/* =====================================================
   tab.css - タブレット (641〜1024px)
===================================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: #fff;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  height: 60px;
}

/* header__inner を上書き（1段構造・tab用） */
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  padding: 0 20px;
  width: 100%;
}

.header__logo {
  display: flex;
  align-items: center;
  margin-right: 0;
}

.header__logo-img {
  height: 36px;
  width: auto;
}

.header__nav-wrap, .header__actions {
  display: none;
}

/* ナビ・ボタン非表示 */

.header__hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
}

.header__hamburger span {
  display: block;
  height: 2px;
  background: #333;
  transition: transform 0.3s, opacity 0.3s;
  transform-origin: center;
}

.header__hamburger.is-open span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.header__hamburger.is-open span:nth-child(2) {
  opacity: 0;
}

.header__hamburger.is-open span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

.mobile-nav {
  position: fixed;
  top: 60px;
  right: -320px;
  width: 320px;
  height: calc(100vh - 60px);
  background: var(--color-green-dark);
  overflow-y: auto;
  z-index: 999;
  transition: right 0.3s ease;
}

.mobile-nav.is-open {
  right: 0;
}

.mobile-nav__overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.45);
  z-index: 998;
}

.mobile-nav__overlay.is-open {
  display: block;
}

.mobile-nav__list {
  padding: 16px 0;
}

.mobile-nav__item {
  border-bottom: 1px solid rgba(255,255,255,0.12);
}

.mobile-nav__parent {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 16px 24px;
  background: none;
  border: none;
  color: #fff;
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 500;
  cursor: pointer;
  text-align: left;
  transition: color 0.2s;
}

.mobile-nav__parent:hover {
  color: var(--color-green-light);
}

.mobile-nav__arrow {
  font-size: 0.75rem;
}

.mobile-nav__sub {
  max-height: 0;
  overflow: hidden;
  background: rgba(0,0,0,0.15);
  transition: max-height 0.3s ease;
}

.mobile-nav__sub.is-open {
  /* max-height はJSでセット */
}

.mobile-nav__sub li a {
  display: block;
  padding: 10px 24px 10px 36px;
  font-family: var(--font-jp);
  font-size: 0.875rem;
  color: rgba(255,255,255,0.85);
  transition: color 0.2s;
}

.mobile-nav__sub li a:hover {
  color: var(--color-green-light);
}

.mobile-nav__item--btn {
  border-bottom: none;
}

.mobile-nav__img-btn {
  display: block;
  width: 90%;
  margin: 20px auto 0;
  line-height: 0;
  transition: opacity 0.2s;
}

.mobile-nav__img-btn:hover {
  opacity: 0.85;
}

.mobile-nav__btn-img {
  display: block;
  width: 100%;
  height: auto;
}

.mobile-nav__link {
  display: block;
  padding: 16px 24px;
  color: rgba(255,255,255,0.85);
  font-family: var(--font-jp);
  font-size: 0.9375rem;
}

.mobile-nav__parent--link {
  display: block;
  width: 100%;
  padding: 16px 24px;
  color: #fff;
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 500;
  text-align: left;
  background: none;
  border: none;
  cursor: pointer;
}

.mv {
  padding-top: 60px;
}

.mv__slider {
  position: relative;
  width: 100%;
  height: 540px;
  /* height: 460px; */
  overflow: hidden;
}

.mv__slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.8s ease;
}

.mv__slide--active {
  opacity: 1;
}

.mv__slide-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.mv__dots {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  padding: 12px 0;
  background: #fff;
}

.mv__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: none;
  background: var(--color-green-mid);
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}

.mv__dot--active {
  background: var(--color-green-dark);
  transform: scale(1.3);
}

.section-header {
  padding-bottom: 28px;
}

.section-header__title {
  font-size: 2.25rem;
}

.info {
  background: var(--color-bg-gray);
  padding: 56px 0 48px;
}

.info__inner {
  padding: 0 32px;
}

.info__list {
  border-top: 1px solid var(--color-border);
}

.info__item {
  display: block;
  padding: 16px 8px 14px;
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.info__item-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}

.info__date {
  font-family: var(--font-en);
  font-size: 0.8125rem;
  color: var(--color-green-mid);
  white-space: nowrap;
}

