/* ============================================================
   ALIFY — header.css · global sticky header (every page)
   Transparent over hero → solid blurred near-black on scroll.
   ============================================================ */

.site-header {
  position: fixed;
  inset-inline: 0; top: 0;
  z-index: var(--z-header);
  border-bottom: 1px solid transparent;
  transition: background-color .4s ease, border-color .4s ease, backdrop-filter .4s, transform .5s cubic-bezier(.7, 0, .2, 1);
}

/* hides on scroll-down, returns on scroll-up (header.js) */
.site-header.is-hidden { transform: translateY(-102%); }

.site-header.is-scrolled {
  background: rgba(13, 13, 13, .82);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom-color: var(--line);
}

.site-header__inner {
  max-width: var(--container-w);
  margin-inline: auto;
  padding-inline: var(--gutter);
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

/* -- brand -- */
.brand {
  display: inline-flex; align-items: center; gap: .45rem;
  font-family: var(--ff-display);
  font-size: 1.5rem; font-weight: 600;
  letter-spacing: .02em;
  color: var(--off);
  text-decoration: none;
}
.brand__dot {
  width: .5rem; height: .5rem;
  background: var(--green);
  border-radius: 1px;
  transform: translateY(-1px);
  transition: transform .4s cubic-bezier(.34, 1.56, .64, 1);
}
.brand:hover .brand__dot { transform: translateY(-1px) rotate(45deg) scale(1.15); }

/* -- desktop nav -- */
.main-nav__list { display: flex; gap: 2.2rem; list-style: none; }

.nav__link {
  position: relative;
  display: inline-block;
  padding-block: .5rem;
  font-family: var(--ff-mono);
  font-size: .78rem; font-weight: 500;
  letter-spacing: .15em; text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
  transition: color .3s;
}
.nav__link::after {
  content: "";
  position: absolute; left: 0; bottom: 0;
  width: 100%; height: 1px;
  background: var(--green);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform .45s cubic-bezier(.7, 0, .2, 1);
}
.nav__link:hover, .nav__link:focus-visible { color: var(--off); }
.nav__link:hover::after, .nav__link:focus-visible::after,
.nav__link--active::after { transform: scaleX(1); transform-origin: left; }
.nav__link--active { color: var(--green); }

/* -- right cluster -- */
.header__right { display: flex; align-items: center; gap: 1rem; }

@media (max-width: 640px) { .header__cta { display: none; } }

/* -- burger -- */
.burger {
  width: 48px; height: 48px; flex: none;
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  border: 1px solid var(--line-2);
  border-radius: 50%;
  background: transparent;
  color: var(--off);
  transition: border-color .3s, background .3s;
}
.burger__line {
  display: block;
  width: 18px; height: 1.5px;
  background: currentColor;
  transition: transform .45s cubic-bezier(.7, 0, .2, 1), opacity .25s;
}
.burger:hover { border-color: var(--green); color: var(--green); }
.burger.is-active { color: var(--off); }
.burger.is-active .burger__line:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.burger.is-active .burger__line:nth-child(2) { opacity: 0; transform: scaleX(.4); }
.burger.is-active .burger__line:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* desktop nav hidden on tablets/phones — push menu takes over */
@media (max-width: 1023px) {
  .main-nav { display: none; }
}