/* AIRIA 空調ダクト工業 — 共有スタイル。クリーン×テクニカルな清潔感を基調 */
:root {
  --bg: #ffffff;
  --fg: #13202b;
  --muted: #5d6b78;
  --accent: #0f9bb0;
  --accent-deep: #0a6f80;
  --surface: #f2f6f8;
  --line: #dde6ea;

  --maxw: 1140px;
  --gap: clamp(1.25rem, 3vw, 2.5rem);
  --radius: 4px;
  --header-h: 68px;

  --font: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Noto Sans JP", Meiryo, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 1rem); }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--fg);
  background: var(--bg);
  line-height: 1.85;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: var(--accent-deep); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 {
  line-height: 1.35;
  letter-spacing: -0.01em;
  font-weight: 700;
  margin: 0 0 0.6em;
}

p { margin: 0 0 1.1em; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: clamp(1.1rem, 4vw, 2rem);
}

.narrow { max-width: 820px; }

/* セクション共通 */
section { padding-block: clamp(3.2rem, 7vw, 6rem); }
.section-surface { background: var(--surface); }

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-deep);
  font-weight: 700;
  margin-bottom: 0.8rem;
}

.section-head { max-width: 760px; margin-bottom: clamp(1.8rem, 4vw, 3rem); }
.section-head h2 { font-size: clamp(1.6rem, 3.4vw, 2.3rem); }
.section-head p { color: var(--muted); margin-bottom: 0; }

/* ボタン */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.85em 1.7em;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  cursor: pointer;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-deep); }
.btn-ghost { border-color: var(--line); color: var(--fg); background: #fff; }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent-deep); }
.btn-light { background: #fff; color: var(--accent-deep); }
.btn-light:hover { background: var(--surface); }
.btn-outline-light { background: transparent; color: #fff; border-color: rgba(255, 255, 255, 0.55); }
.btn-outline-light:hover { background: rgba(255, 255, 255, 0.12); border-color: #fff; color: #fff; }

/* ヘッダー */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.12rem;
  letter-spacing: 0.02em;
  color: var(--fg);
}
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; }
.brand small {
  display: block;
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  color: var(--muted);
  font-weight: 600;
}

.nav { display: flex; align-items: center; gap: 0.3rem; }
.nav a {
  color: var(--fg);
  font-size: 0.92rem;
  font-weight: 600;
  padding: 0.5em 0.85em;
  border-radius: var(--radius);
}
.nav a:hover { color: var(--accent-deep); text-decoration: none; background: var(--surface); }
.nav a[aria-current="page"] { color: var(--accent-deep); }
.nav a[aria-current="page"]::after {
  content: "";
  display: block;
  height: 2px;
  background: var(--accent);
  margin-top: 3px;
  border-radius: 2px;
}
.nav .btn { padding: 0.55em 1.1em; margin-left: 0.4rem; }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  width: 42px;
  height: 38px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
}
.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  display: block;
  width: 20px;
  height: 2px;
  background: var(--fg);
  position: relative;
  transition: transform 0.2s;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }

/* ヒーロー */
.hero {
  position: relative;
  background: var(--surface);
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  align-items: center;
  gap: clamp(1.5rem, 4vw, 3.5rem);
  padding-block: clamp(2.8rem, 6vw, 5rem);
}
.hero-copy h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  line-height: 1.25;
}
.hero-copy .lead { color: var(--muted); font-size: 1.08rem; max-width: 30em; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.8rem; margin-top: 1.6rem; }
.hero-media img {
  width: 100%;
  height: 100%;
  max-height: 460px;
  object-fit: cover;
  border-radius: var(--radius);
  box-shadow: 0 24px 50px -28px rgba(10, 111, 128, 0.5);
}

/* ページヘッダー(下層) */
.page-hero {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding-block: clamp(2.4rem, 5vw, 3.8rem);
}
.page-hero h1 { font-size: clamp(1.8rem, 4vw, 2.7rem); margin-bottom: 0.4rem; }
.page-hero p { color: var(--muted); margin-bottom: 0; max-width: 46em; }
.breadcrumb { font-size: 0.82rem; color: var(--muted); margin-bottom: 0.9rem; }
.breadcrumb a { color: var(--muted); }
.breadcrumb span { margin-inline: 0.4em; }

/* グリッド */
.grid { display: grid; gap: var(--gap); }
.cols-2 { grid-template-columns: repeat(2, 1fr); }
.cols-3 { grid-template-columns: repeat(3, 1fr); }
.cols-4 { grid-template-columns: repeat(4, 1fr); }

/* カード */
.card-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.6rem;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
}
.card-item.lift:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 18px 40px -28px rgba(10, 111, 128, 0.45);
}
.card-item h3 { font-size: 1.18rem; }
.card-item p { color: var(--muted); margin-bottom: 0; font-size: 0.96rem; }
.card-num {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.14em;
}

