Menu is not visible under Hamburger menu (Desktop Version)

Hello everyone! I coded a hamburger menu for desktop, and I also code it so that the menu appears in the bottom left corner of the screen. You can see it here: www.byandreavaldes/about
 

The issues I'm facing are:

1. Desktop version: menu options do not appear

2. Mobile: The menu has been divided in half as mentioned in the code, however I'd like the burger menu to be full screen in the mobile version.

Can anyone help me figure out what I might be doing wrong?
 

Here's the code I used:

.header-nav, .header-actions {

  display: none;

}

.header-burger {

  display: flex;

}

.header--menu-open .header-menu {

visibility: visible;

  opacity: 1;

}

.burger-box {
    width: 24px;
}

  .header-menu {
  min-width: 50%;
  max-width: 35%;
  width: 100%;
    }

What is site url? We can check code easier