/* ============================================================
   KOSEN HERO — 高専LP ファーストビュー（写真ベース v2）
   背景: 人物写真（kosen-hero-bg.webp）＋ダークグラデーションオーバーレイ
   高さ: 100vh（最低 640px）
   アニメーション: rvシステム（rv-left / rv-up）
   z-index: var(--z-content, 10) 必須
   更新: 2026/03/30 — ネイビーベタ+フレア → 写真ベースモダンヒーローにリデザイン
   ============================================================ */

/* ---- Section Base ---- */
.kosen-hero {
  position: relative;
  z-index: var(--z-content, 10);
  min-height: max(100vh, 640px);
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--c-navy-deep, #0D1B2E); /* 写真未読込時のフォールバック */
}

/* ============================================================
   背景レイヤー
   ============================================================ */
.kosen-hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

/* 人物写真 */
.kosen-hero__photo {
  position: absolute;
  inset: 0;
  background-image: url('../../assets/img/kosen-hero-bg.jpg');   /* JPG fallback */
  background-image: url('../../assets/img/kosen-hero-bg.webp');  /* WebP 優先 */
  background-size: cover;
  background-position: center top;
  background-repeat: no-repeat;
}

/* ダークグラデーションオーバーレイ — 左寄りで可読性確保 */
.kosen-hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    105deg,
    rgba(13, 27, 46, 0.85) 0%,
    rgba(13, 27, 46, 0.70) 45%,
    rgba(13, 27, 46, 0.35) 75%,
    rgba(13, 27, 46, 0.18) 100%
  );
}

/* 底部フェード（次セクションとのつなぎ） */
.kosen-hero__fade-bottom {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 160px;
  background: linear-gradient(to bottom, transparent, rgba(13, 27, 46, 0.5));
}

/* ============================================================
   背景装飾テキスト（大文字英字）
   ============================================================ */
.kosen-hero__en-deco {
  position: absolute;
  z-index: 1;
  right: -2vw;
  bottom: -0.15em;
  font-family: var(--f-heading-en, 'Barlow Condensed', sans-serif);
  font-size: clamp(9rem, 22vw, 20rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  color: transparent;
  -webkit-text-stroke: 1px rgba(255, 255, 255, 0.07);
  line-height: 1;
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
}

/* ============================================================
   コンテナ
   ============================================================ */
.kosen-hero__container {
  position: relative;
  z-index: 2;
  max-width: var(--s-container, 1200px);
  width: 100%;
  margin: 0 auto;
  padding: calc(var(--s-header-h, 80px) + 72px) var(--s-gutter, 32px) 120px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

/* ============================================================
   コンテンツ
   ============================================================ */
.kosen-hero__content {
  max-width: 660px;
}

/* ---- eyebrow ---- */
.kosen-hero__eyebrow {
  font-family: var(--f-label, 'Inter', sans-serif);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--c-gold, #C9A84C);
  margin: 0 0 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.kosen-hero__eyebrow::before {
  content: '';
  display: inline-block;
  width: 36px;
  height: 1px;
  background: var(--c-gold, #C9A84C);
  flex-shrink: 0;
}

/* ---- タイトル ---- */
.kosen-hero__title {
  font-family: var(--f-heading-ja, 'Noto Serif JP', serif);
  font-size: clamp(2.2rem, 4.8vw, 3.8rem);
  font-weight: 700;
  line-height: 1.3;
  color: #FFFFFF;
  margin: 0 0 32px;
  letter-spacing: 0.01em;
}

.kosen-hero__title-line {
  display: block;
}

/* 「ふざけるな。」にゴールドアクセント — 高専LPの熱量を表現 */
.kosen-hero__title-line:last-child {
  color: var(--c-gold, #C9A84C);
}

/* ---- サブコピー ---- */
.kosen-hero__subtitle {
  font-family: var(--f-body, 'Noto Sans JP', sans-serif);
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  font-weight: 400;
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.80);
  margin: 0 0 52px;
  letter-spacing: 0.04em;
}

/* ============================================================
   CTA
   ============================================================ */
.kosen-hero__cta {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
}

/* プライマリボタン（オレンジ — 高専LP設計書指定） */
.kosen-hero__btn--primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--c-orange, #E8672A);
  color: #FFFFFF;
  font-family: var(--f-body, 'Noto Sans JP', sans-serif);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  padding: 16px 40px;
  border-radius: 4px;
  transition:
    background var(--t-base, 0.4s) var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1)),
    transform var(--t-base, 0.4s) var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1)),
    box-shadow var(--t-base, 0.4s) var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1));
}

