Menu de Navegação Vertical

<nav class="navside">
	<div class="toggle">
        <button class="switch" type="button" aria-label="Alternar navegação"></button>
    </div>
    <ul class="menu">
        <li class="logotipo">
            <a href="">
                <img src="logotipo.svg" alt="Logotipo">
            </a>
        </li>
        <li><a href="">Painel</a></li>
        <li class="hasub">
            <a href="">Publicações</a>
            <ul class="isub">
                <li><a href="">Todas as publicações</a></li>
                <li><a href="">Adicionar publicação</a></li>
            </ul>
        </li>
        <li class="hasub">
            <a href="">Categorias</a>
            <ul class="isub">
                <li><a href="">Todas as categorias</a></li>
                <li><a href="">Adicionar categoria</a></li>
            </ul>
        </li>
        <li class="hasub">
            <a href="">Mídias</a>
            <ul class="isub">
                <li><a href="">Imagens</a></li>
                <li><a href="">Vídeos</a></li>
                <li><a href="">Audios</a></li>
                <li><a href="">Outros aruivos</a></li>
            </ul>
        </li>
        <li class="hasub">
            <a href="">Páginas</a>
            <ul class="isub">
                <li><a href="">Todas as páginas</a></li>
                <li><a href="">Adicionar página</a></li>
            </ul>
        </li>
        <li class="hasub">
            <a href="">Produtos</a>
            <ul class="isub">
                <li><a href="">Todas os produtos</a></li>
                <li><a href="">Adicionar produto</a></li>
            </ul>
        </li>
        <li class="hasub">
            <a href="">Administradores</a>
            <ul class="isub">
                <li><a href="">Todas os administradores</a></li>
                <li><a href="">Adicionar administrador</a></li>
                <li><a href="">Wellington Pragidi</a></li>
            </ul>
        </li>
        <li class="hasub">
            <a href="">Configurações</a>
            <ul class="isub">
                <li><a href="">Geral</a></li>
                <li><a href="">Mídias</a></li>
                <li><a href="">E-mail</a></li>
                <li><a href="">Personalizar</a></li>
            </ul>
        </li>
        <li><a href="">Comentários</a></li>
        <li><a href="">Sair</a></li>
    </ul>
</nav>
.navside {
    --navside__backgroung: #212121;
    --switch__color: linear-gradient(to bottom, #CCC, #888);
    --menuMobile__width: 230px;
    --itemLight__border: 1px solid rgba(255, 255, 255, 0.12);
    --itemDark__border: 1px solid rgba(0, 0, 0, 1.0);
    --navsideLink__color: #A5A5A5;
    --navsideLinkHover__color: #DDD;
    --navsideLinkHover__background: rgba(255, 255, 255, 0.05);
    --navsideLink__font-family: var(--fontSystem);

    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: 230px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(255, 255, 255, 0.40) rgba(255, 255, 255, 0.30);
    background-color: var(--navside__backgroung);
    z-index: 1023;
}
.navside::-webkit-scrollbar-track { background-color: rgba(255, 255, 255, 0.30) }
.navside::-webkit-scrollbar-thumb { background-color: rgba(255, 255, 255, 0.40) }
.navside::-webkit-scrollbar { width: 6px }

.navside .logotipo {
    height: 50px;
}
.navside .logotipo a {
    text-align: right;
    border-bottom: var(--itemLight__border);
}
.navside .logotipo img {
    display: block;
    max-height: 40px;
    text-align: right;
    margin: 0 0 0 auto;
}
.navside ul {
    list-style: none;
    margin: 0 0;
    padding: 0 0;
}
.navside li {
    position: relative;
    line-height: initial;
}
.navside li a {
    position: relative;
    display: block;
    width: 100%;
    padding: 5px 10px;
    color: var(--navsideLink__color);
    font-size: 1rem;
    font-weight: 400;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    border-top: var(--itemLight__border);
    border-bottom: var(--itemDark__border);
    text-decoration: none;
}
.navside .menu > li:nth-child(2) a {
    border-top: var(--itemDark__border);
}
.navside li a:hover, 
.navside .current a, .navside .active a, .navside .hasub.open > a {
    color: var(--navsideLinkHover__color);
    background: var(--navsideLinkHover__background);
    text-decoration: none;
}
.navside li a:focus, .navside .logotipo a {
    color: var(--navsideLink__color);
    background: var(--navside__background);
    text-decoration: none;
}
.navside .hasub > a {
}
.navside .hasub > a::before, .navside .hasub > a::after {
    position: absolute;
    content: "";
    background: var(--navsideLink__color)
}
.navside .hasub > a::before {
    right: 6px;
    top: 15px;
    width: 10px;
    height: 2px;
}
.navside .hasub > a::after {
    right: 10px;
    top: 11px;
    width: 2px;
    height: 10px;
    transition: transform .4s linear;
}
.navside .hasub.open > a::after {
    transform: rotate(90deg);
    transition: transform .4s linear;
}
.navside .isub li a {
    font-size: 0.9rem;
    padding-left: 15px;
}
.navside .isub .isub, .navside .isub ul, .navside ul ul ul {
    display: none;
}

