.main_menu {
    text-align:         left;
    width:              100%;
    z-index:            15;
    margin-bottom:      50px;     
    font-size:          14px;    
    background: #efefef;     
    background: linear-gradient(top, #efefef 0%, #bbbbbb 100%);  
    background: -moz-linear-gradient(top, #efefef 0%, #bbbbbb 100%); 
    background: -webkit-linear-gradient(top, #efefef 0%,#bbbbbb 100%); 
    box-shadow: 0px 0px 9px rgba(0,0,0,0.15);    
}   

nav {
    font-size:  15px;
    font-family: serif;
    font-weight: bold;
    z-index:    15;    
}

nav ul ul {
    display: none;    
}

nav ul li:hover > ul {
    display: block;
    z-index:    15;
}

nav ul {
    padding: 0 10px;
    border-radius: 5px;  
    list-style: none;
    position: relative;
    display: inline-table;    
    box-shadow: 0px 0px 9px rgba(0,0,0,0.05); 
}

nav ul:after {
    content: ""; 
    clear: both; 
    display: block;    
}

nav ul li {
    float: left;  
    text-align: left;
    white-space: nowrap;       
}
nav ul li:hover {    
    background: #4b545f;
    background: linear-gradient(top, #4f5964 0%, #5f6975 40%);
    background: -moz-linear-gradient(top, #4f5964 0%, #5f6975 40%);
    background: -webkit-linear-gradient(top, #4f5964 0%,#5f6975 40%);    
}

nav ul li:hover a {
    color: #fff;    
}
		
nav ul li a {
    display: block; 
    padding: 5px 50px;
    color: #757575; 
    text-decoration: none;    
    min-height: 24px;
}
		
nav ul ul {
    background: #5f6975; 
    border-radius: 0px; 
    padding: 0;
    position: absolute; 
    top: 100%;    
}

nav ul ul li {
    float: none; 
    border-top: 1px solid #6b727c;
    border-bottom: 1px solid #575f6a; 
    position: relative;    
}

nav ul ul li a {
    padding: 0px 40px;
    color: #fff;    
}	

nav ul ul li a:hover {
    background: #4b545f;    
}
		
nav ul ul ul {
    position: absolute; 
    left: 100%; top:0;    
}

/* IE only hack \*/
* html ul li, * html ul ul li{
border-bottom: 3px solid #FFF;
}

* html ul ul li{
border-top: 0;
}
/* End IE only hack */ 


@media (prefers-color-scheme: dark) {
    .main_menu {
        text-align:         left;
        width:              100%;
        z-index:            15;
        margin-bottom:      50px;     
        font-size:          14px;    
        background: black;     
        background: linear-gradient(top, black 0%, #aaaaaa 100%);  
        background: -moz-linear-gradient(top, black 0%, #aaaaaa 100%); 
        background: -webkit-linear-gradient(top, black 0%,#aaaaaa 100%); 
        box-shadow: 0px 0px 9px rgba(0,0,0,0.15);        
    }  
    
    nav ul li a {
        display: block; 
        padding: 5px 50px;
        color: #ff9900; 
        text-decoration: none;    
        min-height: 24px;
    }
}