/* =========================================================
   Design tokens — 配色・余白をここで一括管理
   コントラスト比 4.5:1 以上を満たす値にすること
   ========================================================= */
:root {
  /* 信頼感・重厚感のあるネイビー×チャコール×ゴールドの配色。
     いずれもコントラスト比 4.5:1 以上を計算のうえ確定。 */
  --color-bg: #ffffff;
  --color-bg-alt: #eef1f5;   /* 薄いクールグレー */
  --color-fg: #1b2430;       /* 本文: 白背景で ~15.6:1 */
  --color-muted: #4b5568;    /* 補助テキスト: 白背景で ~7.5:1 */
  --color-primary: #12314f;  /* ネイビー。白背景リンク/文字で ~13.3:1、白文字ボタン背景でも同等 */
  --color-primary-fg: #ffffff;
  --color-border: #d7dbe2;
  --color-focus: #12314f;    /* 明るい背景用フォーカスリング */

  --color-gold: #c9a227;       /* 装飾用(暗い背景の上でのみ使用) */
  --color-gold-deep: #8a6a1f;  /* 明るい背景上のゴールド文字。白背景で ~5:1 */
  --color-navy-deep: #0a1a2e;  /* ヒーロー/フッターの最も暗い階調 */
  --color-navy: #142c47;
  --color-charcoal: #23262b;

  --color-footer-bg: #0d1b2e;
  --color-footer-fg: #e9ebf1;    /* 紺背景で ~15:1 */
  --color-footer-muted: #b6bfcd; /* 紺背景で ~8.9:1 */
  --color-footer-link: #e3c98a;  /* 紺背景で ~9.7:1 */
  --color-focus-on-dark: #f4d799; /* 暗い背景用フォーカスリング。~12.4:1 */

  --font: system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP",
          "Yu Gothic", Meiryo, sans-serif;
  --maxw: 1100px;
  --radius: 4px;   /* 角丸は控えめに。重厚な印象のためシャープな形状にする */
  --radius-sm: 2px;
  --space: clamp(1rem, 2.5vw, 2rem);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  color: var(--color-fg);
  background: var(--color-bg);
  line-height: 1.7;
  font-size: 1rem;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); }

/* 太めの見出しウェイトでどっしりした印象に */
h1, h2, h3, h4 { font-weight: 800; letter-spacing: -.01em; line-height: 1.3; }

/* フォーカスを消さない(a11y) */
:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: 4px;
}

.container { width: min(100% - 2 * var(--space), var(--maxw)); margin-inline: auto; }
.container--narrow { max-width: 760px; }
.prose h2 { margin-top: 2rem; margin-bottom: .4rem; font-size: 1.25rem; }
.prose p { color: var(--color-muted); }

.skip-link {
  position: absolute; left: 8px; top: -48px;
  background: var(--color-primary); color: var(--color-primary-fg);
  padding: .5rem .9rem; border-radius: var(--radius-sm); z-index: 100;
  transition: top .15s ease;
}
.skip-link:focus { top: 8px; }

/* =========================
   Header / Nav
   ========================= */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  width: min(100% - 2 * var(--space), var(--maxw));
  margin-inline: auto; padding-block: .8rem;
}
.nav__brand {
  font-weight: 800; font-size: 1.15rem; text-decoration: none; color: var(--color-fg);
  letter-spacing: .02em;
}
.nav__menu {
  display: flex; gap: 1.4rem; list-style: none; padding: 0;
}
.nav__menu a {
  text-decoration: none; color: var(--color-fg); font-weight: 600;
  padding-bottom: .2rem; border-bottom: 2px solid transparent; transition: border-color .15s ease, color .15s ease;
}
.nav__menu a:hover { color: var(--color-primary); border-color: var(--color-gold-deep); }
.nav__menu a[aria-current="page"] { color: var(--color-primary); border-color: var(--color-gold-deep); }
.nav__toggle { display: none; }

/* =========================
   Buttons — 角丸は控えめ、シャープな形状
   ========================= */
.btn {
  display: inline-block; padding: .8rem 1.6rem; border-radius: var(--radius-sm);
  font-weight: 700; text-decoration: none; cursor: pointer; letter-spacing: .03em;
  border: 2px solid transparent; transition: transform .15s ease, background .15s ease, box-shadow .15s ease;
}
.btn--primary { background: var(--color-primary); color: var(--color-primary-fg); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(10,26,46,.28); }
.btn--ghost { border-color: var(--color-border); color: var(--color-fg); }
.btn--ghost:hover { transform: translateY(-2px); border-color: var(--color-primary); }
.btn[disabled] { opacity: .6; cursor: not-allowed; transform: none; }

