一

a{ width: 157px;
  line-height: 180%;
  background: #fff;
    text-align: center;
    padding: 5px;
    white-space: nowrap;
    word-wrap: normal;
    text-overflow: ellipsis;
    overflow: hidden;
    border-radius: 8px;
    border: 1px solid #ececec;
    -webkit-transition-duration: .5s;
    transition-duration: .5s;
  height: 38px;-webkit-tap-highlight-color: rgba(255,0,0,0);    color: #333;
    text-decoration: none;
    
} 
a:hover {
    border: 1px solid #4d8cb8;
    transition: all 0.1s ease-in 0s;
}

二

a {
    color: #7fba00;
    font-size: 14px;
    line-height: 38px;
    text-align: center;
    border: 1px dashed rgba(0, 0, 0, .2);
    padding: 0 3px;
    box-sizing: border-box;
    float: left;
    width: 11.5%;
    height: 38px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    margin: 0 0.5% 6px;
    text-decoration: none;
    transition: all .6s;
   font-weight: bold;
}


a:hover {
  
    color: #fff !important;
    background: #7fba00;
    transition: all .6s;
}

三

a {
    width: 130px;
    cursor: pointer;
    max-height: 40px;
    line-height: 40px;
    color: #fff;
    box-shadow: none;
    border: 0;
    overflow: hidden;
    z-index: 10;
    border-radius: 10px;
    margin: 0 0.5% 6px;
    font-size: .7rem;
    display: inline-block;
    text-decoration: none;
    text-align: center;
    background-color: rgba(0, 0, 0, 0.40)!important;
    font-weight: bold;
}

a:hover {
    color: #fff!important;
    transition: all .6s;
    background-color: DeepSkyBlue!important;
}

四

（文字颜色为黑色）彩色需配合：
css循环色超链接样式示例 - 维洛BLOG
https://b.xn--xu0a.cn/index.php/archives/1423/

a {
    width: 15.5%;
    cursor: pointer;
    max-height: 40px;
    line-height: 40px;
    color: #000;
    box-shadow: none;
    border: 1px dotted rgba(0, 0, 0, .5);
    overflow: hidden;
    z-index: 10;
    border-radius: 10px;
    margin: 0 0.5% 6px;
    font-size: .7rem;
    display: inline-block;
    text-decoration: none;
    text-align: center;
    font-weight: bold;
}

a:hover {
    color: #fff!important;
    transform: translateY(-.125rem);
}