div断行防止内容在一行上超出div宽度

overflow:hidden;
word-break: break-all;
word-wrap:break-word;

清除浮动

.clearfix:after {
content:"";
display: block;
clear:both;
}

table border

    table {
         border-collapse: collapse;
    }

    th {
        background-color: #a7c942;
        margin:10px;
        padding: 10px;
    }

    table,tr,td,th {
       border: 1px solid #a7c942
       padding:10px 30px 10px 10px;

    }