Construct ASCII arches I like ascii art and I get bored a lot, so I found some ascii characters and started to make random things, 8-bit mario castle, mazes, and arches. I found that the arches could easily be stacked in a neat way.

╔═══════╗
║╔═════╗║
║║╔═══╗║║
║║║╔═╗║║║
╨╨╨╨─╨╨╨╨


Challenge

Create a program, function, or any other standard format that accepts an integer that is greater than or equal to 0 (unless you are doing the bonus) and outputs  ascii art with the amount of arches specified.

Test Cases

Input:

7


Output:

╔═════════════╗
║╔═══════════╗║
║║╔═════════╗║║
║║║╔═══════╗║║║
║║║║╔═════╗║║║║
║║║║║╔═══╗║║║║║
║║║║║║╔═╗║║║║║║
╨╨╨╨╨╨╨─╨╨╨╨╨╨╨


Alt:

+-------------+
|+-----------+|
||+---------+||
|||+-------+|||
||||+-----+||||
|||||+---+|||||
||||||+-+||||||
||||||| |||||||
---------------


Input:

1


Output:

╔═╗
╨─╨


Alt:

+-+
| |
---



If the integer is 0 then don't output anything
This question will be in utf-8, each character will count as a "byte"
This is codegolf so the shortest answer wins.
You have the option of using +-+ instead of ╔═╗, --- instead of ╨─╨, and | instead of ║


Bonus (not decided whether to allow this on the alternate version because it wouldn't be as hard)

-10% if the program supports negative numbers and flips the arches like so

╥╥╥╥─╥╥╥╥
║║║╚═╝║║║
║║╚═══╝║║
║╚═════╝║
╚═══════╝
Python 2, 106 bytes (94 chars)
n=input();j=1
exec&quot;s=j/2*'║';print s+'╔'+'═'*(2*n-j)+'╗'+s;j+=2;&quot;*n
if n:t='╨'*n;print t+'─'+t

Pretty straightforward. Prints line by line with a changing number of horizontal and vertical bars. The last line is printed separately.
I feel like I'm missing some optimizations. The fact that the chars are multiple bytes means you can't do something like '║╨'[n&gt;0], so I didn't find a good way to print the last line in the loop. It's ugly that there's so much manipulation going on with the counter. I'd like update strings directly, like s+='║', but the index is also used for horizontal bars.