 1px 1px 5px #FF0000;
    box-shadow: 0 0 5px #0000FF;
}