I can't put a section with background above Google Maps iframe

Question

I've got an issue, while trying to create an overlay above google maps iframe. The background-color isn't aplying in CSS. Are there any restrictions from Google and what's a proper solution to this?

.ellenonmap {
    background-color:white!important;
    text-align: center;
    box-sizing: border-box;
    width: 400px;
    height: 400px;
    margin-top: -300px;
    margin-left: 100px;
}

<iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d100621.22936695188!2d23.66829933952863!3d37.990816432734675!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x14a1bd1f067043f1%3A0x2736354576668ddd!2zzpHOuM6uzr3OsQ!5e0!3m2!1sel!2sgr!4v1652863273042!5m2!1sel!2sgr" width="600" height="450" style="border:0;" allowfullscreen="" loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
<section class="ellenonmap">
  <h1>Επικοινωνία</h1><br>
  <i class="fa-solid fa-location-dot"></i><h4>Το κατάστημά μας:</h4><br>
   <h4><i class="fa-solid fa-location-dot"></i>Το κατάστημά μας:</h4><br>
</section>

Answer 1

If you look at the output as zero-indexed matrix, you can note that zero occurs at index (i, j) whenever i + j is even. Using this observation, you could write the following. It is shorter but not necessarily more legible.

n = 5

result = "\n".join(
    "".join("0" if (i + j) % 2 == 0 else "1" for i in range(n))
    for j in range(n)
    )

Answer 2

Here is a solution using itertools and a generator. Generators and itertools.cycle make it easy to repeat things without needing to count. The only trick here is to waste one element at each line in case n is even (as the last number repeats).

from itertools import cycle, islice

c = cycle(['0','1'])
n = 6
print('\n'.join(''.join(islice(c, n+1-n%2))[:n]
                for _ in range(n)))

Output:

010101
101010
010101
101010
010101
101010

This makes it very easy to generalize by just changing the input:

from itertools import cycle, islice

def pattern(l, n):
    c = cycle(l)
    r = 1-n%len(l)
    print ('\n'.join(''.join(islice(c, n+r))[:n]
                     for _ in range(n)))

Example:

>>> pattern(list('012'), 5)
0120
1201
2012
0120
1201

>>> pattern(list('01234'), 7)
012340
123401
234012
340123
401234
012340
123401