* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f6f7fb;
  color: #111;
}
.container {
  max-width: 720px;
  margin: 32px auto;
  padding: 0 16px;
}
.card {
  background: #fff;
  border: 1px solid #e4e7ee;
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 16px;
}
form label { display: block; margin-bottom: 12px; }
input[type="text"], input[type="date"] {
  width: 100%;
  margin-top: 6px;
  padding: 8px;
}
fieldset { border: 1px solid #ddd; border-radius: 8px; margin: 12px 0; }
button {
  background: #1f6feb;
  color: #fff;
  border: 0;
  border-radius: 8px;
  padding: 10px 14px;
  cursor: pointer;
}
#risultato { font-size: 1.2rem; font-weight: 700; letter-spacing: 1px; }
.errore { color: #b00020; min-height: 1em; }