html {
  overflow-x: hidden;
}

body {
	/*font-family: "Roboto","Noto Sans TC",sans-serif;*/
	font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft JhengHei", "PingFang TC", "Noto Sans TC", Arial, sans-serif;
}

.rbs-page-main {
  padding-top: clamp(3rem, 5vw, 4.25rem);
}

.rbs-go-to {
  visibility: hidden;
}

.markdown-content,
.card-body,
.breadcrumb,
.rbs-page-intro {
  overflow-wrap: anywhere;
}

.rbs-page-intro {
  max-width: 52rem;
  margin: 0 0 1.75rem;
  color: #4b5563;
  font-size: 1rem;
  line-height: 1.85;
}

.markdown-content img {
  max-width: 100%;
  height: auto;
}

.rbs-book-card {
  overflow: hidden;
}

.rbs-book-card-img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background-color: #f8f9fa;
}

.spinner {
  display: none;
}

.rbs-spinner-visible {
  display: inline-block;
}

.navbar-brand-logo {
	width: 500px;
	min-width: 6rem;
	max-width: 6rem;
}

.btn-loading {
  pointer-events: none;
  opacity: 0.7;
  position: relative;
  cursor: not-allowed;
}
.btn-loading .spinner {
  margin-left: 8px;
  display: inline-block;
  width: 1em;
  height: 1em;
  vertical-align: middle;
  border: 2px solid #fff;
  border-right: 2px solid #f44336; /* your original button red */
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}
.btn-u-disabled {
  background-color: #ccc !important;
  border-color: #ccc !important;
  color: #888 !important;
  cursor: not-allowed !important;
  opacity: 0.5;
}

@media (max-width: 575.98px) {
  .navbar-brand {
    max-width: calc(100vw - 5rem);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .card-body h4 {
    font-size: 1rem;
    line-height: 1.35;
  }
}