/* ================================================================
   navigation.css — BitTradeBlog
   ヘッダーナビ・スティッキー・メガメニュー・モバイルドロワー
================================================================ */

/* ================================================================
   SITE HEADER
================================================================ */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border-light);
  height: var(--header-height);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  transition: box-shadow 0.2s ease;
}
.site-header.is-scrolled {
  box-shadow: var(--shadow-md);
}

.site-header__inner {
  display: flex;
  align-items: center;
  height: 100%;
  gap: 0;
}

/* ── Logo ── */
.site-logo {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-right: var(--sp-8);
  flex-shrink: 0;
  text-decoration: none;
}
.site-logo__icon {
  width: 30px;
  height: 30px;
  background: var(--color-primary);
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  color: var(--blue-900);
  flex-shrink: 0;
}
.site-logo__text {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1;
}
.site-logo__text em {
  color: var(--color-primary-dark);
  font-style: normal;
}

/* ================================================================
   PRIMARY NAVIGATION (Desktop)
================================================================ */
.primary-nav {
  display: none;
  flex: 1;
  height: var(--header-height);
}
@media (min-width: 1024px) {
  .primary-nav { display: flex; }
}

.primary-nav__list {
  display: flex;
  height: 100%;
  list-style: none;
  margin: 0;
  padding: 0;
}
.primary-nav__item {
  position: relative;
}
.primary-nav__link {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  height: var(--header-height);
  padding: 0 var(--sp-4);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-sub);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: var(--transition-fast);
  white-space: nowrap;
}
.primary-nav__link:hover,
.primary-nav__item.current-menu-item .primary-nav__link,
.primary-nav__item.current-menu-ancestor .primary-nav__link {
  color: var(--color-primary-dark);
  border-bottom-color: var(--color-primary);
}
.primary-nav__link .nav-arrow {
  font-size: 9px;
  transition: transform 0.15s ease;
}
.primary-nav__item:hover .nav-arrow {
  transform: rotate(180deg);
}

/* ── Dropdown base ── */
.primary-nav__dropdown {
  display: none;
  position: absolute;
  top: calc(var(--header-height) - 2px);
  left: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-top: 2px solid var(--color-primary);
  border-radius: 0 0 var(--r-lg) var(--r-lg);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-dropdown);
  min-width: 180px;
  padding: var(--sp-2) 0;
}
.primary-nav__item:hover .primary-nav__dropdown {
  display: block;
}
.primary-nav__dropdown a {
  display: block;
  padding: var(--sp-2) var(--sp-4);
  font-size: var(--text-xs);
  color: var(--color-text-sub);
  text-decoration: none;
  transition: var(--transition-fast);
}
.primary-nav__dropdown a:hover {
  background: var(--color-primary-dim);
  color: var(--color-primary-dark);
}

/* ── Mega menu (チャート銘柄) ── */
.primary-nav__mega {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--color-surface);
  border-top: 2px solid var(--color-primary);
  border-bottom: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-dropdown);
  padding: var(--sp-5) 0;
}
.primary-nav__item--has-mega:hover .primary-nav__mega {
  display: block;
}
.mega-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}
.mega-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--sp-3);
}
.mega-featured {
  display: flex;
  gap: var(--sp-2);
  flex-wrap: wrap;
  margin-bottom: var(--sp-3);
}
.mega-coin-chip {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--r-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: var(--text-xs);
  color: var(--color-text-sub);
  text-decoration: none;
  transition: var(--transition-fast);
  cursor: pointer;
}
.mega-coin-chip:hover {
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
  background: var(--color-primary-dim);
}
.mega-coin-chip--featured {
  border-color: var(--blue-200);
  color: var(--blue-600);
  background: var(--blue-50);
}
.mega-all-link {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-primary-dark);
}
.mega-all-link:hover { color: var(--color-primary); }

