/* =============================================================================
   BANSHO ENGINE — styles.css
   万象機関 公式サイト スタイルシート
   Version: 1.0
   ============================================================================= */

/* ===== CSS カスタムプロパティ ===== */
:root {
  /* カラーパレット */
  --color-bg:          #080e1c;
  --color-bg-mid:      #0c1424;
  --color-bg-surface:  #101828;
  --color-bg-elevated: #162034;
  --color-bg-card:     #111c2d;

  --color-gold:        #c9a84c;
  --color-gold-light:  #e8cc7a;
  --color-gold-dark:   #a87c2a;
  --color-gold-muted:  rgba(201,168,76,0.25);

  --color-cyan:        #4dd9f0;
  --color-cyan-light:  #7de8f8;
  --color-cyan-dark:   #1aa8c5;
  --color-cyan-muted:  rgba(77,217,240,0.15);

  --color-text-primary:   #e8e2d6;
  --color-text-secondary: #a8b4c0;
  --color-text-muted:     #5a6a7a;
  --color-text-gold:      #c9a84c;
  --color-text-cyan:      #4dd9f0;

  --color-border:         rgba(201,168,76,0.2);
  --color-border-cyan:    rgba(77,217,240,0.15);
  --color-border-subtle:  rgba(255,255,255,0.06);

  /* タイポグラフィ */
  --font-serif:   'Georgia', 'Times New Roman', serif;
  --font-sans:    -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-mono:    'Courier New', 'Lucida Console', monospace;
  --font-ja-serif:'Hiragino Mincho ProN', 'Yu Mincho', 'MS Mincho', serif;
  --font-ja-sans: 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', 'Yu Gothic', 'Meiryo', sans-serif;

  /* フォントサイズ */
  --fs-hero-en:   clamp(2.2rem, 6vw, 4.5rem);
  --fs-hero-ja:   clamp(1.6rem, 4vw, 3rem);
  --fs-h1:        clamp(1.8rem, 4vw, 3rem);
  --fs-h2-en:     clamp(1.4rem, 3vw, 2rem);
  --fs-h2-ja:     clamp(1.2rem, 2.5vw, 1.8rem);
  --fs-h3:        clamp(1rem, 2vw, 1.3rem);
  --fs-body:      1rem;
  --fs-small:     0.875rem;
  --fs-xsmall:    0.75rem;
  --fs-label:     0.7rem;

  /* スペーシング */
  --space-xs:   0.5rem;
  --space-sm:   1rem;
  --space-md:   1.5rem;
  --space-lg:   2.5rem;
  --space-xl:   4rem;
  --space-2xl:  6rem;
  --space-3xl:  8rem;

  /* レイアウト */
  --max-width:        1200px;
  --header-height:    72px;
  --border-radius:    4px;
  --border-radius-md: 8px;
  --border-radius-lg: 16px;

  /* トランジション */
  --transition-fast:   150ms ease;
  --transition-base:   300ms ease;
  --transition-slow:   500ms ease;

  /* シャドウ */
  --shadow-gold:  0 0 20px rgba(201,168,76,0.15), 0 0 40px rgba(201,168,76,0.08);
  --shadow-cyan:  0 0 20px rgba(77,217,240,0.12), 0 0 40px rgba(77,217,240,0.06);
  --shadow-card:  0 4px 24px rgba(0,0,0,0.4);
}

/* ===== リセット & ベース ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-ja-sans);
  line-height: 1.75;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* フォーカス表示 */
:focus-visible {
  outline: 2px solid var(--color-cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

/* リンク */
a {
  color: var(--color-cyan);
  text-decoration: none;
  transition: color var(--transition-fast), opacity var(--transition-fast);
}
a:hover {
  color: var(--color-cyan-light);
}

/* 画像 */
img, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

/* 見出し */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
}

/* リスト */
ul, ol {
  list-style: none;
}

/* ===== コンテナ ===== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: clamp(1rem, 4vw, 2rem);
}

/* ===== セクション共通 ===== */
.section {
  padding-block: var(--space-2xl);
  position: relative;
}

