/* ============================================
   nav.css — Header, navigation, hover underline
   ============================================ */

/* --- Site Header --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.site-header.scrolled {
  background: rgba(10, 10, 15, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--border);
  border-bottom: 1px solid var(--border);
}

/* --- Nav Container --- */
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}

/* --- Logo --- */
.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 1001;
  text-decoration: none;
  color: var(--text-primary);
}

.nav__logo img {
  border-radius: 10px;
}

.nav__logo-text {
  font-size: 1.2rem;
  font-weight: 700;
}

/* --- Menu (mobile-first: hidden) --- */
.nav__menu {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  position: absolute;
  top: 72px;
  left: 0;
  right: 0;
  background: rgba(10, 10, 15, 0.96);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 32px 20px;
  border-bottom: 1px solid var(--border);
}

.nav__menu.open {
  display: flex;
}

/* --- Nav Links with underline animation --- */
.nav__link {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.2s ease;
  position: relative;
}

.nav__link::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 50%;
  right: 50%;
  height: 2px;
  background: var(--gradient);
  border-radius: 1px;
  transition: left 0.3s ease, right 0.3s ease;
}

.nav__link:hover {
  color: var(--text-primary);
}

.nav__link:hover::after {
  left: 0;
  right: 0;
}

/* --- Hamburger --- */
.nav__hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 1001;
  padding: 0;
}

.nav__hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* --- Hamburger X animation --- */
.nav__hamburger[aria-expanded="true"] .nav__hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav__hamburger[aria-expanded="true"] .nav__hamburger-line:nth-child(2) {
  opacity: 0;
}

.nav__hamburger[aria-expanded="true"] .nav__hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- Desktop (1024px+) --- */
@media (min-width: 1024px) {
  .nav__hamburger {
    display: none;
  }

  .nav__menu {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 32px;
    position: static;
    background: none;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    padding: 0;
    border-bottom: none;
  }
}