.sp_menu_area {
    position:fixed;
    width:100%;
    height:60px;
    top:0;
    left:0;
    background:#FFF;
    border-bottom:1px solid gray;
    z-index:100;
}

.sp_menu_area_nofixed {
    position:relative;
    width:100%;
    height:60px;
    top:0;
    left:0;
    background:#FFF;
    z-index:100;
}

.sp_menu_area_nofixed+.spanning header{
    margin-top: 0;
    padding-top: 30px;
}

.sp_menu_area_nofixed+.spanning header h1{
    margin-top: 0;
}

.spmenu_btn {
    display:block;
    position:absolute;
    top:14px;
    right:15px;
    width:30px;
    height:22px;
    background:#000;
    border-top:10px solid #fff;
    border-bottom:10px solid #fff;
    -moz-box-sizing:border-box;
    -webkit-box-sizing:border-box;
    box-sizing:border-box;
    -moz-transition:all 0.3s;
    -webkit-transition:all 0.3s;
    transition:all 0.3s;
}
.spmenu_btn:before {
    content:'';
    position:absolute;
    width:30px;
    height:2px;
    background:#000;
    top:-9px;
    right:0;
    -moz-transition:all 0.3s;
    -webkit-transition:all 0.3s;
    transition:all 0.3s;
}
.spmenu_btn:after {
    content:'';
    position:absolute;
    width:30px;
    height:2px;
    background:#000;
    bottom:-9px;
    right:0;
    -moz-transition:all 0.3s;
    -webkit-transition:all 0.3s;
    transition:all 0.3s;
}
.spmenu_btn.active {
    background:#FFF;
}
.spmenu_btn.active:before {
    -moz-transform:rotate(-135deg);
    -webkit-transform:rotate(-135deg);
    transform:rotate(-135deg);
    top:0;
    right:0;
}
.spmenu_btn.active:after {
    -moz-transform:rotate(135deg);
    -webkit-transform:rotate(135deg);
    transform:rotate(135deg);
    bottom:0;
    right:0;
}
 
.spmenu {
    display:none;
    position:absolute;
    top:60px;
    left:0;
    width:100%;
    background:#042A4C;
    z-index: 9999;
}
nav {
    display:block;
    width:100%;
    margin:0 auto;
}
nav li a {
    display:block;
    width:100%;
    color:#FFF;
    padding:10px;
    -webkit-box-sizing:border-box;
    box-sizing:border-box;
    position:relative;
    border-bottom:1px solid #999;
    text-decoration: none;
    padding-left: 35px;
}

@media only screen and (max-height: 502px) {
    nav{
        height: 100vh;
        overflow: scroll;
    }
  }