/* =========================================
   千原組 Webサイト - Main Stylesheet
   CSS Prefix: ch- (CHihara)
   ========================================= */

/* ===== カラー・変数 ===== */
:root {
  /* Primary Colors */
  --ch-navy: #0a3d5c;
  --ch-navy-dark: #06283d;
  --ch-navy-light: #1a5878;

  /* Accent */
  --ch-blue: #2a8fb3;    /* 天草の青 */
  --ch-blue-light: #6bb6d1;
  --ch-red: #c44d3f;     /* 伝統色 朱 */
  --ch-red-dark: #9c3a30;

  /* Neutral */
  --ch-cream: #fafaf7;
  --ch-paper: #f4f1ea;
  --ch-line: #d8d4cb;
  --ch-gray: #6b6b6b;
  --ch-charcoal: #2a2a2a;

  /* Layout */
  --ch-max: 1280px;
  --ch-pad-x: clamp(20px, 5vw, 80px);

  /* Typography */
  --ch-font-mincho: "Shippori Mincho", "游明朝", "Yu Mincho", serif;
  --ch-font-gothic: "Zen Kaku Gothic New", "游ゴシック", "Yu Gothic", sans-serif;
  --ch-font-en: "Shippori Mincho", serif;
}

/* ===== リセット ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--ch-font-gothic);
  font-weight: 400;
  color: var(--ch-charcoal);
  background: var(--ch-cream);
  line-height: 1.8;
  letter-spacing: 0.04em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: opacity 0.3s ease; }
button { background: none; border: none; cursor: pointer; font: inherit; color: inherit; }
ul, ol { list-style: none; }
h1, h2, h3, h4 { font-weight: 500; line-height: 1.4; letter-spacing: 0.04em; }

/* ===== ユーティリティ ===== */
.ch-section-label {
  display: flex;
  align-items: center;
  gap: 16px;
  font-family: var(--ch-font-en);
  margin-bottom: 24px;
}
.ch-section-label__num {
  font-size: 14px;
  color: var(--ch-blue);
  letter-spacing: 0.1em;
}
.ch-section-label__en {
  font-size: 20px;
  letter-spacing: 0.15em;
  color: var(--ch-navy);
  font-weight: 500;
}
.ch-section-label__jp {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: var(--ch-gray);
  padding-left: 16px;
  border-left: 1px solid var(--ch-line);
}
.ch-section-label--light .ch-section-label__num,
.ch-section-label--light .ch-section-label__en {
  color: rgba(255,255,255,0.9);
}
.ch-section-label--light .ch-section-label__jp {
  color: rgba(255,255,255,0.6);
  border-color: rgba(255,255,255,0.2);
}

/* リンク矢印 */
.ch-link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  font-family: var(--ch-font-mincho);
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--ch-navy);
  padding: 8px 0;
  border-bottom: 1px solid var(--ch-navy);
  transition: all 0.4s ease;
}
.ch-link-arrow svg { transition: transform 0.4s ease; }
.ch-link-arrow:hover svg { transform: translateX(8px); }

/* ボタン */
.ch-btn {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 22px 32px;
  font-family: var(--ch-font-mincho);
  font-size: 14px;
  letter-spacing: 0.15em;
  font-weight: 500;
  min-width: 240px;
  position: relative;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.ch-btn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--ch-red);
  transform: translateX(-101%);
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 0;
}
.ch-btn span, .ch-btn svg { position: relative; z-index: 1; }
.ch-btn:hover::before { transform: translateX(0); }
.ch-btn:hover { color: #fff; border-color: var(--ch-red); }

.ch-btn--primary {
  background: var(--ch-navy);
  color: #fff;
  border: 1px solid var(--ch-navy);
}
.ch-btn--ghost {
  background: transparent;
  color: #fff;
  border: 1px solid rgba(255,255,255,0.6);
}
.ch-btn--white {
  background: #fff;
  color: var(--ch-navy);
  border: 1px solid #fff;
}

/* ===== ヘッダー ===== */
.ch-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px var(--ch-pad-x);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(216, 212, 203, 0.4);
  transition: all 0.3s ease;
}
.ch-header__inner {
  max-width: var(--ch-max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
}

.ch-logo {
  display: flex;
  align-items: center;
  gap: 14px;
}
.ch-logo__img {
  height: 44px;
  width: auto;
  display: block;
}
.ch-logo__img--footer {
  filter: brightness(0) invert(1);
  opacity: 0.85;
}
.ch-logo__mark {
  width: 44px;
  height: 44px;
  background: var(--ch-navy);
  color: var(--ch-cream);
  display: grid;
  place-items: center;
  font-family: var(--ch-font-mincho);
  font-size: 22px;
  font-weight: 700;
  transform: rotate(-2deg);
  position: relative;
}
.ch-logo__mark::after {
  content: "";
  position: absolute;
  inset: 4px;
  border: 1px solid rgba(255,255,255,0.3);
}
.ch-logo__mark-img {
  width: 44px;
  height: 44px;
  object-fit: contain;
  display: block;
}
.ch-logo--footer .ch-logo__mark-img {
  opacity: 0.9;
}
.ch-logo__text { display: flex; flex-direction: column; line-height: 1.2; }
.ch-logo__name {
  font-family: var(--ch-font-mincho);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--ch-charcoal);
}
.ch-logo__sub {
  font-family: var(--ch-font-mincho);
  font-size: 10px;
  color: var(--ch-gray);
  letter-spacing: 0.1em;
}

