style.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body{
    background-color: #FFE53B;
    background: linear-gradient(147deg, #FFE53B 0%, #FF2525 74%) center center/cover no-repeat;
    min-height: 100vh;
    font-family: 'Poppins', sans-serif;
}

header,form{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 15vh;
}

header{
    margin-top: 40px;
    font-size: 2rem;
    color: black;
    font-weight: 600;
}

form input,
form button{
    padding: 14px 18px;
    font-size: 1.3rem;
    outline: none;
    border: none;
    background: black;
    color: white;
}

form button{
    background-color: purple;
    cursor: pointer;
    transition: all .4s ease;
}

form button:hover{
    background-color: white;
    color: black;
}

.todo-container{
    display: flex;
    justify-content: center;
    align-items: center;
}

.todo-list{
    list-style: none;
    min-width: 25%;
}

.todo{
    display: flex;
    background: white;
    color: black;
    font-size: 1.3rem;
    font-weight: 600;
    margin: 16px 0;
    height: 40px;
    align-items: center;
    justify-content: space-between;
    transition: all .5s ease;
}

.todo-item{
    flex: 1;
    padding: 8px;
}

.checked-btn,
.removed-btn{
    padding: .7rem;
    font-size: 1rem;
    height: 100%;
    border: none;
    cursor: pointer;
}

.checked-btn{
    background: rgb(1, 194, 1);
}

.checked-btn:hover{
    background: rgb(85, 231, 18);
}

.removed-btn{
    background: rgb(156, 15, 15);
}

.removed-btn:hover{
    background: rgb(250, 11, 11);
}

.fa-trash,.fa-check{
    pointer-events: none;
}

.lineIt{
    text-decoration: line-through;
    opacity: .4;
}

.jharyo{
    transform: translateY(9rem) rotateZ(20deg);
    background-color: blue;
    opacity: 0;
}