.section--alt {
  background-color: var(--color-bg-mid);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.section-label {
  display: inline-block;
  font-family: var(--font-serif);
  font-size: var(--fs-label);
  letter-spacing: 0.25em;
  color: var(--color-cyan);
  text-transform: uppercase;
  margin-bottom: var(--space-xs);
  padding: 0.25em 0.8em;
  border: 1px solid var(--color-border-cyan);
  border-radius: 2px;
}

.section-title-en {
  font-family: var(--font-serif);
  font-size: var(--fs-h2-en);
  color: var(--color-gold);
  letter-spacing: 0.08em;
  margin-bottom: 0.3em;
}

.section-title-ja {
  font-family: var(--font-ja-serif);
  font-size: var(--fs-h2-ja);
  color: var(--color-text-primary);
  font-weight: 400;
  margin-bottom: var(--space-md);
}

.section-description {
  font-size: var(--fs-body);
  color: var(--color-text-secondary);
  max-width: 680px;
  margin-inline: auto;
  line-height: 1.9;
}

/* 区切り線 */
.divider {
  width: 60px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-gold), transparent);
  margin-inline: auto;
  margin-bottom: var(--space-lg);
}

/* ===== ヘッダー ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 1000;
  transition: background-color var(--transition-base), backdrop-filter var(--transition-base);
}

.site-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8,14,28,0.95) 0%, rgba(8,14,28,0) 100%);
  pointer-events: none;
}

.site-header.scrolled {
  background-color: rgba(8,14,28,0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: var(--space-md);
}

/* ロゴ */
.header-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  flex-shrink: 0;
}

.header-logo-mark {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.header-logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.header-logo-en {
  font-family: var(--font-serif);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--color-gold);
}

.header-logo-ja {
  font-family: var(--font-ja-serif);
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  color: var(--color-text-secondary);
}

/* ナビゲーション */
.header-nav {
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.nav-link {
  font-family: var(--font-serif);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
  padding: 0.5em 0.8em;
  border-radius: var(--border-radius);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-gold-light);
  background-color: var(--color-gold-muted);
}

.nav-link--policies {
  font-size: 0.72rem;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  padding: 0.4em 0.7em;
}

.nav-link--policies:hover {
  border-color: var(--color-gold-dark);
  color: var(--color-gold);
  background-color: transparent;
}

/* ハンバーガーメニュー */
.hamburger-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  cursor: pointer;
  padding: 8px;
  transition: border-color var(--transition-fast);
}

.hamburger-btn:hover {
  border-color: var(--color-gold);
}

.hamburger-line {
  display: block;
  width: 22px;
  height: 1.5px;
  background-color: var(--color-text-secondary);
  transition: transform var(--transition-base), opacity var(--transition-fast), background-color var(--transition-fast);
  transform-origin: center;
}

.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
  background-color: var(--color-gold);
}

.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}

.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
  background-color: var(--color-gold);
}

/* モバイルメニュー */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background-color: rgba(8,14,28,0.98);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  z-index: 999;
  transform: translateY(-10px);
  opacity: 0;
  transition: transform var(--transition-base), opacity var(--transition-base);
  pointer-events: none;
}

.mobile-menu.open {
  display: block;
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.mobile-nav-list {
  padding: var(--space-md) var(--space-sm);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.mobile-nav-link {
  display: block;
  font-family: var(--font-serif);
  font-size: 0.95rem;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--border-radius);
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.mobile-nav-link:hover {
  color: var(--color-gold-light);
  border-left-color: var(--color-gold);
  background-color: var(--color-gold-muted);
  padding-left: calc(var(--space-md) + 4px);
}

.mobile-nav-divider {
  height: 1px;
  background: var(--color-border);
  margin: var(--space-xs) 0;
}

/* ===== ヒーローセクション ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding-top: var(--header-height);
}

/* 背景グラデーション */
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 40%, rgba(12,30,60,0.6) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 20% 80%, rgba(77,217,240,0.04) 0%, transparent 60%),
    radial-gradient(ellipse 40% 40% at 80% 20%, rgba(201,168,76,0.05) 0%, transparent 60%);
  pointer-events: none;
}

