.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 48px;
  padding: 0 var(--space-5);
  font-family: inherit;
  font-size: 15px;
  font-weight: 500;
  line-height: 1.2;
  text-align: center;
  white-space: nowrap;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease;
}

.btn:hover {
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Waiting for the server: the label is hidden (the button keeps its width)
   and a spinner in the label's colour takes its place. */
button.is-loading,
.btn.is-loading {
  position: relative;
  cursor: progress;
  -webkit-text-fill-color: transparent;
}

.btn.is-loading:disabled {
  opacity: 0.85;
  cursor: progress;
}

button.is-loading > *,
.btn.is-loading > * {
  visibility: hidden;
}

button.is-loading::after,
.btn.is-loading::after {
  content: "";
  position: absolute;
  inset: 0;
  width: 18px;
  height: 18px;
  margin: auto;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: btn-spin 0.7s linear infinite;
}

.btn-sm.is-loading::after,
.btn-icon.is-loading::after {
  width: 14px;
  height: 14px;
}

@keyframes btn-spin {
  to {
    transform: rotate(360deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  button.is-loading::after,
  .btn.is-loading::after {
    animation-duration: 1.6s;
  }
}

.btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-on-primary);
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-hover);
  color: var(--color-on-primary);
}

.btn-dark {
  background: var(--color-black);
  color: #fff;
}

.btn-dark:hover:not(:disabled) {
  background: #2a2a2e;
  color: #fff;
}

.btn-secondary {
  background: var(--color-bg);
  border-color: var(--color-border-strong);
  color: var(--color-text);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--color-black);
  color: var(--color-text);
}

.btn-danger {
  background: var(--color-bg);
  border-color: #f1b4b4;
  color: var(--color-danger);
}

.btn-danger:hover:not(:disabled) {
  background: var(--color-danger-bg);
  border-color: var(--color-danger);
  color: var(--color-danger);
}

.btn-sm {
  min-height: 36px;
  padding: 0 14px;
  font-size: 14px;
}

.btn-lg {
  min-height: 56px;
  padding: 0 var(--space-6);
  font-size: 16px;
}

/* The smallest phones: a long label wraps instead of pushing the page
   sideways. */
@media (max-width: 400px) {
  .btn-lg {
    max-width: 100%;
    padding-block: var(--space-2);
    white-space: normal;
  }
}

.btn-block {
  display: flex;
  width: 100%;
}

.btn-link {
  background: none;
  border: none;
  padding: 0;
  font-family: inherit;
  font-size: inherit;
  font-weight: 500;
  color: var(--color-primary-text);
  cursor: pointer;
}

.btn-link:hover:not(:disabled) {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.btn-danger-solid {
  background: var(--color-danger);
  color: #fff;
}

.btn-danger-solid:hover:not(:disabled) {
  background: #a51818;
  color: #fff;
}

.btn-icon {
  width: 36px;
  padding: 0;
}

.btn-icon svg {
  width: 16px;
  height: 16px;
}

/* Sign in with Google: white, the multicolour "G" (Google branding rules). */
.btn-google {
  background: #fff;
  color: #1f1f1f;
  border-color: var(--color-border-strong);
  font-weight: 600;
  gap: var(--space-3);
}

.btn-google:hover:not(:disabled) {
  background: var(--color-bg-subtle);
  color: #1f1f1f;
}

.btn-google svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* A document link while its file is being fetched (static/js/download.js). */
a.is-downloading {
  opacity: 0.6;
  cursor: progress;
  pointer-events: none;
}