/* ================================================================
   LANDING-NAV (.ln-nav) — shared between landing.html and
   leaderboard.html (logged-out branch). Loaded BEFORE landing.css
   on landing, and as the only .ln-* stylesheet on leaderboard.

   Cascade order: style.css → ln-nav.css → landing.css (landing only)
   ================================================================ */

/* ================================================================
   TOP NAV
   ================================================================ */
.ln-nav {
  height: 56px;
  border-bottom: 0.5px solid #E8E6E0;
  /* Three-column grid: logo (1fr) | centered links (auto) | actions (1fr).
     Equal-weight outer columns make the middle group truly page-centered
     regardless of differing logo / actions widths. */
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  /* Safety net for consumers (e.g. leaderboard.html) that set
     `style.display = 'flex'` via JS to toggle visibility — that inline
     override defeats the grid layout. With flex, space-between puts
     logo at the start and actions at the end; on mobile (.ln-nav-links
     hidden via media query) this becomes a clean two-end layout. With
     grid, justify-content has no effect since 1fr+auto+1fr fills the row. */
  justify-content: space-between;
  padding: 0 2.5rem;
  background: white;
  position: sticky;
  top: 0;
  z-index: 100;
}
[data-theme="dark"] .ln-nav { background: var(--bg-primary); border-bottom-color: var(--border); }

.ln-nav-logo {
  font-size: 14px; font-weight: 500; color: var(--text-primary);
  text-decoration: none; display: flex; align-items: center; gap: 6px;
  justify-self: start;
}
.ln-nav-links { display: flex; gap: 2rem; justify-self: center; }
.ln-nav-link {
  font-size: 13px; color: #666; text-decoration: none; transition: color 0.15s;
}
.ln-nav-link:hover { color: #0F0F0F; }
.ln-nav-link-active { color: #0F0F0F; font-weight: 500; }
[data-theme="dark"] .ln-nav-link { color: var(--text-secondary); }
[data-theme="dark"] .ln-nav-link:hover,
[data-theme="dark"] .ln-nav-link-active { color: var(--text-primary); }

.ln-nav-actions { display: flex; gap: 1rem; align-items: center; justify-self: end; }
.ln-theme-btn {
  background: none; border: none; cursor: pointer;
  display: flex; align-items: center; color: var(--text-muted); padding: 4px;
}
.ln-theme-btn:hover { color: var(--text-primary); }
.ln-signin {
  font-size: 13px; color: #666; text-decoration: none; transition: color 0.15s;
  cursor: pointer; background: none; border: none; font-family: inherit; padding: 0;
}
.ln-signin:hover { color: #0F0F0F; }
[data-theme="dark"] .ln-signin { color: var(--text-secondary); }
.ln-get-access {
  height: 34px; background: #0F0F0F; color: white; border: none;
  border-radius: 6px; font-size: 13px; font-weight: 500; padding: 0 16px;
  cursor: pointer; font-family: inherit; text-decoration: none;
  display: inline-flex; align-items: center; transition: background 0.15s;
}
.ln-get-access:hover { background: #2A2A2A; }

/* --- Hamburger button + slide-down mobile menu (≤640px only) --- */
.ln-hamburger {
  display: none; /* shown via media query below */
  width: 44px; height: 44px;
  align-items: center; justify-content: center;
  background: transparent; border: none; cursor: pointer;
  color: var(--text-primary); padding: 0;
}
.ln-mobile-menu {
  display: none;
  position: fixed;
  top: 56px; left: 0; right: 0;
  background: white;
  border-bottom: 0.5px solid #E8E6E0;
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
  z-index: 99;
  padding: 8px 0;
}
[data-theme="dark"] .ln-mobile-menu { background: var(--bg-primary); border-bottom-color: var(--border); }
body.ln-mobile-menu-open .ln-mobile-menu { display: block; }
.ln-mobile-menu a,
.ln-mobile-menu button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 14px 20px;
  font-size: 15px;
  color: var(--text-primary);
  text-decoration: none;
  background: transparent;
  border: none;
  font-family: inherit;
  cursor: pointer;
  min-height: 44px;
}
.ln-mobile-menu a:hover,
.ln-mobile-menu button:hover { background: var(--bg-secondary, #F5F4F1); }
.ln-mobile-menu .ln-mobile-divider { height: 0.5px; background: #E8E6E0; margin: 4px 0; }
[data-theme="dark"] .ln-mobile-menu .ln-mobile-divider { background: var(--border); }

/* Mobile breakpoint: collapse centered links + Sign in into hamburger.
   Logo and Get Access stay visible. */
@media (max-width: 640px) {
  .ln-nav { padding: 0 1rem; grid-template-columns: auto auto 1fr; }
  .ln-nav-links { display: none; }
  .ln-signin { display: none; }
  .ln-nav-actions { gap: 8px; }
  .ln-hamburger { display: inline-flex; }
}