/* 背景グリッド */
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(201,168,76,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(201,168,76,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  opacity: 0.5;
}

.hero-content {
  position: relative;
  z-index: 2;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
  padding-block: var(--space-2xl);
}

.hero-text {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.hero-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.2em;
  color: var(--color-cyan);
  text-transform: uppercase;
}

.hero-label::before {
  content: '';
  display: inline-block;
  width: 20px;
  height: 1px;
  background-color: var(--color-cyan);
}

.hero-title-en {
  font-family: var(--font-serif);
  font-size: var(--fs-hero-en);
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.1;
  color: var(--color-gold);
  text-shadow: 0 0 40px rgba(201,168,76,0.3);
}

.hero-title-ja {
  font-family: var(--font-ja-serif);
  font-size: var(--fs-hero-ja);
  font-weight: 400;
  letter-spacing: 0.12em;
  color: var(--color-text-primary);
  margin-top: -0.3em;
}

.hero-catchcopy {
  display: flex;
  flex-direction: column;
  gap: 0.3em;
}

.hero-catchcopy-en {
  font-family: var(--font-serif);
  font-size: clamp(0.9rem, 2vw, 1.15rem);
  letter-spacing: 0.05em;
  color: var(--color-cyan);
  font-style: italic;
}

.hero-catchcopy-ja {
  font-family: var(--font-ja-serif);
  font-size: clamp(0.85rem, 1.8vw, 1.05rem);
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
}

.hero-description {
  font-size: clamp(0.85rem, 1.5vw, 0.95rem);
  color: var(--color-text-secondary);
  line-height: 1.9;
  max-width: 520px;
  border-left: 1px solid var(--color-border);
  padding-left: var(--space-sm);
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-xs);
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.engine-core-wrapper {
  width: min(480px, 100%);
  aspect-ratio: 1;
  position: relative;
}

.engine-core-svg {
  width: 100%;
  height: 100%;
}

/* ===== ボタン ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  font-family: var(--font-serif);
  font-size: 0.85rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.85em 1.8em;
  border-radius: var(--border-radius);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition:
    background-color var(--transition-base),
    border-color var(--transition-base),
    color var(--transition-base),
    transform var(--transition-fast),
    box-shadow var(--transition-base);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

/* ボタン光流れエフェクト */
.btn::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 60%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255,255,255,0.08),
    transparent
  );
  transition: left 0.5s ease;
  pointer-events: none;
}

.btn:hover::after {
  left: 150%;
}

.btn:active {
  transform: scale(0.98);
}

/* プライマリボタン（金） */
.btn--primary {
  background: linear-gradient(135deg, var(--color-gold-dark), var(--color-gold));
  border-color: var(--color-gold);
  color: #0a1628;
  font-weight: 700;
}

.btn--primary:hover {
  background: linear-gradient(135deg, var(--color-gold), var(--color-gold-light));
  box-shadow: var(--shadow-gold);
  color: #0a1628;
}

/* セカンダリボタン（枠線） */
.btn--secondary {
  background: transparent;
  border-color: var(--color-gold-dark);
  color: var(--color-gold);
}

.btn--secondary:hover {
  background: var(--color-gold-muted);
  border-color: var(--color-gold);
  color: var(--color-gold-light);
}

/* テキストボタン（シアン） */
.btn--text {
  background: transparent;
  border-color: var(--color-border-cyan);
  color: var(--color-cyan);
  padding: 0.85em 1.5em;
}

.btn--text:hover {
  background: var(--color-cyan-muted);
  border-color: var(--color-cyan-dark);
  color: var(--color-cyan-light);
}

/* エンジン起動ボタン */
.btn--ignite {
  background: linear-gradient(135deg, #0c1e38, #152a4a);
  border-color: var(--color-gold);
  border-width: 1.5px;
  color: var(--color-gold-light);
  font-size: 0.9rem;
  padding: 0.9em 2em;
  box-shadow: 0 0 0 rgba(201,168,76,0);
  transition:
    background var(--transition-base),
    box-shadow var(--transition-slow),
    color var(--transition-fast),
    transform var(--transition-fast);
}