.ch-nav__list {
  display: flex;
  gap: 32px;
}
.ch-nav__list a {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  font-weight: 500;
  color: var(--ch-charcoal);
  padding: 8px 0;
  position: relative;
}
.ch-nav__list a span {
  font-family: var(--ch-font-en);
  font-size: 10px;
  color: var(--ch-blue);
}
.ch-nav__list a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--ch-red);
  transition: width 0.4s ease;
}
.ch-nav__list a:hover::after { width: 100%; }

/* ── ナビ・アコーディオン（会社案内／事業紹介／採用情報／お問い合わせ） ── */
.ch-nav__item { position: relative; display: flex; align-items: center; }
.ch-nav__item--has-sub { gap: 2px; }
.ch-nav__toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  background: none;
  border: none;
  padding: 0;
  color: var(--ch-charcoal);
  cursor: pointer;
}
.ch-nav__toggle-icon {
  display: inline-block;
  font-family: var(--ch-font-en);
  font-size: 16px;
  line-height: 1;
  transition: transform 0.3s ease;
}
/* 「＋」を45度回転させて「×」に見せる＝開いている状態の表現 */
.ch-nav__item.is-open .ch-nav__toggle-icon { transform: rotate(45deg); }
.ch-nav__sub { list-style: none; }

/* PC：項目の直下に展開するドロップダウン */
.ch-nav__sub {
  position: absolute;
  top: 100%;
  left: 0;
  margin-top: 14px;
  min-width: 200px;
  background: #fff;
  border: 1px solid var(--ch-line);
  border-top: 2px solid var(--ch-navy);
  box-shadow: 0 16px 32px rgba(10, 61, 92, 0.14);
  padding: 6px 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
  z-index: 60;
}
.ch-nav__item.is-open .ch-nav__sub {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
/* PC（1025px以上）：クリックではなくマウスホバー／キーボードフォーカスで開閉 */
@media (min-width: 1025px) {
  .ch-nav__item--has-sub:hover .ch-nav__sub,
  .ch-nav__item--has-sub:focus-within .ch-nav__sub {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
  .ch-nav__item--has-sub:hover .ch-nav__toggle-icon,
  .ch-nav__item--has-sub:focus-within .ch-nav__toggle-icon {
    transform: rotate(45deg);
  }
}
.ch-nav__sub li a {
  display: block;
  padding: 10px 20px;
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: var(--ch-charcoal);
  white-space: nowrap;
}
.ch-nav__sub li a:hover { background: var(--ch-paper); color: var(--ch-navy); }

.ch-header__cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: var(--ch-navy);
  color: #fff;
  font-family: var(--ch-font-en);
  font-size: 12px;
  letter-spacing: 0.15em;
  font-weight: 500;
  transition: background 0.3s ease;
}
.ch-header__cta:hover { background: var(--ch-red); }

.ch-burger { display: none; }

/* ===== ヒーロー ===== */
.ch-hero {
  position: relative;
  min-height: 100vh;
  padding: 140px var(--ch-pad-x) 80px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.ch-hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.ch-hero__slides {
  position: absolute;
  inset: 0;
}
.ch-hero__slide {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  will-change: opacity, transform;
}
.ch-hero__slide--active { opacity: 1; }
/* スライド画像（PC=横長 / スマホ=縦トリミング版に切替） */
.ch-hero__slide--1 { background-image: url('../images/top1.jpeg'); }
.ch-hero__slide--3 { background-image: url('../images/top3.jpeg'); }
.ch-hero__slide--4 { background-image: url('../images/top4.jpeg'); }
@media (max-width: 768px) {
  .ch-hero__slide--1 { background-image: url('../images/top1-sp.jpeg'); }
  .ch-hero__slide--3 { background-image: url('../images/top3-sp.jpeg'); }
  .ch-hero__slide--4 { background-image: url('../images/top4-sp.jpeg'); }
}
.ch-hero__bg-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(10, 61, 92, 0.7) 0%, rgba(10, 61, 92, 0.4) 50%, rgba(10, 61, 92, 0.6) 100%);
  z-index: 1;
}
.ch-hero__grain {
  position: absolute;
  inset: 0;
  z-index: 1;
  opacity: 0.4;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.15'/%3E%3C/svg%3E");
}

.ch-hero__content {
  position: relative;
  z-index: 3;
  max-width: var(--ch-max);
  margin: 0 auto;
  width: 100%;
}

.ch-hero__meta {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 60px;
  animation: chFadeUp 1s ease 0.2s both;
}
.ch-hero__since {
  font-family: var(--ch-font-en);
  font-size: 14px;
  letter-spacing: 0.2em;
  color: rgba(255,255,255,0.9);
  font-weight: 500;
}
.ch-hero__divider {
  width: 60px;
  height: 1px;
  background: rgba(255,255,255,0.6);
}
.ch-hero__years {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  letter-spacing: 0.15em;
  color: rgba(255,255,255,0.9);
}

.ch-hero__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(26px, 5vw, 64px);
  font-weight: 600;
  line-height: 1.21;
  letter-spacing: 0.02em;
  color: #fff;
  margin-bottom: 60px;
}
.ch-hero__title-line {
  display: block;
  overflow: hidden;
}
.ch-hero__title-line span,
.ch-hero__title-line {
  animation: chFadeUp 1.2s cubic-bezier(0.4, 0, 0.2, 1) both;
}
.ch-hero__title-line--1 { animation-delay: 0.4s; }
.ch-hero__title-line--2 {
  animation-delay: 0.6s;
}
.ch-hero__title-line--3 {
  animation-delay: 0.8s;
  font-size: 1.2em;
}
.ch-hero__glow {
  color: #fff;
  text-shadow: 0 0 30px rgba(196, 77, 63, 0.9), 0 0 80px rgba(196, 77, 63, 0.6), 0 0 120px rgba(196, 77, 63, 0.3);
}

