html, body {
    margin: 0;
    border: 0;
    padding: 0;
    background: #000;
    height: 100%;
}
html * {
    font-size: 1.6em;
    font-family: Monospace;
}
::placeholder {
    color: #0f0;
    opacity: 1;
}
.crpt {
    width: 98%;
    margin: 1%;
    height: 60vh;
    resize: vertical;
    color: #0f0;
    background: #002b04;
    border: 1px solid #0f0;
}
.btn {
    margin: 0 0 0 1%;
    background: #000;
    border: 1px solid #0f0;
    color: #0f0;
}
.index {
    width: 100%;
    height: 100%;
    background-image: url(../img/nu.jpg);
    background-size: contain;
    background-position: center center;
    background-repeat: no-repeat;
    background-color: #000;
}
.container {
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.secret-form {
    width: 80%;
    max-width: 521px;
}

.secret-form input {
    width: 100%;
    background: #000;
    border: 1px solid #0f0;
    color: #0f0;
    text-align: center;
}