:root {
  --background-color : #0f4f75;
  --background-color-light : #3282b8;
  --blue-component : #4fc6d1;
  --yellow-title : #dce120;
  --dark-bg : #1c1c1c;
}

* {
  margin: 0;
  padding: 0;
}

header {
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: var(--background-color-light);
  background-image: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)), url("../img/equipe_hydro2024.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  margin-bottom: 4rem;
  background-attachment: fixed;

  /* https://developer.mozilla.org/fr/docs/Web/CSS/CSS_transitions/Using_CSS_transitions */
  transition: 
    opacity 0.1s easy-in-out,;
    /* background-image 1s linear; */
    /* background 0.5s lienar; */
}

#header_proj{
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: var(--background-color-light);
  background-image: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url("../img/ZephyrMontain3.png");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  margin-bottom: 4rem;
  background-attachment: fixed;

  /* https://developer.mozilla.org/fr/docs/Web/CSS/CSS_transitions/Using_CSS_transitions */
  transition: 
    opacity 0.1s easy-in-out,;
}

.fondu{
  background-color: var(--background-color-light);
}

nav {
  z-index: 1;
  position: fixed;
  background: #000;
  height: 60px;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 50px;
  box-sizing: border-box;
  border-bottom: 2px solid #4fc6d1;
}

.logo_nav{
  height: 40px;
  width: 40px;
}

a {
  text-decoration: none;
  color: #fff;
}

footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-evenly;
  min-height: 15vh;
  background-color: var(--dark-bg);
  margin-top: 5rem;
}

footer ul {
  display: flex;
  justify-content: space-evenly;
  align-items: center;
  width : 60%;
}

footer li, nav li {
  list-style: none;
}

footer a{
  text-decoration: underline;
  color: #fff;
}

footer p {
  color: #fff;
}

@media screen and (max-width: 768px) {
  header li {
    font-size: 0.75rem;
  }
}