/*
 * F&S株式会社 コーポレートサイト
 *
 * デザインDNA: opa の「罫線・活字 / エディトリアル」を継承しつつ、
 * 地色をオフホワイトから深海のダークネイビーへ反転させたダークテーマ。
 *   - レイアウトの基本単位は罫線(border)。カード・影・ピルは使わない
 *   - キッカー + 極太見出し、数字・日付は mono、記号は活字(→ ↗ › ><>)
 *   - アクセントは clear-cyan(情報・アクティブ) / sand(注意・募集)
 */

:root {
  /* === 海のダークブルー基調ブランドトークン === */
  --ink-abyss: #050f1b;        /* ページ地(深海) */
  --ink-deep: #081a2c;         /* 一段浅い海(セクション交互地) */
  --ink-navy: #0d2740;         /* さらに浅い(ホバー地) */
  --foam: #f2f5f1;             /* 文字(オフホワイト) */
  --cyan: #3fc1d4;             /* clear-cyan 派生(ダーク地用に明度上げ) */
  --sand: #d4ab60;             /* sand 派生(ダーク地用に明度上げ) */

  /* 文字の不透明度の階段(DNA: 階層は不透明度でつくる) */
  --foam-80: rgba(242, 245, 241, 0.8);
  --foam-65: rgba(242, 245, 241, 0.65);
  --foam-55: rgba(242, 245, 241, 0.55);
  --foam-45: rgba(242, 245, 241, 0.45);
  --foam-30: rgba(242, 245, 241, 0.3);

  /* 罫線の階段 */
  --rule-strong: var(--foam);
  --rule: rgba(242, 245, 241, 0.16);
  --rule-soft: rgba(242, 245, 241, 0.1);

  --font-sans: "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", sans-serif;
  --font-display: "Shippori Mincho B1", "Hiragino Mincho ProN", serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas,
    "Zen Kaku Gothic New", monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  background-color: var(--ink-abyss);
  /* 海面から差す光。DNAはグラデ背景禁止だが、ダーク反転版では
     「深度」を出すためのごく淡い光条のみ許容する */
  background-image: radial-gradient(
    ellipse 130% 55% at 50% -12%,
    rgba(63, 193, 212, 0.09) 0%,
    transparent 68%
  );
  color: var(--foam);
  font-family: var(--font-sans);
  font-size: 14.5px;
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background-color: var(--cyan);
  color: var(--ink-abyss);
}

.container {
  margin: 0 auto;
  max-width: 1200px;
  padding-inline: 20px;
  width: 100%;
}

@media (min-width: 1024px) {
  .container {
    padding-inline: 48px;
  }
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* ========== キッカー ========== */

.kicker {
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.kicker-attn {
  color: var(--sand);
}

.kicker-jp {
  border-left: 1px solid var(--rule);
  color: var(--foam-45);
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: 0.14em;
  margin-left: 0.9em;
  padding-left: 0.9em;
}

/* ========== リンク・ボタン(DNA §4) ========== */

.link-underline {
  color: var(--foam);
  font-size: 13px;
  font-weight: 500;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.18s ease;
}

.link-underline:hover {
  color: var(--cyan);
}

.btn-primary {
  background: var(--foam);
  border-radius: 4px;
  color: var(--ink-abyss);
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  padding: 10px 22px;
  text-decoration: none;
  transition: background-color 0.18s ease;
}

.btn-primary:hover {
  background: var(--cyan);
}

.btn-secondary {
  border: 1px solid var(--foam-30);
  border-radius: 4px;
  color: var(--foam);
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  padding: 9px 18px;
  text-decoration: none;
  transition: background-color 0.18s ease, border-color 0.18s ease;
}

.btn-secondary:hover {
  background: rgba(242, 245, 241, 0.06);
  border-color: var(--foam-45);
}

/* ========== 水深計 ========== */

.depth-gauge {
  align-items: center;
  display: none;
  flex-direction: column;
  gap: 10px;
  position: fixed;
  right: 22px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 40;
}

@media (min-width: 1360px) {
  .depth-gauge {
    display: flex;
  }
}

.depth-gauge-label {
  color: var(--foam-45);
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.22em;
  writing-mode: vertical-rl;
}

.depth-gauge-value {
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  writing-mode: vertical-rl;
}

.depth-gauge-track {
  background: var(--rule);
  display: block;
  height: 180px;
  position: relative;
  width: 1px;
}

.depth-gauge-fill {
  background: var(--cyan);
  display: block;
  height: 0%;
  left: 0;
  position: absolute;
  top: 0;
  width: 1px;
}

