/* ISAEV — Navigation */

.nav {
  position: fixed; top: 0; left: 0; right: 0;
  height: 52px;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 22px;
  z-index: 200;
  background: rgba(245,245,247,.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--divider);
}

.nav--dark {
  background: rgba(29,29,31,.72);
  border-bottom-color: rgba(255,255,255,.08);
}

.nav-logo {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 17px;
  letter-spacing: .08em;
  color: var(--black);
  text-decoration: none;
}
.nav--dark .nav-logo { color: #fff; }

.nav-links {
  display: flex; gap: 28px; list-style: none;
}
.nav-links a {
  font-size: 13px; font-weight: 400;
  color: var(--gray); text-decoration: none;
  transition: color var(--dur-fast);
}
.nav-links a:hover { color: var(--black); }
.nav--dark .nav-links a { color: rgba(255,255,255,.55); }
.nav--dark .nav-links a:hover { color: #fff; }

.nav-cta {
  display: inline-flex; align-items: center;
  font-size: 13px; font-weight: 400;
  color: #fff;
  background: var(--blue);
  padding: 7px 18px;
  border-radius: var(--radius-pill);
  text-decoration: none;
  transition: background var(--dur-fast);
}
.nav-cta:hover { background: var(--blue-dark); }

/* Mobile menu toggle (shown on small screens via nav.js) */
.nav-toggle {
  display: none;
  width: 28px; height: 22px;
  position: relative;
}
.nav-toggle span {
  position: absolute; left: 0; right: 0;
  height: 1.5px; background: currentColor;
  transition: transform var(--dur-mid), opacity var(--dur-fast), top var(--dur-mid);
}
.nav-toggle span:nth-child(1) { top: 4px; }
.nav-toggle span:nth-child(2) { top: 50%; transform: translateY(-50%); }
.nav-toggle span:nth-child(3) { top: calc(100% - 4px); }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { top: 50%; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { top: 50%; transform: rotate(-45deg); }

@media (max-width: 720px) {
  .nav-links {
    position: fixed; top: 52px; left: 0; right: 0;
    background: rgba(245,245,247,.96);
    backdrop-filter: blur(20px);
    flex-direction: column; gap: 0; padding: 24px 28px 32px;
    transform: translateY(-12px); opacity: 0; pointer-events: none;
    transition: transform var(--dur-mid), opacity var(--dur-fast);
    border-bottom: 1px solid var(--divider);
  }
  .nav-links.open {
    transform: translateY(0); opacity: 1; pointer-events: auto;
  }
  .nav-links a {
    display: block; padding: 14px 0;
    font-size: 17px;
    border-bottom: 1px solid var(--divider);
  }
  .nav-links li:last-child a { border-bottom: none; }
  .nav-toggle { display: block; }
  .nav-cta { display: none; }
}