#topmenu{
    width: 100%;
    height: 40px;
    position: fixed;
    box-shadow: 0 0 10px 0.1px #144552;
    z-index: 1000;
    background: #e2ece9;
}
.topmenu{
    width: 1170px;
    height: 100%;
    margin: 0 auto;
}
.topmenu>ul{
    width: 100%;
}
.topmenu>ul>li{
    float: right;
}
.topmenu>ul>li>a{
    line-height: 40px;
    color: #144552;
    font-size: 18px;
    margin-left: 30px;
}
.topmenu>ul>li>a:hover{
    color: #8bbbb9;
}
.search{
    float: left;
    line-height: 40px;
}
.search>form>input{
    border: 1px solid #8bbbb9;
    border-radius: 4px;
    padding: 2px 5px;
    font-family: far;
    font-size: 14px;
    width: 200px;
}
.search>form>input:focus{
    outline: none;
}
/****************banner*****************/
#banner{
    width: 100%;
    height: 120px;
    position: relative;
    background: red;
    top: 40px;
    background: url('../img/banner.jpg') repeat-x 0 40px fixed;
    opacity: 70%;
    display: flex;
    flex-flow: row;
    justify-content: center;
}
.banner{
    max-width: max-content;
    line-height: 120px;
    position: fixed;
}
.banner>.title{
    margin: 0 auto;
    
}
.banner>.title>a{
    color: #f1fffa;
    text-align: center;
    font-size: 34px;
    
}
.logo{
    width: 120px;
    height: 120px;
    position: absolute;
    top: 0;
    left: 0;
    background: url('../img/logonomymath3.png') no-repeat 0 40px fixed;
    opacity: 40%;
}
.logo:hover{
    opacity: 70%;
}