style.css

@charset "utf-8";
/* CSS Document */

* {
	margin:0; padding:0;
	font-family: Gotham, "Helvetica Neue", Helvetica, Arial, "sans-serif";
}

#global { background-image: url("background.jpg"); width:device-width; position:absolute; }
#intro {background-color:white; opacity: 0.7; text-align: justify; padding-top: 20px; padding-bottom: 20px; padding-left: 70px; padding-right: 70px; font-size: large;}
h1, h2, #footer { height:50px; background-color:black; opacity: 0.7; color:white; text-align:center; padding-top: 20px;}
#footer a:link {color: white; text-decoration: none;}
#footer a:visited {color: white;text-decoration: none;}
#footer a:hover {color: rgb(150, 148, 148); text-decoration: none;}
a:visited {color: rgb(55, 55, 97);}
h3 {text-align: center; padding-top: 10px; padding-bottom: 10px;} 

#menugauche { float:left; width:110px; background-color: black; opacity: 0.7; color:white; padding:20px;}
#menudroit { padding:20px;float:right; width:110px; background-color: black; opacity: 0.7; color:white;}

#contenu {border-style: solid; height:500px; overflow:auto; padding:20px; margin:0 50px;  background-color: rgb(255, 255, 255, 0.7) ; text-align: justify;}
#contenu p { margin-bottom:20px; font-size: large;}
img {object-fit: contain; opacity:1; border-style:solid; border-color: black; border-width: 1px; margin-top: 10px; margin-bottom: 10px; max-width: 100%; height: auto; z-index:auto;}
/* got an issue with the image display: how to remove the transparency resulting from the opacity of the background (image and/or color?) 
- need to make background transparent for the space of #contenu through some other means than background opacity 
GOT IT! thanks to Philippe: the attribute "opacity" applies to the content; for the colour one must define it as the 4th property of RGB colour choice*/
article {border: groove 2px black; padding: 10px; border-radius: 5px; margin-bottom: 20px;}
/* iframe {width:100%; height:500px; outline:none; padding:none; margin: none;} */
#menudroit ul, #menugauche ul {list-style-type:none;}
#menudroit li, #menugauche {text-align: center; }
#menudroit li {padding: 10px;}
#menudroit li a, #menugauche li a {color:white; text-decoration: none;}
#menudroit li a:visited, #menugauche li a:visited { color:white; text-decoration: none;}
#menudroit li a:hover, #menugauche li a:hover { color:rgb(150, 148, 148); text-decoration: none;}
#menudroit h2, #menugauche h2 { font-size:17px;}


@media print {
	.noprint { display:none;}
	#contenu { height:auto; margin:0; }
#global {  width:auto; position:relative; top:0; left:0; margin:0;}
}