.site-header {
  position: fixed;
  z-index: 100;
  top: var(--header-top);
  right: var(--header-inset);
  left: var(--header-inset);
  height: var(--header-height);
  padding: 0 var(--header-padding-x);
  background: var(--surface);
  border-radius: var(--header-radius);
  box-shadow: var(--shadow-header);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: 24px;
}

/*
The CTA appears in the markup only once — inside .site-header__nav — so that on mobile it
lands inside the dropdown panel. On desktop the container dissolves, and the menu and the
button become direct children of the header flex row.
*/
.site-header__nav {
  display: contents;
}

/* 188px is the logo container width from the design; space-between is measured from it. */
.site-header__logo {
  display: block;
  flex: 0 0 188px;
}

.site-header__logo img,
.site-header__logo svg {
  display: block;
  width: var(--logo-width);
  height: auto;
}

@media (max-width: 900px) {
  .site-header__logo {
    flex: 0 0 auto;
  }
}

.site-nav__list {
  display: flex;
  gap: var(--nav-gap);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav__list a {
  position: relative;
  display: inline-block;
  font-size: var(--fs-nav);
  font-weight: 500;
  letter-spacing: var(--ls-nav);
  line-height: var(--lh-tight);
  white-space: nowrap;
}

/*
The design defines no hover states — this is a minimal colour highlight.
Anything more pronounced has to come from the designer rather than be invented here.
*/
.site-nav__list a {
  transition: color var(--dur) var(--ease);
}

.site-nav__list a:hover {
  color: var(--accent);
}

.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: var(--cta-height);
  padding: 0 var(--cta-padding-x);
  background: var(--ink);
  color: var(--surface);
  border-radius: var(--radius-pill);
  font-size: var(--fs-cta);
  font-weight: 500;
  letter-spacing: var(--ls-cta);
  line-height: var(--lh-tight);
  text-transform: uppercase;
  white-space: nowrap;
  transition:
    background-color var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.btn-cta:hover {
  background: var(--ink-hover);
  transform: translateY(-1px);
}

/*
The burger is two 52px bars with 8px between their centres. Vertical padding grows the tap
target to 43px without moving the bars: horizontal padding is zero, so the right edge of the
button lines up with the right edge of the bars.
*/
.site-header__burger {
  display: none;
  flex: 0 0 auto;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--burger-gap);
  width: var(--burger-width);
  padding: var(--burger-hit-y) 0;
}

.site-header__burger span {
  display: block;
  width: 100%;
  height: var(--burger-bar);
  background: var(--burger-ink);
  border-radius: var(--radius-pill);
  transition: transform var(--dur) var(--ease);
}

.site-header.is-menu-open .site-header__burger span:first-child {
  transform: translateY(calc((var(--burger-bar) + var(--burger-gap)) / 2)) rotate(45deg);
}

.site-header.is-menu-open .site-header__burger span:last-child {
  transform: translateY(calc((var(--burger-bar) + var(--burger-gap)) / -2)) rotate(-45deg);
}

@media (max-width: 900px) {
  .site-header__burger {
    display: flex;
  }

  .site-header__nav {
    display: block;
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    left: 0;
    padding: 20px;
    background: var(--surface);
    border-radius: var(--header-radius);
    box-shadow: var(--shadow-panel);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition:
      opacity var(--dur) var(--ease),
      transform var(--dur) var(--ease),
      visibility var(--dur);
  }

  .site-header.is-menu-open .site-header__nav {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .site-nav__list {
    flex-direction: column;
    gap: 18px;
  }

  .site-header__nav .btn-cta {
    display: flex;
    width: 100%;
    margin-top: 20px;
  }
}