html5-css3-sidebar-menu-without-javascript/style.css

@import url('https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css');

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    transition: background 0.3s, color 0.3s;
    display: flex;
}

body.dark {
    background: #333;
    color: #f4f4f4;
}

.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 60px;
    height: 100%;
    background: #231f20;
    padding: 20px;
    box-sizing: border-box;
    transition: width 0.3s ease-in-out;
    overflow: hidden;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.sidebar.close {
    width: 60px;
}

.sidebar.close .profile-label span,
.sidebar.close a span {
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease-in-out, visibility 0.3s ease-in-out;
}

.sidebar:not(.close) .profile-label span,
.sidebar:not(.close) a span {
    opacity: 1;
    visibility: visible;
    transition: opacity 0.3s ease-in-out, visibility 0.3s ease-in-out;
}

.sidebar ul {
    margin-left: -6px;
    padding: 0;
    list-style: none;
}

.sidebar ul li span {
    margin-left: 10px;
}

.sidebar ul li a:has(img) {
    padding: 0;
}

.sidebar .toggle {
    cursor: pointer;
    font-size: 23px;
    color: #ddd;
    display: block;
    margin: 0 0 20px -3px;
}

.sidebar .toggle-switch {
    cursor: pointer;
    color: #ddd;
    display: flex;
    align-items: center;
    margin-top: auto;
}

.sidebar .toggle-switch .mode-text {
    margin-left: 10px;
}

.content {
    margin-left: 60px;
    padding: 20px;
    transition: margin-left 0.3s ease-in-out;
    flex-grow: 1;
}

#toggle-sidebar:checked ~ .sidebar {
    width: 250px;
}

#toggle-sidebar:checked ~ .content {
    margin-left: 250px;
}

#toggle-sidebar:checked ~ .sidebar .profile-label span,
#toggle-sidebar:checked ~ .sidebar a span {
    opacity: 1;
    visibility: visible;
    transition: opacity 0.3s ease-in-out, visibility 0.3s ease-in-out;
}

.sidebar .profile-label,
.sidebar a {
    display: flex;
    align-items: center;
    font-size: 18px;
    color: #ddd;
    text-decoration: none;
    margin: 10px 0;
    transition: font-size 0.3s ease-in-out, visibility 0.3s ease-in-out;
    position: relative;
    padding: 5px 0 0 5px;
}

.sidebar a:hover, .sidebar label:hover {
    color: #fff;
}

.sidebar .profile-label:before,
.sidebar a:before {
    content: attr(data-icon);
    font-size: 24px;
    display: inline-block;
    width: 30px;
    text-align: center;
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
}

#toggle-dark-mode:checked ~ body {
    background: #333;
    color: #f4f4f4;
}

#toggle-dark-mode:checked ~ .sidebar {
    background: #333;
}

#toggle-dark-mode:checked ~ .sidebar a,
#toggle-dark-mode:checked ~ .sidebar .profile-label,
#toggle-dark-mode:checked ~ .sidebar .toggle-switch .mode-text {
    color: #f4f4f4;
}

.sidebar .top-menu {
    flex-grow: 1;
}

.sidebar .bottom-menu {
    margin-top: 20px;
}

.sidebar .bottom-menu ul li {
    height: 40px;
    display: flex;
    align-items: center;
}

@media screen and (max-width: 768px) {
    .sidebar {
        width: 60px;
    }

    .content {
        margin-left: 60px;
        padding: 10px;
    }

    #toggle-sidebar:checked ~ .sidebar {
        width: 250px;
    }

    #toggle-sidebar:checked ~ .content {
        margin-left: 250px;
    }

    .sidebar .toggle {
        display: block;
        margin: 10px 0;
    }

    .sidebar .toggle-switch {
        display: none;
    }
}

@media screen and (max-width: 480px) {
    .sidebar .toggle {
        font-size: 18px;
    }

    .content h1 {
        font-size: 24px;
    }
}