.info__tag {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-green-mid);
  color: #fff;
  font-family: var(--font-jp);
  font-size: 0.6875rem;
  padding: 3px 8px;
  border-radius: 3px;
  white-space: nowrap;
  min-width: 60px;
}

.info__link {
  display: inline;
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  color: var(--color-green-dark);
  line-height: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.info__link:hover {
  color: var(--color-green-mid);
}

.info__item > img,
.info__link > img {
  display: inline-block;
  width: 16px;
  height: 16px;
  max-width: none;
  margin: 0 0.25em;
  vertical-align: -2px;
}

.info__file {
  display: inline-flex;
  align-items: center;
  gap: 0.25em;
  margin: 0 0.1em 0 0.25em;
  color: var(--color-text);
  white-space: nowrap;
  vertical-align: -2px;
}

.info__file > img {
  display: block;
  width: 16px;
  height: 16px;
  max-width: none;
  margin: 0;
  flex-shrink: 0;
}

.info__btn-wrap {
  margin-top: 36px;
  text-align: center;
}

.info__more-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: var(--color-green-dark);
  color: #fff;
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 500;
  padding: 9px 40px;
  border-radius: 50px;
  min-width: 220px;
  transition: opacity 0.2s;
}

.info__more-btn:hover {
  opacity: 0.85;
}

.info__more-arrow {
  position: absolute;
  right: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  background: #fff;
  border-radius: 50%;
  flex-shrink: 0;
}

.info__more-arrow span {
  display: block;
  width: 4px;
  height: 4px;
  border-top: 1.5px solid var(--color-green-dark);
  border-right: 1.5px solid var(--color-green-dark);
  transform: rotate(45deg) translate(-1px, 1px);
  margin-left: 2px;
}

.aj-sns {
  background: #fff;
  padding: 56px 0 48px;
}

.aj-sns__inner {
  padding: 0 32px;
  display: flex;
  flex-direction: row;
  gap: 48px;
  align-items: flex-start;
}

/* タブ：journalは固定幅、snsは残り幅 */
.aj-sns__col--journal {
  flex: 0 0 auto;
}

.aj-sns__col--sns {
  flex: 1;
  min-width: 0;
  margin-top: 32px;
}

.aj-sns__col--sns .x_link {
  max-width: 100%;
  width: 320px;
  margin: 10px auto 0;
}
.aj-sns__col--sns .x_link img {
  width: 100%;
  height: auto;
}
.aj-sns__col--sns .x_link img:hover {
  opacity: .6;
}

/* journal見出し：books幅（160px×2+gap20px=340px）に揃えてセンター */
.aj-sns__col--journal .section-header,
.aj-sns__col--journal .section-header--left {
  text-align: center;
  width: 340px;
}

.aj-sns__col--sns .section-header,
.aj-sns__col--sns .section-header--left {
  text-align: center;
}

.journal__books {
  display: flex;
  gap: 20px;
  margin-top: 16px;
  width: 340px;
}

.journal__book {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  flex: 1;
}

.journal__book-img {
  width: 160px;
  height: auto;
  display: block;
  margin-bottom: 10px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.12);
}

.journal__book-name-btn {
  display: block;
  width: 160px;
  background: transparent;
  border: 1px solid var(--color-green-dark);
  border-radius: 50px;
  padding: 7px 10px;
  font-family: var(--font-jp);
  font-size: 0.6875rem;
  color: var(--color-green-dark);
  line-height: 1.5;
  text-align: center;
  transition: background 0.2s;
}

.journal__book-name-btn:hover {
  background: var(--color-green-light);
}

/* .sns__content {
  margin-top: 16px;
  background: #fff;
  border: 1px solid #ddd;
  min-height: 300px;
  display: block;
  overflow: hidden;
}

.sns__content .twitter-timeline,
.sns__content iframe {
  display: block !important;
  width: 100% !important;
}

.sns__placeholder {
  font-family: var(--font-jp);
  font-size: 1.25rem;
  color: var(--color-green-dark);
} */

.research-group {
  background: var(--color-bg-gray);
  padding: 32px 0;
}

.research-group__inner {
  padding: 0 32px;
  display: flex;
  align-items: stretch;
  height: 220px;
}