.kosen-hero__btn--primary:hover {
  background: #d45a22;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(232, 103, 42, 0.40);
}

.kosen-hero__btn-arrow {
  font-size: 1.1em;
  transition: transform var(--t-base, 0.4s) var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1));
}

.kosen-hero__btn--primary:hover .kosen-hero__btn-arrow {
  transform: translateX(4px);
}

/* CTAノート */
.kosen-hero__cta-note {
  font-family: var(--f-body, 'Noto Sans JP', sans-serif);
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.45);
  margin: 0;
  letter-spacing: 0.06em;
}

/* ============================================================
   キーナンバーバッジ（右下・PC表示）
   ============================================================ */
.kosen-hero__badge {
  position: absolute;
  right: var(--s-gutter, 32px);
  bottom: 120px;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 20px;
  border: 1px solid rgba(201, 168, 76, 0.3);
  border-radius: 8px;
  background: rgba(13, 27, 46, 0.55);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.kosen-hero__badge-num {
  font-family: var(--f-heading-en, 'Barlow Condensed', sans-serif);
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--c-gold, #C9A84C);
}

.kosen-hero__badge-unit {
  font-family: var(--f-heading-en, 'Barlow Condensed', sans-serif);
  font-size: 1.5rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.6);
  margin-top: 2px;
}

.kosen-hero__badge-label {
  font-family: var(--f-body, 'Noto Sans JP', sans-serif);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: rgba(255, 255, 255, 0.5);
  margin-top: 8px;
}

/* ============================================================
   スクロールインジケーター
   ============================================================ */
.kosen-hero__scroll {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  animation: kosen-hero-scroll-bounce 2s ease-in-out infinite;
}

@keyframes kosen-hero-scroll-bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%      { transform: translateX(-50%) translateY(6px); }
}

.kosen-hero__scroll-text {
  font-family: var(--f-label, 'Inter', sans-serif);
  font-size: 0.65rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.40);
}

.kosen-hero__scroll-line {
  display: block;
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, rgba(201, 168, 76, 0.7), transparent);
  animation: kosen-hero-scroll-line 2s ease-in-out infinite;
}

@keyframes kosen-hero-scroll-line {
  0%   { transform: scaleY(0); transform-origin: top; opacity: 0; }
  50%  { transform: scaleY(1); transform-origin: top; opacity: 1; }
  100% { transform: scaleY(1); transform-origin: bottom; opacity: 0; }
}

/* ============================================================
   レスポンシブ
   ============================================================ */
@media (max-width: 1024px) {
  .kosen-hero__container {
    padding-left: 28px;
    padding-right: 28px;
  }

  .kosen-hero__title {
    font-size: clamp(2rem, 4.2vw, 3rem);
  }

  .kosen-hero__en-deco {
    font-size: clamp(8rem, 18vw, 16rem);
    right: -1vw;
  }

  .kosen-hero__badge {
    right: 28px;
    bottom: 100px;
  }
}

@media (max-width: 768px) {
  .kosen-hero {
    min-height: 90vh;
  }

  .kosen-hero__container {
    padding: calc(var(--s-header-h, 80px) + 48px) 20px 100px;
  }

  .kosen-hero__content {
    max-width: 100%;
  }

  .kosen-hero__title {
    font-size: clamp(1.9rem, 7.5vw, 2.8rem);
    margin-bottom: 24px;
  }

  .kosen-hero__subtitle {
    font-size: 0.96rem;
    margin-bottom: 40px;
  }

  .kosen-hero__btn--primary {
    font-size: 0.95rem;
    padding: 14px 32px;
  }

  /* オーバーレイを左寄りから全面に変更（モバイルは全体暗め） */
  .kosen-hero__overlay {
    background: linear-gradient(
      to bottom,
      rgba(13, 27, 46, 0.78) 0%,
      rgba(13, 27, 46, 0.68) 100%
    );
  }

  .kosen-hero__en-deco {
    font-size: clamp(5rem, 28vw, 10rem);
    right: -1vw;
    bottom: -0.1em;
  }

  /* バッジを非表示（モバイルでは数字バーセクションで表示） */
  .kosen-hero__badge {
    display: none;
  }
}

@media (max-width: 480px) {
  .kosen-hero__title {
    font-size: clamp(1.7rem, 8.5vw, 2.2rem);
  }

  .kosen-hero__eyebrow {
    font-size: 0.7rem;
  }

  .kosen-hero__btn--primary {
    width: 100%;
    justify-content: center;
  }

  .kosen-hero__en-deco {
    font-size: clamp(4.5rem, 30vw, 8rem);
  }
}