style.css

* {
    font-family: Arial, Helvetica, sans-serif;
    font-weight: 400;
    font-style: normal;
}
  
body {
    background: linear-gradient(-45deg, #16060f, #f05092);
    display: flex;
    flex-direction: column;
    align-items: center;
}

h1 {
    margin: 5px;
    padding: 5px;
    color: #fff;
    font-size: clamp(2rem, 6vw, 4rem);
    font-weight: bold;
}

label {
    margin: 0px;
    padding: 0px;
    color: #fff;
}

h2{
    font-size: 1rem;
}

#inputText, #encryptedText, #decryptedText {
    max-width: 750px;
    width: auto;
    width: 90%;
    height: 400px;

    margin: 5px;
    padding: 5px;
    border-radius: 1rem;
    border: none;
}
#rotation{
    border: none;
    border-radius: 1rem;
    font-size: 1rem;
    padding: 5px;
}


.oneto {
    color: #fff;
    margin: 5px;
    padding: 5px;
}
.matter{
    display: flex;
    flex-direction: column;
}
.mainsection, .encryptsection, .decryptsection {
    display: flex;
    flex-direction: column;
    align-items: center
}

button{
    margin: 5px;
    padding: 5px;
    border: none;
    border-radius: 1rem;
    font-size: 1rem;
    font-weight: bold;
    color: #fff;
    background: black;
    cursor: pointer;
}

@media (max-width: 768px) {
    #inputText, #encryptedText, #decryptedText {
        width: 100%;
        max-width: 100%;
    }
}
@media (min-width: 768.1px) {
    #inputText, #encryptedText, #decryptedText {
        width: 100%;
        max-width: 100%;
    }
    #inputText, #encryptedText, #decryptedText {
        width: 750px;
    }
}