Can't align to center orizontally/vertically with many ways

Question

So.. my problem is:

I try to align a div to center vertically but doesn't work.. Tried with flex-box, text align, with 2 divs ,etc..

# html  

<div class="center">
    <div class="lol">
        <h1 id="textual"></h1>
        <h1 id="author"></h1>
        <input type="submit" value="Click Me" id="cheese" class="button">
        <button type="submit" id="bttn">Submit</div>
    </div>
</div>

# css

.lol {
    max-width: 700px;
    min-width: 700px;
    padding-left: 20px;
    padding-right: 20px;
    padding-bottom: 20px;
    background-color: white;
    overflow: hidden;
    border: 1px white solid;
    border-radius: 5px;
    margin: 0 auto;
}

Do you know guys what's the problem? I used some script, just to get JSON API but i don't think that affects..

Thanks in advance.