/* ==========================================================================
   layout.css — header, overlay navigation, footer
   ========================================================================== */

/* --- Header -------------------------------------------------------------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 130;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: clamp(1.1rem, 2.4vw, 1.9rem) var(--pad-x);
  border-bottom: 1px solid transparent;
  mix-blend-mode: difference;
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease),
    padding 0.4s var(--ease);
}

/* Once past the hero the bar gets its own ground so oversized section titles
   never read through it. */
.site-header.is-scrolled {
  padding-block: clamp(0.8rem, 1.7vw, 1.15rem);
  background: rgba(11, 11, 12, 0.74);
  border-bottom-color: var(--line-soft);
  backdrop-filter: blur(14px) saturate(140%);
  mix-blend-mode: normal;
}

/* With the overlay open the bar must not sit on its own frosted slab. */
body.is-locked .site-header {
  background: transparent;
  border-bottom-color: transparent;
  backdrop-filter: none;
  mix-blend-mode: normal;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.08em;
}

.brand__dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2.6s var(--ease) infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.35; transform: scale(0.75); }
}

.menu-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.35rem 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.menu-toggle__bars {
  display: grid;
  gap: 4px;
  width: 22px;
}

.menu-toggle__bars i {
  display: block;
  height: 1px;
  background: currentColor;
  transition: transform 0.4s var(--ease);
}

.menu-toggle[aria-expanded="true"] .menu-toggle__bars i:first-child {
  transform: translateY(2.5px) rotate(9deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle__bars i:last-child {
  transform: translateY(-2.5px) rotate(-9deg);
}

/* --- Overlay menu -------------------------------------------------------- */
.overlay-menu {
  position: fixed;
  inset: 0;
  z-index: 125;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: clamp(2rem, 6vh, 4rem);
  padding: 7rem var(--pad-x) 3rem;
  background: rgba(11, 11, 12, 0.94);
  backdrop-filter: blur(18px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.45s var(--ease), visibility 0.45s;
}

.overlay-menu[hidden] {
  display: none;
}

.overlay-menu.is-open {
  opacity: 1;
  visibility: visible;
}

.overlay-menu__list a {
  display: flex;
  align-items: baseline;
  gap: clamp(0.8rem, 2vw, 2rem);
  padding: clamp(0.45rem, 1.3vh, 0.9rem) 0;
  font-size: clamp(2rem, 6.5vw, 4.6rem);
  line-height: 1.05;
  letter-spacing: -0.035em;
  color: var(--ink-dim);
  border-bottom: 1px solid var(--line-soft);
  transition: color 0.35s var(--ease), padding-left 0.35s var(--ease);
}

.overlay-menu__list a:hover,
.overlay-menu__list a:focus-visible {
  color: var(--ink);
  padding-left: 0.6rem;
}

.overlay-menu__list .num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.overlay-menu__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2.5rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--ink-faint);
}

.overlay-menu__meta p {
  margin: 0;
}

.overlay-menu__meta a {
  border-bottom: 1px solid var(--line);
  padding-bottom: 2px;
}

.overlay-menu__meta a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* --- Footer -------------------------------------------------------------- */
.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.85rem 2rem;
  padding: 2.25rem var(--pad-x) 2.75rem;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

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

@media (max-width: 640px) {
  .site-header {
    mix-blend-mode: normal;
  }
}