.btn--ignite:hover {
  background: linear-gradient(135deg, #152a4a, #1e3a62);
  box-shadow: 0 0 20px rgba(201,168,76,0.3), 0 0 40px rgba(201,168,76,0.15);
  color: var(--color-gold-light);
}

.btn--ignite.active {
  box-shadow: 0 0 30px rgba(201,168,76,0.5), 0 0 60px rgba(201,168,76,0.25);
}

.btn-sub-label {
  display: block;
  font-family: var(--font-ja-sans);
  font-size: 0.65rem;
  letter-spacing: 0.05em;
  text-transform: none;
  opacity: 0.75;
  margin-top: 1px;
}

/* ===== エンジン起動演出オーバーレイ ===== */
.engine-boot-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(8,14,28,0.85);
  backdrop-filter: blur(4px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-slow);
}

.engine-boot-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.engine-boot-message {
  text-align: center;
}

.engine-boot-status {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.25em;
  color: var(--color-cyan);
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
  opacity: 0.8;
}

.engine-boot-title-en {
  font-family: var(--font-serif);
  font-size: clamp(1.4rem, 4vw, 2.2rem);
  letter-spacing: 0.15em;
  color: var(--color-gold);
  margin-bottom: 0.3em;
}

.engine-boot-title-ja {
  font-family: var(--font-ja-serif);
  font-size: clamp(1rem, 3vw, 1.5rem);
  letter-spacing: 0.2em;
  color: var(--color-text-primary);
}

.engine-boot-bar {
  width: 240px;
  height: 1px;
  background: var(--color-bg-elevated);
  margin: var(--space-md) auto 0;
  overflow: hidden;
  border-radius: 2px;
}

.engine-boot-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--color-gold-dark), var(--color-gold-light));
  transition: width 0.8s ease;
}

/* ===== What Is / エンジンについて ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: start;
}

.about-text-block {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.about-title-en {
  font-family: var(--font-serif);
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  color: var(--color-gold);
  letter-spacing: 0.06em;
}

.about-title-ja {
  font-family: var(--font-ja-serif);
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  color: var(--color-text-primary);
  font-weight: 400;
  margin-top: -0.4em;
}

.about-body {
  color: var(--color-text-secondary);
  line-height: 1.95;
  font-size: 0.95rem;
}

.about-note {
  padding: var(--space-sm) var(--space-md);
  background: var(--color-bg-elevated);
  border-left: 2px solid var(--color-cyan-dark);
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.about-note strong {
  color: var(--color-cyan);
  font-weight: 600;
}

.about-visual-block {
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-mark {
  width: min(280px, 100%);
  opacity: 0.85;
}

/* ===== エンジンフロー ===== */
.flow-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-sm);
  position: relative;
}

.flow-grid::after {
  content: '';
  position: absolute;
  top: 52px;
  left: calc(10% + 1rem);
  right: calc(10% + 1rem);
  height: 1px;
  background: linear-gradient(90deg,
    transparent,
    var(--color-gold-muted),
    var(--color-gold),
    var(--color-gold-muted),
    transparent
  );
  pointer-events: none;
}

.flow-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-sm);
  position: relative;
  z-index: 1;
}

.flow-step-number {
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  margin-bottom: -0.3em;
}

.flow-step-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
  flex-shrink: 0;
}

.flow-step:hover .flow-step-icon,
.flow-step.highlighted .flow-step-icon {
  border-color: var(--color-gold);
  box-shadow: var(--shadow-gold);
}

.flow-step-icon svg {
  width: 28px;
  height: 28px;
}

.flow-step-en {
  font-family: var(--font-serif);
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  color: var(--color-gold);
  text-transform: uppercase;
}

.flow-step-ja {
  font-family: var(--font-ja-serif);
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ===== 運用原則 ===== */
.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-md);
}

.principle-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--border-radius-md);
  transition: border-color var(--transition-base), background-color var(--transition-base);
}

