style.css

body{
    background: linear-gradient(violet, lightblue);
    background-repeat: no-repeat;
    height: 100vh;
    display: flex;
    justify-content: center;
    font-family: cursive;
}

section{
    margin-top: 80px; 
}

h1{
    text-align: center;
    color: aliceblue;
   font-size: 50px;
   margin-bottom: 60px;
}

.wrapper{
    width: 500px;
}

.input-container{
    display: flex;
    justify-content:center;
    height: 52px;
}

input, button{
    border: none;
    outline: none;
}

.input-container input{
    padding: 18px 15px;
    font-size: 15px;
    border-top-left-radius: 5px;
    border-bottom-left-radius: 5px;
    width: 320px;
}

.input-container button{
    border-top-right-radius: 5px;
    border-bottom-left-radius: 5px;
    cursor: pointer;
    padding: 13px 25px;
    color: #ff5762;
    background: #fff;
    border-left: 2px solid #eee;
}

.input-container button:hover{
    color: #fff;
    background: #ff5762;
}

.top-container{
    padding: 0;
}

.todo-container .todo{
    margin: 0 auto;
    margin-bottom: 12px;
    display: flex;
    justify-content: flex-end;
    flex-direction: row;
    background: #fff;
    border-radius: 5px;
}

.todo-container.todo.completed{
    width: 90%;
    text-decoration: line-through;
    color: #7e7e7e;
    opacity: 0.7;
}

.todo-container button{
    padding: 16px;
    flex: 1;
    margin: 0;
}

.todo-container .todo-check{
    color: #05cf5b;
    background: #fff;
    border-left: 2px solid #fff;
    font-size: 16px;
}

.todo-container .todo-check:hover{
    color: #fff;
    background: #05cf5b;
    cursor: pointer;
}

.todo-container .todo-delete{
    color: #ff5762;
    background: #fff;
    font-size: 16px;
    border-left: 2px solid #eee;
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

.todo-container .todo-delete:hover{
    color: #fff;
    background: #ff5762;
    cursor: pointer;
}

.todo-container .todo li{
    flex: 10;
    padding: 16px;
    list-style-type: none;
    margin: 0;
    line-height: 1.5;
}