.research-group__photo {
  flex: 0 0 42%;
  overflow: hidden;
}

.research-group__photo-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.research-group__panel {
  flex: 1;
  position: relative;
  background: var(--color-green-dark);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 28px 36px;
  overflow: hidden;
  text-decoration: none;
}

.research-group__texture {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.12;
  transition: opacity 0.3s;
}

.research-group__content {
  position: relative;
  z-index: 1;
}

.research-group__en {
  font-family: var(--font-en);
  font-size: 1rem;
  color: rgba(255,255,255,0.9);
  display: block;
  margin-bottom: 6px;
  letter-spacing: 0.04em;
}

.research-group__title {
  font-family: var(--font-jp);
  font-size: 1.75rem;
  font-weight: 700;
  color: #fff;
}

.research-group__arrow-btn {
  position: absolute;
  right: 20px;
  bottom: 16px;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border: 2px solid rgba(255,255,255,0.8);
  border-radius: 50%;
  color: #fff;
}

.geographical {
  background: #fff;
  padding: 56px 0 48px;
}

.geographical__inner {
  padding: 0 32px;
}

.geographical__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.geographical__item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-green-light);
  border: 1px solid var(--color-green-mid);
  padding: 14px 20px 14px 24px;
  border-radius: 12px;
  font-family: var(--font-jp);
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--color-green-mid);
  min-height: 70px;
  transition: background 0.2s;
}

.geographical__item-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  background: var(--color-green-mid);
  border-radius: 50%;
}

.geographical__item-arrow::after {
  content: '';
  display: block;
  width: 6px;
  height: 6px;
  border-top: 2px solid #fff;
  border-right: 2px solid #fff;
  transform: rotate(45deg) translate(-1px, 1px);
}

.bnr-3col {
  background: var(--color-bg-gray);
  padding: 28px 0;
}

.bnr-3col__inner {
  padding: 0 32px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.bnr-3col__img {
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
}

.bnr-sample {
  background: var(--color-bg-bnr);
  padding: 48px 0;
}

.bnr-sample__inner {
  padding: 0 32px;
}

.bnr-sample__row--wide {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 12px;
}

.bnr-sample__row--small {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.bnr-sample__item {
  display: flex;
  align-items: center;
  justify-content: center;
  background: #fff;
}

.bnr-sample__item--wide {
  width: 100%;
  height: 100px;
}

.bnr-sample__item--small {
  height: 56px;
}

.bnr-sample__text {
  font-family: var(--font-jp);
  font-size: 1rem;
  color: #aaa;
}

.footer__inner {
  padding: 40px 32px 0;
}

.footer__logo-wrap {
  margin-bottom: 32px;
}

.footer__logo-img {
  height: 40px;
}

.footer__nav {
  grid-template-columns: repeat(2, 1fr);
  gap: 28px 32px;
  padding-bottom: 40px;
}

.footer__bottom {
  padding: 16px 0 24px;
}

.footer__copy {
  font-size: 0.75rem;
}

/* =====================================================
   下層ページ：「雑草学」って何？ (about_ws)
===================================================== */
.what_ws {
  padding-top: 88px; /* 固定ヘッダー(60px)分の余白 */
}

/* ── アンカーナビ（目次） ── */
.what_ws .anchor_nav .section_inner {
  width: 88%;
  max-width: 900px;
  margin: 0 auto;
}
.what_ws .anchor_nav .section_inner > h2 {
  text-align: center;
  font-size: 1.875rem;
  color: #0f9900;
}
.what_ws .anchor_nav .section_inner > h3 {
  color: #666;
  font-weight: 500;
  text-align: center;
}
.what_ws .anchor_nav .section_inner .nav_wrap {
  margin-top: 40px;
}
.what_ws .anchor_nav .section_inner .nav_wrap > h3 {
  font-size: 1.375rem;
  font-weight: 700;
}
.what_ws .anchor_nav .section_inner .nav_wrap > ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  margin-top: 14px;
}
/* 目次リンクは2カラム */
.what_ws .anchor_nav .section_inner .nav_wrap > ul li {
  width: 48.5%;
  border: solid 1px #ddd;
  border-radius: 4px;
  margin-bottom: 16px;
}
.what_ws .anchor_nav .section_inner .nav_wrap > ul li a {
  display: block;
  padding: 12px 24px;
}
.what_ws .anchor_nav .section_inner .nav_wrap > ul li a:hover {
  background-color: #ddd;
}
.what_ws .anchor_nav .section_inner .nav_wrap > ul li a span {
  padding: 2px 6px;
  border-radius: 4px;
  background-color: #0f9900;
  color: #fff;
  margin-right: 8px;
}

