/* ==========================================================================
   Seiryu-Theme — Header & Navigation
   ========================================================================== */

/* --------------------------------------------------------------------------
   Header Base
   -------------------------------------------------------------------------- */
.seiryu-header {
  position: relative;
  z-index: 100;
  width: 100%;
  background-color: var(--seiryu-color-bg);
  border-bottom: 1px solid var(--seiryu-color-border);
  transition:
    background-color var(--seiryu-duration-base) var(--seiryu-easing-default),
    box-shadow var(--seiryu-duration-base) var(--seiryu-easing-default);
}

.seiryu-header__inner {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--seiryu-space-4) var(--seiryu-space-8);
  min-height: var(--seiryu-header-height, 72px);
  padding-block: var(--seiryu-space-2);
}

/* --------------------------------------------------------------------------
   Header Styles
   -------------------------------------------------------------------------- */
/* Transparent (on hero) */
.seiryu-header--transparent {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  background-color: transparent;
  border-bottom-color: transparent;
}

.seiryu-header--transparent .nav-link,
.seiryu-header--transparent .site-title {
  color: var(--seiryu-color-text-inverse);
}

.seiryu-header--transparent.is-scrolled {
  background-color: var(--seiryu-color-bg);
  border-bottom-color: var(--seiryu-color-border);
  box-shadow: var(--seiryu-shadow-sm);
}

.seiryu-header--transparent.is-scrolled .nav-link,
.seiryu-header--transparent.is-scrolled .site-title {
  color: var(--seiryu-color-text);
}

/* Transparent: switch logo */
.seiryu-header--transparent .logo-dark  { display: block; }
.seiryu-header--transparent .logo-light { display: block; position: absolute; top: 0; left: 0; }

.seiryu-header--transparent.is-scrolled .logo-light { opacity: 0; }
.seiryu-header--transparent:not(.is-scrolled) .logo-dark  { opacity: 0; }
/* ライトロゴ未設定時はダークロゴを常時表示 */
.seiryu-header--transparent .seiryu-header__logo.no-light-logo .logo-dark { opacity: 1; }

/* Transparent + sticky: position:sticky が position:absolute を上書きするため
   セレクター特異度を上げて fixed で確定させる */
.seiryu-header--transparent.seiryu-header--sticky-always,
.seiryu-header--transparent.seiryu-header--sticky-scroll-up {
  position: fixed;
}

/* Hidden */
.seiryu-header--hidden { display: none; }

/* --------------------------------------------------------------------------
   Sticky
   -------------------------------------------------------------------------- */
.seiryu-header--sticky-always {
  position: sticky;
  top: 0;
}

.seiryu-header--sticky-scroll-up {
  position: sticky;
  top: 0;
  transition:
    transform var(--seiryu-duration-base) var(--seiryu-easing-default),
    background-color var(--seiryu-duration-base) var(--seiryu-easing-default),
    box-shadow var(--seiryu-duration-base) var(--seiryu-easing-default);
}

.seiryu-header--sticky-scroll-up.is-hidden {
  transform: translateY(-100%);
}

.seiryu-header.is-scrolled {
  box-shadow: var(--seiryu-shadow-sm);
}

/* --------------------------------------------------------------------------
   Logo
   -------------------------------------------------------------------------- */
.seiryu-header__logo {
  flex-shrink: 0;
}

.seiryu-header__logo a {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  position: relative;
}

.seiryu-header__logo img {
  height: var(--seiryu-logo-max-height, 48px);
  width: auto;
  max-width: 100%;
  transition: opacity var(--seiryu-duration-fast) var(--seiryu-easing-default);
}

.logo-light { opacity: 1; }
.logo-dark  { opacity: 1; }

.site-title {
  font-family: var(--seiryu-font-heading);
  font-size: var(--seiryu-text-xl);
  font-weight: 700;
  color: var(--seiryu-color-primary);
  text-decoration: none;
}

/* --------------------------------------------------------------------------
   Primary Navigation
   -------------------------------------------------------------------------- */
.seiryu-header__nav {
  flex: 1;
  display: flex;
  justify-content: flex-end;
}

.seiryu-nav-primary {
  display: flex;
  align-items: center;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--seiryu-space-1);
  padding: var(--seiryu-space-2) var(--seiryu-space-4);
  font-size: var(--seiryu-header-menu-font-size, var(--seiryu-text-sm));
  font-weight: 500;
  color: var(--seiryu-color-text);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--seiryu-duration-fast) var(--seiryu-easing-default);
  border-radius: var(--seiryu-radius-sm);
}

