body {
  font-family: Arial, sans-serif;
  background: #f5f5f5;
  padding: 0px;
  margin: 0;
}

.main-header {
  text-align: center;
  margin-bottom: 20px;
}

.books-container {
 /*display:flex;
  justify-content: center;
  gap:20px;
  flex-wrap: wrap;
  width:60%;*/
  
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 10px;
  width:50%;
  margin: 0 auto; /* Centraliza o contêiner na página */


  }


/* Estilos para as colunas */
.div_velho,
.div_novo {
  background: #fff;
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  flex: 1 1 calc(40% - 10px); 
  min-width: 0;              /* permite encolher bem */
}

@media (max-width: 900px) {
  .books-container {
    width:100%;

  }

  .div_velho,
  .div_novo {
    flex-basis: 100%;
  }
}

@media (max-width: 900px) {
  .div_velho,
  .div_novo {
    width:50px;


  }
}

@media (max-width: 400px) {
  .div_velho,
  .div_novo {
    flex: 1 1 100%; /* aí sim empilha */
  }
}


.book-list {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

.book-list li {
  margin: 5px 0;
}

.book-list a {
  display: block;
  padding: 10px;
  font-size: 16px;
  background: #f9f9f9;
  border-radius: 5px;
  color: #007BFF;
  text-decoration: none;
  transition: all 0.3s ease;
}

.book-list a:hover {
  background: #28a745;
  color: #fff;
}