/* ========== マストヘッド ========== */

.masthead {
  backdrop-filter: blur(8px);
  background: rgba(5, 15, 27, 0.86);
  border-bottom: 1px solid var(--rule);
  /* 新聞の題字下の二重罫 */
  box-shadow: 0 3px 0 -2px var(--rule-soft);
  position: sticky;
  top: 0;
  z-index: 50;
}

.masthead-inner {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  justify-content: space-between;
  padding-block: 14px;
}

.brand {
  align-items: baseline;
  display: inline-flex;
  gap: 12px;
  text-decoration: none;
}

.brand-wordmark {
  color: var(--foam);
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 800;
  letter-spacing: 0.02em;
  line-height: 1;
}

.brand-wordmark-sm {
  font-size: 20px;
}

.brand-amp {
  color: var(--cyan);
}

.brand-kk {
  font-size: 0.62em;
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-left: 0.35em;
}

.brand-latin {
  border-left: 1px solid var(--foam-30);
  color: var(--foam-55);
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.18em;
  line-height: 1.4;
  padding-left: 12px;
}

.global-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 22px;
}

.global-nav a {
  color: var(--foam-65);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.18s ease;
}

.global-nav a:hover {
  color: var(--cyan);
}

/* ========== ヒーロー ========== */

.hero {
  border-bottom: 1px solid var(--rule);
  overflow: hidden;
  position: relative;
}

.hero-inner {
  padding-block: 96px 72px;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(32px, 6.4vw, 76px);
  font-weight: 800;
  letter-spacing: 0.03em;
  line-height: 1.32;
  margin-top: 26px;
}

.hero-copy {
  color: var(--foam-65);
  font-size: 14.5px;
  line-height: 2.1;
  margin-top: 28px;
  max-width: 560px;
}

.hero-actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  margin-top: 36px;
}

.hero-stats {
  border-top: 2px solid var(--rule-strong);
  display: grid;
  gap: 0;
  grid-template-columns: minmax(0, 1fr);
  margin-top: 72px;
  max-width: 720px;
}

.hero-stat {
  align-items: baseline;
  border-bottom: 1px solid var(--rule-soft);
  display: flex;
  gap: 16px;
  justify-content: space-between;
  padding-block: 14px;
}

@media (min-width: 720px) {
  .hero-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .hero-stat {
    border-bottom: 0;
    border-right: 1px solid var(--rule-soft);
    display: block;
    padding: 18px 20px 4px 0;
  }

  .hero-stat + .hero-stat {
    padding-left: 20px;
  }

  .hero-stat:last-child {
    border-right: 0;
  }
}

.hero-stat dt {
  color: var(--foam-45);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
}

.hero-stat dd {
  align-items: baseline;
  display: flex;
  gap: 8px;
  margin-top: 6px;
}

.stat-num {
  color: var(--foam);
  font-family: var(--font-mono);
  font-size: clamp(26px, 3vw, 38px);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  line-height: 1;
}

.stat-unit {
  color: var(--foam-45);
  font-size: 11.5px;
  font-weight: 500;
}

/* ヒーローを泳ぐ活字の魚(記号は活字で、のDNA拡大解釈) */
.hero-fish {
  inset: 0;
  pointer-events: none;
  position: absolute;
  z-index: 0;
}

.fish {
  color: var(--foam-30);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: -0.05em;
  position: absolute;
  white-space: nowrap;
}

/* > <> は右向き。左から右へ泳がせる */
.f1 { animation: swim-right 34s linear infinite; top: 18%; }
.f2 { animation: swim-right 46s linear infinite; animation-delay: -18s; color: rgba(63, 193, 212, 0.28); top: 30%; }
.f3 { animation: swim-right 40s linear infinite; animation-delay: -30s; font-size: 11px; top: 64%; }
.f5 { animation: swim-right 52s linear infinite; animation-delay: -8s; font-size: 16px; top: 78%; }
/* <>< は左向き。右から左へ */
.f4 { animation: swim-left 44s linear infinite; animation-delay: -12s; top: 46%; }
.f6 { animation: swim-left 38s linear infinite; animation-delay: -26s; color: rgba(212, 171, 96, 0.25); font-size: 11px; top: 86%; }

@keyframes swim-right {
  from { transform: translateX(-8vw); }
  to { transform: translateX(108vw); }
}

@keyframes swim-left {
  from { transform: translateX(108vw); }
  to { transform: translateX(-8vw); }
}

@media (prefers-reduced-motion: reduce) {
  .fish {
    animation: none;
    left: 50%;
  }
  .f1 { left: 12%; }
  .f2 { left: 68%; }
  .f3 { left: 80%; }
  .f4 { left: 42%; }
  .f5 { left: 26%; }
  .f6 { left: 58%; }
}