.icon-badge {
  width: 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--accent-deep);
  margin-bottom: 1rem;
}
.icon-badge svg { width: 24px; height: 24px; }

/* メディア+テキストの交互セクション */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(1.5rem, 4vw, 3.2rem);
  align-items: center;
}
.feature-row.reverse .feature-media { order: 2; }
.feature-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}
.feature-media.wide img { aspect-ratio: 16 / 9; }
.feature-body :is(h2, h3) { font-size: clamp(1.3rem, 2.6vw, 1.7rem); }
.feature-body p { color: var(--muted); }
.feature-body ul { color: var(--muted); padding-left: 1.2em; margin: 0 0 1em; }
.feature-body li { margin-bottom: 0.35em; }

/* 数値カウント */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
  text-align: center;
}
.stat .num {
  font-size: clamp(2.2rem, 5vw, 3.1rem);
  font-weight: 700;
  color: var(--accent-deep);
  line-height: 1;
  letter-spacing: -0.02em;
}
.stat .num small { font-size: 0.45em; margin-left: 0.15em; color: var(--accent); }
.stat .label { color: var(--muted); font-size: 0.92rem; margin-top: 0.5rem; }

/* 業種チップ */
.chips { display: flex; flex-wrap: wrap; gap: 0.6rem; }
.chip {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  padding: 0.45em 1.1em;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--fg);
}

/* リスト(チェック) */
.check-list { list-style: none; padding: 0; margin: 0; }
.check-list li {
  position: relative;
  padding-left: 1.7em;
  margin-bottom: 0.7em;
  color: var(--muted);
}
.check-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.55em;
  width: 9px; height: 9px;
  border-right: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
  transform: rotate(45deg);
}

/* テーブル */
.spec-table { width: 100%; border-collapse: collapse; font-size: 0.96rem; }
.spec-table th, .spec-table td {
  text-align: left;
  padding: 0.95em 1.1em;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.spec-table th {
  width: 30%;
  color: var(--fg);
  background: var(--surface);
  font-weight: 700;
  white-space: nowrap;
}
.spec-table td { color: var(--muted); }

/* タイムライン(沿革・流れ) */
.timeline { list-style: none; padding: 0; margin: 0; }
.timeline li {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 1.2rem;
  padding-bottom: 1.4rem;
  border-left: 2px solid var(--line);
  margin-left: 6px;
  padding-left: 1.6rem;
  position: relative;
}
.timeline li::before {
  content: "";
  position: absolute;
  left: -7px; top: 0.4em;
  width: 12px; height: 12px;
  background: #fff;
  border: 3px solid var(--accent);
  border-radius: 50%;
}
.timeline .year { font-weight: 700; color: var(--accent-deep); }
.timeline .body { color: var(--muted); }
.timeline .body strong { color: var(--fg); display: block; }

/* プロセス(番号付き) */
.process { counter-reset: step; display: grid; gap: 1.1rem; }
.process .step {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 1.2rem;
  align-items: start;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
}
.process .step::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  width: 44px; height: 44px;
  display: grid; place-items: center;
  border-radius: var(--radius);
  font-size: 1.05rem;
}
.process .step h4 { margin-bottom: 0.25em; font-size: 1.1rem; }
.process .step p { color: var(--muted); margin-bottom: 0; font-size: 0.95rem; }

/* 実績フィルタ */
.filter-bar { display: flex; flex-wrap: wrap; gap: 0.55rem; margin-bottom: 2rem; }
.filter-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--fg);
  border-radius: 999px;
  padding: 0.5em 1.2em;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.filter-btn:hover { border-color: var(--accent); }
.filter-btn.is-active { background: var(--accent); color: #fff; border-color: var(--accent); }

.work-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.work-card .thumb { aspect-ratio: 16 / 10; overflow: hidden; background: var(--surface); }
.work-card .thumb img { width: 100%; height: 100%; object-fit: cover; }
.work-card .body { padding: 1.3rem 1.4rem; flex: 1; display: flex; flex-direction: column; }
.work-card .cat {
  font-size: 0.74rem; font-weight: 700; letter-spacing: 0.08em;
  color: var(--accent-deep); margin-bottom: 0.4rem;
}
.work-card h3 { font-size: 1.1rem; margin-bottom: 0.5rem; }
.work-card p { color: var(--muted); font-size: 0.9rem; margin-bottom: 0; }
.work-meta { display: flex; gap: 1rem; margin-top: auto; padding-top: 1rem; font-size: 0.82rem; color: var(--muted); }
.work-meta span strong { color: var(--fg); }

