body {
   margin: 0;
   padding: 0;
   font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
   background-color: #000;
   color: #e2e2e2;
   text-align: center;
}

h2 {
   margin-top: 80px;
   font-size: 48px;
   letter-spacing: 3px;
   color: #00eaff;
   text-shadow: 0 0 15px #00eaff;
}
button {
   font-size: 20px;
   padding: 12px 30px;
   margin-top: 25px;
   background: #00eaff;
   border: none;
   border-radius: 8px;
   color: #000;
   font-weight: bold;
   box-shadow: 0 0 15px #00eaff;
}
button:hover {
   box-shadow: 0 0 25px #00eaff;
}
form {
   margin-top: 120px;
    background: #000;
   display: inline-block;
   padding: 30px 40px;
   border-radius: 12px;
   box-shadow: 0 0 25px rgba(0, 234, 255, 0.3);
}
label {
   display: block;
   font-size: 22px;
   margin-bottom: 15px;
   color: #00eaff;
   text-shadow: 0 0 8px #00eaff;
}

input[type="number"] {
   padding: 10px;
   width: 150px;
   font-size: 18px;
   border-radius: 8px;
   border: 2px solid #00eaff;
   outline: none;
   background: #000;
   color: #00eaff;
   text-align: center;
   box-shadow: 0 0 10px #00eaff;
}
input[type="number"]:focus {
   box-shadow: 0 0 20px #00eaff;
}
a{
   text-decoration: underline;
   color: rgb(255, 255, 255);
}

#proba{
   margin: 0 auto;
   font-size: 20px;
   padding: 12px 30px;
   margin-top: 300px;
   background: #000;
   border: 2px solid #00eaff;
   border-radius: 8px;
   color: #ffffff;
   font-weight: bold;
   box-shadow: 0 0 10px #00eaff;
   width: 300px;
}