.principle-item:hover {
  border-color: var(--color-border);
  background: var(--color-bg-elevated);
}

.principle-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}

.principle-icon svg {
  width: 20px;
  height: 20px;
}

.principle-text {
  display: flex;
  flex-direction: column;
  gap: 0.2em;
}

.principle-ja {
  font-family: var(--font-ja-sans);
  font-size: var(--fs-small);
  color: var(--color-text-primary);
  line-height: 1.6;
}

.principle-en {
  font-family: var(--font-serif);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  font-style: italic;
}

/* ===== プロジェクト ===== */
.project-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  max-width: 700px;
  margin-inline: auto;
  transition: box-shadow var(--transition-base);
}

.project-card:hover {
  box-shadow: var(--shadow-gold);
}

.project-card-header {
  padding: var(--space-lg) var(--space-xl);
  border-bottom: 1px solid var(--color-border-subtle);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-md);
}

.project-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.2em;
  color: var(--color-cyan);
  border: 1px solid var(--color-border-cyan);
  padding: 0.25em 0.7em;
  border-radius: 2px;
  flex-shrink: 0;
}

.project-badge-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-cyan);
  animation: pulse 2s ease infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.project-title {
  font-family: var(--font-serif);
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  color: var(--color-gold);
  letter-spacing: 0.04em;
}

.project-card-body {
  padding: var(--space-lg) var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.project-visual {
  width: 100%;
  aspect-ratio: 16/7;
  background: var(--color-bg);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border-subtle);
}

.project-description-ja {
  font-size: 0.95rem;
  color: var(--color-text-primary);
  line-height: 1.95;
}

.project-description-en {
  font-family: var(--font-serif);
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
  font-style: italic;
  line-height: 1.8;
}

/* 今後のプロジェクト */
.future-projects {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-xl);
  border: 1px dashed var(--color-border);
  border-radius: var(--border-radius-lg);
  text-align: center;
  max-width: 600px;
  margin-inline: auto;
}

.future-en {
  font-family: var(--font-serif);
  font-size: clamp(1rem, 2.5vw, 1.3rem);
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
}

.future-ja {
  font-family: var(--font-ja-serif);
  font-size: clamp(0.85rem, 2vw, 1rem);
  letter-spacing: 0.12em;
  color: var(--color-text-muted);
}

/* ===== ポリシーリンク ===== */
.policies-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-sm);
  max-width: 900px;
  margin-inline: auto;
}

.policy-link-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.4em;
  padding: var(--space-md) var(--space-sm);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--border-radius-md);
  text-decoration: none;
  transition: all var(--transition-base);
}

.policy-link-item:hover {
  border-color: var(--color-gold-dark);
  background: var(--color-bg-elevated);
  transform: translateY(-2px);
}

.policy-link-en {
  font-family: var(--font-serif);
  font-size: var(--fs-small);
  letter-spacing: 0.05em;
  color: var(--color-gold);
}

.policy-link-ja {
  font-size: var(--fs-xsmall);
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

/* ===== お問い合わせ ===== */
.contact-wrapper {
  max-width: 600px;
  margin-inline: auto;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.contact-email-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: clamp(0.85rem, 2vw, 1rem);
  letter-spacing: 0.05em;
  color: var(--color-cyan);
  padding: var(--space-sm) var(--space-lg);
  border: 1px solid var(--color-border-cyan);
  border-radius: var(--border-radius-md);
  background: var(--color-bg-card);
  transition: all var(--transition-base);
  text-decoration: none;
}

.contact-email-link:hover {
  border-color: var(--color-cyan-dark);
  background: var(--color-cyan-muted);
  color: var(--color-cyan-light);
  box-shadow: var(--shadow-cyan);
}

.contact-note {
  font-size: var(--fs-small);
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* ===== フッター ===== */
.site-footer {
  background: var(--color-bg-mid);
  border-top: 1px solid var(--color-border-subtle);
  padding-top: var(--space-xl);
}

.footer-upper {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border-subtle);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  margin-bottom: 0.5em;
}

