.sfondo{
   margin: 0px;
  background-image: url(https://static.vecteezy.com/ti/vettori-gratis/p3/16829862-vettore-illustrazione-di-graffiti-sfondo-senza-soluzione-di-continuita-graffiti-arte-textures-nel-un-disegnato-a-mano-stile-vecchio-scuola-e-urbano-strada-arte-tema-per-maglietta-disegno-tessile-sfondo-sfondo-e-stampe-vettoriale.jpg);
  background-attachment: fixed;
  background-repeat: no-repeat;
  background-size: 100%;
}


    html,
    body {
      position: relative;
      height: 100%;
    }

    body {
      background: #eee;
      font-family: Helvetica Neue, Helvetica, Arial, sans-serif;
      font-size: 14px;
      color: #000;
      margin: 0;
      padding: 0;
    }

    .swiper {
      width: 100%;
      height: 100%;
    }

    .swiper-slide {
      text-align: center;
      font-size: 18px;
      background: #fff;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .swiper-slide img {
      display: block;
      width:100%;
      height:100%;
      object-fit: cover;
    }
H1{
  font-size: 20px;
  font-family: Helvetica;
  text-align: center;
  color:white;
}
p{
  font-size: 17px;
  font-family: Helvetica;
  text-align: center;
  color:white;
}
.riquadro{
  border: 1px solid orange; 
  background-color:black;
  color:white; 
  padding: 20px;
  border-radius: 15px;
  margin-top: 60px;
  text-align:center;
  margin-bottom:40px;
}
.box{
  border:1px solid orange; 
  background-color:black;
  color:white; 
  padding: 20px;
  border-radius: 20px;
  margin-top: 50px;
  opacity:90%;
  margin-bottom: 40px;
}


footer{
  background-color: black;
  text-align:center;
  font-size:12px;
  color: white;
  border-top: 1px solid orange;
  opacity:90%;
  }
riquadri-gialli{
  border: 3px solid orange
}
b{
  font-style:italic;
}