/* --- Header --- */
.header {
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 100;
  transition: background 0.4s ease;
  border-bottom: 1px solid transparent;
}

.header.scrolled {
  background: rgba(8, 10, 15, 0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

/* Make logo/button stay above overlay */
.logo {
  font-family: var(--font-serif-en);
  font-size: 1.2rem;
  letter-spacing: 0.1em;
  color: #fff;
  z-index: 101;
  font-weight: 600;
  text-transform: uppercase;
}

/* PC Menu */
.nav-menu {
  display: flex;
  gap: 40px;
}

.nav-link {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0;
  height: 1px;
  background: #fff;
  transition: width 0.3s ease;
}

.nav-link:hover { color: #fff; }
.nav-link:hover::after,
.nav-link.active::after { width: 100%; }
.nav-link.active { color: #fff; }

/* --- Buttons --- */
.btn {
  display: inline-block;
  padding: 14px 40px;
  border: 1px solid var(--border-color);
  background: transparent;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: all 0.4s ease;
  text-align: center;
  text-transform: uppercase;
}

.btn:hover { background: #fff; color: #000; border-color: #fff; }

.btn-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #fff;
  border-bottom: 1px solid rgba(255,255,255,0.3);
  padding-bottom: 4px;
  transition: border-color 0.3s ease;
  font-size: 0.9rem;
}

.btn-link:hover { border-color: #fff; }

/* --- Mobile Menu --- */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  cursor: pointer;
  z-index: 101;
  font-family: var(--font-serif-en);
  font-size: 0.9rem;
  letter-spacing: 0.1em;
  padding: 10px 12px; /* tap area */
}

/* Optional: lock scroll when menu is open (needs JS to add class on body) */
body.nav-open {
  overflow: hidden;
  touch-action: none;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  /* Slightly shorter header on mobile */
  :root { --header-height: 72px; }

  .menu-toggle { display: block; }

  /* Fullscreen overlay */
  .nav-menu {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;

    background: rgba(8, 10, 15, 0.96);
    backdrop-filter: blur(14px);

    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 28px;

    opacity: 0;
    pointer-events: none;
    transition: opacity 0.35s ease;
    z-index: 100;
  }

  .nav-menu.open {
    opacity: 1;
    pointer-events: all;
  }

  .nav-link {
    font-size: 1.35rem;
    font-family: var(--font-serif-en);
    letter-spacing: 0.08em;
  }

  /* remove tiny underline animation weirdness on big font */
  .nav-link::after { bottom: -8px; }
}

@media (max-width: 420px) {
  :root { --header-height: 68px; }

  .logo { font-size: 1.05rem; }
  .nav-link { font-size: 1.2rem; }
}