:root {
  --main-width: 960px;
  --side-top: 180px;

  --side-width-wide: 220px;
  --side-width-mid: 170px;
  --side-space: 220px;

  --side-color: #1f447a;
  --side-hover: #1b5292;

  --title-clearance: 260px;

  --card-bg: #f2f5fb;
  --card-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);

  --submenu-gap: 14px;
  --submenu-min-width: 280px;
}


/* =========================
   レイアウト
========================= */
.frame {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  width: 100%;
  max-width: 100%;
}
.frame::after {
  content: "";
  flex: 0 0 var(--side-space);
  width: var(--side-space);
}
.frame > main {
  flex: 1 1 auto;
  width: auto;
  max-width: min(
    var(--main-width),
    calc(100% - (var(--side-space) * 2))
  );
  min-width: 0;
  margin-left: 0 !important;
  margin-right: 0 !important;
}


/* =========================
   サイドメニュー本体
========================= */
#side-menu {
  position: sticky;
  top: var(--side-top);
  align-self: flex-start;
  flex: 0 0 var(--side-space);
  width: var(--side-space);
  height: 0;
  padding-top: 8px;
  box-sizing: border-box;
  overflow: visible;
  z-index: 100;
}
.frame:has(main .page-top-marker) #side-menu {
  margin-top: var(--title-clearance);
}
#side-menu .side-menu-inner {
  position: relative;
  width: 80%;
}
#side-menu a {
  color: var(--side-color);
  text-decoration: none;
}
#side-menu .side-nav,
#side-menu .side-nav-level {
  margin: 0;
  padding: 0;
  list-style: none;
}
#side-menu .side-nav {
  position: relative;
}


/* =========================
   TOPリンク
========================= */
#side-menu .home-label-vertical {
  display: none;
}
#side-menu .side-menu-home {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 26px;
  color: var(--side-color);
  font-size: 14px;
  font-weight: 700;
}
#side-menu .side-menu-home::before {
  content: "";
  width: 5px;
  height: 9px;
  background: url(/nism/common/images/ico_arrow03.png)
              no-repeat center;
  background-size: 5px auto;
}
#side-menu .side-menu-home:hover {
  color: var(--side-hover);
  text-decoration: underline;
}


/* =========================
   1階層目
========================= */
#side-menu .side-nav-level1 > li {
  position: static;
}
#side-menu .side-nav-level1 > li + li {
  margin-top: 12px;
}

/* タイトル＋ジャンプボタン */
#side-menu .side-nav-row {
  position: relative;
  display: flex;
  align-items: stretch;
  border-left: 3px solid transparent;
  transition:
    background-color 0.18s ease,
    border-color 0.18s ease;
}
#side-menu .side-nav-row:active {
  transform: translateY(1px);
  background: rgba(31, 68, 122, 0.12);
}

/* hoverの隙間を埋める */
#side-menu .side-nav-row::after {
  content: "";
  position: absolute;
  top: 0;
  left: 100%;
  width: var(--submenu-gap);
  height: 100%;
}

/* 1階層タイトル */
#side-menu .side-nav-trigger {
  flex: 1;
  display: block;
  padding: 4px;

  color: var(--side-color);
  text-decoration: none;

  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;

  text-align: left;
}

/* トップページ該当位置へ移動するマーク */
#side-menu .side-nav-jump {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  border: 0;
  border-left: 1px solid rgba(31, 68, 122, 0.15);
  background: transparent;
  color: var(--side-color);
  font-family: inherit;
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  transition:
    opacity 0.18s ease,
    background-color 0.18s ease;
}

/* hover・固定 */
#side-menu .side-nav-level1 > li:hover > .side-nav-row,
#side-menu .side-nav-level1 > li.is-pinned > .side-nav-row {
  background: rgba(31, 68, 122, 0.10);
  border-left-color: var(--side-color);
  box-shadow: inset 0 0 0 1px rgba(31, 68, 122, 0.10);
}
#side-menu .side-nav-level1 > li:hover .side-nav-jump,
#side-menu .side-nav-row:focus-within .side-nav-jump {
  opacity: 1;
}
#side-menu .side-nav-level1 > li.is-pinned .side-nav-jump {
  opacity: 1;
  background: rgba(31, 68, 122, 0.12);
}

#side-menu .side-nav-jump span {
  display: inline-block;
  transition: transform 0.18s ease;
}

#side-menu .side-nav-level1 > li.is-pinned .side-nav-jump span {
  transform: rotate(90deg);
}
#side-menu .side-nav-jump:hover {
  background: rgba(31, 68, 122, 0.12);
  color: var(--side-hover);
}

/* 接続ライン */
#side-menu .side-nav-level1 > li:hover > .side-nav-row::before,
#side-menu .side-nav-level1 > li.is-pinned > .side-nav-row::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 100%;
  width: var(--submenu-gap);
  height: 2px;
  background: var(--side-hover);
  transform: translateY(-50%);
}


/* =========================
   2階層目
========================= */
#side-menu .side-nav-level2 {
  position: absolute;
  top: 0;
  left: calc(100% + var(--submenu-gap));
  min-width: var(--submenu-min-width);
  padding: 12px;
  box-sizing: border-box;
  background: var(--card-bg);
  border: 1px solid rgba(31, 68, 122, 0.18);
  border-left: 4px solid var(--side-color);
  border-radius: 2px;
  box-shadow: var(--card-shadow);
  opacity: 0;
  visibility: hidden;
  transition:
    opacity 0.15s ease,
    visibility 0.15s ease;
  z-index: 200;
}

/* submenuまでの隙間 */
#side-menu .side-nav-level2::before {
  content: "";
  position: absolute;
  top: 0;
  right: 100%;
  width: var(--submenu-gap);
  height: 100%;
}