.ch-hero__lead {
  font-family: var(--ch-font-mincho);
  font-size: clamp(14px, 1.4vw, 17px);
  line-height: 2.2;
  color: rgba(255,255,255,0.9);
  margin-bottom: 50px;
  max-width: 600px;
  animation: chFadeUp 1s ease 1.0s both;
}

.ch-hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  animation: chFadeUp 1s ease 1.2s both;
}

.ch-hero__scroll {
  position: absolute;
  bottom: 40px;
  left: var(--ch-pad-x);
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  font-family: var(--ch-font-en);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: rgba(255,255,255,0.8);
  writing-mode: vertical-rl;
}
.ch-hero__scroll-line {
  width: 1px;
  height: 60px;
  background: rgba(255,255,255,0.4);
  position: relative;
  overflow: hidden;
}
.ch-hero__scroll-line::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 30px;
  background: var(--ch-red);
  animation: chScrollLine 2s ease-in-out infinite;
}
@keyframes chScrollLine {
  0% { transform: translateY(-100%); }
  100% { transform: translateY(200%); }
}

.ch-hero__numbers {
  position: absolute;
  right: var(--ch-pad-x);
  bottom: 40px;
  z-index: 3;
  display: flex;
  gap: 32px;
  padding: 24px 32px;
  background: rgba(10, 61, 92, 0.6);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.1);
  animation: chFadeUp 1s ease 1.4s both;
}
.ch-hero__num { text-align: center; }
.ch-hero__num-value {
  display: block;
  font-family: var(--ch-font-en);
  font-size: 32px;
  font-weight: 500;
  color: #fff;
  line-height: 1;
}
.ch-hero__num-label {
  display: block;
  font-family: var(--ch-font-mincho);
  font-size: 11px;
  color: rgba(255,255,255,0.7);
  margin-top: 8px;
  letter-spacing: 0.1em;
}

@keyframes chFadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== メッセージ ===== */
.ch-message {
  position: relative;
  padding: 160px var(--ch-pad-x);
  background: var(--ch-cream);
  overflow: hidden;
}
.ch-message__container {
  max-width: var(--ch-max);
  margin: 0 auto;
  position: relative;
  z-index: 2;
}
.ch-message__label {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 60px;
  font-family: var(--ch-font-en);
}
.ch-message__label-num {
  font-size: 14px;
  color: var(--ch-blue);
  letter-spacing: 0.1em;
}
.ch-message__label-en {
  font-size: 20px;
  letter-spacing: 0.15em;
  color: var(--ch-navy);
}
.ch-message__label-jp {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: var(--ch-gray);
  padding-left: 16px;
  border-left: 1px solid var(--ch-line);
}

.ch-message__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 500;
  line-height: 1.5;
  color: var(--ch-navy);
  margin-bottom: 60px;
  max-width: 900px;
}
.ch-message__title span { display: block; }
.ch-message__title span:last-child {
  color: var(--ch-red);
  padding-left: 1em;
}

.ch-message__body p {
  font-family: var(--ch-font-mincho);
  font-size: 16px;
  line-height: 2.4;
  color: var(--ch-charcoal);
  margin-bottom: 24px;
}
.ch-message__body strong {
  color: var(--ch-red);
  font-weight: 600;
  padding: 0 4px;
  position: relative;
}
.ch-message__body strong::before {
  content: "";
  position: absolute;
  inset: -2px -4px;
  background: rgba(196, 77, 63, 0.08);
  z-index: -1;
}

.ch-message__photo-bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/amakusa-dolphins.jpeg');
  background-size: cover;
  background-position: center;
  opacity: 0.08;
  z-index: 0;
}
.ch-message__deco {
  position: absolute;
  top: 50%;
  right: -50px;
  transform: translateY(-50%);
  font-family: var(--ch-font-mincho);
  font-size: 480px;
  font-weight: 700;
  color: var(--ch-paper);
  opacity: 0.5;
  z-index: 1;
  line-height: 1;
  user-select: none;
}

.ch-message__map {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 460px;
  height: 460px;
  opacity: 0.5;
  z-index: 1;
  pointer-events: none;
  user-select: none;
}
.ch-message__map img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
@media (max-width: 768px) {
  .ch-message__map { width: 280px; height: 280px; }
}

.ch-message a.ch-link-arrow {
  margin-top: 60px;
}

/* ===== 事業紹介 ===== */
.ch-business {
  padding: 160px var(--ch-pad-x);
  background: var(--ch-paper);
}
.ch-business__head {
  max-width: var(--ch-max);
  margin: 0 auto 80px;
}
.ch-business__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(28px, 4vw, 44px);
  color: var(--ch-navy);
  line-height: 1.6;
}

.ch-business__grid {
  max-width: var(--ch-max);
  margin: 0 auto 100px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--ch-line);
  border-left: 1px solid var(--ch-line);
}

