/* ============ NAV ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(20, 18, 16, 0.82);
  backdrop-filter: saturate(140%) blur(14px);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 15px var(--section-px);
}
.nav__logo {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--text-head);
  white-space: nowrap;
}
.nav__logo-mark {
  display: inline-grid;
  place-items: center;
  width: 26px; height: 26px;
  border: 1px solid var(--copper);
  color: var(--copper);
  border-radius: 5px;
  font-weight: 700;
  font-size: 14px;
}
.nav__logo-sep { color: var(--text-muted-2); }
.nav__logo-sub { color: var(--copper); }

.nav__menu {
  display: flex;
  align-items: center;
  gap: 26px;
}
.nav__link {
  font-size: 14px;
  color: var(--text-2);
  transition: color .15s ease;
}
.nav__link:hover { color: var(--text-head); }
.nav__link--back { color: var(--text-muted); font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.04em; }
.nav__cta { margin-left: 4px; padding: 11px 18px; }

/* Hamburger */
.nav__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 42px; height: 42px;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border-2);
  border-radius: var(--r-btn);
  cursor: pointer;
}
.nav__burger span {
  display: block;
  width: 18px; height: 2px;
  background: var(--text);
  transition: transform .2s ease, opacity .2s ease;
}
.nav[data-open="true"] .nav__burger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav[data-open="true"] .nav__burger span:nth-child(2) { opacity: 0; }
.nav[data-open="true"] .nav__burger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 860px) {
  .nav__inner { padding: 13px var(--section-px-tablet); }
  .nav__burger { display: flex; }
  .nav__menu {
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: rgba(16, 14, 12, 0.98);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
    padding: 8px var(--section-px-tablet) 18px;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    pointer-events: none;
    transition: max-height .25s ease, opacity .2s ease;
  }
  .nav[data-open="true"] .nav__menu {
    max-height: 80vh;
    opacity: 1;
    pointer-events: auto;
  }
  .nav__link { padding: 13px 2px; border-bottom: 1px solid var(--border); font-size: 16px; }
  .nav__link--back { border-bottom: none; }
  .nav__cta { margin-top: 14px; justify-content: center; }
}