/* ========== セクション共通 ========== */

.section {
  padding-block: 88px;
}

.section:nth-of-type(odd) {
  background: var(--ink-deep);
}

.section-heading {
  align-items: flex-end;
  border-bottom: 2px solid var(--rule-strong);
  display: flex;
  gap: 16px;
  justify-content: space-between;
  margin-bottom: 40px;
  padding-bottom: 12px;
}

.section-heading-attn {
  border-bottom-color: var(--sand);
}

.section-heading h2 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-top: 8px;
}

.section-heading-en {
  color: var(--foam-30);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  padding-bottom: 4px;
  white-space: nowrap;
}

/* フェードイン(控えめ) */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ========== お知らせ ========== */

.news-list {
  list-style: none;
}

.news-row {
  align-items: baseline;
  border-bottom: 1px solid var(--rule-soft);
  display: grid;
  gap: 6px 24px;
  grid-template-columns: auto;
  padding-block: 18px;
}

@media (min-width: 720px) {
  .news-row {
    grid-template-columns: 110px 92px minmax(0, 1fr);
  }
}

.news-date {
  color: var(--foam-55);
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-variant-numeric: tabular-nums;
}

/* ステータスは色ピルではなく活字で(DNA §2) */
.news-cat {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.16em;
}

.news-cat-info {
  color: var(--cyan);
}

.news-cat-attn {
  color: var(--sand);
}

.news-title {
  color: var(--foam-80);
  font-size: 14px;
}

/* ========== 事業内容 ========== */

.business-list {
  list-style: none;
}

.business-row {
  border-bottom: 1px solid var(--rule-soft);
  display: grid;
  gap: 12px 40px;
  grid-template-columns: auto;
  padding-block: 36px;
}

.business-row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

@media (min-width: 720px) {
  .business-row {
    grid-template-columns: 96px minmax(0, 1fr);
  }
}

.business-num {
  color: var(--foam-30);
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 600;
  line-height: 1;
}

.business-body h3 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.business-body p {
  color: var(--foam-65);
  font-size: 13.5px;
  line-height: 2;
  margin-top: 12px;
  max-width: 640px;
}

.business-body .link-underline {
  display: inline-block;
  margin-top: 14px;
}

/* ========== 会社概要 ========== */

.company-grid {
  display: grid;
  gap: 56px;
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 900px) {
  .company-grid {
    gap: 72px;
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
}

/* 2カラム定義リスト + 行罫線(DNA §3) */
.company-dl div {
  border-bottom: 1px solid var(--rule-soft);
  display: grid;
  gap: 4px 24px;
  grid-template-columns: auto;
  padding-block: 16px;
}

.company-dl div:first-child {
  border-top: 2px solid var(--rule);
}

@media (min-width: 600px) {
  .company-dl div {
    grid-template-columns: 140px minmax(0, 1fr);
  }
}

.company-dl dt {
  color: var(--foam-45);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.company-dl dd {
  color: var(--foam-80);
  font-size: 13.5px;
}

.company-history-title {
  border-bottom: 1px solid var(--rule);
  color: var(--foam-55);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding-bottom: 10px;
}

.history-list {
  list-style: none;
}

.history-list li {
  border-bottom: 1px solid var(--rule-soft);
  display: flex;
  gap: 20px;
  padding-block: 14px;
}

.history-list time {
  color: var(--cyan);
  flex-shrink: 0;
  font-size: 12.5px;
  font-variant-numeric: tabular-nums;
}

.history-list span {
  color: var(--foam-80);
  font-size: 13.5px;
}

/* ========== 強み ========== */

.strength-lead {
  color: var(--foam-80);
  font-family: var(--font-display);
  font-size: clamp(19px, 2.6vw, 26px);
  font-weight: 700;
  line-height: 2;
  margin-bottom: 44px;
}

.strength-x {
  color: var(--cyan);
  font-family: var(--font-mono);
  font-weight: 600;
  padding-inline: 0.1em;
}

/* ========== お問い合わせ ========== */

.contact-body p {
  color: var(--foam-65);
  font-size: 13.5px;
}

.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 28px;
}

/* ========== フッター ========== */

.footer {
  background: var(--ink-abyss);
  border-top: 2px solid var(--rule-strong);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 32px 64px;
  justify-content: space-between;
  padding-block: 48px 40px;
}

.footer-mission {
  color: var(--foam-45);
  font-size: 12px;
  margin-top: 12px;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
}

.footer-nav a {
  color: var(--foam-55);
  font-size: 12.5px;
  text-decoration: none;
  transition: color 0.18s ease;
}

.footer-nav a:hover {
  color: var(--cyan);
}

.footer-bottom {
  border-top: 1px solid var(--rule-soft);
  color: var(--foam-30);
  display: flex;
  flex-wrap: wrap;
  font-size: 11px;
  gap: 8px 24px;
  justify-content: space-between;
  padding-block: 18px 26px;
}