/* ==========================================================================
   FIT BY SCIENCE - NAVIGATION
   ========================================================================== */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding-block: var(--space-4);
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color var(--duration-base) var(--ease-standard),
              border-color var(--duration-base) var(--ease-standard),
              padding-block var(--duration-base) var(--ease-standard),
              backdrop-filter var(--duration-base) var(--ease-standard);
}

.nav.is-scrolled {
  background: rgba(11, 13, 15, 0.85);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom-color: rgba(167, 168, 165, 0.15);
  padding-block: var(--space-3);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.nav__wordmark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--bone);
}

.nav__links {
  display: none;
  align-items: center;
  gap: var(--space-8);
}

.nav__links a {
  font-size: var(--text-body-sm);
  font-weight: 500;
  color: var(--stone);
  transition: color var(--duration-fast) var(--ease-standard);
  position: relative;
}

.nav__links a:hover {
  color: var(--bone);
}

.nav__links a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 1px;
  background: var(--bone);
  transition: width var(--duration-fast) var(--ease-standard);
}

.nav__links a:hover::after {
  width: 100%;
}

.nav__cta {
  display: none;
}

.nav__menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: transparent;
  border: none;
  padding: var(--space-1);
  z-index: 110;
}

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

@media (min-width: 1024px) {
  .nav__links { display: flex; }
  .nav__cta { display: inline-flex; }
  .nav__menu-toggle { display: none; }
}

/* ---- Mobile menu overlay ---- */
.nav__mobile-panel {
  position: fixed;
  inset: 0;
  background: var(--obsidian);
  z-index: 105;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  gap: var(--space-6);
  padding: var(--space-8) var(--container-pad-mobile);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--duration-base) var(--ease-standard),
              visibility var(--duration-base) var(--ease-standard);
}

.nav__mobile-panel.is-open {
  opacity: 1;
  visibility: visible;
}

.nav__mobile-panel a {
  font-family: var(--font-display);
  font-size: var(--text-display-sm);
  font-weight: 700;
  color: var(--bone);
}

.nav__mobile-panel .btn {
  margin-top: var(--space-4);
}

@media (min-width: 1024px) {
  .nav__mobile-panel { display: none; }
}

body.nav-open {
  overflow: hidden;
}