The source code is as follows
- css code
.menu {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  padding: 0 50px;
}
.menu__item {
  all: unset;
  flex-grow: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 9px 0 14px;
  text-align: center;
  cursor: pointer;
}
.icon {
  width: 42px;
  height: 42px;
  stroke: white;
  fill: transparent;
  stroke-width: 1pt;
  stroke-miterlimit: 10;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 400;
}
- html code
<menu class="menu">
  <button class="menu__item"><svg class="icon" viewBox="0 0 24 24">...</svg>item1</button>
  <button class="menu__item"><svg class="icon" viewBox="0 0 24 24">...</svg>item2</button>
  <button class="menu__item"><svg class="icon" viewBox="0 0 24 24">...</svg>item3</button>
</menu>
Packed and viewed in the browser, the flex style that should be on the 'menu__item' is not working, only the 'menu' has!!!
- css in F12
.menu, .menu__item {
    display: flex;
    align-items: center;
    justify-content: center;
}
.menu {
    font-size: 16px;
    padding: 0 50px;
}
.menu__item {
    all: unset;
    flex-grow: 1;
    padding: 9px 0 14px;
    text-align: center;
    cursor: pointer;
}
 
    