style.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    background-image: url(bacground.png);
    background-size: cover;
    background-position: center;  
}
header{
    width: 100%;
    position: sticky;
    top:0;
    z-index: 1;
    background-color: transparent;
}
.container{
    height: 10vh;
    width: 100%;
    margin: 0 auto;
    padding: 0 50px;
}
.logo{
    display: flex;
    gap: 14px;
    align-items: center;
}
.logo img{
    height: 100px;
    width: 150px;
    display: block;
    margin-top:40px;
    filter: drop-shadow(30px 30px 50px rgb(21, 15, 208));

} 
#sign{
    height: 50px;
    width: 200px;
    margin-right:1px;   
}
.box p{
    font-family: Georgia, 'Times New Roman', Times, serif;
    font-size: 40px;
    font-weight: 500;
    cursor: default;
    text-align: center;
    margin-top: 2%;

}
a{
    text-decoration: none;
    color: white;
}
ul{
    display: flex;
    gap: 14px;
    list-style: none;
}
li{
    font-size: 30px;

}
nav{
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px;

}
.main{
    width: 100%;
    height: 90vh;
    position: absolute;

}
.main img{
    display: block;
    margin: auto;
    height: 100%;
    filter: drop-shadow(10px 20px 15px rgb(247, 247, 247));
}
.content{
    width: 100%;
    height: 100%;
    display: block;
    margin: auto;
    position: absolute;
    top:0;
    left:0;
}
.content .box{
    justify-content: center;
    display: flex;
    flex-direction: column;
    width: 400px;
    margin: auto;
    height:100%;
}
.todo{
    display: flex;
    padding: 15px;

}
.todo_value{
    cursor: inherit;
    background: transparent;
    border: none;
    outline: none;
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    font-size: 15px;
    font-weight: bold;
    flex-grow: 1;
    border-bottom: 2px solid rgb(6, 6, 6);
}
.todo_checkbox{
    cursor: inherit;
}
.todo:has(.todo_checkbox:checked){
    color: rgb(4, 3, 2);
    background: rgb(249, 247, 247);
    text-decoration: line-through 1.5px;
    order: 1;


}