.ch-biz-card {
  padding: 48px 32px;
  background: var(--ch-cream);
  border-right: 1px solid var(--ch-line);
  border-bottom: 1px solid var(--ch-line);
  position: relative;
  transition: all 0.5s ease;
  display: flex;
  flex-direction: column;
  min-height: 380px;
}
.ch-biz-card:hover {
  background: var(--ch-navy);
  color: #fff;
}
.ch-biz-card__num {
  font-family: var(--ch-font-en);
  font-size: 14px;
  color: var(--ch-blue);
  letter-spacing: 0.1em;
  margin-bottom: 24px;
}
.ch-biz-card__visual {
  width: 80px;
  height: 80px;
  margin-bottom: 32px;
  color: var(--ch-navy);
  transition: color 0.5s ease;
}
.ch-biz-card:hover .ch-biz-card__visual { color: var(--ch-blue-light); }
.ch-biz-card:hover .ch-biz-card__num { color: var(--ch-blue-light); }

.ch-biz-card__title {
  font-family: var(--ch-font-mincho);
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: 0.08em;
}
.ch-biz-card__en {
  font-family: var(--ch-font-en);
  font-size: 13px;
  color: var(--ch-gray);
  letter-spacing: 0.1em;
  margin-bottom: 24px;
  transition: color 0.5s ease;
}
.ch-biz-card:hover .ch-biz-card__en { color: rgba(255,255,255,0.6); }

.ch-biz-card__desc {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  line-height: 1.9;
  color: var(--ch-charcoal);
  margin-bottom: auto;
  transition: color 0.5s ease;
}
.ch-biz-card:hover .ch-biz-card__desc { color: rgba(255,255,255,0.85); }

.ch-biz-card__arrow {
  font-size: 24px;
  align-self: flex-end;
  margin-top: 24px;
  transition: transform 0.3s ease;
  font-family: var(--ch-font-en);
}
.ch-biz-card:hover .ch-biz-card__arrow {
  transform: translateX(8px);
  color: var(--ch-red);
}

.ch-biz-card--accent {
  background: var(--ch-navy);
  color: #fff;
}
.ch-biz-card--accent .ch-biz-card__visual { color: var(--ch-blue-light); }
.ch-biz-card--accent .ch-biz-card__en { color: rgba(255,255,255,0.6); }
.ch-biz-card--accent .ch-biz-card__desc { color: rgba(255,255,255,0.85); }
.ch-biz-card--accent .ch-biz-card__num { color: var(--ch-blue-light); }
.ch-biz-card--accent:hover { background: var(--ch-red); }
.ch-biz-card--accent:hover .ch-biz-card__visual { color: #fff; }

/* ICT特集 */
.ch-ict {
  max-width: var(--ch-max);
  margin: 0 auto;
  background: linear-gradient(135deg, var(--ch-navy) 0%, var(--ch-navy-dark) 100%);
  color: #fff;
  padding: 80px 60px;
  position: relative;
  overflow: hidden;
}
.ch-ict::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}
.ch-ict__tag {
  position: absolute;
  top: 32px;
  right: 32px;
  font-family: var(--ch-font-en);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ch-blue-light);
  padding: 8px 16px;
  border: 1px solid var(--ch-blue-light);
}
.ch-ict__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 2;
}
.ch-ict__inner > * { min-width: 0; }
.ch-ict__year {
  font-family: var(--ch-font-en);
  font-size: 18px;
  letter-spacing: 0.15em;
  color: var(--ch-blue-light);
  margin-bottom: 16px;
}
.ch-ict__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(24px, 3vw, 36px);
  margin-bottom: 24px;
  letter-spacing: 0.05em;
}
.ch-ict__desc {
  font-family: var(--ch-font-mincho);
  font-size: 14px;
  line-height: 2;
  color: rgba(255,255,255,0.8);
}
.ch-ict__visual { color: var(--ch-blue-light); }

/* ===== 沿革 ===== */
.ch-history {
  padding: 160px var(--ch-pad-x);
  background: var(--ch-navy);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.ch-history::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 70% 20%, rgba(42, 143, 179, 0.2), transparent 50%);
}
.ch-history__container {
  max-width: var(--ch-max);
  margin: 0 auto;
  position: relative;
  z-index: 2;
}
.ch-history__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(32px, 5vw, 56px);
  margin-bottom: 100px;
  line-height: 1.5;
}
.ch-history__title span { color: var(--ch-blue-light); }

.ch-history__timeline {
  position: relative;
  padding-left: 0;
  max-width: 900px;
}
.ch-history__timeline::before {
  content: "";
  position: absolute;
  left: 100px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: rgba(255,255,255,0.2);
}

.ch-history__item {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 60px;
  padding: 0 0 60px;
  position: relative;
}
.ch-history__item::before {
  content: "";
  position: absolute;
  left: 96px;
  top: 12px;
  width: 9px;
  height: 9px;
  background: var(--ch-blue-light);
  border-radius: 50%;
  z-index: 2;
}
.ch-history__item--latest::before {
  background: var(--ch-red);
  width: 13px;
  height: 13px;
  left: 94px;
  top: 10px;
  box-shadow: 0 0 0 6px rgba(196, 77, 63, 0.2);
}

.ch-history__year {
  font-family: var(--ch-font-en);
  font-size: 42px;
  font-weight: 500;
  line-height: 1;
  color: var(--ch-blue-light);
  text-align: right;
}
.ch-history__era {
  position: absolute;
  left: 0;
  top: 50px;
  width: 100px;
  text-align: right;
  font-family: var(--ch-font-mincho);
  font-size: 11px;
  color: rgba(255,255,255,0.5);
  letter-spacing: 0.1em;
}
.ch-history__content { padding-left: 30px; }
.ch-history__content h3 {
  font-family: var(--ch-font-mincho);
  font-size: 20px;
  margin-bottom: 12px;
  color: #fff;
}
.ch-history__content p {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  line-height: 2;
  color: rgba(255,255,255,0.7);
}

