*{
    margin:0;
    padding:0;
    font-family: Arial, Helvetica, sans-serif;
    box-sizing: border-box;
}
.container{
    width: 100%;
    min-height: 100vh;
    background: linear-gradient(135deg,#153677,#4e085f);
    padding: 10px;
}
.todo{
   width: 100%;
   max-width: 540px; 
   background-color: white;
   margin: 100px auto 20px;
   padding: 40px 30px 70px;
   border-radius: 10px;
}
.todo h2{
 color: rgb(97, 24, 24);
 display: flex;
 align-items: center;
 margin-bottom: 20px;
 font-size: 30px;
 font-weight: 800;
}
.todo img{
    width: 40px;
    margin-left: 10px;
    
}
.row{
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: #b2b4b8;
    padding-left: 20px;
    margin-bottom:25px ;
    border-radius: 30px;
}
input{
    flex: 1;
    border: none;
    outline: none;
    background: transparent;
    padding: 10px;
    font-weight: 14px;
}
button{
    border: none;
    outline: none;
    padding: 16px 50px;
    background: #e4620b;
    color: #fff;
    cursor: pointer;
    border-radius: 40px;
}
ul li{
    list-style: none;
    font-size: 17px;
    padding: 12px 8px 12px 50px;
    user-select:none;
    cursor: pointer;
    position: relative;
}
ul li::before{
    content: '';
    position: absolute;
    height: 28px;
    width: 28px;
    border-radius: 50%;
    background-image: url(unchecked.jpg);
    background-size: cover;
    background-position: center;
    top: 12px;
    left: 8px;
}
ul li.checked{
    color: #555;
    text-decoration: line-through;
}
ul li.checked::before{
    background-image: url(checked.jpg);
}
ul li span{
    position: absolute;
    right: 0;
    top: 5px;
    width: 40px;
    height: 40px;
    font-size: 22px;
    color: #555;
    line-height: 40px;
    text-align: center;
}
ul li span:hover{
    background: #b4b2b2;
    border-radius: 20px;
}