.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: cover;
}

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;
}

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;
  
}

.container {
  max-width: 600px;
  margin-top: 60px;
}

label {
  display: block;
  margin-bottom: 10px;
}

input,
textarea {
  width: 100%;
  padding: 10px;
  margin-bottom: 20px;
  border: 1px solid #ccc;
  border-radius: 4px;
}

textarea {
  height: 150px;
}

button {
  background-color: #333;
  color: #fff;
  padding: 10px 20px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

button:hover {
  background-color: #555;
}

.success-message {
  color: green;
  margin-bottom: 20px;
}

.error-message {
  color: red;
  margin-bottom: 20px;
}

footer {
  background-color: black;
  text-align: center;
  font-size: 12px;
  color: white;
  border-top: 1px solid orange;
  opacity: 0.9;
}

.riquadri-gialli {
  border: 3px solid orange;
}

b {
  font-style: italic;
}