/* ===== 採用CTA ===== */
.ch-recruit-cta {
  padding: 160px var(--ch-pad-x);
  background: #fff;
  position: relative;
  overflow: hidden;
}
.ch-recruit-cta__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 90% 10%, rgba(196, 77, 63, 0.08), transparent 40%),
    radial-gradient(circle at 10% 90%, rgba(42, 143, 179, 0.08), transparent 40%);
}
.ch-recruit-cta__container {
  max-width: var(--ch-max);
  margin: 0 auto;
  position: relative;
  z-index: 2;
  text-align: center;
}
.ch-recruit-cta__label {
  font-family: var(--ch-font-en);
  font-size: 14px;
  letter-spacing: 0.3em;
  color: var(--ch-red);
  margin-bottom: 24px;
}
.ch-recruit-cta__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(32px, 5vw, 64px);
  color: var(--ch-navy);
  line-height: 1.4;
  margin-bottom: 32px;
}
.ch-recruit-cta__lead {
  font-family: var(--ch-font-mincho);
  font-size: 15px;
  line-height: 2.2;
  color: var(--ch-charcoal);
  margin-bottom: 80px;
}
/* 職種カード（写真入りダイナミック版） */
.ch-recruit-cta__jobs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  margin-bottom: 60px;
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
}
.ch-job-card {
  position: relative;
  display: block;
  height: 480px;
  overflow: hidden;
  cursor: pointer;
}
.ch-job-card__photo {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center top;
  transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}
.ch-job-card:hover .ch-job-card__photo {
  transform: scale(1.08);
}
.ch-job-card__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to top,
    rgba(6, 40, 61, 0.92) 0%,
    rgba(6, 40, 61, 0.5) 50%,
    rgba(6, 40, 61, 0.1) 100%
  );
  transition: background 0.5s ease;
}
.ch-job-card:hover .ch-job-card__overlay {
  background: linear-gradient(
    to top,
    rgba(196, 77, 63, 0.85) 0%,
    rgba(10, 61, 92, 0.6) 50%,
    rgba(10, 61, 92, 0.15) 100%
  );
}
.ch-job-card__body {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 40px 32px;
  z-index: 2;
}
.ch-job-card__tag {
  display: inline-block;
  font-family: var(--ch-font-mincho);
  font-size: 11px;
  letter-spacing: 0.15em;
  color: rgba(255,255,255,0.9);
  padding: 5px 12px;
  border: 1px solid rgba(255,255,255,0.5);
  margin-bottom: 16px;
  align-self: flex-start;
  transition: all 0.4s ease;
}
.ch-job-card:hover .ch-job-card__tag {
  background: rgba(255,255,255,0.2);
  border-color: #fff;
}
.ch-job-card__title {
  font-family: var(--ch-font-mincho);
  font-size: 28px;
  font-weight: 600;
  color: #fff;
  line-height: 1.4;
  margin-bottom: 8px;
  letter-spacing: 0.05em;
}
.ch-job-card__en {
  font-family: var(--ch-font-mincho);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.6);
  margin-bottom: 24px;
}
.ch-job-card__arrow {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: rgba(255,255,255,0.8);
  letter-spacing: 0.1em;
  transform: translateY(8px);
  opacity: 0;
  transition: all 0.4s ease;
  display: block;
}
.ch-job-card:hover .ch-job-card__arrow {
  opacity: 1;
  transform: translateY(0);
}

/* 旧スタイル削除 */
.ch-recruit-cta__job { display: none; }
.ch-recruit-cta__job-tag { display: none; }

.ch-recruit-cta a.ch-btn {
  margin-top: 40px;
  background: var(--ch-navy);
  color: #fff;
  border-color: var(--ch-navy);
}

/* ===== お知らせ ===== */
.ch-news {
  padding: 160px var(--ch-pad-x);
  background: #fff;
}
.ch-news__container {
  max-width: var(--ch-max);
  margin: 0 auto;
}
.ch-news__head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 60px;
  flex-wrap: wrap;
  gap: 24px;
}
.ch-news__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(32px, 4vw, 48px);
  color: var(--ch-navy);
}
.ch-news__list { border-top: 1px solid var(--ch-line); }
/* 記事の読み込み中に表示する中立的なプレースホルダー（架空記事を置かないための共通スタイル） */
.ch-news__placeholder {
  padding: 48px 16px;
  text-align: center;
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: var(--ch-gray);
  margin: 0;
}
.ch-news__item {
  display: grid;
  grid-template-columns: 120px 120px 1fr;
  gap: 32px;
  align-items: center;
  padding: 32px 16px;
  border-bottom: 1px solid var(--ch-line);
  transition: all 0.3s ease;
  cursor: pointer;
}
.ch-news__item:hover {
  background: var(--ch-paper);
  padding-left: 32px;
}
.ch-news__item time {
  font-family: var(--ch-font-en);
  font-size: 15px;
  color: var(--ch-gray);
  letter-spacing: 0.05em;
}
.ch-news__cat {
  display: inline-block;
  padding: 6px 12px;
  font-family: var(--ch-font-mincho);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-align: center;
  border: 1px solid;
}
.ch-news__cat--news { color: var(--ch-navy); border-color: var(--ch-navy); }
.ch-news__cat--works { color: var(--ch-blue); border-color: var(--ch-blue); }
.ch-news__cat--recruit { color: var(--ch-red); border-color: var(--ch-red); }
.ch-news__item h3 {
  font-family: var(--ch-font-mincho);
  font-size: 16px;
  font-weight: 500;
  color: var(--ch-charcoal);
}

