burger-menu.css

/*
 HTML & CSS only burger button
 Author: Alice Peters
 Website: https://alicepeters.de/
*/

body {
    background-color: #383838;
    margin: 0;
    padding: 0;
}

/* Example Opening Animation */

@keyframes open {
    from {
        left: -100vw;
    }
    to {
        left: 0;
    }
}

/* Hiding the checkbox because it would look stupid */

#burgerbutton {
    display: none;
}

/* You probably want to replace the text part of the label element with a background via css in productive use */

.burgerimage {
    position: absolute;
    top: 0;
    left: 10px;
    font-size: 28pt;
    cursor: pointer;
    transition: transform 0.8s ease;
    color: #ff0000;
}

/* Example styling of the menu */

nav {
    background-color: #ffffff;
    display: block;
    height: 50px;
    border-bottom: 3px solid #ff0000;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
}

nav ul {
    display: none;
    position: fixed;
    top: 53px;
    margin: 0;
    padding: 0;
    width: 50vw;
    list-style: none;
}

nav ul li {
    display: block;
    width: auto;
}

nav ul li a {
    text-decoration: none;
    color: #ff0000;
    background-color: #ffffff;
    border-bottom: 1px solid #8b0000;
    display: block;
    padding: 15px;
    height: 50px;
    transition: background 0.5s ease;
    box-sizing: border-box;
}

nav ul li a:hover {
    background-color: #ffc0cb;
    color: #8b0000;
}

/* Displaying the menu when #burgerbutton is checked */

#burgerbutton:checked~ul {
    display: block;
    animation-name: open;
    animation-duration: 0.8s;
}

/* And rotate the visible burger button label when its activated */

#burgerbutton:checked~.burgerimage {
    transform: rotate(360deg);
}