/**
 * BYD Shares and Stocks - Header & Navigation Styles
 * 
 * Includes: Main navigation, mobile menu, theme toggle, language selector
 * 
 * Structure:
 * .header (fixed wrapper)
 *   .container (max-width container)
 *     .header-inner (visible bar with background)
 *       .nav (flex navigation)
 */

/* ============================================
   1. HEADER WRAPPER (Fixed positioning)
   ============================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  padding: var(--space-4) 0;
  z-index: var(--z-fixed);
  pointer-events: none; /* Allow clicking through padding area */
  transition: padding var(--transition-normal);
}

.header.is-scrolled {
  padding: var(--space-3) 0;
}

/* Container inside header */
.header > .container {
  pointer-events: auto; /* Re-enable clicks for nav */
}

/* ============================================
   1.1 HEADER INNER (Visible navigation bar)
   ============================================ */
.header-inner {
  display: flex;
  align-items: center;
  height: var(--header-height);
  padding: 0 var(--space-6);
  background-color: transparent;
  border-radius: var(--radius-xl);
  transition: var(--transition-normal);
}

/* On scroll or solid pages - add background */
.header.is-scrolled .header-inner,
.header:not(.is-transparent) .header-inner {
  background-color: var(--color-bg-primary);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border-light);
}

[data-theme="dark"] .header.is-scrolled .header-inner,
[data-theme="dark"] .header:not(.is-transparent) .header-inner {
  background-color: var(--color-bg-secondary);
  border-color: var(--color-border-light);
}

/* ============================================
   2. NAVIGATION CONTAINER
   ============================================ */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: var(--space-8);
  position: relative;
}

/* ============================================
   3. LOGO
   ============================================ */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-primary);
  font-size: var(--text-h5);
  font-weight: var(--weight-bold);
  color: var(--color-text-primary);
  text-decoration: none;
  flex-shrink: 0;
  z-index: 1;
}

.nav-logo img,
.nav-logo svg {
  height: 32px;
  width: auto;
}

/* Desktop-only logo size bump (~+30%) */
@media (min-width: 1025px) {
  .nav-logo img,
  .nav-logo svg {
    height: 42px;
  }
}

.logo-text {
  color: var(--color-text-primary);
}

.logo-accent {
  color: var(--color-primary);
}

/* ============================================
   4. MAIN MENU
   ============================================ */
.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-primary);
  font-size: var(--text-body);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-text-primary);
  background-color: var(--color-bg-tertiary);
}

.nav-link.active {
  color: var(--color-primary);
}

/* Active indicator */
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: var(--space-4);
  right: var(--space-4);
  height: 2px;
  background-color: var(--color-primary);
  border-radius: var(--radius-full);
}

/* ============================================
   5. HEADER ACTIONS (Right side)
   ============================================ */
.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

/* Language Toggle */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-body-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  background: none;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition-fast);
}

.lang-toggle:hover {
  color: var(--color-text-primary);
  border-color: var(--color-border-medium);
  background-color: var(--color-bg-tertiary);
}

.lang-toggle svg {
  width: 16px;
  height: 16px;
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: none;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.theme-toggle:hover {
  border-color: var(--color-border-medium);
  background-color: var(--color-bg-tertiary);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
}

/* Sun icon (shown in light mode) */
.icon-sun {
  position: absolute;
  transform: rotate(0deg);
  opacity: 1;
}

/* Moon icon (shown in dark mode) */
.icon-moon {
  position: absolute;
  transform: rotate(-90deg);
  opacity: 0;
}

[data-theme="dark"] .icon-sun {
  transform: rotate(90deg);
  opacity: 0;
}

[data-theme="dark"] .icon-moon {
  transform: rotate(0deg);
  opacity: 1;
}

/* Auth Buttons */
.nav-auth {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* ============================================
   6. MOBILE NAVIGATION TOGGLE
   ============================================ */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: calc(var(--z-fixed) + 10);
  flex-shrink: 0;
  margin-left: auto;
}

.hamburger {
  position: relative;
  width: 24px;
  height: 2px;
  background-color: var(--color-text-primary);
  border-radius: var(--radius-full);
  transition: var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: inherit;
  border-radius: inherit;
  transition: var(--transition-normal);
}

