/* ============================================================
   KOSEN HERO — GuildBord風メカニカル/テック ヒーロー
   背景: パーティクルネットワーク（Canvas）+ ダークネイビーグラデーション
   カラー: シアン/ターコイズ系アクセント（#00BCD4）
   作成: 2026/04/08 — K2 GuildBord風リデザイン
   ============================================================ */

/* ---- kosen専用カラー変数（ローカルスコープ） ---- */
.kosen-hero {
  --kosen-cyan: #00BCD4;
  --kosen-cyan-light: #26C6DA;
  --kosen-cyan-pale: #4DD0E1;
  --kosen-cyan-glow: rgba(0, 188, 212, 0.30);
  --kosen-cyan-subtle: rgba(0, 188, 212, 0.12);
  --kosen-dark: #060A14;
  --kosen-dark-mid: #0A0E1A;
  --kosen-dark-navy: #0D1B2E;
}

/* ---- 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: radial-gradient(ellipse at 30% 40%, var(--kosen-dark-mid) 0%, var(--kosen-dark) 70%);
}

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

/* Canvas（パーティクルネットワーク） */
.kosen-hero__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* ラジアルグロー装飾 */
.kosen-hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.35;
  pointer-events: none;
}

.kosen-hero__glow--center {
  width: 600px;
  height: 600px;
  top: 30%;
  left: 20%;
  background: radial-gradient(circle, rgba(0, 188, 212, 0.18) 0%, transparent 70%);
}

.kosen-hero__glow--top-right {
  width: 400px;
  height: 400px;
  top: -10%;
  right: 5%;
  background: radial-gradient(circle, rgba(38, 198, 218, 0.12) 0%, transparent 70%);
}

/* グリッドライン装飾（薄い水平線で技術感） */
.kosen-hero__grid-lines {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to bottom, transparent 0%, transparent 49.5%, rgba(0, 188, 212, 0.03) 50%, transparent 50.5%);
  background-size: 100% 80px;
  pointer-events: none;
}

/* 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: 180px;
  background: linear-gradient(to bottom, transparent, var(--kosen-dark));
  z-index: 1;
}

/* ============================================================
   背景装飾テキスト（大文字英字）— シアンストローク
   ============================================================ */
.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(0, 188, 212, 0.08);
  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(--kosen-cyan);
  margin: 0 0 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.kosen-hero__eyebrow-icon {
  font-size: 0.5rem;
  color: var(--kosen-cyan);
  animation: kosen-pulse 2.5s ease-in-out infinite;
}

@keyframes kosen-pulse {
  0%, 100% { opacity: 0.5; }
  50% { opacity: 1; }
}

/* ---- 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;
}

/* タイトルアクセント行（「ふざけるな。」）— シアンに変更 */
.kosen-hero__title-accent {
  color: var(--kosen-cyan-light);
  text-shadow: 0 0 40px var(--kosen-cyan-glow);
}

/* ---- 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, 0.75);
  margin: 0 0 52px;
  letter-spacing: 0.04em;
}

/* ============================================================
   CTA — シアングローボタン
   ============================================================ */
.kosen-hero__cta {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
}

.kosen-hero__btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: transparent;
  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: 1.5px solid var(--kosen-cyan);
  border-radius: 4px;
  position: relative;
  overflow: hidden;
  transition:
    background 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    box-shadow 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    border-color 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.kosen-hero__btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--kosen-cyan-subtle), transparent 60%);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.kosen-hero__btn:hover {
  background: rgba(0, 188, 212, 0.12);
  border-color: var(--kosen-cyan-light);
  transform: translateY(-2px);
  box-shadow: 0 0 24px var(--kosen-cyan-glow), 0 8px 28px rgba(0, 0, 0, 0.3);
}

.kosen-hero__btn:hover::before {
  opacity: 1;
}

.kosen-hero__btn-icon {
  font-size: 1.3em;
  color: var(--kosen-cyan-light);
  position: relative;
  z-index: 1;
}

.kosen-hero__btn-arrow {
  font-size: 1.1em;
  position: relative;
  z-index: 1;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.kosen-hero__btn: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, 0.38);
  margin: 0;
  letter-spacing: 0.06em;
}

/* ============================================================
   キーナンバーバッジ（右下・PC）— シアンテーマ
   ============================================================ */
.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(0, 188, 212, 0.25);
  border-radius: 8px;
  background: rgba(10, 14, 26, 0.65);
  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(--kosen-cyan);
  text-shadow: 0 0 20px var(--kosen-cyan-glow);
}

.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, 0.55);
  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, 0.42);
  margin-top: 8px;
}

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

@keyframes kosen-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, 0.35);
}

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

@keyframes kosen-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; }
}

/* ============================================================
   アクセシビリティ: prefers-reduced-motion
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  .kosen-hero__canvas {
    display: none;
  }

  .kosen-hero__eyebrow-icon,
  .kosen-hero__scroll,
  .kosen-hero__scroll-line {
    animation: none;
  }
}

/* ============================================================
   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;
  }

  .kosen-hero__glow--center {
    width: 400px;
    height: 400px;
  }
}

@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 {
    font-size: 0.95rem;
    padding: 14px 32px;
  }

  /* 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;
  }

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

  .kosen-hero__glow--center {
    width: 250px;
    height: 250px;
  }

  .kosen-hero__glow--top-right {
    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 {
    width: 100%;
    justify-content: center;
  }

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