/* Version switch for the classic 2020 pages (added in 2026).
   Self-contained and drawn in the 2020 style: black → #297acf gradient, Dodgerblue glow. */
.vswitch {
    position: fixed;
    top: 14px;
    right: 14px;
    z-index: 10000;
    display: flex;
    align-items: center;
    gap: 2px;
    padding: 3px;
    border: 1px solid rgba(30, 144, 255, .35);
    border-radius: 999px;
    background: linear-gradient(0deg, rgba(41, 122, 207, .4), rgba(0, 0, 0, .88) 72%);
    box-shadow: 0 8px 10px -5px rgba(0, 0, 0, .2), 0 16px 24px 2px rgba(0, 0, 0, .14), 0 6px 30px 5px rgba(0, 0, 0, .12);
    font: 500 13px/1 'Roboto', system-ui, -apple-system, 'Segoe UI', sans-serif;
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    animation: vswitch-in .6s ease-out 2.6s both; /* after the 2020 "Hello!" screen */
}
.vswitch_bottom {
    top: auto;
    bottom: 18px;
    right: 28px;
    animation-delay: .3s;
}
.vswitch__item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    height: 30px;
    padding: 0 12px;
    border-radius: 999px;
    color: #e0dfe2;
    text-decoration: none;
    white-space: nowrap;
    transition: color .2s, background-color .2s, box-shadow .2s;
}
.vswitch__item_current {
    background: rgba(0, 0, 0, .55);
    color: #8fb8e6;
}
.vswitch__item_new {
    background: linear-gradient(90deg, #1766d1, #1e90ff);
    color: #fff;
}
a.vswitch__item:hover,
a.vswitch__item:focus-visible {
    color: #fff;
    box-shadow: 0 4px 14px Dodgerblue;
    outline: none;
}
.vswitch__item svg {
    width: 12px;
    height: 12px;
    fill: currentColor;
}
@keyframes vswitch-in {
    from { opacity: 0; transform: translateY(-8px); }
}
/* Phones: the big title fills the top, so the switch sits above the footer */
@media (max-width: 620px) {
    .vswitch {
        top: auto;
        bottom: 58px;
        right: 50%;
        transform: translateX(50%);
        font-size: 12px;
        animation-name: vswitch-in-mobile;
    }
    .vswitch_bottom { bottom: 14px; }
    @keyframes vswitch-in-mobile {
        from { opacity: 0; transform: translate(50%, 8px); }
    }
}
@media (prefers-reduced-motion: reduce) {
    .vswitch { animation: none; }
}