nav {
   position: fixed;
   top: 0;
   left: 0;
   width: 100%;
   background-color: var(--main-bg-color);
   border-bottom: 2px solid var(--main-surface-color);
   padding: 20px 0;
   z-index: 1000;
}

nav ul {
   list-style: none;
   display: flex;
   justify-content: center;
   align-items: center;
   gap: 50px;
   max-width: 1200px;
   margin: 0 auto;
   padding: 0 20px;
}

nav ul li a {
   color: var(--main-text-color);
   text-decoration: none;
   font-size: 18px;
   font-weight: 500;
   letter-spacing: 2px;
   padding: 10px 20px;
   border-radius: 4px;
   transition: all 0.3s ease;
   position: relative;
}

nav ul li a:hover {
   color: var(--main-bg-color);
   background-color: var(--main-surface-color);
   transform: translateY(-2px);
}

nav ul li a::after {
   content: '';
   position: absolute;
   bottom: 0;
   left: 0;
   width: 0;
   height: 2px;
   background-color: var(--main-surface-color);
   transition: width 0.3s ease;
}

nav ul li a:hover::after {
   width: 100%;
}

/* Mobile responsiveness */
@media (max-width: 768px) {
   nav ul {
       gap: 20px;
       padding: 0 15px;
   }

   nav ul li a {
       font-size: 16px;
       letter-spacing: 1px;
       padding: 3px 2px;
   }
}

@media (max-width: 600px) {
   nav ul {
       gap: 15px;
       flex-wrap: wrap;
       justify-content: center;
   }

   nav ul li a {
       font-size: 14px;
       padding: 3px 2px;
   }
}