/* Fondo general más sobrio */
body {
  background-image: url('../img/fondo.png');
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center center;
  background-attachment: fixed;
}

/* Tarjetas de certificados */
.certificado {
  text-decoration: none;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  border: none;
  border-radius: 0.5rem;
  overflow: hidden;
}

.certificado:hover {
  transform: scale(1.03);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

/* Imagen de certificado */
.card-img-top {
  height: 200px;
  object-fit: contain;
  background-color: #e5aaec;
  padding: 1rem;
  border-bottom: 1px solid #fd007f;
}

/* Título */
.card-title {
  font-size: 1rem;
  color: #333;
  text-align: center;
}

/* Encabezado */
header {
  background-color: #0d6efd;
  color: #fff;
  padding: 2rem 1rem;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

header h1 {
  font-weight: bold;
}

/* Botón de regreso */
header a.btn {
  font-weight: 500;
  border-radius: 20px;
}

/* Footer */
footer {
  font-size: 0.9rem;
}