子菜单在视图中重叠粘性导航并且全角打开很奇怪

Question

我试图让我的子菜单在主菜单下方打开全角。然而，它的行为很奇怪，只向右侧打开全角，而不向左侧打开。此外，当我向下滚动网页时，子菜单与我的粘性导航重叠。

旁注： 我试图像这样打开它网站

这是我的html代码：

<header class="header">

    <video autoplay loop muted plays-inline class="back-video">
      <source src="videos/Screen Print Halftones Portraits _ a look into Unfinished Legacy.mp4" type="video/mp4">
    </video>

    <div class="background-blur"></div>

    <div class="nav type-a">
      <nav class="left">
        <ul class="nav-interior">
          <li class="nav-item"><a href="#">Mens</a>
            <!-- Sub-menu -->
            <ul class="sub-menu">
              <h9>Shop Mens</h9>
              <li><a href="#">Link 1</a></li>
              <li><a href="#">Link 2</a></li>
              <li><a href="#">Link 3</a></li>
            </ul>
          </li>
          <li class="nav-item"><a href="#">Womens</a>
          </li>
          <li class="nav-item"><a href="#">Accesories</a>
          </li>
        </ul>
      </nav>


      <!-- <img src="images/dist.png" alt="Garment Dist." class="logo"> -->
      <h1 class="logo">Garment Dist.</h1>


      <nav class="right">
        <ul class="nav-interior">
          <li class="nav-item"><a href="#">Search</a></li>
          <li class="nav-item"><a href="#">Bag</a></li>
        </ul>
      </nav>
    </div>


    <div class="content">
      <p>Act I</p>
      <!-- <a id="content-link" href="#">Discover</a> -->
    </div>
  </header>

这是我的CSS：

* {
  margin: 0;
  padding: 0;
  color: white;
  box-sizing: border-box;
  outline: none;

}

body {
  color: black;
  font-family: 'HelveticaNeueLTPro-Cn', arial, sans-serif;
  font-size: 11px;
  text-transform: uppercase;
  line-height: 1.5;
  letter-spacing: 0.1em;
}

div,
a {
  margin: 0;
  padding: 0;
  border: 0;
  font: inherit;
  font-size: 100%;
  vertical-align: baseline;
}

/* NAV CSS */
.header {
  width: 100%;
  height: 100vh;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.nav {
  width: 100%;
  height: 4.53125vw;
  position: fixed;
  top: 0;
  left: 0;
  padding-left: 40px;
  padding-right: 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  z-index: 1;
  /* overflow: hidden; */
}

.type-a {
  font-size: 12px;
  line-height: 1.5em;
  letter-spacing: .15em;
  font-weight: 500;
}


.sticky {
  background-color: white;
  position: fixed;
  transition: 400ms ease-in-out;
}

.sticky ul a,
.sticky h1 {
  color: black;
}

.header .logo {
  font-family: inherit;
  font-size: 1.5vw;
  font-weight: 600;
  height: auto;
  display: flex;
  min-width: 90px;
  min-height: 15px;
}

.left .nav-interior .nav-item {
  margin-right: 1.875vw;
  position: relative;
}

.right .nav-interior .nav-item {
  margin-left: 20px;
  position: 3;

}

.back-video {
  position: absolute;
  right: 0;
  bottom: 0;
  z-index: -1;
}

@media (min-aspect-ratio: 16/9) {
  .back-video {
    width: 100%;
    height: auto;
  }
}

@media (max-aspect-ratio: 16/9) {
  .back-video {
    width: auto;
    height: 100%;
  }
}

.content {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  text-align: center;
}

.content p {
  font-size: 5.9375vw;
  color: white;
  font-weight: 200;
  margin: 0;
  display: flex;
  letter-spacing: -.02em;
  font-family: Optima, Optima, sans-serif;

}

#content-link {
  margin: 0;
  padding: 0;
  border: 0;
  display: inline-block;
  border-bottom: 1px solid white;
  color: white;
  text-decoration: none;
  font-size: 0.90vw;
}


h1.logo {
  margin-bottom: 0px;
}

/* Footer CSS */

footer {
  margin-top: 30px;
  padding-top: 10px;
  padding-bottom: 10px;
}

.footer-content {
  padding: 50px;
  display: block;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
  width: auto;
}

.nav-footer {
  margin: 0;
  padding: 0;
  border: 0;
  height: 100%;
  font: inherit;
  font-size: 0.72vw;
  vertical-align: baseline;
  display: flex;
  justify-content: flex-end;
}

.nav-footer-item a {
  margin-right: 0;
  margin-left: 1.875vw;
  list-style: none;
  color: black;
  text-decoration: none;
}

.newsletter {
  width: inherit;
  height: inherit;
}

.newsletter img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

/* Main Section CSS */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-gap: 20px;
  padding: 20px;
}

figure {
  margin: 0;
  padding: 0;
  position: relative;
  text-align: center;
  font-family: Optima, Optima, sans-serif;
}

img {
  max-width: 100%;
  height: auto;
}

figcaption {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  text-align: center;
  flex-direction: column;
  justify-content: center;
  font-size: 4vw;
  display: flex;
  font-family: inherit;
}


.left {
  width: 40%;
  height: 100%;
}

.right {
  width: 40%;
  height: 100%;
}

.nav-interior {
  display: flex;
  height: 100%;
  justify-content: flex-start;
  line-height: 1.5em;
  position: relative;
}

.right .nav-interior {
  justify-content: flex-end;
}

nav {
  display: block;
  margin: 0;
  padding: 0;
  border: 0;
  font: inherit;
  font-size: 100%;
}

nav ul,
nav ol,
nav li {
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav .nav-interior {
  height: 100%;
  display: flex;
  align-items: center;
  padding: 0.52083vw 0;
}

nav a {
  text-decoration: none;
  color: inherit;
  font-family: 'HelveticaPro';
}

/* .nav .nav-interior .nav-item a {
  position: relative;
  display: block;
} */

/* Hover Effects CSS */

.nav-interior .nav-item>a:hover,
.nav-footer-item a:hover {
  color: black;
  text-decoration: none;
  border-bottom: 1px solid;
  transition: opacity .2s ease;
}

.sub-menu {
  display: none;
  position: absolute;
  background-color: #555;
  width: 50vw;
  left: 0;
}

/* Display sub-menu when hovering over main menu item */
.nav-interior li:hover .sub-menu {
  display: block;
}

.sub-menu li a {
  color: #fff;
  display: block;
  padding: 10px 10px;
  text-decoration: none;
  left: 0;
}