/* Shared public-page control, independent of each page's theme variables. */
#cpx-back-to-top {
    box-sizing: border-box;
    position: fixed;
    right: max(16px, env(safe-area-inset-right));
    bottom: max(16px, env(safe-area-inset-bottom));
    z-index: 60;
    width: 44px;
    height: 44px;
    margin: 0;
    padding: 0;
    border: 1px solid rgba(15, 23, 42, .18);
    border-radius: 14px;
    background: rgba(255, 255, 255, .86);
    color: rgba(15, 23, 42, .55);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    box-shadow: 0 1px 0 rgba(255, 255, 255, .88), 0 18px 38px rgba(2, 8, 23, .14);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    appearance: none;
}
#cpx-back-to-top[hidden] { display: none; }
#cpx-back-to-top svg { width: 18px; height: 18px; }
#cpx-back-to-top:hover { border-color: rgba(15, 23, 42, .26); }
#cpx-back-to-top:focus-visible { outline: 3px solid #2e7d5a; outline-offset: 3px; }