/* ========================================================================
   Navigation
   ======================================================================== */
#main-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px var(--container-pad);
  background: transparent;
  transition:
    background var(--dur-base) var(--ease-out),
    backdrop-filter var(--dur-base) var(--ease-out),
    padding var(--dur-base) var(--ease-out),
    border-color var(--dur-base) var(--ease-out);
  border-bottom: 1px solid transparent;
}

#main-nav.scrolled {
  background: rgba(13, 13, 13, 0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 14px var(--container-pad);
  border-bottom-color: var(--color-border);
}

/* Logo */
#main-nav .logo {
  display: inline-flex;
  align-items: center;
  z-index: 2;
}
#main-nav .logo img {
  height: 44px;
  width: auto;
  filter: invert(1);
  transition: transform var(--dur-fast) var(--ease-out), height var(--dur-base) var(--ease-out);
}
#main-nav.scrolled .logo img { height: 36px; }
#main-nav .logo:hover img { transform: scale(1.04); }

/* Nav links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-links a {
  position: relative;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.5px;
  color: var(--color-text-white);
  padding: 6px 2px;
}
.nav-links a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 1px;
  background: var(--color-accent);
  transition: width var(--dur-fast) var(--ease-out);
}
.nav-links a:hover::after,
.nav-links a.active::after { width: 100%; }
.nav-links a.active { color: var(--color-accent); }

/* Right side */
.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
  z-index: 2;
}

#lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--color-text-white);
  padding: 8px 14px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  transition: border-color var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}
#lang-toggle:hover { border-color: rgba(255,255,255,0.4); }
#lang-toggle .lang-opt { opacity: 0.5; transition: opacity var(--dur-fast) var(--ease-out); }
#lang-toggle .lang-sep { opacity: 0.35; }
body[data-lang="ko"] #lang-toggle .lang-opt[data-val="ko"],
body[data-lang="en"] #lang-toggle .lang-opt[data-val="en"] { opacity: 1; color: var(--color-accent); }

/* Hamburger */
.hamburger {
  display: none;
  width: 40px;
  height: 40px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  z-index: 2;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-white);
  transition: transform var(--dur-fast) var(--ease-out), opacity var(--dur-fast) var(--ease-out);
}
body.nav-open .hamburger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
body.nav-open .hamburger span:nth-child(2) { opacity: 0; }
body.nav-open .hamburger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile */
@media (max-width: 1024px) {
  .nav-links {
    position: fixed;
    inset: 0;
    left: 0;
    top: 0;
    width: 100%;
    height: 100vh;
    flex-direction: column;
    justify-content: center;
    gap: 24px;
    background: rgba(13, 13, 13, 0.97);
    backdrop-filter: blur(20px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--dur-base) var(--ease-out);
  }
  .nav-links a { font-size: 28px; font-weight: 700; }
  body.nav-open .nav-links { opacity: 1; pointer-events: auto; }
  .hamburger { display: inline-flex; }
  #lang-toggle { padding: 6px 10px; font-size: 11px; }
}