@charset "utf-8";

/* --------------------------------------------------
   1. 初期化・共通設定
-------------------------------------------------- */
*,
::before,
::after {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

ul,
ol {
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

body {
  color: #ffffff;
  background-color: #2b2b2b;
  font-family: sans-serif;
  font-size: 16px;
  line-height: 1;
}

.dark-mode {
  background-color: #2b2b2b;
  color: #fff;
}

/* --------------------------------------------------
   2. ヘッダー本体のスタイル (モダン化)
-------------------------------------------------- */
.header {
  position: sticky;
  /* 常に上部に固定 */
  top: 0;
  width: 100%;
  background-color: rgba(43, 43, 43, 0.85);
  /* すりガラス効果 */
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

/* JSでスクロール時に付与されるクラス */
.header.is-scrolled {
  background-color: rgba(30, 30, 30, 0.95);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.header-inner {
  max-width: 1400px;
  height: 80px;
  /* 110pxからスリム化して画面を広く */
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.toggle-menu-button {
  display: none;
}

.header-logo {
  display: block;
  width: 65px;
  transition: transform 0.2s ease;
}

.header-logo:hover {
  transform: scale(1.05);
}

/* --------------------------------------------------
   3. ナビゲーションメニュー (PC)
-------------------------------------------------- */
.header-site-menu {
  flex: 1;
  display: flex;
  justify-content: flex-end;
  overflow-x: auto;
  /* 画面が狭い時は横スクロール可能に */
  scrollbar-width: none;
}

.header-site-menu::-webkit-scrollbar {
  display: none;
}

.site-menu ul {
  display: flex;
  align-items: center;
  gap: 24px;
  padding-right: 5px;
}

.site-menu ul li {
  white-space: nowrap;
}

.site-menu ul li a {
  font-family: 'Noto Sans JP', sans-serif;
  font-weight: bold;
  font-size: 14px;
  color: #dcdcdc;
  padding: 8px 0;
  position: relative;
  transition: color 0.3s ease;
}

.site-menu ul li a:hover,
.site-menu ul li a.active {
  color: #ffffff;
}

/* ピンクを避けたブルー系のモダンな下線アニメーション */
.site-menu ul li a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: #3f98ef;
  transition: width 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  border-radius: 2px;
}

.site-menu ul li a:hover::after,
.site-menu ul li a.active::after {
  width: 100%;
}

/* --------------------------------------------------
   4. トップへ戻るボタン (元の設定を維持)
-------------------------------------------------- */
#page_top {
  display: none;
  width: 50px;
  height: 50px;
  position: fixed;
  right: 0;
  bottom: 50px;
  background: #3f98ef;
  opacity: 0.6;
  border-radius: 50%;
  z-index: 999;
}

#page_top a {
  position: relative;
  display: block;
  width: 50px;
  height: 50px;
  text-decoration: none;
}

#page_top a::before {
  font-family: 'Font Awesome 5 Free';
  font-weight: 900;
  content: '\f102';
  font-size: 25px;
  color: #fff;
  position: absolute;
  width: 25px;
  height: 25px;
  top: -5px;
  bottom: 0;
  right: 0;
  left: 0;
  margin: auto;
  text-align: center;
}

/* --------------------------------------------------
   5. モバイル設定 (max-width: 800px)
-------------------------------------------------- */
@media (max-width: 800px) {
  .header {
    position: fixed;
    height: 50px;
    background-color: #2b2b2b;
    border-bottom: none;
    backdrop-filter: none;
    /* モバイルでは動作を軽くするためオフ */
  }

  .header.is-scrolled {
    background-color: #222222;
  }

  .header-inner {
    height: 100%;
  }

  .header-logo {
    width: 45px;
  }

  .site-menu ul {
    display: block;
    text-align: center;
  }

  /* 以下は hamburger.css で開閉されるため初期状態を非表示に */
  .header-site-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
  }

  .header-site-menu.is-show {
    display: block;
  }
}