마우스 호버시 밑줄이 나옵니다. 왜 이럴까요?

html 코드이고요

<section class="content-layout">
				<div class="list">
					<div class="list-module">
						<span class="post-meta">Apr 20, 2020 , 홍길동</span>
						<a href="#">
							<h2 class="post-link">여러분 안녕하세요</h2>	
							<p class="post-description">반가워요 ㅎㅎ</p>
						</a>
					</div>

.list{
float:left; width:65%;	
}@media screen and (max-width: 600px){.list{width:100%}}
.list-module{
padding:30px 0;
border-bottom:1px solid #dddddd;
}
.list-module h2{
margin:10px 0 0
}
.post-meta{
font-size:15.75px;
color:#262626
}
.post-link{
display:block;
font-size:2em;
line-height:1.5;
color:#212121;
}
.post-link:hover{
color: grey;
}
.post-link:visited{
color:#212121
}
.post-description{
font-size:0.8em;
color:#424242;
text-decoration: none;
}