/* --- TOP BAR: DEEP HYDRO PREMIUM SYSTEM --- */
.top-bar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: 72px;
  
  /* Initial State: Transparent */
  background: transparent;
  border-bottom: 1px solid transparent;
  
  transition: 
    transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    background 0.3s ease,
    border-color 0.3s ease,
    backdrop-filter 0.3s ease;
}

/* Scrolled State: Glass Effect */
.top-bar.scrolled {
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid color-mix(in srgb, var(--stroke) 60%, transparent);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

/* Smart Hide (Scroll Down) */
.top-bar.hidden {
  transform: translateY(-100%);
}

.top-bar__container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  height: 100%;
  padding: 0 1.5rem;
}

/* --- BRANDING --- */
.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text);
  transition: opacity 0.2s;
}
.brand-link:hover { opacity: 0.9; }

.logo-mark {
  position: relative;
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
}

/* Logo Core */
.logo-core {
  width: 10px; height: 10px;
  background: var(--brand);
  border-radius: 50%;
  box-shadow: 0 0 15px var(--brand);
  z-index: 2;
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Logo Ring */
.logo-ring {
  position: absolute; inset: 0;
  border: 1.5px solid color-mix(in srgb, var(--brand) 30%, transparent);
  border-top-color: var(--brand);
  border-radius: 50%;
  transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.brand-link:hover .logo-core { transform: scale(1.2); }
.brand-link:hover .logo-ring { transform: rotate(180deg); }

.brand-name {
  font-size: 1.15rem; font-weight: 700; letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--text) 60%, var(--brand-2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}

/* --- DESKTOP NAVIGATION (Center Pill) --- */
.nav-menu {
  display: flex; align-items: center; gap: 4px;
  background: color-mix(in srgb, var(--elev-1) 60%, transparent);
  border: 1px solid var(--glass-highlight);
  padding: 4px; border-radius: 100px;
  backdrop-filter: blur(10px);
  transition: 0.3s;
}
/* Hide pill border when nav is fully scrolled for cleaner look */
.top-bar.scrolled .nav-menu { background: transparent; border-color: transparent; backdrop-filter: none; }

.nav-item {
  position: relative; padding: 8px 20px;
  text-decoration: none; color: var(--text-muted);
  font-size: 0.9rem; font-weight: 500;
  border-radius: 50px; transition: color 0.3s ease;
  overflow: hidden;
}

.nav-item:hover { color: var(--text); }
.nav-item.active { color: var(--text); font-weight: 600; }

/* The "Glow" Pill */
.nav-glow {
  position: absolute; inset: 0;
  background: var(--elev-3);
  border-radius: 50px;
  opacity: 0; transform: scale(0.9);
  transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1); z-index: -1;
}
.nav-item:hover .nav-glow { opacity: 0.6; transform: scale(1); }
.nav-item.active .nav-glow {
  background: color-mix(in srgb, var(--brand) 10%, var(--elev-3));
  border: 1px solid color-mix(in srgb, var(--brand) 20%, transparent);
  opacity: 1; transform: scale(1);
}

/* --- ACTIONS (Right Side) --- */
.nav-actions { display: flex; align-items: center; gap: 1.5rem; }

.action-link {
  font-size: 0.9rem; color: var(--text-muted); font-weight: 500;
  text-decoration: none; transition: color 0.2s;
}
.action-link:hover { color: var(--brand); }

.action-btn {
  display: flex; align-items: center; gap: 8px;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: var(--text-inverse); padding: 8px 20px;
  border-radius: 100px; font-size: 0.9rem; font-weight: 700;
  text-decoration: none; transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 4px 15px var(--brand-glow);
}
.action-btn:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 8px 25px var(--brand-glow);
}
.action-btn svg { width: 16px; height: 16px; stroke-width: 2.5; transition: transform 0.3s ease; }
.action-btn:hover svg { transform: translateX(3px); }

/* --- MOBILE TOGGLE --- */
.menu-toggle {
  display: none; background: transparent; border: none; cursor: pointer; padding: 10px; z-index: 1001;
}
.hamburger {
  width: 24px; height: 14px;
  display: flex; flex-direction: column; justify-content: space-between;
  position: relative;
}
.hamburger span {
  display: block; width: 100%; height: 2px;
  background: var(--text); border-radius: 4px;
  transition: transform 0.3s, opacity 0.3s, background-color 0.3s;
}
/* Active Hamburger */
.menu-toggle.active .hamburger span:nth-child(1) { transform: translateY(6px) rotate(45deg); background: var(--brand); }
.menu-toggle.active .hamburger span:nth-child(2) { opacity: 0; transform: translateX(-10px); }
.menu-toggle.active .hamburger span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); background: var(--brand); }

/* --- MOBILE OVERLAY --- */
.mobile-menu-overlay {
  position: fixed; top: 0; left: 0; right: 0; bottom: 0; height: 100dvh;
  background: color-mix(in srgb, var(--bg) 95%, transparent);
  backdrop-filter: blur(40px); -webkit-backdrop-filter: blur(40px);
  padding-top: 100px;
  opacity: 0; visibility: hidden; pointer-events: none;
  transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 999;
  display: flex; flex-direction: column; align-items: center;
}
.mobile-menu-overlay.open { opacity: 1; visibility: visible; pointer-events: auto; }

.mobile-nav-content { display: flex; flex-direction: column; gap: 2rem; align-items: center; width: 100%; max-width: 400px; }

.m-link {
  font-size: 2rem; font-weight: 800; color: var(--text); text-decoration: none;
  letter-spacing: -0.02em; transform: translateY(30px); opacity: 0;
  transition: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}
/* Staggered Entrance */
.mobile-menu-overlay.open .m-link:nth-child(1) { transition-delay: 0.1s; transform: translateY(0); opacity: 1; }
.mobile-menu-overlay.open .m-link:nth-child(2) { transition-delay: 0.15s; transform: translateY(0); opacity: 1; }
.mobile-menu-overlay.open .m-link:nth-child(3) { transition-delay: 0.2s; transform: translateY(0); opacity: 1; }
.mobile-menu-overlay.open .m-link:nth-child(4) { transition-delay: 0.25s; transform: translateY(0); opacity: 1; }
.mobile-menu-overlay.open .m-link:nth-child(5) { transition-delay: 0.3s; transform: translateY(0); opacity: 1; }

.m-link:hover, .m-link.active { color: var(--brand); }

.m-cta {
  margin-top: 2rem; width: 80%; text-align: center; padding: 18px;
  background: var(--brand); color: var(--text-inverse); font-weight: 700; border-radius: 20px;
  font-size: 1.1rem; text-decoration: none;
  transform: translateY(40px); opacity: 0;
  transition: 0.5s cubic-bezier(0.16, 1, 0.3, 1) 0.4s;
}
.mobile-menu-overlay.open .m-cta { transform: translateY(0); opacity: 1; }

/* --- SCROLL PROGRESS --- */
.scroll-progress-bar {
  position: absolute; bottom: 0; left: 0; height: 1px; width: 0%;
  background: linear-gradient(90deg, transparent, var(--brand), var(--brand-2));
  box-shadow: 0 0 10px var(--brand); transition: width 0.1s linear; opacity: 0;
}
.top-bar.scrolled .scroll-progress-bar { opacity: 1; }

/* --- RESPONSIVE --- */
@media (max-width: 968px) {
  .nav-menu, .action-link, .action-btn { display: none; }
  .menu-toggle { display: block; }
}