/* ── Header actions ── */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  margin-left: auto;
}
.header-search {
  display: none;
  align-items: center;
  gap: var(--sp-2);
  width: 140px;
  height: 32px;
  background: var(--gray-50);
  border: 1px solid var(--color-border);
  border-radius: var(--r-full);
  padding: 0 var(--sp-3);
  cursor: pointer;
  transition: var(--transition-fast);
}
@media (min-width: 768px) {
  .header-search { display: flex; }
}
.header-search:hover { border-color: var(--color-primary); }
.header-search__icon {
  width: 13px;
  height: 13px;
  border: 1.5px solid var(--color-text-muted);
  border-radius: 50%;
  position: relative;
  flex-shrink: 0;
}
.header-search__icon::after {
  content: '';
  position: absolute;
  width: 5px;
  height: 1.5px;
  background: var(--color-text-muted);
  transform: rotate(45deg);
  bottom: -3px;
  right: -3px;
}
.header-search__text {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* ── Hamburger button ── */
.menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: var(--sp-2);
  border: 1px solid var(--color-border);
  border-radius: var(--r-md);
  background: transparent;
  cursor: pointer;
  flex-shrink: 0;
}
@media (min-width: 1024px) { .menu-toggle { display: none; } }

.menu-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: var(--r-full);
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.menu-toggle[aria-expanded="true"] .menu-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.menu-toggle[aria-expanded="true"] .menu-toggle__bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.menu-toggle[aria-expanded="true"] .menu-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ================================================================
   MOBILE DRAWER
================================================================ */
.mobile-drawer {
  display: none;
  position: fixed;
  inset: 0;
  z-index: calc(var(--z-sticky) + 1);
  pointer-events: none;
}
.mobile-drawer.is-open {
  display: block;
  pointer-events: auto;
}

/* Overlay */
.mobile-drawer__overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  transition: opacity 0.3s ease;
}
.mobile-drawer.is-open .mobile-drawer__overlay {
  opacity: 1;
}

/* Panel */
.mobile-drawer__panel {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(320px, 90vw);
  background: var(--color-surface);
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
}
.mobile-drawer.is-open .mobile-drawer__panel {
  transform: translateX(0);
}

/* Drawer header */
.mobile-drawer__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-4) var(--sp-5);
  border-bottom: 1px solid var(--color-border-light);
  flex-shrink: 0;
}
.mobile-drawer__close {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--r-md);
  border: 1px solid var(--color-border);
  font-size: 18px;
  color: var(--color-text-sub);
  cursor: pointer;
  background: transparent;
}

/* Drawer nav */
.mobile-drawer__nav { flex: 1; padding: var(--sp-3) 0; }
.mobile-nav__item { border-bottom: 1px solid var(--color-border-light); }
.mobile-nav__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-4) var(--sp-5);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  cursor: pointer;
}
.mobile-nav__link:hover { background: var(--gray-50); }
.mobile-nav__toggle {
  font-size: 12px;
  color: var(--color-text-muted);
  transition: transform 0.2s ease;
}
.mobile-nav__item.is-open .mobile-nav__toggle { transform: rotate(180deg); }

/* Sub menu */
.mobile-nav__sub {
  display: none;
  background: var(--gray-50);
  padding: var(--sp-2) 0;
}
.mobile-nav__item.is-open .mobile-nav__sub { display: block; }
.mobile-nav__sub-link {
  display: block;
  padding: var(--sp-2) var(--sp-8);
  font-size: var(--text-xs);
  color: var(--color-text-sub);
  text-decoration: none;
}
.mobile-nav__sub-link:hover { color: var(--color-primary-dark); }

/* Drawer footer */
.mobile-drawer__footer {
  padding: var(--sp-5);
  border-top: 1px solid var(--color-border-light);
  flex-shrink: 0;
}

/* ================================================================
   READING PROGRESS BAR
================================================================ */
.reading-progress {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-border-light);
  z-index: var(--z-sticky);
  pointer-events: none;
}
.reading-progress__fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: 0 var(--r-full) var(--r-full) 0;
  width: 0%;
  transition: width 0.1s linear;
}