/* Lemon Blog — Header / Navigation */

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(13, 13, 13, 0.72);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 0.5px solid var(--border-subtle);
  transition: background var(--transition-med), border-color var(--transition-med);
}

[data-theme="light"] .site-header { background: rgba(250, 250, 250, 0.78); border-bottom-color: rgba(0,0,0,0.07); }
.site-header.scrolled { background: rgba(13, 13, 13, 0.92); }
[data-theme="light"] .site-header.scrolled { background: rgba(250, 250, 250, 0.96); }

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  gap: 16px;
}

.nav-logo {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.3px;
  flex-shrink: 0;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: opacity var(--transition-fast);
}
.nav-logo:hover { opacity: 0.75; color: var(--text-primary); }
.nav-logo-lemon { color: var(--accent); }
.nav-logo-sep { color: var(--border-strong); font-weight: 300; margin: 0 2px; }
.nav-logo-blog { color: var(--text-secondary); font-weight: 400; }

.nav-links { display: flex; align-items: center; gap: 2px; flex: 1; justify-content: center; }

.nav-link {
  font-size: 13px;
  font-weight: 400;
  color: var(--text-secondary);
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
  letter-spacing: -0.1px;
}
.nav-link:hover { color: var(--text-primary); background: var(--bg-elevated); }
.nav-link.active { color: var(--text-primary); }

.nav-right { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }

.theme-toggle {
  width: 30px; height: 30px;
  border-radius: 50%;
  border: 0.5px solid var(--border-default);
  background: transparent;
  color: var(--text-muted);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: border-color var(--transition-fast), color var(--transition-fast), background var(--transition-fast);
  flex-shrink: 0;
}
.theme-toggle:hover { border-color: var(--border-strong); color: var(--text-primary); background: var(--bg-elevated); }

.nav-search-btn {
  width: 30px; height: 30px;
  border-radius: 50%;
  border: 0.5px solid transparent;
  background: transparent;
  color: var(--text-muted);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast);
  flex-shrink: 0;
}
.nav-search-btn:hover { color: var(--text-primary); border-color: var(--border-default); }

.search-overlay {
  position: fixed; inset: 0; z-index: 2000;
  background: rgba(13,13,13,0.85);
  backdrop-filter: blur(8px);
  display: flex; align-items: flex-start; justify-content: center;
  padding-top: 120px;
  opacity: 0; pointer-events: none;
  transition: opacity var(--transition-med);
}
.search-overlay.open { opacity: 1; pointer-events: all; }
.search-overlay-inner { width: 100%; max-width: 560px; padding: 0 24px; }
.search-overlay-input {
  width: 100%;
  background: var(--bg-surface);
  border: 0.5px solid var(--border-default);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
  font-size: 18px;
  font-family: var(--font-sans);
  padding: 16px 20px;
  outline: none;
  transition: border-color var(--transition-fast);
}
.search-overlay-input::placeholder { color: var(--text-faint); }
.search-overlay-input:focus { border-color: var(--accent); }
.search-overlay-hint { font-size: 12px; color: var(--text-faint); margin-top: 10px; text-align: center; }

.hamburger { display: none; flex-direction: column; justify-content: center; gap: 5px; width: 32px; height: 32px; background: transparent; border: none; padding: 4px; cursor: pointer; }
.ham-line { display: block; width: 18px; height: 1.5px; background: var(--text-secondary); transition: transform 0.22s ease, opacity 0.22s ease; border-radius: 2px; }
.hamburger.open .ham-line:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.open .ham-line:nth-child(2) { opacity: 0; }
.hamburger.open .ham-line:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

.mobile-menu { display: none; position: fixed; top: var(--nav-height); left: 0; right: 0; background: var(--bg-surface); border-bottom: 0.5px solid var(--border-subtle); z-index: 999; padding: 12px 0 20px; flex-direction: column; }
.mobile-menu.open { display: flex; }
.mobile-link { display: block; font-size: 15px; color: var(--text-secondary); padding: 11px 24px; transition: color var(--transition-fast), background var(--transition-fast); border: none; background: none; text-align: left; cursor: pointer; text-decoration: none; }
.mobile-link:hover, .mobile-link.active { color: var(--text-primary); background: var(--bg-elevated); }
.mobile-menu-actions { display: flex; gap: 8px; padding: 12px 24px 0; border-top: 0.5px solid var(--border-subtle); margin-top: 8px; }

@media (max-width: 768px) { .nav-links { display: none; } .hamburger { display: flex; } .hide-mobile { display: none !important; } }
@media (max-width: 480px) { .nav-inner { padding: 0 16px; } }