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

.nav-item.current-menu-item > .nav-link,
.nav-item.current-menu-ancestor > .nav-link {
  color: var(--seiryu-color-primary);
}

.dropdown-icon {
  transition: transform var(--seiryu-duration-fast) var(--seiryu-easing-default);
  flex-shrink: 0;
}

.nav-item.has-dropdown:hover > .nav-link .dropdown-icon,
.nav-item.has-dropdown > .nav-link[aria-expanded="true"] .dropdown-icon {
  transform: rotate(180deg);
}

/* Dropdown */
.nav-dropdown {
  position: absolute;
  top: calc(100% + var(--seiryu-space-2));
  left: 0;
  min-width: 200px;
  background: var(--seiryu-color-bg);
  border-radius: var(--seiryu-radius-md);
  box-shadow: var(--seiryu-shadow-lg);
  border: 1px solid var(--seiryu-color-border);
  list-style: none;
  padding: var(--seiryu-space-2) 0;
  margin: 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition:
    opacity var(--seiryu-duration-fast) var(--seiryu-easing-default),
    visibility var(--seiryu-duration-fast),
    transform var(--seiryu-duration-fast) var(--seiryu-easing-default);
  z-index: 200;
}

.nav-item.has-dropdown:hover > .nav-dropdown,
.nav-item.has-dropdown:focus-within > .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown .nav-link {
  padding: var(--seiryu-space-2) var(--seiryu-space-4);
  font-size: var(--seiryu-header-menu-font-size, var(--seiryu-text-sm));
  border-radius: 0;
  width: 100%;
}

.nav-dropdown .nav-link:hover {
  background-color: var(--seiryu-color-bg-alt);
}

/* --------------------------------------------------------------------------
   Header Actions
   -------------------------------------------------------------------------- */
.seiryu-header__actions {
  display: flex;
  align-items: center;
  gap: var(--seiryu-space-3);
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   Hamburger Button
   -------------------------------------------------------------------------- */
.seiryu-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 0;
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: var(--seiryu-radius-sm);
  transition: background-color var(--seiryu-duration-fast) var(--seiryu-easing-default);
}

.seiryu-hamburger:hover {
  background-color: var(--seiryu-color-bg-alt);
}

.seiryu-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: currentColor;
  border-radius: 2px;
  transition: transform var(--seiryu-duration-base) var(--seiryu-easing-default),
              opacity var(--seiryu-duration-base) var(--seiryu-easing-default);
}

.seiryu-hamburger.is-active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.seiryu-hamburger.is-active span:nth-child(2) {
  opacity: 0;
}

.seiryu-hamburger.is-active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   Mobile Navigation
   -------------------------------------------------------------------------- */
@media (max-width: 1023px) {
  .seiryu-header__nav { display: none; }
  .seiryu-hamburger   { display: flex; }

  /* ロゴが残りスペースを占有し、アクションを右端に押し出す */
  .seiryu-header__logo { flex: 1; }

  /* CTAボタンは非表示、言語スイッチャー・ハンバーガーは表示 */
  .seiryu-header__actions .btn { display: none; }
}

.seiryu-mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 999;
  visibility: hidden;
}

.seiryu-mobile-nav.is-open {
  visibility: visible;
}

.mobile-nav-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.5);
  opacity: 0;
  transition: opacity var(--seiryu-duration-base) var(--seiryu-easing-default);
}

.seiryu-mobile-nav.is-open .mobile-nav-overlay {
  opacity: 1;
}

.mobile-nav-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: min(360px, 90vw);
  height: 100%;
  background: var(--seiryu-color-bg);
  padding: var(--seiryu-space-6);
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform var(--seiryu-duration-base) var(--seiryu-easing-default);
  display: flex;
  flex-direction: column;
  gap: var(--seiryu-space-6);
}

.seiryu-mobile-nav.is-open .mobile-nav-panel {
  transform: translateX(0);
}

.mobile-nav-close {
  align-self: flex-end;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: var(--seiryu-radius-sm);
  color: var(--seiryu-color-text);
}

.mobile-nav-close:hover {
  background-color: var(--seiryu-color-bg-alt);
}

.mobile-nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
}

.mobile-nav-list .menu-item > a {
  display: block;
  padding: var(--seiryu-space-3) 0;
  font-size: max(var(--seiryu-header-menu-font-size, 14px), var(--seiryu-text-lg));
  font-weight: 500;
  color: var(--seiryu-color-text);
  text-decoration: none;
  border-bottom: 1px solid var(--seiryu-color-border);
}

