Code Playground

</menu>

html {

box-sizing: border-box;
    --bgColorMenu : #1d1d27;
    --duration: .7s;

}

html *,
html *::before,
html *::after {

box-sizing: inherit;

}

body{
    
    margin: 0;
    display: flex;
    height: 100vh;
    overflow: hidden;
    align-items: center;
    justify-content: center;
    background-color: #ffb457;
    -webkit-tap-highlight-color: transparent;
    transition: background-color var(--duration);

}

.menu{

margin: 0;
    display: flex;
    /* Works well with 100% width  */
    width: 32.05em;
    font-size: 1.5em;
    padding: 0 2.85em;
    position: relative;
    align-items: center;
    justify-content: center;
    background-color: var(--bgColorMenu);
    
}

.menu__item{
    
    all: unset;
    flex-grow: 1;
    z-index: 100;
    display: flex;
    cursor: pointer;
    position: relative;
    border-radius: 50%;
    align-items: center;
    will-change: transform;
    justify-content: center;
    padding: 0.55em 0 0.85em;
    transition: transform var(--timeOut , var(--duration));
    
}

.menu__item::before{
    
    content: "";
    z-index: -1;
    width: 4.2em;
    height: 4.2em;
    border-radius: 50%;
    position: absolute;
    transform: scale(0);
    transition: background-color var(--duration), transform var(--duration);
    
}

.menu__item.active {

transform: translate3d(0, -.8em , 0);

}

.menu__item.active::before{
    
    transform: scale(1);
    background-color: var(--bgColorItem);

}

.icon{
    
    width: 2.6em;
    height: 2.6em;
    stroke: white;
    fill: transparent;
    stroke-width: 1pt;
    stroke-miterlimit: 10;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-dasharray: 400;
    
}

.menu__item.active .icon {

animation: strok 1.5s reverse;
    
}

@keyframes strok {

100% {

stroke-dashoffset: 400;

}

.menu__border{

left: 0;
    bottom: 99%;
    width: 10.9em;
    height: 2.4em;
    position: absolute;
    clip-path: url(#menu);
    will-change: transform;
    background-color: var(--bgColorMenu);
    transition: transform var(--timeOut , var(--duration));
    
}

.svg-container {

width: 0;
    height: 0;
}

@media screen and (max-width: 50em) {
    .menu{
        font-size: .8em;
    }
}

// Designed by:  Mauricio Bucardo
// Original image:
// https://dribbble.com/shots/5619509-Animated-Tab-Bar

"use strict";

const body = document.body;
const bgColorsBody = ["#ffb457", "#ff96bd", "#9999fb", "#ffe797", "#cffff1"];
const menu = body.querySelector(".menu");
const menuItems = menu.querySelectorAll(".menu__item");
const menuBorder = menu.querySelector(".menu__border");
let activeItem = menu.querySelector(".active");

function clickItem(item, index) {

menu.style.removeProperty("--timeOut");
    
    if (activeItem == item) return;
    
    if (activeItem) {
        activeItem.classList.remove("active");
    }

item.classList.add("active");
    body.style.backgroundColor = bgColorsBody[index];
    activeItem = item;
    offsetMenuBorder(activeItem, menuBorder);
    
    
}

function offsetMenuBorder(element, menuBorder) {

const offsetActiveItem = element.getBoundingClientRect();
    const left = Math.floor(offsetActiveItem.left - menu.offsetLeft - (menuBorder.offsetWidth  - offsetActiveItem.width) / 2) +  "px";
    menuBorder.style.transform = `translate3d(${left}, 0 , 0)`;

}

offsetMenuBorder(activeItem, menuBorder);

menuItems.forEach((item, index) => {

item.addEventListener("click", () => clickItem(item, index));
    
})

window.addEventListener("resize", () => {
    offsetMenuBorder(activeItem, menuBorder);
    menu.style.setProperty("--timeOut", "none");
});

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