*{
  margin: 0px;
  padding: 0px;
  box-sizing: border-box;
  text-decoration: none;
  list-style: none;
}

html {
  scroll-behavior: smooth;
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 100%;
  font-family: Arial, Helvetica, sans-serif;
}

header, footer {
  background-color:  rgb(228, 228, 228);
  position: sticky;
  width: 100%;
  padding-top: 5px;
  padding-bottom: 5px;
  border-right: solid thin black;
  border-left: solid thin black;
}
header {
  top: 0px;
  border-bottom: solid thin black;
  border-bottom-right-radius: 3px;
  border-bottom-left-radius: 3px;
}
footer {
  bottom: 0px;
  border-top: solid thin black;
  border-top-right-radius: 3px;
  border-top-left-radius: 3px;
}

main {
  flex-grow: 1;
}

h1 {
  padding: 10px;
  text-align: center;
}

h2 {
  margin: 20px 0 5px 10px;
}

p {
  margin: 0 20px;
  text-align: justify;
}

.indent {
  text-indent: 20px;
}

@media (max-width: 410px) {
  header, footer {
    font-size: smaller;
  }
    h1 {
    font-size: x-large;
  }
  h2 {
    margin: 20px 0 10px 30px;
    font-size: x-large;
  }
  p {
    margin: 0 5px;
  }
  .indent {
    text-indent: 10px;
  }
}

a:link, a:visited, a:hover {
  color: blue;
}
a:hover {
  text-decoration: underline;
}

.bloc {
  border: solid thin grey;
  border-radius: 10px;
  margin: 5px;
  padding: 5px;
}

.icons {
  display: flex;
  justify-content: space-evenly;
  flex-wrap: wrap;
}

.icon_ref {
  display: flex;
  flex-direction: column;
}

.icon_size {
  width : 50px;
  height : 50px;
}

.bloc_item {
  padding: 5px;
}

.center_txt {
  text-align: center;
}

.italic{
  font-style: italic;
}

.txt_size_small {
  font-size: small;
}

.nomarg_txt {
  margin: 0;
}

.center_img {
  text-align: center;
}

.images {
  display: flex;
  flex-direction: column;
}

.img_ref {
  display: flex;
  flex-direction: column;
}

.img_size {
  width: 100%;
}