/* Sticky Header */
#header {
  position: sticky;
  top: 0;
  z-index: 1000;
}
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  background-color: rgba(0, 0, 0, 0.7);
  transition: background 0.3s ease;
}

/* Logo */
.nav .logo img,
.overlay-header .logo img {
  height: 50px;
  filter: brightness(0) invert(1);
}

/* Desktop Nav Links */
.nav-links {
  display: flex;
  gap: 2rem;
}
.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.2rem;
  position: relative;
  padding-bottom: 4px;
  transition: color 0.3s ease;
}


/* Hamburger Icon (Mobile only) */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 24px;
  height: 18px;
  cursor: pointer;
  z-index: 1001;
}
.hamburger span {
  display: block;
  height: 3px;
  width: 100%;
  background: white;
  border-radius: 2px;
  transition: all 0.3s ease;
  transform-origin: center;
}
.hamburger.open span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 4px);
}
.hamburger.open span:nth-child(2) {
  opacity: 0;
}
.hamburger.open span:nth-child(3) {
  transform: rotate(-45deg) translate(4px, -4px);
}

/* Overlay Menu (Mobile Nav) */
.overlay-menu {
  display: none;
  position: fixed;
  inset: 0;
  
  color: white;
  flex-direction: column;
  opacity: 0;
  transform: translateY(-100%);
  transition: transform 0.5s ease, opacity 0.5s ease;
  backdrop-filter: blur(12px);
  background: rgba(0, 0, 0, 0.85);
  z-index: 2000;
}
.overlay-menu.show {
  display: flex;
  opacity: 1;
  transform: translateY(0);
}

/* Overlay Header */
.overlay-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
}
.close-btn {
  background: none;
  border: none;
  font-size: 2.5rem;
  color: #fff;
  cursor: pointer;
}

/* Overlay Links */
.overlay-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
  margin-top: 3rem;
}
.overlay-content a {
  font-size: 2.5rem;
  font-weight: bold;
  color: white;
  text-decoration: none;
  opacity: 0;
  transform: translateY(30px);
  animation: slideIn 0.5s forwards;
  animation-delay: var(--delay);
  position: relative;
}

/* Slide-in Animation for Overlay Links */
@keyframes slideIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Handwritten-style underline animation */
@keyframes underline-draw {
  from {
    transform: scaleX(0);
    opacity: 0;
  }
  to {
    transform: scaleX(1);
    opacity: 1;
  }
}

/* Responsive Behavior */
@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }
  .nav-links {
    display: none;
  }
}