.tab-menu {
    --tag-item-checked-color: #5555ff;
    --tab-menu-width: 100%;
    --tab-menu-item-height: 50px;
    --i: 0;
    display: flex;
    flex-wrap: wrap;
    width: var(--tab-menu-width);
    position: relative;
}

.tab-menu > input {
    display: none;
}

.select,
.tab-menu .tab-menu-item,
.tab-menu-item:hover::before
{
    border-radius: 15px 15px 0px 0px;
    height: var(--tab-menu-item-height);
}

.tab-menu .tab-menu-item {
    align-items: center;
    border: 1px solid #aaa;
    border-bottom: none;
    display: flex;
    flex: 1;
    justify-content: center;
    order: -1;
    position: relative;
}

.tab-menu .tab-menu-item::before {
    background-color: #eee;
    content: "";
    width: 0%;
    height: 0px;
    transition: width 0.5s, height 0.5s;
    position: absolute;
    z-index: -1;
}

.tab-menu .tab-menu-item:hover::before {
    width: 100%;
    height: var(--tab-menu-item-height);
}

.tab-menu > input:checked + .tab-menu-item {
    background-color: var(--tag-item-checked-color);
    border-color: var(--tag-item-checked-color);
    background-color: transparent;
    color: #fff;
}

.tab-menu .tab-menu-contents {
    width: 100%;
    height: 0px;
    opacity: 0;
    margin: 0;
    padding: 0;
    border: 0;
}

.tab-menu > input:checked + .tab-menu-item + .tab-menu-contents {
    border: 1px solid #aaa;
    border-top: 3px solid var(--tag-item-checked-color);
    height: 300px;
    opacity: 1;
    transition: opacity 0.5s;
}

.select {
    z-index: -1;
    position: absolute;
    left: calc(var(--tab-menu-width) / 3 * var(--i));
    flex: 1;
    width: calc(var(--tab-menu-width) / 3);
    border-bottom: 1px solid var(--tag-item-checked-color);
    background-color: var(--tag-item-checked-color);
    border-color: var(--tag-item-checked-color);
    transition: left 0.2s;
}

.tab-menu > input.index-0:checked ~ .select {
    --i: 0;
}

.tab-menu > input.index-1:checked ~ .select {
    --i: 1;
}

.tab-menu > input.index-2:checked ~ .select {
    --i: 2;
}