html {
  scroll-behavior: smooth;
}

/* -----------------------------------
   DESKTOP NAV BAR
----------------------------------- */
.top-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 48px;
  background: rgba(11,18,32,0.85);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  z-index: 9998;
}

:root.light .top-nav {
  background: rgba(244,247,251,0.85);
}

/* Desktop: nav-links sit centered on top of the nav bar */
.nav-links {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 48px;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 24px;
  z-index: 9999;
}

.nav-controls {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  gap: 8px;
  align-items: center;
}

/* Override fixed positioning when buttons live inside nav-links */
.nav-controls #theme-toggle,
.nav-controls #lang-toggle {
  position: static;
  top: auto;
  right: auto;
  transform: none;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.25s ease;
}

.nav-links a:hover {
  color: var(--accent);
}

.nav-links a.active {
  color: var(--accent);
}

.nav-links a::after {
  display: none;
}

/* -----------------------------------
   HAMBURGER BUTTON (hidden on desktop)
----------------------------------- */
.hamburger {
  display: none;
  position: fixed;
  top: 16px;
  left: 16px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(11,18,32,0.7);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,0.1);
  cursor: pointer;
  z-index: 10001;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 15px rgba(0,0,0,0.3);
  transition: background 0.25s ease, border-color 0.25s ease;
}

:root.light .hamburger {
  background: rgba(244,247,251,0.7);
  border: 1px solid rgba(0,0,0,0.08);
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.hamburger:hover {
  border-color: var(--accent);
}

.hamburger span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger span + span {
  margin-top: 4px;
}

/* Animate to X when open */
.hamburger.open span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.hamburger.open span:nth-child(2) {
  opacity: 0;
}
.hamburger.open span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* -----------------------------------
   MOBILE MENU
----------------------------------- */
@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }

  /* Hide desktop nav bar background */
  .top-nav {
    display: none;
  }

  /* Slide-down glassy panel */
  .nav-links {
    position: fixed;
    top: 16px;
    left: 16px;
    width: 220px;
    height: auto;
    flex-direction: column;
    justify-content: flex-start;
    gap: 0;
    padding: 60px 0 16px;
    border-radius: 16px;

    /* Glassy premium effect */
    background: rgba(11,18,32,0.55);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    backdrop-filter: blur(24px) saturate(180%);
    border: 1px solid rgba(255,255,255,0.1);
    box-shadow: 0 16px 48px rgba(0,0,0,0.4);

    /* Hidden by default */
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px) scale(0.95);
    transform-origin: top left;
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
    z-index: 10000;
  }

  :root.light .nav-links {
    background: rgba(244,247,251,0.55);
    border: 1px solid rgba(0,0,0,0.08);
    box-shadow: 0 16px 48px rgba(0,0,0,0.15);
  }

  .nav-links.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
  }

  .nav-links a {
    font-size: 1.1rem;
    padding: 12px 24px;
    text-align: left;
    width: 100%;
    border-bottom: 1px solid rgba(255,255,255,0.05);
  }

  :root.light .nav-links a {
    border-bottom: 1px solid rgba(0,0,0,0.04);
  }

  .nav-links a:last-of-type {
    border-bottom: none;
  }

  /* Controls at bottom of mobile panel */
  .nav-controls {
    position: static;
    transform: none;
    justify-content: flex-start;
    padding: 12px 24px 0;
    gap: 10px;
    border-top: 1px solid rgba(255,255,255,0.08);
    margin-top: 4px;
  }

  :root.light .nav-controls {
    border-top: 1px solid rgba(0,0,0,0.06);
  }
}

/* -----------------------------------
   SCROLL TO TOP BUTTON
----------------------------------- */
#scrollTopBtn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--accent);
  color: var(--bg);
  padding: 12px 14px;
  border-radius: 50%;
  font-size: 1.4rem;
  cursor: pointer;
  display: none;
  box-shadow: 0 8px 20px rgba(0,0,0,0.3);
  transition: opacity 0.3s ease;
}