* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #000000;
    color: #ffffff;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

/* Zurück-Button oben links */
.back-btn {
    position: absolute;
    top: 20px;
    left: 20px;
    color: #ffffff;
    text-decoration: none;
    background-color: #222222;
    padding: 8px 14px;
    border-radius: 6px;
    font-size: 14px;
    transition: background 0.2s;
}

.back-btn:hover {
    background-color: #333333;
}

.register-container {
    background-color: #222222;
    padding: 30px;
    border-radius: 12px;
    width: 100%;
    max-width: 480px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6);
}

h1 {
    font-size: 24px;
    margin-bottom: 8px;
    color: #ffffff;
}

.subtitle {
    font-size: 14px;
    color: #aaaaaa;
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 16px;
}

label {
    display: block;
    font-size: 13px;
    margin-bottom: 6px;
    color: #cccccc;
}

input[type="text"],
input[type="date"] {
    width: 100%;
    padding: 10px 12px;
    background-color: #000000;
    border: 1px solid #444444;
    border-radius: 6px;
    color: #ffffff;
    font-size: 14px;
}

input:focus {
    outline: none;
    border-color: #ffffff;
}

.copy-field {
    display: flex;
    gap: 8px;
}

.action-btn {
    background-color: #333333;
    color: #ffffff;
    border: 1px solid #555555;
    padding: 0 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 12px;
    white-space: nowrap;
    transition: background 0.2s;
}

.action-btn:hover {
    background-color: #444444;
}

.action-btn.copied {
    background-color: #4CAF50;
    border-color: #4CAF50;
}

.hint {
    display: block;
    font-size: 11px;
    color: #888888;
    margin-top: 4px;
}

.submit-btn {
    width: 100%;
    padding: 12px;
    background-color: #ffffff;
    color: #000000;
    border: none;
    border-radius: 6px;
    font-weight: bold;
    font-size: 15px;
    cursor: pointer;
    margin-top: 10px;
    transition: opacity 0.2s, background-color 0.2s;
}

.submit-btn:disabled {
    background-color: #444444;
    color: #888888;
    cursor: not-allowed;
}

.submit-btn:not(:disabled):hover {
    background-color: #e0e0e0;
}

.login-redirect {
    text-align: center;
    margin-top: 20px;
    font-size: 13px;
    color: #aaaaaa;
}

.login-redirect a {
    color: #ffffff;
    text-decoration: underline;
    margin-left: 4px;
}

/* ==========================================
   RESPONSIVES DESIGN / MEDIA QUERIES FÜR HANDYS
   ================================---------- */
@media (max-width: 480px) {
    body {
        padding: 10px;
        align-items: flex-start;
    }

    .register-container {
        padding: 20px;
        margin-top: 50px;
        box-shadow: none;
    }

    .back-btn {
        top: 10px;
        left: 10px;
        padding: 6px 10px;
        font-size: 12px;
    }

    h1 {
        font-size: 20px;
    }

    input[type="text"],
    input[type="date"] {
        font-size: 13px;
        padding: 8px 10px;
    }
}