details.item > .a {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  padding-top: 0;
  padding-bottom: 0;
  transition:
    max-height .35s ease,
    opacity .25s ease,
    padding .35s ease;
}

details.item[open] > .a {
  opacity: 1;
  padding-top: 0;
  padding-bottom: 14px;
}

details.item.is-closing > .a {
  opacity: 0 !important;
  padding-bottom: 0 !important;
}

/* Hide default marker */
summary.q::-webkit-details-marker { display: none; }
summary.q { list-style: none; }

:root {
  --text: #111;
  --muted: #666;
  --line: #ddd;
  --bg: #fff;
  --chip: #f5f5f5;
  --accent: #111;
  --radius: 10px;
  --max: 980px;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans JP", sans-serif;
  color: var(--text);
  background: var(--bg);
}

.wrap { max-width: var(--max); margin: 0 auto; padding: 28px 16px 80px; }
.page_container { width: 1100px; margin: 0 auto; }

.headbx { margin-top: 150px; text-align: center; }
.headbx h3 { font-size: 1.8rem; font-weight: 500; }
.headbx h3 span { display: block; }
.headbx p { margin-top: 40px; }

h1 { font-size: 28px; margin: 0 0 6px; }
.sub { color: var(--muted); margin: 0 0 18px; }

.tabs {
  display: flex; flex-wrap: wrap; gap: 8px;
  margin: 40px 0 26px;
  padding: 10px 0; z-index: 10;
  justify-content: center;
}

.tabs a {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 12px;
  text-decoration: none;
  border: 1px solid #000;
  text-align: center;
  font-size: 14px;
}

section { scroll-margin-top: 86px; }

.sec-title {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px;
  margin: 28px 0 10px;
  padding: 12px 0;
}

.sec-title h2 { font-size: 18px; margin: 0; }
.sec-note { color: var(--muted); font-size: 13px; margin: 0; }

.accordion {}
.item { border-top: 1px solid var(--line); }
.item:last-child { border-bottom: 1px solid var(--line); }
.nested:last-child { border-bottom: none !important; }

.q {
  width: 100%;
  text-align: left;
  padding: 14px 14px;
  background: #fff;
  border: 0;
  cursor: pointer;
  display: flex; align-items: center; justify-content: space-between;
  gap: 10px;
  font-size: 15px;
}

.q .label { display: flex; gap: 10px; align-items: flex-start; }
.q .title { line-height: 1.4; font-weight: 500; }

/* ＋ / − 切り替え */
.q .icon {
  position: relative;
  display: inline-block;
  width: 1em;
  right: 20px;
  text-align: center;
  font-weight: 500;
  transition: transform .2s ease;
}

.q .icon::before { content: "＋"; }

/* 親カテゴリ（accordion直下）だけ：開いたら − */
.accordion > details.item[open] > summary.q .icon::before { content: "−"; }

/* 子カテゴリ（nested）：開いたら −（閉じてる時は＋のまま） */
details.nested.item[open] > summary.q .icon::before { content: "−"; }

.a {
  padding: 0 14px 14px;
  color: #222;
  line-height: 1.75;
  font-size: 14px;
}

.a p { margin: 10px 0 0; }
.a ul { margin: 10px 0 0; padding-left: 18px; }
.a li { margin: 6px 0;list-style: disc!important; }

.link {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--accent);
  text-decoration: underline;
}

.snsbx {
  max-width: 1100px;
  width: 100%;
  padding: 100px 0;
}

.snsbx h3 {
  text-align: center;
  font-weight: 500;
  line-height: 1.8;
}

.snsbx h3 span {
  display: block;
  font-size: 2rem;
  text-decoration-line: underline;
}

.snsbx ul {
  width: 15%;
  margin: 20px auto 0;
  display: flex;
  flex-wrap: wrap;
}

.snsbx ul li {
  width: 32%;
  padding: 6%;
  margin-bottom: 20px;
}

.snsbx ul li a {
  display: block;
  padding: 1.5% 2.5% 1.5% 1.5%;
}

.snsbx ul li:hover { opacity: 0.8; }

#page_top {
  width: 40px;
  height: 40px;
  position: fixed;
  right: 20px;
  bottom: 10px;
  background: #AAA;
  border-radius: 50%;
  opacity: 0;
  visibility: hidden;
  transform: translateY(30px);
  transition: all 0.3s ease;
  z-index: 99;
}

#page_top::before {
  content: '';
  border-bottom: solid 2px #FFF;
  border-left: solid 2px #FFF;
  width: 12px;
  height: 12px;
  transform: rotate(135deg);
  position: absolute;
  right: 14px;
  bottom: 12px;
}

#page_top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

@keyframes fadeIn {
  0% { opacity: 0; transform: translateY(-10px); }
  100% { opacity: 1; transform: none; }
}

#pagetitle { margin: 30px 0; }
#pagetitle span { line-height: 1.3em; }

@media only screen and (max-width:834px) {
  .page_container {
    width: 100%;
  }

  .tabs {
    margin: 30px 0 26px;
    padding: 10px;
  }

  .tabs a {
    width: 32%;
    justify-content: center;
  }

  section {
    width: 87%;
    margin: 0 auto;
  }

  .sec-title {
    padding: 12px;
  }

  .snsbx ul {
    width: 30%;
  }

  .snsbx {
    margin: 40px auto 0;
    padding: 0;
  }
}