* {
    margin: 0;
    padding: 0;
}

html {
    background: url("https://wuus.fr/img/fond3.jpg") no-repeat center / cover;
    background-attachment: fixed;
    height: 100%;
    width: 100%;
}

body {
    background: rgba(0, 0, 0, 0.7);
    font-family: Arial, Helvetica, sans-serif;
    font-size: 1em;
    color: whitesmoke;
    width: 100%;
}

a {
    color: navajowhite;
    text-decoration: none;
}

li {
    list-style-type: none;
}

a:hover {
    color: #cccccc;
}

/*************************** Menu ******************************/
header {
    position: fixed;
    top: 0px;
    z-index: 4;
    width: 100%;
    text-align: center;
    padding: 10px;
}

.menu {
    font-size: 2em;
}

.menu a {
    color: black;
}

.menu a:hover {
    text-decoration: none;
    color: darkgray;
}

.menu li {
    display: inline;
    margin: 10px;
}

.menu li a {
    list-style-type: none;
    background-color: whitesmoke;
    ;
    padding: 5px;
}

/************************* Contenu ****************************/

.contenu {
    width: 1000px;
    margin: 0 auto;
    padding: 50px 15px 15px 15px;
}

/* bloc retractable */
.collapsible {
    cursor: pointer;
    width: 100%;
}

/*.active, .collapsible:hover {
    background-color: #555;
}*/

h4 span:hover {
    background-color: #555;
}

.content {
    padding: 0 18px;
    display: none;
    overflow: hidden;
}

/************************* SECTIONS ****************************/

#section1 {
    text-align: center;
}

#section1 figure {
    border: none;
    margin: auto;
    padding: 5px;
    max-width: 200px;
}

#section1 img {
    max-width: 200px;
}

/***************************************************************/

#section2 {
    text-align: center;
}

#section2 h3 {
    text-align: left;
}

.box {
    display: inline-grid;
    grid-template-columns: 1fr 1fr;
    grid-gap: 10px 2em;
    text-align: center;
}

.box :first-child {
    align-self: center;
}

#section2 figure {
    border: none;
    margin: auto;
    padding: 5px;
    max-width: 400px;
}

#section2 img {
    max-width: 400px;
}

figcaption {
    background-color: #222;
    font-style: italic;
    padding: 10px;
}

/************************************************************/

/*#section3 {}:*/

#bloctips {
    background-color: rgba(0, 0, 0, 0.7);
    padding: 15px;
}

#section3 li {
    list-style-type: circle;
    text-align: left;
}

#section3 p {
    /* texte align� � gauche*/
    text-align: left;
}

#section3 ul {
    /* mise en page liste */
    padding-left: 20px;
}

#section3 figure {
    border: none;
    margin: auto;
    padding: 5px;
    text-align: center;
}

#video {
    text-align: center;
}

#section3 iframe {
    /*width: 560px;
    height: 315px;*/
}

/************************************************************/

h1 {
    font-size: 3em;
}

h2 {
    font-size: 2em;
}

h3 {
    font-size: 1.5em;
    margin-top: 10px;
    margin-bottom: 10px;
}

h3 span {
    background-color: black;
    padding: 5px 30px 5px 5px;
}

h4 {
    font-size: 1.2em;
    margin-top: 10px;
    margin-bottom: 10px;
}

h4 span {
    background-color: #222;
    padding: 5px 10px 5px 5px;
}

h5 {
    font-size: 1.1em;
    margin-top: 10px;
    margin-bottom: 10px;
}

h5 span {
    background-color: #444;
    padding: 5px 10px 5px 5px;
}

/************************************* footer *********************/
footer {
    text-align: center;
    font-size: 0.8em;
    padding: 15px;
}

footer div a{
    margin-right: 15px;
}