#contact_text {
    display: flex; justify-content: center; margin: 5px;
}
#contact_form #contact_error_msg {
    color: red; font-size: 110%; font-weight: 700;
}
#contact_form #contact_ok_msg {
    color: green; font-size: 110%; font-weight: 700;
}
#contact_form {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 375px;
    padding: 5px;
    margin: auto;
}
#contact_form textarea, #contact_form input:not([type="submit"]) {
    background-color: var(--col_bg2);
}
    #contact_form textarea, #contact_form input, 
    #contact_form textarea::placeholder, #contact_form input::placeholder {
        font-family: var(--font_main); font-size: 100%;
    }
    #contact_form label {
        display: block;
        width: 100%;
        margin-bottom: 10px;
    }
        #contact_form .label_text {
            display: block;
            margin-bottom: 3px;
            font-size: 110%;
        }
        #contact_form label input:not(input[type="checkbox"]), #contact_form textarea, #contact_form select {
            box-sizing: border-box; /* avoid overflow due to padding / border */
            width: 100%;
            outline: none; /* avoid blue border when selected on firefox */
            padding: 3px;
        }
    #contact_form #_robot {
        display: none;
    }
    #contact_form textarea {
        resize: vertical;
    }
    #contact_form #msg_remaining_characters {
        font-weight: 700;
    }
    #contact_form #robot {
        display: flex; align-items: center;
        width: fit-content;
        margin-right: auto;
    }
    #contact_form input:not(input[type="submit"]):invalid, #contact_form textarea:invalid {
        border-radius: 4px;
        border: 2px ridge darkred;
        color: darkred; /*SEO*/;
    }
    #contact_form input[name="robot"]:invalid {
        outline-offset: -1px;
        outline: 2px ridge darkred;
    }   #contact_form input[name="robot"]:invalid + #robot_message {
            color: red; font-weight: 600;
        }
    #contact_form input:not(input[type="submit"]):valid, #contact_form textarea:valid, #contact_form select:valid {
        border-radius: 4px;
        border: 2px ridge green;
    }
    #contact_form input[name="robot"]:valid {
    outline-offset: -1px;
    outline: 2px ridge green;
    accent-color: green; /* checkbox */
    }
    #contact_form input::placeholder, #contact_form textarea::placeholder {
        font-style: italic;
    }
    #contact_form input[type="submit"] {
        margin-bottom: 5px;
        filter: grayscale(1);
    }