Botões de número de entrada do estilo HTML

/* Mozilla */
input[type=number] { 
    -moz-appearance: textfield;
    appearance: textfield;
    margin: 0; 
}
/* Chrome */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button { 
      -webkit-appearance: none; 
      margin: 0; 
}
KostasX