/* hover / click固定で表示 */
#side-menu .side-nav-level1 > li:hover > .side-nav-level2,
#side-menu .side-nav-level1 > li.is-pinned > .side-nav-level2 {
  opacity: 1;
  visibility: visible;
}

/* 固定中に別の1階層目へhoverした場合はhover側を優先 */
#side-menu .side-nav-level1:has(> li:hover)
> li.is-pinned:not(:hover)
> .side-nav-level2 {
  opacity: 0;
  visibility: hidden;
}
#side-menu .side-nav-level2 > li {
  position: static;
}
#side-menu .side-nav-level2 > li + li {
  margin-top: 3px;
}
#side-menu .side-nav-level2 > li > a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px;
  color: var(--side-color);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  transition:
    background-color 0.15s ease,
    color 0.15s ease;
}
#side-menu .side-nav-level2 > li > a:hover {
  background: rgba(31, 68, 122, 0.08);
  color: var(--side-hover);

  text-decoration: underline;
  text-underline-offset: 3px;
}

/* 3階層目がある項目 */
#side-menu .side-nav-level2 > .has-children > a::after {
  content: "›";
  margin-left: 16px;
  font-size: 22px;
  font-weight: 400;
}


/* =========================
   3階層目
========================= */
#side-menu .side-nav-level3 {
  position: absolute;
  top: 0;
  left: calc(100% + var(--submenu-gap));
  min-width: 250px;
  padding: 12px;
  box-sizing: border-box;
  background: var(--card-bg);
  border: 1px solid rgba(31, 68, 122, 0.18);
  border-left: 4px solid var(--side-color);
  border-radius: 2px;
  box-shadow: var(--card-shadow);
  opacity: 0;
  visibility: hidden;
  transition:
    opacity 0.15s ease,
    visibility 0.15s ease;
  z-index: 210;
}

/* 2階層目 → 3階層目の隙間 */
#side-menu .side-nav-level3::before {
  content: "";
  position: absolute;
  top: 0;
  right: 100%;
  width: var(--submenu-gap);
  height: 100%;
}

/* 2階層目hoverで表示 */
#side-menu .side-nav-level2 > li:hover > .side-nav-level3,
#side-menu .side-nav-level2 > li:focus-within > .side-nav-level3 {
  opacity: 1;
  visibility: visible;
}
#side-menu .side-nav-level3 li + li {
  margin-top: 3px;
}
#side-menu .side-nav-level3 a {
  display: block;
  padding: 4px;
  color: var(--side-color);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  transition:
    background-color 0.15s ease,
    color 0.15s ease;
}
#side-menu .side-nav-level3 a:hover {
  background: rgba(31, 68, 122, 0.08);
  color: var(--side-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}


@media screen and (min-width: 1500px) {
  :root {
    --side-space: clamp(
      var(--side-width-wide),
      calc((100vw - var(--main-width)) / 2 - 60px),
      260px
    );
  }
}

@media screen and (max-width: 1499px) and (min-width: 1281px) {
  :root {
    --side-space: clamp(
      var(--side-width-mid),
      calc((100vw - var(--main-width)) / 2 - 58px),
      190px
    );

    --submenu-min-width: 240px;
  }
  #side-menu .side-menu-home {
    font-size: 12px;
  }
  #side-menu .side-nav-trigger {
    font-size: 14px;
  }
  #side-menu .side-nav-level2 > li > a {
    font-size: 14px;
  }
}

/* =========================
   1025 ～ 1280px
   縦文字サイドメニュー
========================= */
@media screen and (max-width: 1280px) and (min-width: 1025px) {
  :root {
    --side-space: 72px;
    --submenu-gap: 10px;
    --submenu-min-width: 240px;
  }
  #side-menu .side-menu-inner {
    width: 100%;
  }
  /* TOP */
  #side-menu .home-label-pc {
    display: none;
  }
  #side-menu .home-label-vertical {
    display: inline;
  }
  #side-menu .side-menu-home {
    justify-content: center;
    width: 100%;
    margin-bottom: 12px;
    font-size: 12px;
  }
  #side-menu .side-menu-home::before {
    content: none;
  }
  /* 1階層 */
  #side-menu .side-nav-level1 > li + li {
    margin-top: 8px;
  }
  #side-menu .side-nav-row {
    flex-direction: column;
    align-items: center;
  }
  #side-menu .side-nav-trigger {
    flex: none;
    padding: 4px;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    white-space: nowrap;
    font-size: 11px;
    line-height: 1;
    text-align: left;
  }
  #side-menu .side-nav-jump {
    width: 100%;
    height: 15px;
    border-left: 0;
    border-top: 1px solid rgba(31, 68, 122, 0.15);
    font-size: 10px;
  }
  /* 接続ライン */
  #side-menu .side-nav-level1 > li:hover > .side-nav-row::before,
  #side-menu .side-nav-level1 > li.is-pinned > .side-nav-row::before {
    top: 50%;
    left: 100%;
  }
  #side-menu .side-nav-level2 {
    min-width: 240px;
  }
  #side-menu .side-nav-level2 > li > a {  
    font-size: 12px;
  }
  #side-menu .side-nav-level3 {
    min-width: 240px;
  }  
  #side-menu .side-nav-level3 a {
    font-size: 12px;
  }
}

/* =========================
   1024px以下
   サイドメニュー非表示
========================= */
@media screen and (max-width: 1024px) {
  :root {
    --side-space: 0px;
  }
  #side-menu {
    display: none !important;
  }
  .frame::after {
    content: none;
    display: none;
    flex: 0 0 0;
    width: 0;
  }
  .frame > main {
    flex: 1 1 auto;
    width: auto;
    max-width: 100%;
    margin-left: 0 !important;
    margin-right: 0 !important;
  }
}