/* ============================================================
   NAV
   ============================================================ */

nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.75rem 4rem;
  /* Allow absolute centering of nav-links */
  isolation: isolate;
  background: linear-gradient(to bottom, rgba(4,4,8,.75) 0%, transparent 100%);
  transition: background .4s, padding .4s, border-color .4s, backdrop-filter .4s;
}

nav.stuck {
  background: rgba(13,13,15,.88);
  backdrop-filter: blur(24px) saturate(180%);
  padding: 1rem 4rem;
}

.logo {
  font-family: 'Space Mono', monospace;
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -.02em;
  text-decoration: none;
  color: var(--off-white);
  display: flex;
  align-items: center;
  gap: 2px;
}
.logo span { color: var(--teal); }

.nav-links {
  list-style: none;
  display: flex;
  gap: 2.5rem;
  align-items: center;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}
.nav-links a {
  text-decoration: none;
  color: var(--gray);
  font-size: .8rem;
  font-weight: 500;
  letter-spacing: .08em;
  text-transform: uppercase;
  transition: color .3s;
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 1px;
  background: var(--teal);
  transition: width .3s;
}
.nav-links a:hover               { color: var(--off-white); }
.nav-links a:hover::after        { width: 100%; }

.nav-btn {
  text-decoration: none;
  padding: .55rem 1.4rem;
  border: 1.5px solid var(--teal);
  border-radius: 6px;
  color: var(--teal);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  transition: background .3s, color .3s;
  cursor: none;
}
.nav-btn:hover {
  background: var(--teal);
  color: var(--charcoal);
}

/* ── Hamburger button ── */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  padding: 6px;
  cursor: pointer;
  z-index: 1001;
  position: relative;
}
.nav-hamburger span {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--off-white);
  border-radius: 2px;
  transition: transform .35s cubic-bezier(.23,1,.32,1), opacity .25s;
  transform-origin: center;
}

/* Hamburger → X animation */
.nav-hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* Mobile nav slide-in panel */
@media (max-width: 680px) {
  .nav-hamburger { display: flex; }
  .nav-btn#navCta { display: none; }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: min(75vw, 300px);
    height: 100dvh;
    background: rgba(10,10,12,.97);
    backdrop-filter: blur(24px) saturate(160%);
    border-left: 1px solid var(--border);
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding: 5rem 2.5rem;
    gap: 2.5rem;
    transform: translateX(100%);
    transition: transform .38s cubic-bezier(.23,1,.32,1);
    z-index: 1000;
    list-style: none;
  }
  .nav-links.open {
    transform: translateX(0);
    box-shadow: -20px 0 60px rgba(0,0,0,.5);
  }
  .nav-links a {
    font-size: 1rem;
    letter-spacing: .12em;
    color: var(--off-white);
  }

  /* CTA button inside mobile menu */
  .nav-links::after {
    content: 'Falar com a Scalex';
    display: inline-block;
    margin-top: 1rem;
    padding: .7rem 1.5rem;
    border: 1.5px solid var(--teal);
    border-radius: 6px;
    color: var(--teal);
    font-size: .8rem;
    font-weight: 600;
    letter-spacing: .06em;
    text-transform: uppercase;
    cursor: pointer;
  }

  /* Backdrop overlay */
  .nav-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.5);
    z-index: 999;
    opacity: 0;
    pointer-events: none;
    transition: opacity .35s;
  }
  .nav-backdrop.open {
    opacity: 1;
    pointer-events: all;
  }
}