help please, the problem is that the fieldset labels are mismatched from their container on the right side of the sheet, when viewed on small devices:
*{box-sizing: border-box;}
#controlesFactura{
margin-bottom: 7px;
}
.btn{
border: 2px solid black;
background-color: #4CAF50;
color: white;
padding: 14px 28px;
font-size: 16px;
cursor: pointer;
}
.enviar{
border-color: #4CAF50;
color: white;
}
.enviar:hover {
background-color: #339933;
color: white;
}
#tablaFactura{
border: 5px solid black;
}
/*ESTILOS FACTURA*/
#clienteDatos input[type=text]{
width: 100%;
/*border:none;*/
}
#tblFactura{
border:#339933;
}
/*CENTRANDO LA FACTURA*/
#facturaContenedor{
display: flex;
justify-content: center;
align-items: flex-start;
overflow: auto;
}
/*FACTURA GENERAL*/
#facturaCabecera, #facturaCliente, #facturaItems{
width: 100%;
}
/*TAMAÑOS DE CELDAS TABLA ITEMS*/
.faCodP{
width: 30px;
}
.faDesP{
width: 200px;
}
.faCanP{
width: 40px;
}
.faPreP{
width: 50px;
}
.faSub{
width: 70px;
}
.faIva{
width: 40px;
}
.faTot{
width: 80px;
}
#facturaItems input[type=text]{
width: 100%;
}
<!DOCTYPE html>
<html>
<head>
<title>Factura</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<!--HOJAS DE ESTILO-->
<link rel="stylesheet" type="text/css" href="../css/estilosFactura.css">
<link rel="stylesheet" type="text/css" href="../css/estilosGenerales.css">
</head>
<body>
<div class="contenedores">
<fieldset id="facturaCabecera">
<legend>Datos Factura</legend>
<table>
<tbody>
<tr>
<td>001</td>
<td>001</td>
<td>00000</td>
<td>claveacces111111111111111111111</td>
<td>fecha11111111111111</td>
<td style="width: 5%;"></td>
</tr>
</tbody>
</table>
</fieldset>
<fieldset id="facturaCliente">
<legend>Datos Cliente</legend>
<table>
<tbody>
<tr>
<td><select><option>Consumidor Final</option></select></td>
<td><input type="text"></td>
<td><input type="button" value="Buscar"></td>
<td><a>Nuevo Cliente</a></td>
<td style="width:5%;"></td>
</tr>
</tbody>
</table>
<div id="clienteDatos">
<input type="text">
<input type="text">
<input type="text">
<input type="text">
<input type="text">
</div>
</fieldset>
<fieldset id="facturaItems">
<legend>Items</legend>
<div id="facturaContenedor">
<table id="tblFactura">
<thead class="tablaCabecera">
<tr>
<th>Cod</th>
<th>Descripcion</th>
<th>Cant</th>
<th>P.Unit</th>
<th>Subtotal</th>
<th>Iva</th>
<th>P.Total</th>
<th>Eliminar</th>
</tr>
</thead>
<tbody class="tablaCuerpo">
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
<tr>
<td class="faCodP"><input type="text"></td>
<td class="faDesP"><input type="text"></td>
<td class="faCanP"><input type="text"></td>
<td class="faPreP"><input type="text"></td>
<td class="faSub"><input type="text"></td>
<td class="faIva"><input type="text"></td>
<td class="faTot"><input type="text"></td>
<td class="faEli"><input type="button" value="Eliminar"></td>
</tr>
</tbody>
<tfoot class="tablaPie">
<tr>
<td>subotoal</td>
<td>0.00</td>
</tr>
<tr>
<td>Grava 0</td>
<td>0.00</td>
</tr>
<tr>
<td>Grava Iva</td>
<td>0.00</td>
</tr>
<tr>
<td>Iva</td>
<td>0.00</td>
</tr>
<tr>
<td>Total</td>
<td>0.00</td>
</tr>
</tfoot>
</table>
</div>
</fieldset>
</div>
</body>
</html>