body{
font-family: Arial, Helvetica, sans-serif;
min-height:100vh;
display:flex;
flex-direction:column;
}

/* contenedor principal */

.main-container{
flex:1;
display:flex;
align-items:center;
justify-content:center;
padding:40px 20px;
}

/* tarjetas */

.card{
border-radius:12px;
transition:all .3s ease;
}

.card:hover{
transform:translateY(-6px);
box-shadow:0 12px 30px rgba(0,0,0,.2);
}

/* botones */

.btn{
transition:all .3s ease;
}

.btn:hover{
transform:scale(1.05);
}

/* inputs */

input,textarea{
transition:all .3s ease;
}

input:focus,textarea:focus{
box-shadow:0 0 8px rgba(13,110,253,.4);
border-color:#0d6efd;
}

/* footer */

footer{
margin-top:auto;
}

/* responsive */

@media(max-width:768px){

h1{
font-size:28px;
}

.card{
margin-bottom:20px;
}

}