/* ヒーロー上のボタン(暗い背景用の配色) */
.hero .btn--primary { background: var(--color-gold); color: #14181f; }
.hero .btn--primary:hover { box-shadow: 0 10px 24px rgba(201,162,39,.35); }
.hero .btn--ghost { border-color: rgba(255,255,255,.55); color: #ffffff; }
.hero .btn--ghost:hover { border-color: var(--color-gold); color: var(--color-gold); }

/* =========================
   Hero — 写真は使わず、CSSのグラデーションと幾何学的な線・図形で
   「堅牢さ・重厚感」を表現する
   ========================= */
.hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(4.5rem, 10vw, 8.5rem);
  background:
    linear-gradient(150deg, var(--color-navy-deep) 0%, var(--color-navy) 48%, var(--color-charcoal) 100%);
  color: #ffffff;
  border-bottom: 3px solid var(--color-gold);
}
/* ヒーロー背景写真(施工現場) */
.hero__photo {
  position: absolute; inset: 0; z-index: 0;
  width: 100%; height: 100%; object-fit: cover; object-position: center right;
  opacity: .38;
}
/* 設計図面のようなグリッド線(装飾。読み上げ対象外) */
.hero__grid {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(255,255,255,.06) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, rgba(255,255,255,.06) 0 1px, transparent 1px 72px);
  mask-image: linear-gradient(180deg, rgba(0,0,0,.9), rgba(0,0,0,.15));
}
/* 鉄骨トラスを思わせる斜め線・角の装飾(すべて border/clip-path。画像不使用) */
.hero__truss {
  position: absolute; inset: 0; pointer-events: none;
}
.hero__truss::before,
.hero__truss::after {
  content: "";
  position: absolute;
  border: 1.5px solid rgba(201,162,39,.4);
}
.hero__truss::before {
  top: -18%; right: -8%; width: 46%; height: 160%;
  clip-path: polygon(38% 0, 100% 0, 62% 100%, 0 100%);
  border-color: rgba(201,162,39,.5);
}
.hero__truss::after {
  bottom: -30%; left: -10%; width: 40%; height: 140%;
  clip-path: polygon(0 0, 60% 0, 100% 100%, 40% 100%);
  border-color: rgba(255,255,255,.18);
}
.hero__corner {
  position: absolute; left: 6%; bottom: 8%; width: 120px; height: 120px;
  border-left: 3px solid var(--color-gold); border-bottom: 3px solid var(--color-gold);
  opacity: .55; pointer-events: none;
}
.hero__inner { position: relative; z-index: 1; text-align: center; }
.hero__eyebrow {
  display: inline-block; font-weight: 700; letter-spacing: .28em; font-size: .8rem;
  color: var(--color-gold); text-transform: uppercase; margin-bottom: 1.1rem;
}
.hero__title { font-size: clamp(2.1rem, 6vw, 3.6rem); line-height: 1.2; letter-spacing: -.01em; }
.hero__lead { color: #dbe1ea; font-size: clamp(1rem, 2.5vw, 1.25rem); margin-top: 1.1rem; max-width: 46rem; margin-inline: auto; }
.hero__actions { margin-top: 2.2rem; display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.hero :focus-visible { outline-color: var(--color-focus-on-dark); }

/* 下層ページ用のコンパクトなヒーロー */
.hero--page { padding-block: clamp(2.6rem, 6vw, 4rem); }
.hero__title--page { font-size: clamp(1.8rem, 5vw, 2.6rem); }
.breadcrumb {
  font-size: .85rem; color: rgba(255,255,255,.72); margin-bottom: 1rem;
}
.breadcrumb a { color: #ffffff; text-decoration: underline; text-underline-offset: .2em; }
.breadcrumb a:hover { color: var(--color-gold); }
.breadcrumb [aria-current] { color: var(--color-gold); }

/* ページ内のトップへ戻る導線などに使う小さめリンク */
.teaser-link { display: inline-block; margin-top: 1rem; font-weight: 700; color: var(--color-primary); text-decoration: none; }
.teaser-link:hover { text-decoration: underline; }
.section--alt .teaser-link, .teaser-link--on-alt { color: var(--color-gold-deep); }
.teaser-wrap { text-align: center; }
.text-center { text-align: center; }