/* ── 本文 ── */
.what_ws .content_wrap {
  width: 88%;
  max-width: 900px;
  margin: 0 auto;
  padding-bottom: 48px;
  border-bottom: solid 1px #ccc;
}
.what_ws .content_wrap .section_inner {
  padding-top: 90px; /* アンカー位置＋固定ヘッダー分のオフセット */
}
.what_ws .content_wrap .section_inner .return_nav {
  width: 100%;
  text-align: right;
}
.what_ws .content_wrap .section_inner .return_nav a {
  font-size: 1.0625rem;
  color: #004d99;
  text-decoration: underline;
}
.what_ws .content_wrap .section_inner .return_nav a:hover {
  text-decoration: none;
}
.what_ws .content_wrap .section_inner > h2 {
  font-size: 1.625rem;
  line-height: 1.5em;
  font-weight: 700;
  text-align: center;
  margin-bottom: 52px;
}
.what_ws .content_wrap .section_inner > h2 span {
  font-size: 1.375rem;
  background-color: #0f9900;
  color: #fff;
  border-radius: 6px;
  padding: 3px 8px;
  margin-right: 12px;
}
.what_ws .content_wrap .section_inner > h3 {
  font-size: 1.1875rem;
  line-height: 1.5em;
  font-weight: 700;
  margin-bottom: 18px;
}
/* 2カラム（横並びを維持し比率を微調整） */
.what_ws .content_wrap .section_inner .two_column {
  display: flex;
  justify-content: space-between;
  margin-bottom: 64px;
}
.what_ws .content_wrap .section_inner .two_column .text_wrap {
  width: 50%;
}
.what_ws .content_wrap .section_inner .two_column .text_wrap > h4 {
  font-weight: 600;
  margin-bottom: 8px;
}
.what_ws .content_wrap .section_inner .two_column .text_wrap > p {
  line-height: 1.7em;
  margin-bottom: 16px;
}
.what_ws .content_wrap .section_inner .two_column .photo_wrap {
  width: 46%;
}
.what_ws .content_wrap .section_inner .two_column .photo_wrap .photo img {
  width: 100%;
  height: auto;
}
.what_ws .content_wrap .section_inner .two_column .photo_wrap .caption {
  font-size: 0.875rem;
  color: #555;
  text-align: center;
  margin-top: 6px;
}
/* 1カラム */
.what_ws .content_wrap .section_inner .one_column {
  margin-bottom: 64px;
}
.what_ws .content_wrap .section_inner .one_column > p {
  line-height: 1.7em;
  margin-bottom: 16px;
}
.what_ws .content_wrap .section_inner .one_column .photo_wrap {
  width: 72%;
  margin: 48px auto 0;
}
.what_ws .content_wrap .section_inner .one_column .photo_wrap .photo img {
  width: 100%;
  height: auto;
}
.what_ws .content_wrap .section_inner .one_column .photo_wrap .caption {
  font-size: 0.875rem;
  color: #555;
  text-align: center;
  margin-top: 6px;
}
.one_column a {
  font-weight: 600;
  color: #004d99;
  text-decoration: underline;
}
.one_column a:hover {
  text-decoration: none;
}
.ending {
  text-align: right;
  line-height: 1.7em;
}
.copyright {
  text-align: center;
  font-size: 0.875rem;
  line-height: 1.7em;
  margin: 48px 0 28px;
}
.return_top {
  width: 340px;
  margin: 56px auto 24px;
}
.return_top a {
  display: block;
  text-align: center;
  border: solid 1px #ccc;
  border-radius: 8px;
  padding: 10px 14px;
}
.return_top a:hover {
  background-color: #ccc;
}