.flex-container{
     display: flex;
     flex-wrap: wrap;
     justify-content: center;
     color: #333; 
     font-family: sans-serif;
    
    }
 
 
 body{
     overflow-x: hidden;
 }
 
 .flex-item{
    flex-grow: 1;
    margin: 20px;
min-width: 300px;
border: 2px solid #333;
padding: 0 20px;
 }
.flex-item:hover{
    border-color:#71e154 ;
    box-shadow: 0px 0px 22px #317024;
}
.flex-item:focus{
    border-color:#71e154 ;
    box-shadow: 0px 0px 22px #317024;
}
 h2,h3{
     margin: 0;

 }
 h3{
     color: #999;
 }
 p b{
     color: #71e154;
 }
#llave-img{
     width: 300px;

 } 
 form{
     width: 100%;
     text-align: center;
     padding: 50px;
     
 }
 input[type="submit"]{
     background: #317024;
     color: #fff;
     border: none;
     padding: 12px 36px;
     font-size: 17px;
     letter-spacing:1px ;
 }