/* =========================
   Sections
   ========================= */
.section { padding-block: clamp(3rem, 7vw, 5.5rem); }
.section--alt { background: var(--color-bg-alt); }
.section__eyebrow {
  display: block; text-align: center; font-weight: 700; letter-spacing: .22em; font-size: .78rem;
  color: var(--color-gold-deep); text-transform: uppercase; margin-bottom: .6rem;
}
.section__title { font-size: clamp(1.6rem, 4vw, 2.2rem); text-align: center; }
.section__lead { color: var(--color-muted); text-align: center; max-width: 60ch; margin: 1rem auto 2.5rem; }
.subsection__title {
  font-size: 1.2rem; margin: 2.4rem 0 1.2rem; padding-left: .8rem;
  border-left: 4px solid var(--color-gold-deep);
}
.subsection__title:first-of-type { margin-top: 1rem; }

.grid { display: grid; gap: 1.4rem; }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

/* セクション見出しの上に敷く写真帯。HPの背景として直接貼り付ける */
.photo-strip { position: relative; max-width: 900px; margin: 0 auto 2.4rem; overflow: hidden; border-radius: var(--radius); }
.photo-strip img {
  display: block; width: 100%; height: clamp(220px, 32vw, 380px);
  object-fit: cover;
}

.card {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius); padding: 1.6rem;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 12px 28px rgba(10,26,46,.14); border-left-color: var(--color-gold-deep); }
.card__title { font-size: 1.15rem; margin-bottom: .5rem; }

.work-card__meta {
  display: inline-block; font-weight: 700; font-size: .78rem; letter-spacing: .06em;
  color: var(--color-gold-deep); margin-bottom: .5rem;
}

/* =========================
   数字で見る(統計帯)
   ========================= */
.stats {
  display: flex; flex-wrap: wrap; gap: 2.2rem; justify-content: center;
  margin: 2.2rem 0 0; padding: 2rem 0;
  border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border);
}
.stats__item { text-align: center; min-width: 130px; }
.stats__num { display: block; font-size: clamp(1.9rem, 4.2vw, 2.7rem); font-weight: 800; color: var(--color-primary); letter-spacing: -.02em; }
.stats__unit { font-size: 1rem; font-weight: 700; margin-left: .1em; }
.stats__label { display: block; margin-top: .3rem; font-size: .82rem; color: var(--color-muted); }

/* =========================
   一言(引用)
   ========================= */
.quote {
  max-width: 640px; margin: 2.6rem auto 0; padding: 1.6rem 1.8rem;
  border-left: 4px solid var(--color-gold-deep); background: var(--color-bg-alt); border-radius: var(--radius);
}
.quote p { font-size: 1.05rem; color: var(--color-fg); }
.quote cite { display: block; margin-top: .8rem; font-size: .85rem; color: var(--color-muted); font-style: normal; }
.section--alt .quote { background: var(--color-bg); }

/* =========================
   番号つき特徴リスト(カードグリッドの代替)
   ========================= */
.feature-list { display: grid; gap: 2.1rem; max-width: 760px; margin: 0 auto; }
.feature-list__item { display: grid; grid-template-columns: auto 1fr; gap: 1.2rem; align-items: start; }
.feature-list__num { font-size: 1.9rem; font-weight: 800; color: var(--color-gold-deep); line-height: 1.1; }
.feature-list__item h3 { font-size: 1.15rem; margin-bottom: .4rem; }
.feature-list__item p { color: var(--color-muted); }

/* =========================
   サービス一覧(横並びリスト)
   ========================= */
.service-list { display: grid; gap: 0; max-width: 820px; margin: 0 auto; border-top: 1px solid var(--color-border); }
.service-list__item {
  display: grid; grid-template-columns: minmax(140px, 220px) 1fr; gap: 1.4rem;
  padding-block: 1.3rem; border-bottom: 1px solid var(--color-border);
}
.service-list__item h3 { font-size: 1.1rem; color: var(--color-primary); }
.service-list__item p { color: var(--color-muted); }
@media (max-width: 560px) { .service-list__item { grid-template-columns: 1fr; } }

/* =========================
   問い合わせ先などの簡易リスト(カード代替)
   ========================= */
.info-list { max-width: 620px; margin: 0 auto; display: grid; gap: 0; }
.info-list__row {
  display: grid; grid-template-columns: 8rem 1fr; gap: 1rem;
  padding-block: .9rem; border-bottom: 1px solid var(--color-border);
}
.info-list__row dt { font-weight: 700; color: var(--color-muted); font-size: .9rem; }
.info-list__row dd { margin: 0; }
@media (max-width: 480px) { .info-list__row { grid-template-columns: 1fr; } }

/* =========================
   会社概要・募集要項などの情報テーブル
   ========================= */
.info-table {
  width: 100%; max-width: 760px; margin-inline: auto;
  border-collapse: collapse; border-top: 1px solid var(--color-border);
}
.info-table th, .info-table td {
  text-align: left; padding: .9rem 1rem; border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}
.info-table th {
  width: 9rem; color: var(--color-muted); font-weight: 700; font-size: .92rem;
}