/* ===== お問い合わせCTA ===== */
.ch-contact-cta {
  padding: 160px var(--ch-pad-x);
  background: linear-gradient(135deg, var(--ch-navy-dark) 0%, var(--ch-navy) 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.ch-contact-cta::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(42, 143, 179, 0.2), transparent 50%);
}

/* 背景画像バージョン */
.ch-contact-cta--photo {
  background: none;
}
.ch-contact-cta--photo::before {
  background-image: url('../images/under-bk.jpeg');
  background-size: cover;
  background-position: center;
}
.ch-contact-cta--photo::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(4, 22, 38, 0.85) 0%,
    rgba(10, 61, 92, 0.72) 50%,
    rgba(4, 22, 38, 0.80) 100%
  );
  z-index: 1;
}
.ch-contact-cta--photo .ch-contact-cta__container { z-index: 2; }
.ch-contact-cta__container {
  max-width: var(--ch-max);
  margin: 0 auto;
  position: relative;
  z-index: 2;
  text-align: center;
}
.ch-contact-cta__en {
  font-family: var(--ch-font-en);
  font-size: 14px;
  letter-spacing: 0.3em;
  color: var(--ch-blue-light);
  margin-bottom: 24px;
}
.ch-contact-cta__title {
  font-family: var(--ch-font-mincho);
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.4;
  margin-bottom: 80px;
}
.ch-contact-cta__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
}
.ch-contact-cta__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 48px 32px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  backdrop-filter: blur(8px);
  transition: all 0.4s ease;
}
.ch-contact-cta__item:hover {
  background: rgba(255,255,255,0.1);
  border-color: var(--ch-blue-light);
  transform: translateY(-4px);
}
.ch-contact-cta__item-label {
  font-family: var(--ch-font-mincho);
  font-size: 12px;
  letter-spacing: 0.15em;
  color: rgba(255,255,255,0.7);
}
.ch-contact-cta__item-value {
  font-family: var(--ch-font-en);
  font-size: 32px;
  font-weight: 500;
  letter-spacing: 0.05em;
}
.ch-contact-cta__item-note {
  font-family: var(--ch-font-mincho);
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

/* ===== フッター ===== */
.ch-footer {
  background: var(--ch-navy-dark);
  color: rgba(255,255,255,0.7);
  padding: 100px var(--ch-pad-x) 32px;
}
.ch-footer__container {
  max-width: var(--ch-max);
  margin: 0 auto;
}
.ch-footer__main {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 80px;
  padding-bottom: 60px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.ch-logo--footer .ch-logo__mark { background: rgba(255,255,255,0.1); }
.ch-logo--footer .ch-logo__name { color: #fff; }
.ch-logo--footer .ch-logo__sub { color: rgba(255,255,255,0.5); }

.ch-footer__address {
  margin-top: 24px;
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  line-height: 2;
}
.ch-footer__license {
  margin-top: 16px;
  font-family: var(--ch-font-mincho);
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

.ch-footer__nav {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 32px 28px;
}
.ch-footer__nav-col h4 {
  font-family: var(--ch-font-en);
  font-size: 14px;
  letter-spacing: 0.15em;
  color: var(--ch-blue-light);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.ch-footer__nav-col ul li { margin-bottom: 12px; }
.ch-footer__nav-col ul a {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: rgba(255,255,255,0.7);
  transition: color 0.3s ease;
}
.ch-footer__nav-col ul a:hover { color: #fff; }

.ch-footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 32px;
  flex-wrap: wrap;
  gap: 16px;
}
.ch-footer__copy {
  font-family: var(--ch-font-en);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.5);
}
.ch-footer__legal {
  display: flex;
  gap: 24px;
}
.ch-footer__legal a {
  font-family: var(--ch-font-mincho);
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

/* =========================================
   レスポンシブ
   ========================================= */
@media (max-width: 1024px) {
  .ch-nav { display: none; }

  /* ── モバイルメニュー（ヘッダー直下のドロップダウン・全項目一覧表示） ── */
  .ch-nav.is-open {
    display: block;
    position: absolute;      /* 固定ヘッダー(.ch-header)基準で直下に展開 */
    top: 100%;
    left: 0;
    right: 0;
    background: #fff;
    border-top: 1px solid var(--ch-line);
    border-bottom: 2px solid var(--ch-navy);
    box-shadow: 0 16px 32px rgba(10, 61, 92, 0.15);
    padding: 4px var(--ch-pad-x) 12px;
    max-height: calc(100vh - 90px);   /* 画面が低い端末では内部スクロール */
    overflow-y: auto;
    animation: ch-nav-fade 0.25s ease;
  }
  @keyframes ch-nav-fade {
    from { opacity: 0; transform: translateY(-6px); }
    to { opacity: 1; transform: translateY(0); }
  }
  .ch-nav.is-open .ch-nav__list {
    flex-direction: column;
    gap: 0;
  }
  .ch-nav.is-open .ch-nav__list li:not(:last-child) {
    border-bottom: 1px solid var(--ch-line);
  }
  .ch-nav.is-open .ch-nav__list a {
    font-size: 15px;
    padding: 15px 4px;
  }
  .ch-nav.is-open .ch-nav__list a span {
    font-size: 11px;
    min-width: 22px;
  }

