nouveau-theatre-de-besancon/assets/css/src/nav.css

.main-header {
  position: sticky;
  top: 0;
  background-color: #fff;
  z-index: 2;
}
/* Nav */

/* Expanded nav */

.expanded-nav {
  position: fixed;
  width: 100%;
  box-sizing: border-box;
  top: -32rem;
  z-index: 2;
  background-color: var(--color-brown-light);
  display: grid;
  grid-template-columns: 2fr 8fr 1fr;
  transition: top 0.4s var(--curve-quick-slow);
  padding: 2rem var(--space-m) 2rem 1rem;
  border-bottom: var(--border);
}
.expanded-nav.open {
  top: 0rem;
}

.expanded-nav__logo-link {
  height: fit-content;
}

.expanded-nav__columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  row-gap: 6rem;
}

.expanded-nav .close-btn {
  position: relative;
  width: 1.5rem;
  height: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  justify-self: end;
}

.expanded-nav .close-btn__line,
.expanded-nav .close-btn__line::before {
  content: "";
  width: 100%;
  height: 3px;
  background-color: #000;
  position: absolute;
}

.expanded-nav .close-btn__line {
  transform: rotate(-45deg);
}
.expanded-nav .close-btn__line::before {
  transform: rotate(90deg);
}

.expanded-nav__category {
  margin-bottom: 1rem;
}
.expanded-nav__subcategory {
  font-size: var(--font-size-s);
}

/* Header */

.main-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: var(--border);
  padding: 1rem;
  padding-right: var(--space-m);
}

.main-nav__right {
  display: flex;
  align-items: center;
}

.main-nav__featured-pages {
  display: flex;
}

.main-nav__right > *:not(:last-child),
.main-nav__featured-pages li:not(:last-child) {
  margin-right: 2.69rem;
}

.main-nav .burger-btn {
  position: relative;
  width: 1.5rem;
  height: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.main-nav .burger-btn__line,
.main-nav .burger-btn__line::before,
.main-nav .burger-btn__line::after {
  content: "";
  width: 100%;
  height: 3px;
  background-color: #000;
  position: absolute;
}

.main-nav .burger-btn__line::before {
  transform: translateY(-0.5rem);
}

.main-nav .burger-btn__line::after {
  transform: translateY(0.5rem);
}

/* Main nav small */

.main-nav--small .logo__detail {
  opacity: 0;
  pointer-events: none;
}

.main-nav--small .logo > *:not(:first-child) {
  margin-left: 1.4ch;
}