/* =========================
   CTA帯(トップページ末尾)
   ========================= */
.cta-band {
  padding-block: clamp(3rem, 7vw, 4.5rem);
  background: linear-gradient(150deg, var(--color-navy-deep) 0%, var(--color-navy) 100%);
  color: #ffffff; text-align: center;
}
.cta-band__title { font-size: clamp(1.4rem, 3.6vw, 2rem); }
.cta-band__lead { color: #dbe1ea; margin-top: .8rem; }
.cta-band__actions { margin-top: 1.8rem; display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.cta-band .btn--primary { background: var(--color-gold); color: #14181f; }
.cta-band .btn--primary:hover { box-shadow: 0 10px 24px rgba(201,162,39,.35); }
.cta-band .btn--ghost { border-color: rgba(255,255,255,.55); color: #ffffff; }
.cta-band .btn--ghost:hover { border-color: var(--color-gold); color: var(--color-gold); }
.cta-band :focus-visible { outline-color: var(--color-focus-on-dark); }

/* =========================
   Forms
   ========================= */
.form { max-width: 620px; margin-inline: auto; display: grid; gap: 1.2rem; }
.form__row { display: grid; gap: .4rem; }
.form label { font-weight: 600; }
.req { color: #b91c1c; }
.form input, .form textarea {
  font: inherit; padding: .7rem .9rem;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  background: var(--color-bg); color: var(--color-fg); width: 100%;
}
.form input:focus, .form textarea:focus { border-color: var(--color-primary); outline: none; }
.field-error { color: #b91c1c; font-size: .9rem; min-height: 1.2em; }
.form__status { min-height: 1.4em; font-weight: 600; }
.form__status[data-state="ok"] { color: #15803d; }
.form__status[data-state="err"] { color: #b91c1c; }

/* ハニーポット: 視覚・スクリーンリーダー両方から隠す */
.hp-field {
  position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden;
}

/* =========================
   Footer — ネイビーの重厚な帯
   ========================= */
.site-footer {
  background: var(--color-footer-bg); color: var(--color-footer-fg);
  border-top: 3px solid var(--color-gold); padding-block: 3rem 2rem;
}
.site-footer__inner { display: flex; justify-content: space-between; gap: 2rem; flex-wrap: wrap; align-items: flex-start; }
.site-footer__brand { font-weight: 800; font-size: 1.1rem; letter-spacing: .02em; margin-bottom: .6rem; color: var(--color-footer-fg); }
.site-footer__col p { color: var(--color-footer-muted); margin-bottom: .3rem; }
.site-footer__label {
  font-size: .85rem; letter-spacing: .12em; text-transform: uppercase;
  color: var(--color-footer-link) !important; margin-bottom: .7rem; font-weight: 700;
}
.site-footer__links { display: flex; flex-direction: column; gap: .5rem; list-style: none; padding: 0; }
.site-footer__links a { color: var(--color-footer-muted); text-decoration: none; }
.site-footer__links a:hover { color: var(--color-footer-link); }
.site-footer__bottom {
  margin-top: 2.4rem; padding-top: 1.4rem; border-top: 1px solid rgba(255,255,255,.12);
  color: var(--color-footer-muted); font-size: .85rem; text-align: center;
}
.site-footer :focus-visible { outline-color: var(--color-focus-on-dark); }

/* =========================
   Reveal animation(ちょっとした動き)
   IntersectionObserver が .is-visible を付与する
   ========================= */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* =========================
   Mobile nav
   ========================= */
@media (max-width: 720px) {
  .nav__toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 44px; height: 44px; background: none; border: 1px solid var(--color-border);
    border-radius: var(--radius-sm); cursor: pointer;
  }
  .nav__toggle-bar, .nav__toggle-bar::before, .nav__toggle-bar::after {
    content: ""; display: block; width: 20px; height: 2px; background: var(--color-fg);
    position: relative; transition: transform .2s ease;
  }
  .nav__toggle-bar::before { position: absolute; top: -6px; }
  .nav__toggle-bar::after { position: absolute; top: 6px; }
  .nav__menu {
    position: absolute; inset-inline: 0; top: 100%;
    flex-direction: column; gap: 0; background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    max-height: 0; overflow: hidden; transition: max-height .25s ease;
  }
  .nav__menu li { border-top: 1px solid var(--color-border); }
  .nav__menu a { display: block; padding: .9rem var(--space); }
  .nav[data-open="true"] .nav__menu { max-height: 380px; }
}

/* =========================
   動きを減らす設定を尊重(a11y 必須)
   ========================= */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}