  /* ── モバイル：サブメニューはドロップダウンではなくその場で開閉するアコーディオンに ── */
  .ch-nav__item { flex-wrap: wrap; }
  .ch-nav__item--has-sub { justify-content: space-between; }
  .ch-nav__toggle { width: 44px; height: 44px; }
  .ch-nav__sub {
    position: static;
    flex-basis: 100%;
    width: 100%;
    max-height: 0;
    overflow: hidden;
    opacity: 1;
    visibility: visible;
    transform: none;
    margin-top: 0;
    padding: 0;
    background: var(--ch-paper);
    border: none;
    box-shadow: none;
    transition: max-height 0.3s ease;
  }
  .ch-nav__item.is-open .ch-nav__sub {
    max-height: 300px;
    padding: 4px 0 8px;
  }
  .ch-nav.is-open .ch-nav__sub a {
    padding: 10px 20px;
    font-size: 13px;
  }

  .ch-burger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    width: 32px;
    height: 32px;
    position: relative;
    z-index: 101;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
  }
  .ch-burger span {
    display: block;
    width: 24px;
    height: 1px;
    background: var(--ch-navy);
    transition: transform 0.3s ease, opacity 0.3s ease;
  }
  /* ── バーガー → ×（閉じる）アニメーション ── */
  .ch-burger.is-active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .ch-burger.is-active span:nth-child(2) { opacity: 0; }
  .ch-burger.is-active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .ch-business__grid { grid-template-columns: repeat(2, 1fr); }
  .ch-ict__inner { grid-template-columns: 1fr; gap: 40px; }
  .ch-footer__main { grid-template-columns: 1fr; gap: 60px; }
  .ch-hero__numbers { position: static; margin-top: 60px; justify-content: center; }
  .ch-hero__scroll { display: none; }
}

@media (max-width: 768px) {
  .ch-header__cta span { display: none; }
  .ch-header__cta { padding: 10px 12px; }

  .ch-hero { padding-top: 120px; padding-bottom: 60px; min-height: auto; }
  .ch-hero__meta { margin-bottom: 40px; flex-wrap: wrap; }
  .ch-hero__title { margin-bottom: 40px; }
  .ch-hero__actions { flex-direction: column; }
  .ch-btn { width: 100%; min-width: 0; }
  .ch-hero__numbers { gap: 20px; padding: 16px 20px; }
  .ch-hero__num-value { font-size: 24px; }

  .ch-message { padding: 100px var(--ch-pad-x); }
  .ch-message__deco { font-size: 280px; right: -30px; }

  .ch-business { padding: 100px var(--ch-pad-x); }
  .ch-business__grid { grid-template-columns: 1fr; }
  .ch-biz-card { min-height: auto; }
  .ch-ict { padding: 48px 24px; }
  .ch-ict__tag { position: static; display: inline-block; margin-bottom: 16px; }

  .ch-history { padding: 100px var(--ch-pad-x); }
  .ch-history__timeline::before { left: 40px; }
  .ch-history__item { grid-template-columns: 80px 1fr; gap: 24px; }
  .ch-history__item::before { left: 36px; }
  .ch-history__item--latest::before { left: 34px; }
  .ch-history__year { font-size: 28px; }
  .ch-history__era { width: 80px; }
  .ch-history__content { padding-left: 16px; }

  .ch-recruit-cta { padding: 100px var(--ch-pad-x); }
  .ch-recruit-cta__jobs { grid-template-columns: 1fr; gap: 2px; }
  .ch-job-card { height: 320px; }

  .ch-news { padding: 100px var(--ch-pad-x); }
  .ch-news__item { grid-template-columns: 1fr; gap: 12px; padding: 24px 16px; }
  .ch-news__item:hover { padding-left: 16px; }
  .ch-news__cat { justify-self: start; }

  .ch-contact-cta { padding: 100px var(--ch-pad-x); }
  .ch-contact-cta__grid { grid-template-columns: 1fr; }

  .ch-footer { padding: 60px var(--ch-pad-x) 24px; }
  .ch-footer__nav { grid-template-columns: 1fr; gap: 32px; }
  .ch-footer__bottom { flex-direction: column; align-items: flex-start; }
}

