/* Spinner compatible con Bootstrap 3.3 */
.spinner-border {
  display: inline-block;
  width: 2rem;
  height: 2rem;
  vertical-align: text-bottom;
  border: 0.25em solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  -webkit-animation: spinner-border .75s linear infinite;
  animation: spinner-border .75s linear infinite;
}

.spinner-border-sm {
  width: 1rem;
  height: 1rem;
  border-width: 0.2em;
}

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

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

/* Colores compatibles con clases de Bootstrap 3 */
.text-primary { color: #337ab7; }
.text-success { color: #3c763d; }
.text-danger  { color: #a94442; }
.text-warning { color: #8a6d3b; }
.text-info    { color: #31708f; }

/* Ocultar texto para accesibilidad sin romper el layout */
.sr-only-spinner {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}