.mobile-nav-list .menu-item > a:hover {
  color: var(--seiryu-color-primary);
}

.mobile-nav-list .sub-menu {
  list-style: none;
  padding-left: var(--seiryu-space-4);
  margin: 0;
}

.mobile-nav-list .sub-menu .menu-item > a {
  font-size: max(calc(var(--seiryu-header-menu-font-size, 14px) - 1px), var(--seiryu-text-base));
  color: var(--seiryu-color-text-muted);
}

.mobile-nav-cta {
  margin-top: auto;
}

.mobile-nav-cta .btn {
  width: 100%;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   Language Switcher
   -------------------------------------------------------------------------- */
.seiryu-lang-switcher {
  font-size: var(--seiryu-text-sm);
}

/* --------------------------------------------------------------------------
   Search Toggle & Overlay
   -------------------------------------------------------------------------- */
.seiryu-search-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: var(--seiryu-radius-sm);
  color: var(--seiryu-color-text);
  transition: background-color 0.2s, color 0.2s;
}

.seiryu-search-toggle:hover {
  background-color: var(--seiryu-color-bg-alt);
}

.seiryu-header--transparent:not(.is-scrolled) .seiryu-search-toggle {
  color: var(--seiryu-color-text-inverse);
}

.seiryu-search-overlay {
  position: fixed;
  inset: 0;
  z-index: 9998;
  background: rgba(15, 30, 46, 0.92);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s;
}

.seiryu-search-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.seiryu-search-overlay__inner {
  width: 100%;
  max-width: 700px;
  margin-inline: auto;
  position: relative;
  padding-block: var(--seiryu-space-16);
}

/* WordPress デフォルトの search-form をリセット */
.seiryu-search-overlay .search-form {
  display: flex;
  gap: 0;
  border: 2px solid rgba(255,255,255,0.3);
  border-radius: var(--seiryu-radius-full);
  overflow: hidden;
  background: rgba(255,255,255,0.1);
}

.seiryu-search-overlay .search-form label { display: none; }

.seiryu-search-overlay .search-field {
  flex: 1;
  background: transparent;
  border: none;
  padding: var(--seiryu-space-4) var(--seiryu-space-6);
  font-size: var(--seiryu-text-xl);
  color: #fff;
  outline: none;
  font-family: var(--seiryu-font-body);
}

.seiryu-search-overlay .search-field::placeholder { color: rgba(255,255,255,0.5); }

.seiryu-search-overlay .search-submit {
  background: var(--seiryu-color-primary);
  border: none;
  padding: var(--seiryu-space-4) var(--seiryu-space-6);
  color: #fff;
  font-size: var(--seiryu-text-base);
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}

.seiryu-search-overlay .search-submit:hover {
  background: var(--seiryu-color-primary-light);
}

.seiryu-search-overlay__close {
  position: absolute;
  top: var(--seiryu-space-4);
  right: 0;
  background: transparent;
  border: none;
  color: rgba(255,255,255,0.7);
  cursor: pointer;
  padding: var(--seiryu-space-2);
  border-radius: var(--seiryu-radius-sm);
  transition: color 0.2s;
}
.seiryu-search-overlay__close:hover { color: #fff; }

/* --------------------------------------------------------------------------
   Mega Menu
   -------------------------------------------------------------------------- */
.nav-item.has-mega-menu { position: static; }

.nav-mega-panel {
  position: absolute;
  top: calc(100% + var(--seiryu-space-2));
  left: 0;
  right: 0;
  width: 100%;
  background: var(--seiryu-color-bg);
  border-radius: var(--seiryu-radius-md);
  box-shadow: var(--seiryu-shadow-lg);
  border: 1px solid var(--seiryu-color-border);
  padding: var(--seiryu-space-6);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition:
    opacity 0.2s ease,
    visibility 0.2s,
    transform 0.2s ease;
  z-index: 200;
}

.nav-item.has-mega-menu:hover > .nav-mega-panel,
.nav-item.has-mega-menu:focus-within > .nav-mega-panel {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-mega-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--seiryu-space-1);
}

.nav-mega-list .nav-item { position: static; }

.nav-mega-list .nav-link {
  padding: var(--seiryu-space-3) var(--seiryu-space-3);
  border-radius: var(--seiryu-radius-sm);
  white-space: normal;
  line-height: 1.5;
}

.nav-mega-list .nav-link:hover {
  background: var(--seiryu-color-bg-alt);
}

/* 使い方: WP管理 > 外観 > メニュー > 「CSS Classes」フィールドに mega-menu を追加 */