body {
    background-color: #eeeee4;
}

.container {
    background-color: #e5e5e5;
    width: 460px;
    height: 680px;
    margin: 0 auto;
}

button {
    padding: 7px 14px;
    background-color: #00b0ff;
    border: none;
    border-radius: 4px;
    color: #fafafa;
}

.element-list {
    height: 550px;
}

ul {
    padding: 15px;
}

li {
    list-style: none;
    padding: 10px 5px;
    background-color: #fff;
    margin: 12px 0;
    border: 5px solid #f5f5f5;
    border-radius: 3px;
    transition: .4s;
}

button:hover {
    background-color: #1565c0;
}

.checked {
    text-decoration: line-through;
    background-color: #e0e0e0;
}