style.css

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

body {
    background-image: linear-gradient(to bottom right, rgb(47, 30, 199), white) !important;
    background-attachment: fixed;
}

.container {
    width: 900px;
    position:absolute;
    top: 20%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.header {
    color: white;
    font-weight: bold;
    font-size: 20px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin-bottom: 100px;
    display: flex;
    justify-content: center;
    margin-top: 100px;
}

.note-input {
    display: flex;
    justify-content: center;
}

.note-box{
    max-height: 20px;
}

#note-input-form {
    width: 400px;
    height: 50px;
    padding: 15px;
    font-size: larger;
}

#note-input-button {
    align-self: center;
    width: 30px;
    height: 30px;
    background-color: orange;
    border-radius: 5px;
    border-color: orange;
    color: white;
    position: relative;
    left: -50px;
}

#note-box-items {
    margin-left: 50px;
    list-style-type: none;
}

.form-check {
    display: flex;
    align-items: center;
    margin-block: 25px;
}

.form-check-label {
    background-color: white;
    color: black;
    padding: 5px;
    display: block;
    width: 700px;
    margin: 5px;
    padding: 10px;
}

.form-check-label:hover{
    background-color: gray;
}

.form-check-input {
    height: 15px;
    width: 15px;
}

.checkbox{
    display: flex;
}

#check{
    background-color: orange;
    padding: 10px;
    margin-left: 0;
}

#remove{
    background-color: rgb(44, 160, 85);
    padding: 10px;
    margin-left: 0;

}

.form-check-label.checked {
    text-decoration: line-through;
    background-color: rgb(198, 198, 198);
}