/*
 * サイトのヘッダー（header.php）。ページ上部の暗い写真の上では透明で、
 * 文字は白（data-over="true"）。ページをスクロールすると assets/js/site.js が白い背景に切り替える。
 */
.site-header {
  position: fixed;
  inset-inline: 0;
  top: 0;
  z-index: 50;
  background: rgb(255 255 255 / 0.9);
  box-shadow: 0 1px 0 rgba(15, 23, 41, 0.06);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  transition: background-color 0.3s var(--ease);
}

.site-header[data-over="true"] {
  background: transparent;
  box-shadow: none;
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 80rem;
  height: var(--header-height);
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.site-header__logo {
  position: relative;
  z-index: 10;
  display: block;
}

.site-header__logo img {
  width: auto;
  height: 2rem;
}

/* 白地では紺色のロゴ、写真の上では白いロゴ */
.site-header__logo-white,
.site-header[data-over="true"] .site-header__logo-navy {
  display: none;
}

.site-header[data-over="true"] .site-header__logo-white {
  display: block;
}

/* パソコン用のメニュー（1024px 以上） */
.site-header__nav {
  display: none;
}

.site-header__menu {
  display: flex;
  align-items: center;
  gap: 2.25rem;
}

.site-header__link {
  position: relative;
  padding-block: 0.5rem;
  color: var(--color-navy-900);
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1.4286;
  letter-spacing: 0.05em;
  transition: color 0.15s var(--ease);
}

.site-header[data-over="true"] .site-header__link {
  color: var(--color-white);
}

/* ホバーで伸び、今いるセクションでは出たままになる下線 */
.site-header__link::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  bottom: -0.125rem;
  height: 0.125rem;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.15s var(--ease);
}

.site-header__link:hover::after,
.site-header__link[aria-current="page"]::after {
  transform: scaleX(1);
}

.site-header__contact {
  display: inline-block;
  border-radius: var(--radius-round);
  background: var(--color-navy-900);
  padding: 0.75rem 1.5rem;
  color: var(--color-white);
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1.4286;
  letter-spacing: 0.05em;
  transition: background-color 0.15s var(--ease), color 0.15s var(--ease);
}

.site-header__contact:hover {
  background: var(--color-yellow-soft);
  color: var(--color-navy-900);
}

.site-header[data-over="true"] .site-header__contact {
  background: var(--color-white);
  color: var(--color-navy-900);
}

.site-header[data-over="true"] .site-header__contact:hover {
  background: var(--color-yellow-soft);
}

/* スマホ・タブレット用のメニューボタン：2本の線が X に変わる */
.menu-toggle {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  cursor: pointer;
}

.menu-toggle__icon {
  position: relative;
  display: block;
  width: 1.5rem;
  height: 0.875rem;
}

.menu-toggle__line {
  position: absolute;
  left: 0;
  width: 1.5rem;
  height: 0.125rem;
  background: var(--color-navy-900);
  transition: all 0.3s var(--ease);
}

.menu-toggle__line:first-child {
  top: 0;
}

.menu-toggle__line:last-child {
  top: 0.75rem;
}

.site-header[data-over="true"] .menu-toggle__line {
  background: var(--color-white);
}

.menu-toggle[aria-expanded="true"] .menu-toggle__line:first-child {
  top: 0.375rem;
  transform: rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle__line:last-child {
  top: 0.375rem;
  transform: rotate(-45deg);
}

/* スマホ・タブレット用の全画面メニュー */
.mobile-menu {
  position: fixed;
  inset: 0;
  top: var(--header-height);
  z-index: 40;
  overflow-y: auto;
  background: var(--color-white);
}

.mobile-menu__nav {
  padding: 2rem 1.25rem;
}

.mobile-menu__list {
  border-block: 1px solid var(--color-line);
}

.mobile-menu__list > li + li {
  border-top: 1px solid var(--color-line);
}

.mobile-menu__link {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding-block: 1.25rem;
}

.mobile-menu__label {
  color: var(--color-navy-900);
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.5556;
}

.mobile-menu__en {
  color: var(--color-muted);
  font-family: var(--font-en);
  font-size: 0.75rem;
  line-height: 1.3333;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

@media (min-width: 640px) {
  .site-header__inner {
    padding-inline: 2rem;
  }

  .site-header__logo img {
    height: 2.25rem;
  }

  .mobile-menu__nav {
    padding-inline: 2rem;
  }
}

@media (min-width: 1024px) {
  .site-header__nav {
    display: block;
  }

  .menu-toggle,
  .mobile-menu {
    display: none;
  }
}