/* ---------- responsive nav: burger icon + slide-out drawer ---------- */
.nav-burger {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  height: 28px;
  padding: 0 10px;
  background: transparent;
  border: 1px solid var(--syntax-border);
  color: var(--fontcolor);
  text-decoration: none;
  cursor: pointer;
}

.nav-burger:link,
.nav-burger:visited,
.nav-burger:hover {
  color: var(--fontcolor);
  text-decoration: none;
}

.nav-burger span {
  display: block;
  width: 22px;
  height: 2px;
  background: currentColor;
}

.nav-burger:hover {
  background: var(--syntax-border);
  color: var(--syntax-foreground);
}

.nav-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  z-index: 10001;
}

.nav-backdrop.open {
  opacity: 1;
  visibility: visible;
}

#nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  height: 100%;
  width: min(320px, 82vw);
  display: flex;
  flex-direction: column;
  background: var(--dimcolor);
  border-left: 1px solid var(--linecolor);
  transform: translateX(100%);
  transition: transform 0.3s ease;
  visibility: hidden;
  overflow-y: auto;
  z-index: 10002;
}

#nav-drawer.open {
  transform: none;
  visibility: visible;
}

.nav-drawer-head {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding: 14px 16px;
  border-bottom: 1px solid var(--linecolor);
}

.nav-drawer-title {
  font-weight: bold;
}

.nav-drawer-close {
  border: 1px solid var(--syntax-border);
  background: transparent;
  color: var(--fontcolor);
  font-size: 22px;
  line-height: 1;
  padding: 4px 10px;
}

.nav-drawer-close:hover {
  background: var(--syntax-border);
  color: #000;
}

.nav-drawer-menu {
  display: flex;
  flex-direction: column;
  padding: 12px;
  margin: 0;
}

.nav-drawer-menu .menu-special {
  display: block;
  margin: 4px 0;
  text-align: left;
}

@media all and (width <= 768px) {
  /* keep the first three nav buttons inline, tuck the rest behind the burger */
  .navbar .menu-special:nth-child(n+4) {
    display: none;
  }
  .nav-burger {
    display: flex;
    margin-left: auto;
  }

  /* smaller brand icon and scaled-down headings for small screens */
  #brand .icon {
    width: 50px;
    max-height: 50px;
  }
  #brand h1 {
    font-size: 24px;
  }
  #brand h3 {
    font-size: 16px;
  }
  h1 {
    font-size: 26px;
  }
  h2 {
    font-size: 21px;
  }
  h3 {
    font-size: 18px;
  }
  h4 {
    font-size: 16px;
  }
}

@media all and (width > 768px) {
  .nav-burger {
    display: none;
  }
  #nav-drawer,
  .nav-backdrop {
    display: none;
  }
}