sub navigation drop down with wrong position

Hello there!

I have a problem with sub navigation in wrong position.
https://soonhwan.kr/

The sub navigation should appear underneath the corresponding parent navigation.
But it doesn’t work.
I’ve tried to fix the css, the code ‘position: relative;’ and ‘position: absolute;’.
But unfortunately I couldn’t fix it perfectly.

Please help me how to solve it!

Thank you.
Eunjae.

================================================================================
/* =Menu
————————————————————– */

.home #access {
margin: 0 auto 30px 0;
width: 940px;
text-align: center;
font-size: 15px;

}
#access {
margin:0 auto 7px 0;
}
.menu {text-align:center;}
.menu ul li {display:inline;}

#access .menu-header,
div.menu {
border-top:0px dashed #AAA;
border-bottom:0px dashed #AAA;
font-size: 15px;
margin-left: 12px;
width: 80%;
margin:0 auto;
}
#access .menu-header ul,
div.menu ul {
font-size: 15px;
position: relative;
text-align: center;
list-style: none;
margin: 0;
display:block;
}
#access .menu-header li,

#access a {
color: #999;
display: inline;
line-height: 38px;
padding: 0 10px;
text-decoration: none;
font-weight:800;
font-size: 15px;
letter-spacing: 0px;
}
#access ul ul {
box-shadow: 0px 0px 0px rgba(0,0,0,0.1);
-moz-box-shadow: 0px 0px 0px rgba(0,0,0,0.1);
-webkit-box-shadow: 0px 0px 0px rgba(0,0,0,0.1);
visibility:hidden;
position: absolute;
display:block;
text-align: left;
top: 0px;
left: 0;
width: 150px;
z-index: 999;
border:0px solid #BBB;
}
#access ul ul li {
min-width: 180px;

}
#access ul ul ul {
position: absolute;
left: 0px;
top: 0px;
display:inline;
}

#access ul ul a {display:block; }

#access ul ul a {
color:#AAA;
background: #FFF;
line-height: 1em;
padding: 10px;
width: 160px;
height: auto;
}
#access ul ul li:hover > a,
#access ul ul :hover > a {
background: #F5FFFD;
color: #00EDC3;
}

#access li:hover > a {
color: #00EDC3;
}

#access ul li:hover > ul {
visibility:visible;

}
#access ul li.current_page_item > a,
#access ul li.current-menu-ancestor > a,
#access ul li.current-menu-item > a,
#access ul li.current-menu-parent > a {
color: #999;
}
* html #access ul li.current_page_item a,
* html #access ul li.current-menu-ancestor a,
* html #access ul li.current-menu-item a,
* html #access ul li.current-menu-parent a,
* html #access ul li a:hover {
color: #fff;
}