@media (width < 768px) {
    .navside .toggle {
        position: fixed;
        top: 10px;
        left: 10px;
        display: block;
        width: 37px;
        height: 31px;
        overflow: hidden;
        z-index: 1024;
    }
    .navside .toggle, .navside .toggle * {
        cursor: pointer;
    }
    .navside .switch, .navside .switch::before, .navside .switch::after {
        position: absolute;
        display: block;
        width: 37px;
        z-index: 1024;
    }
    .navside .switch, .navside .switch::before, .navside .switch::after {
        right: 0;
        width: 100%;
        height: 5px;
        background: var(--switch__color);
        border-radius: 5px;
    }
    .navside .switch {
        top: 0;
        border: none;
        padding: 0 0;
    }
    .navside .switch::before, .navside .switch::after {
        content: "";
        transition: transform 0.4s;
    }
    .navside .switch::before {
        top: 12px;
    }
    .navside .switch::after {
        top: 24px;
    }
    .navside .toggle.focus .switch {
        width: 0;
        height: 0;
        overflow: visible;
    }
    .navside .toggle.focus .switch::before, .navside .toggle.focus .switch::after {
        top: 12px;
        width: 38px;
        height: 5.5px;
        overflow: visible;
    }
    .navside .toggle.focus .switch::after {
        transform: rotate(45deg);
    }
    .navside .toggle.focus .switch::before {
        transform: rotate(-45deg);
    }
    .navside .toggle, .navside .toggle.focus {
        transform: scale(1.15, 1.1);
    }
    .navside {
        width: 0;
        overflow: hidden;
        transition: width 0.9s;
    }
    .navside.visible {
        width: var(--menuMobile__width);
    }
}
@media (width >= 768px) {
    .navside .toggle {
        display: none;
    }
    .navside .logotipo img {
        margin: 0 0 0 0;
    }
}

Requer toggle.js

let navside = {
    toggle:   document.querySelector(".navside .toggle"),
    navLinks: document.querySelectorAll(".navside a"),
    hasubLink: document.querySelectorAll(".navside .hasub > a"),
    isubLink: document.querySelectorAll(".navside .isub a"),
    menu: function() {
        /* toggle mobile */
        this.toggle.addEventListener('click', function() {
            this.classList.toggle("focus");
            this.closest(".navside").classList.toggle("visible");
        });
        /* class current na no link da pagina atual */
        this.navLinks.forEach( element => {
            if(element.href == document.URL) {
                element.parentElement.classList.add("current");
            } 
        });
        /* abre submenu e adiciona class open no click */
        this.hasubLink.forEach( element => {
            element.onclick = function() { return false; }
            element.nextElementSibling.style.display = "none";
            element.addEventListener('click', function() {
                toggle.slide( element.nextElementSibling );
                if( this.parentElement.classList.contains("open") ) {
                    this.parentElement.classList.remove("open");
                } else {
                    this.parentElement.classList.add("open");
                }
            });
        });
        /* mantem submenu aberto quando link do mesmo for ativo */
        this.isubLink.forEach( element => {
            if( element.parentElement.classList.contains("current") ) {
                element.closest(".hasub").classList.add("open");
                element.closest(".isub").style.display = "block";
            }
        });
    }
}.menu();