/* Top navigation bar — logo, center links, theme toggle + auth actions. */

.nav {
  position: sticky;
  top: 0;
  z-index: 40;
  /* transparent at the top so it blends into the hero */
  background: transparent;
  transition: padding-top 0.55s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: padding-top;
}
.nav.scrolled { padding-top: 8px; }

/* one shared silky curve for every property that changes on collapse */
.nav-inner {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-block: 11px;
  max-width: 100%;
  margin-inline: auto;
  border: 1px solid transparent;
  border-radius: 30px;
  will-change: max-width, padding, background;
  transition:
    max-width 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    padding 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    border-radius 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    background 0.45s ease,
    border-color 0.45s ease,
    box-shadow 0.45s ease;
}

/* scrolled → narrower floating dark pill that matches the hero tone */
.nav.scrolled .nav-inner {
  max-width: 940px;
  margin-inline: auto;
  padding: 7px 10px 7px 18px;
  border-color: var(--line-strong);
  border-radius: 30px;
  background: color-mix(in srgb, #0b1a16 90%, transparent);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: var(--shadow-soft);
}
:root[data-theme="light"] .nav.scrolled .nav-inner {
  background: color-mix(in srgb, #e8f3ee 88%, transparent);
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.98rem;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.brand-2 { color: var(--aqua); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-inline: auto;
}
.nav-links a {
  color: var(--ink-2);
  font-size: 0.86rem;
  font-weight: 500;
  padding: 6px 11px;
  border-radius: var(--r-pill);
  transition: color 0.2s ease, background 0.2s ease;
}
.nav-links a:hover { color: var(--ink); background: var(--surface); }

.nav-actions { display: flex; align-items: center; gap: 8px; }
.nav-guest, .nav-authed { display: inline-flex; align-items: center; gap: 8px; }

/* Auth state: show a shimmer skeleton in place of the auth buttons until Firebase
   resolves, so an authed visitor never sees a "Sign in / Sign up" flash first. */
.nav-auth-skeleton { display: none; align-items: center; gap: 8px; }
html:not(.sb-auth-ready) .nav-auth-skeleton { display: inline-flex; }
html:not(.sb-auth-ready) .nav-guest,
html:not(.sb-auth-ready) .nav-authed { display: none !important; }
.nas-pill { height: 36px; border-radius: 10px; background: #e6efe9; position: relative; overflow: hidden; }
.nas-pill::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.7), transparent);
  transform: translateX(-100%); animation: nasShimmer 1.15s ease-in-out infinite;
}
.nas-pill.a { width: 66px; }
.nas-pill.b { width: 84px; }
@keyframes nasShimmer { to { transform: translateX(100%); } }

/* compact buttons — nav only, leaves site-wide .btn untouched */
.nav .btn {
  font-size: 0.86rem;
  padding: 7px 15px;
  border-radius: 11px;
}

/* hamburger (mobile only) */
.nav-hamburger {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface);
  cursor: pointer;
}
.nav-hamburger span {
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--ink);
}

@media (max-width: 860px) {
  .nav-links { display: none; }
  .nav-desktop { display: none; }
  .nav-hamburger { display: inline-flex; }
  .nav-actions { margin-left: auto; }
  html:not(.sb-auth-ready) .nav-auth-skeleton { display: none; }
}