/* ============================================================
   NAV — sticky header with frosted glass
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  /* Fallback for browsers without color-mix */
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  position: relative;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Logo: name + tagline */
.nav-logo {
  display: flex;
  align-items: baseline;
  gap: 14px;
  text-decoration: none;
}

.nav-logo__name {
  font: 500 21px var(--font-serif);
  letter-spacing: -.01em;
  color: var(--ink);
  line-height: 1;
  transition: color var(--duration) var(--ease);
}

.nav-logo:hover .nav-logo__name {
  color: var(--accent);
}

.nav-logo__tagline {
  font: 500 10px var(--font-mono);
  letter-spacing: .14em;
  color: var(--sub);
}

/* Nav links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  list-style: none;
}

.nav-link {
  font: 500 11px var(--font-mono);
  letter-spacing: .08em;
  color: var(--sub);
  text-decoration: none;
  transition: color var(--duration) var(--ease);
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--ink);
}

.nav-link.is-active {
  border-bottom: 1.5px solid var(--accent);
  padding-bottom: 2px;
}

/* Contact CTA in nav */
.nav-cta {
  font: 600 11px var(--font-grotesk);
  letter-spacing: .02em;
  color: var(--ink);
  border: 1.5px solid var(--ink);
  padding: 8px 15px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: background var(--duration) var(--ease),
              color var(--duration) var(--ease);
}

.nav-cta:hover {
  background: var(--ink);
  color: var(--paper);
}

/* Mobile hamburger toggle: hidden on desktop */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--ink);
  transition: transform var(--duration) var(--ease),
              opacity var(--duration) var(--ease);
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

@media (max-width: 780px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--border);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--duration) var(--ease);
  }

  .nav-menu.is-open {
    max-height: 320px;
  }

  .nav-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 8px var(--pad-x) 20px;
  }

  .nav-links li {
    width: 100%;
  }

  .nav-link {
    display: block;
    padding: 14px 0;
    width: 100%;
  }

  .nav-link.is-active {
    border-bottom: none;
    color: var(--accent);
  }

  .nav-cta {
    display: inline-block;
    margin-top: 10px;
  }
}