/* Spinner + loading affordance for in-flight form submits.
   Loaded on both base.html (authenticated shell) and the standalone login page. */
.spinner-border {
    display: inline-block;
    vertical-align: -0.125em;
    border: 0.2em solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: spinner-border 0.75s linear infinite;
}

.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.15em;
}

@keyframes spinner-border {
    to { transform: rotate(360deg); }
}

/* Applied to a button while its form submit is in flight. */
.is-loading {
    opacity: 0.65;
    cursor: not-allowed;
}

@media (prefers-reduced-motion: reduce) {
    .spinner-border { animation-duration: 1.5s; }
}