/* ==========================================================================
   CLEAN EXECUTIVE NAVIGATION HEADER & THEME TOGGLE
   ========================================================================== */

.observatory-hud {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--hud-height);
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--space-surface-border);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

/* Left Brand Emblem */
.hud-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

.hud-emblem {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.hud-emblem-icon {
  width: 34px;
  height: 34px;
  border: 1.5px solid var(--cyan-beam);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--cyan-beam);
  box-shadow: 0 0 10px rgba(2, 132, 199, 0.3);
}

.hud-brand-titles {
  display: flex;
  flex-direction: column;
}

.hud-brand-name {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.hud-brand-sub {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--cyan-beam);
  letter-spacing: 0.08em;
  font-weight: 600;
}

/* Center Clean Navigation Links */
.hud-center-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 6px;
  transition: all 0.2s ease;
}

.nav-link:hover {
  color: var(--text-main);
  background: rgba(2, 132, 199, 0.08);
}

.nav-link.active {
  color: var(--cyan-beam);
  font-weight: 700;
  background: rgba(2, 132, 199, 0.12);
}

/* Right Controls: YouTube, Theme Toggle, SFX, Telemetry */
.hud-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* YouTube Button */
.hud-yt-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #ff0033;
  color: #ffffff !important;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 6px;
  text-decoration: none;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(255, 0, 51, 0.25);
}

.hud-yt-btn:hover {
  background: #e6002e;
  transform: translateY(-1px);
}

/* Theme Toggle Button */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--space-surface);
  border: 1px solid var(--space-surface-border);
  color: var(--text-main);
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
  border-color: var(--cyan-beam);
  color: var(--cyan-beam);
}

/* SFX Audio Button */
.hud-audio-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--space-surface);
  border: 1px solid var(--space-surface-border);
  color: var(--text-main);
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.hud-audio-btn:hover {
  border-color: var(--cyan-beam);
  color: var(--cyan-beam);
}

.hud-audio-btn.active {
  border-color: var(--quantum-emerald);
  color: var(--quantum-emerald);
  background: rgba(0, 230, 118, 0.1);
}

/* Telemetry Drawer Toggle */
.telemetry-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--space-surface);
  border: 1px solid var(--space-surface-border);
  color: var(--text-muted);
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  transition: all 0.2s ease;
}

.telemetry-toggle-btn:hover {
  color: var(--cyan-beam);
  border-color: var(--cyan-beam);
}

/* Collapsible Telemetry Dropdown Drawer */
.telemetry-drawer {
  position: absolute;
  top: calc(var(--hud-height) + 8px);
  right: 28px;
  background: var(--space-surface);
  backdrop-filter: blur(16px);
  border: 1px solid var(--space-surface-border);
  border-radius: 10px;
  padding: 16px 20px;
  box-shadow: var(--box-shadow-panel);
  display: none;
  flex-direction: column;
  gap: 12px;
  z-index: 1001;
  min-width: 280px;
}

.telemetry-drawer.open {
  display: flex;
}

.drawer-telemetry-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.drawer-label {
  color: var(--text-muted);
}

.drawer-val {
  color: var(--text-main);
  font-weight: 600;
}

.redshift-slider-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-top: 1px solid var(--space-surface-border);
  padding-top: 10px;
}

.redshift-slider-input {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 5px;
  background: linear-gradient(to right, #00f2fe, #ff5722);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

.redshift-slider-input::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #ffffff;
  border: 2px solid var(--cyan-beam);
  cursor: pointer;
}

/* Mobile Menu Toggle */
.mobile-menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--space-surface-border);
  color: var(--text-main);
  width: 34px;
  height: 34px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 1.1rem;
}

/* Responsive adjustments */
@media (max-width: 1100px) {
  .hud-center-nav {
    display: none;
  }
  .mobile-menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .observatory-hud {
    padding: 0 20px;
  }
}

/* Mobile Navigation Dropdown */
.mobile-nav-drawer {
  position: fixed;
  top: var(--hud-height);
  left: 0;
  width: 100%;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--space-surface-border);
  display: none;
  flex-direction: column;
  padding: 16px 24px;
  gap: 12px;
  z-index: 999;
}

.mobile-nav-drawer.open {
  display: flex;
}

.mobile-nav-drawer a {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-main);
  text-decoration: none;
  padding: 8px 0;
  border-bottom: 1px solid var(--space-surface-border);
}

@media (max-width: 600px) {
  .observatory-hud {
    padding: 0 14px;
  }
  .hud-brand-sub {
    display: none;
  }
  .hud-brand-name {
    font-size: 0.95rem;
  }
  .hud-right {
    gap: 6px;
  }
  .theme-toggle-btn span:last-child,
  .hud-audio-btn span:last-child {
    display: none;
  }
  .theme-toggle-btn, .hud-audio-btn {
    padding: 6px 8px;
  }
}