/* ===== ニュースアコーディオン（トップページ・お知らせページ共通） ===== */
.ch-news-accordion{border-top:1px solid var(--ch-line);}
.ch-news-accordion__item{border-bottom:1px solid var(--ch-line);}
.ch-news-accordion__header{display:grid;grid-template-columns:140px 120px 1fr 40px;gap:24px;align-items:center;padding:28px 16px;cursor:pointer;transition:background .2s;}
.ch-news-accordion__header:hover{background:rgba(10,61,92,.03);}
.ch-news-accordion__header.is-open{background:rgba(10,61,92,.04);}
.ch-news-accordion__date{font-family:var(--ch-font-mincho);font-size:15px;color:var(--ch-gray);letter-spacing:.05em;white-space:nowrap;}
.ch-news-accordion__cat{display:inline-block;padding:5px 12px;font-family:var(--ch-font-mincho);font-size:11px;letter-spacing:.1em;text-align:center;border:1px solid;white-space:nowrap;}
.ch-news-accordion__cat--news{color:var(--ch-navy);border-color:var(--ch-navy);}
.ch-news-accordion__cat--works{color:var(--ch-blue);border-color:var(--ch-blue);}
.ch-news-accordion__cat--recruit{color:var(--ch-red);border-color:var(--ch-red);}
.ch-news-accordion__title{font-family:var(--ch-font-mincho);font-size:16px;font-weight:500;color:var(--ch-charcoal);line-height:1.6;}
.ch-news-accordion__arrow{width:32px;height:32px;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:transform .3s;}
.ch-news-accordion__arrow svg{display:block;}
.ch-news-accordion__header.is-open .ch-news-accordion__arrow{transform:rotate(180deg);}
.ch-news-accordion__body{display:none;padding:0 16px 40px;max-width:800px;}
.ch-news-accordion__body.is-open{display:block;}
.ch-news-accordion__eyecatch{width:100%;max-height:400px;object-fit:cover;display:block;margin-bottom:32px;}
.ch-news-accordion__content{font-family:var(--ch-font-mincho);font-size:15px;line-height:2.2;color:var(--ch-charcoal);}
.ch-news-accordion__content h2{font-size:20px;font-weight:700;margin:32px 0 16px;color:var(--ch-navy);}
.ch-news-accordion__content h3{font-size:17px;font-weight:600;margin:28px 0 12px;color:var(--ch-navy);}
.ch-news-accordion__content p{margin:0 0 20px;}
.ch-news-accordion__content ul,.ch-news-accordion__content ol{padding-left:1.5em;margin:0 0 20px;}
.ch-news-accordion__content li{margin-bottom:8px;}
.ch-news-accordion__content img{max-width:100%;height:auto;display:block;margin:24px auto;}
.ch-news-accordion__content a{color:var(--ch-blue);text-decoration:underline;}
@media(max-width:768px){
  .ch-news-accordion__header{grid-template-columns:1fr 40px;grid-template-rows:auto auto;gap:10px 8px;padding:20px 12px;}
  .ch-news-accordion__date{grid-column:1;grid-row:1;font-size:13px;}
  .ch-news-accordion__cat{grid-column:1;grid-row:1;justify-self:end;font-size:10px;padding:4px 10px;}
  .ch-news-accordion__title{grid-column:1;grid-row:2;font-size:14px;}
  .ch-news-accordion__arrow{grid-column:2;grid-row:1/3;align-self:center;}
  .ch-news-accordion__body{padding:0 12px 32px;}
}

/* ===== ページネーション（お知らせ・施工実績 共通） ===== */
.ch-pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 56px;
}
.ch-pagination button {
  min-width: 42px;
  height: 42px;
  padding: 0 12px;
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  background: #fff;
  color: var(--ch-charcoal);
  border: 1px solid var(--ch-line);
  cursor: pointer;
  transition: all 0.2s ease;
}
.ch-pagination button:hover:not(:disabled):not(.is-current) {
  border-color: var(--ch-navy);
  color: var(--ch-navy);
}
.ch-pagination button.is-current {
  background: var(--ch-navy);
  color: #fff;
  border-color: var(--ch-navy);
  cursor: default;
}
.ch-pagination button:disabled {
  opacity: 0.35;
  cursor: default;
}
.ch-pagination__ellipsis {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: var(--ch-gray);
  padding: 0 2px;
}

/* ===== ページトップへ戻るボタン ===== */
.ch-scrolltop {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--ch-navy);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s, background 0.3s ease;
  z-index: 999;
  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}
.ch-scrolltop.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.ch-scrolltop:hover {
  background: var(--ch-red);
}
@media (max-width: 768px) {
  .ch-scrolltop { right: 16px; bottom: 16px; width: 44px; height: 44px; }
}

/* ===== 差し込み写真スライダー（本文内・複数カットの自動切替） ===== */
.pg-photo-slider__slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  background-size: cover;
  background-position: center;
  transition: opacity 1s ease;
}
.pg-photo-slider__slide--active {
  opacity: 1;
  z-index: 1;
}
.pg-photo-slider__dots {
  position: absolute;
  left: 50%;
  bottom: 14px;
  transform: translateX(-50%);
  display: flex;
  gap: 7px;
  z-index: 3;
}
.pg-photo-slider__dots span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(255,255,255,0.6);
  border: 1px solid rgba(0,0,0,0.15);
  transition: background 0.3s ease;
}
.pg-photo-slider__dots span.is-active {
  background: var(--ch-navy);
}

/* ===== 社用車両紹介（PC：3枚横並び常時表示／モバイル：自動スライドショー） ===== */
.pg-vehicle-group { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.pg-vehicle-group__photo {
  aspect-ratio: 4/3;
  background-size: cover;
  background-position: center;
}
.pg-vehicle-group__caption {
  font-family: var(--ch-font-mincho);
  font-size: 13px;
  color: var(--ch-gray);
  margin-top: 16px;
  text-align: center;
}
.pg-vehicle-group__dots { display: none; }

@media (max-width: 768px) {
  .pg-vehicle-group { display: block; }
  .pg-vehicle-group__item { display: none; }
  .pg-vehicle-group__item--active { display: block; }
  .pg-vehicle-group__caption { text-align: left; }
  .pg-vehicle-group__dots {
    display: flex;
    justify-content: center;
    gap: 7px;
    margin-top: 16px;
  }
  .pg-vehicle-group__dots span {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: rgba(0,0,0,0.15);
    border: 1px solid rgba(0,0,0,0.1);
  }
  .pg-vehicle-group__dots span.is-active { background: var(--ch-navy); }
}