Refine sign now spacing and bump to 1.2.16

frontend/src/pages/signatures/SignaturesPage.jsx

@@ -286,7 +286,7 @@ export default function SignaturesPage() {
               )}
               {uploadingDocument && <small className="field-hint">Subiendo documento...</small>}
             </div>
-            <div className="field">
+            <div className="field sign-certificate-field">
               <label><Shield size={14} /> Certificado digital</label>
               <select name="certificateId" value={form.certificateId} onChange={handleChange} required>
                 <option value="">Selecciona un certificado...</option>
@@ -296,7 +296,7 @@ export default function SignaturesPage() {
             </div>
             <button
               type="button"
-              className="btn btn-ghost btn-inline-toggle"
+              className="btn btn-ghost btn-inline-toggle sign-details-toggle"
               onClick={() => setShowAdvancedOptions((current) => !current)}
             >
               {showAdvancedOptions ? <EyeOff size={16} /> : <Eye size={16} />}
@@ -322,7 +322,7 @@ export default function SignaturesPage() {
                 </div>
               </>
             )}
-            <button className="btn btn-primary btn-full" onClick={handleGoToPlace}>
+            <button className="btn btn-primary btn-full sign-place-button" onClick={handleGoToPlace}>
               <MapPin size={16} /> Elegir posición de firma →
             </button>
           </div>