.mail-submit-progress[hidden],
.mail-submit-label[hidden] {
    display: none;
}
.mail-spinner {
    display: inline-block;
    width: 0.85em;
    height: 0.85em;
    margin-right: 0.4em;
    vertical-align: -0.08em;
    border: 2px solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: mail-spin 0.8s linear infinite;
}
@keyframes mail-spin {
    to { transform: rotate(360deg); }
}
@media (prefers-reduced-motion: reduce) {
    .mail-spinner { animation: none; }
}