.hamburger::before {
  top: -8px;
}

.hamburger::after {
  top: 8px;
}

/* Hamburger to X animation */
.nav-toggle.is-active .hamburger {
  background-color: transparent;
}

.nav-toggle.is-active .hamburger::before {
  top: 0;
  transform: rotate(45deg);
  background-color: var(--color-text-primary);
}

.nav-toggle.is-active .hamburger::after {
  top: 0;
  transform: rotate(-45deg);
  background-color: var(--color-text-primary);
}

/* ============================================
   7. MOBILE MENU
   ============================================ */
.mobile-menu {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  max-width: 400px;
  background-color: var(--color-bg-primary);
  transform: translateX(100%);
  transition: transform var(--duration-slow) var(--ease-out);
  z-index: var(--z-fixed);
  display: flex;
  flex-direction: column;
}

.mobile-menu.is-open {
  transform: translateX(0);
}

/* Mobile Menu Overlay */
.mobile-menu-overlay {
  position: fixed;
  inset: 0;
  background-color: var(--color-overlay);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-normal);
  z-index: calc(var(--z-fixed) - 1);
}

.mobile-menu-overlay.is-visible {
  opacity: 1;
  visibility: visible;
}

/* Mobile Menu Header */
.mobile-menu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border-light);
}

.mobile-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  font-size: var(--text-h4);
  color: var(--color-text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  transition: var(--transition-fast);
}

.mobile-close:hover {
  color: var(--color-text-primary);
}

/* Mobile Menu Navigation */
.mobile-nav {
  flex: 1;
  padding: var(--space-6);
  overflow-y: auto;
}

.mobile-link {
  display: block;
  padding: var(--space-4) 0;
  font-family: var(--font-primary);
  font-size: var(--text-h5);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border-light);
  transition: var(--transition-fast);
}

.mobile-link:hover,
.mobile-link.active {
  color: var(--color-primary);
}

/* Mobile Menu Actions */
.mobile-actions {
  padding: var(--space-6);
  border-top: 1px solid var(--color-border-light);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

/* Mobile Menu Settings (theme, language) */
.mobile-settings {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  padding: var(--space-4);
  border-top: 1px solid var(--color-border-light);
}

.mobile-settings .theme-toggle {
  width: 44px;
  height: 44px;
}

.mobile-settings .lang-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: none;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition-fast);
  color: var(--color-text-secondary);
}

.mobile-settings .lang-toggle:hover {
  border-color: var(--color-border-medium);
  background-color: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.mobile-settings .lang-toggle svg {
  width: 18px;
  height: 18px;
}

.mobile-settings .lang-toggle span {
  font-size: var(--text-body-sm);
  margin-left: var(--space-1);
}

/* ============================================
   8. RESPONSIVE STYLES
   ============================================ */
@media (max-width: 1024px) {
  .nav-menu {
    display: none;
  }
  
  .nav-auth {
    display: none;
  }
  
  .nav-toggle {
    display: flex;
  }
}

@media (max-width: 768px) {
  .header {
    height: var(--header-height-mobile);
    padding: var(--space-2) 0;
  }
  
  .header-inner {
    padding: 0 var(--space-4);
    height: auto;
    min-height: 56px;
  }
  
  .nav {
    gap: var(--space-4);
  }
  
  .nav-logo img,
  .nav-logo svg {
    height: 28px;
    width: auto;
  }
  
  .lang-toggle {
    display: none;
  }
  
  .theme-toggle {
    width: 36px;
    height: 36px;
  }
  
  .theme-toggle svg {
    width: 18px;
    height: 18px;
  }
  
  .nav-toggle {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
  }
  
  .hamburger {
    width: 20px;
    height: 2px;
  }
  
  .mobile-menu {
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .header-inner {
    padding: 0 var(--space-3);
  }
  
  .nav {
    gap: var(--space-2);
  }
  
  .nav-logo img,
  .nav-logo svg {
    height: 24px;
    width: auto;
  }
  
  .theme-toggle {
    width: 32px;
    height: 32px;
  }
  
  .theme-toggle svg {
    width: 16px;
    height: 16px;
  }
  
  .nav-toggle {
    width: 32px;
    height: 32px;
  }
  
  .hamburger {
    width: 18px;
  }
}

/* ============================================
   9. PREVENT BODY SCROLL WHEN MENU OPEN
   ============================================ */
body.menu-open {
  overflow: hidden;
}