/* CTAバンド */
.cta-band { background: var(--accent-deep); color: #fff; }
.cta-band h2 { color: #fff; font-size: clamp(1.5rem, 3.4vw, 2.2rem); }
.cta-band p { color: rgba(255,255,255,0.82); max-width: 40em; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 2rem; flex-wrap: wrap; }
.cta-actions { display: flex; gap: 0.8rem; flex-wrap: wrap; }

/* バナー(採用) */
.banner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.banner img { width: 100%; height: 100%; min-height: 260px; object-fit: cover; }
.banner .banner-body { padding: clamp(1.8rem, 4vw, 3rem); display: flex; flex-direction: column; justify-content: center; }
.banner .banner-body h2 { font-size: clamp(1.4rem, 3vw, 2rem); }
.banner .banner-body p { color: var(--muted); }

/* インタビュー引用 */
.quote {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.6rem 1.8rem;
}
.quote p { font-size: 1.05rem; margin-bottom: 0.8rem; }
.quote cite { color: var(--muted); font-style: normal; font-size: 0.9rem; font-weight: 600; }

/* FAQ アコーディオン */
.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 1.2em 2.4em 1.2em 0;
  font-weight: 700;
  position: relative;
  color: var(--fg);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  position: absolute;
  right: 0.4em; top: 50%;
  transform: translateY(-50%);
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--accent);
}
.faq details[open] summary::after { content: "−"; }
.faq .answer { color: var(--muted); padding: 0 0 1.3em; margin: 0; }

/* フォーム */
.form-grid { display: grid; gap: 1.2rem; }
.field { display: flex; flex-direction: column; gap: 0.4rem; }
.field label { font-weight: 600; font-size: 0.92rem; }
.field label .req { color: #c0392b; font-size: 0.8rem; margin-left: 0.3em; }
.field input, .field select, .field textarea {
  font: inherit;
  padding: 0.75em 0.9em;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--fg);
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
}
.field textarea { resize: vertical; min-height: 140px; }
.form-note { font-size: 0.85rem; color: var(--muted); }

/* 連絡先ブロック */
.contact-info { display: grid; gap: 1.1rem; }
.contact-info .row { display: grid; grid-template-columns: 110px 1fr; gap: 1rem; padding-bottom: 1rem; border-bottom: 1px solid var(--line); }
.contact-info .row .k { font-weight: 700; color: var(--fg); }
.contact-info .row .v { color: var(--muted); }
.map-placeholder {
  background: var(--surface);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  min-height: 280px;
  color: var(--muted);
  font-size: 0.9rem;
  text-align: center;
}

/* フッター */
.site-footer {
  background: #0e1b24;
  color: #c7d2da;
  padding-block: clamp(2.5rem, 5vw, 3.5rem) 1.5rem;
  font-size: 0.92rem;
}
.footer-top { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 2rem; padding-bottom: 2rem; border-bottom: 1px solid rgba(255,255,255,0.12); }
.footer-brand { display: flex; align-items: center; gap: 0.6rem; color: #fff; font-weight: 700; font-size: 1.1rem; margin-bottom: 0.8rem; }
.footer-brand img { width: 28px; height: 28px; }
.site-footer p { color: #9fb0bb; margin-bottom: 0; }
.footer-col h4 { color: #fff; font-size: 0.92rem; letter-spacing: 0.08em; margin-bottom: 0.9rem; }
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 0.55em; }
.footer-col a { color: #c7d2da; }
.footer-col a:hover { color: #fff; }
.footer-bottom { padding-top: 1.4rem; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.6rem; color: #8195a1; font-size: 0.82rem; }

/* フェードイン */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* レスポンシブ */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-media { order: -1; }
  .feature-row, .feature-row.reverse { grid-template-columns: 1fr; }
  .feature-row.reverse .feature-media { order: -1; }
  .cols-4 { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .banner { grid-template-columns: 1fr; }
  .banner img { min-height: 220px; }
  .footer-top { grid-template-columns: 1fr 1fr; }

  .nav-toggle { display: inline-flex; }
  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 0.6rem 1rem 1.2rem;
    gap: 0.1rem;
    transform: translateY(-120%);
    transition: transform 0.25s ease;
    box-shadow: 0 18px 30px -20px rgba(0,0,0,0.3);
  }
  .nav.is-open { transform: translateY(0); }
  .nav a { padding: 0.85em 0.6em; border-radius: 0; }
  .nav a[aria-current="page"]::after { display: none; }
  .nav .btn { margin: 0.5rem 0 0; justify-content: center; }
}

@media (max-width: 560px) {
  .cols-2, .cols-3 { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr 1fr; }
  .cta-inner { flex-direction: column; align-items: flex-start; }
  .spec-table th { width: 38%; }
  .timeline li { grid-template-columns: 1fr; gap: 0.2rem; }
  .footer-top { grid-template-columns: 1fr; }
  .contact-info .row { grid-template-columns: 1fr; gap: 0.2rem; }
}