.footer-logo-mark {
  width: 40px;
  height: 40px;
}

.footer-brand-name {
  font-family: var(--font-serif);
  font-size: 1rem;
  letter-spacing: 0.1em;
  color: var(--color-gold);
}

.footer-brand-name-ja {
  font-family: var(--font-ja-serif);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
}

.footer-tagline {
  font-family: var(--font-serif);
  font-size: var(--fs-small);
  color: var(--color-text-muted);
  font-style: italic;
}

.footer-nav-column h3 {
  font-family: var(--font-serif);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.footer-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.5em;
}

.footer-nav-link {
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: flex;
  flex-direction: column;
  gap: 0.1em;
}

.footer-nav-link:hover {
  color: var(--color-gold-light);
}

.footer-nav-link span {
  font-size: var(--fs-xsmall);
  color: var(--color-text-muted);
}

.footer-lower {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-md);
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.footer-copyright {
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

.footer-domain {
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

/* ===== ページ内部ヘッダー ===== */
.page-hero {
  padding-top: calc(var(--header-height) + var(--space-2xl));
  padding-bottom: var(--space-xl);
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, rgba(12,30,60,0.5) 0%, transparent 70%);
  position: relative;
}

.page-hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border), transparent);
}

.page-hero-label {
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.25em;
  color: var(--color-cyan);
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
}

.page-hero-title-en {
  font-family: var(--font-serif);
  font-size: var(--fs-h1);
  color: var(--color-gold);
  letter-spacing: 0.08em;
  margin-bottom: 0.2em;
}

.page-hero-title-ja {
  font-family: var(--font-ja-serif);
  font-size: clamp(1.2rem, 3vw, 1.8rem);
  color: var(--color-text-primary);
  font-weight: 400;
  letter-spacing: 0.12em;
  margin-bottom: var(--space-md);
}

.page-hero-desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  max-width: 680px;
  line-height: 1.9;
}

/* ===== system.html 用 ===== */
.system-modules-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-md);
}

.system-module {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--border-radius-md);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.system-module:hover {
  border-color: var(--color-border);
  box-shadow: var(--shadow-card);
}

.system-module-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
}

.system-module-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.system-module-icon svg {
  width: 20px;
  height: 20px;
}

.system-module-title {
  display: flex;
  flex-direction: column;
  gap: 0.15em;
}

.module-step {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
}

.module-title-en {
  font-family: var(--font-serif);
  font-size: 1rem;
  letter-spacing: 0.06em;
  color: var(--color-gold);
}

.module-title-ja {
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
}

.system-module-body {
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
  line-height: 1.9;
}

/* YouTubeポリシー */
.youtube-policy-box {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-cyan);
  border-radius: var(--border-radius-md);
  padding: var(--space-lg) var(--space-xl);
  max-width: 800px;
  margin-inline: auto;
}

.youtube-policy-title {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--color-cyan);
  letter-spacing: 0.06em;
  margin-bottom: var(--space-sm);
}

.youtube-policy-list {
  display: flex;
  flex-direction: column;
  gap: 0.6em;
}

.youtube-policy-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.6em;
  font-size: var(--fs-small);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.youtube-policy-list li::before {
  content: '—';
  color: var(--color-cyan-dark);
  flex-shrink: 0;
  margin-top: 0.05em;
}

/* 安全設計 */
.safety-arch-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-md);
}

.safety-item {
  padding: var(--space-md);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--border-radius-md);
  background: var(--color-bg-card);
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  transition: border-color var(--transition-base);
}

.safety-item:hover {
  border-color: var(--color-gold-dark);
}

.safety-icon {
  width: 48px;
  height: 48px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.safety-icon svg {
  width: 32px;
  height: 32px;
}

.safety-title {
  font-family: var(--font-serif);
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  color: var(--color-gold);
}

.safety-desc {
  font-size: var(--fs-xsmall);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* ===== projects.html 用 ===== */
.project-full-card {
  max-width: 800px;
  margin-inline: auto;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
}

.project-full-visual {
  width: 100%;
  aspect-ratio: 16/6;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border-subtle);
}

.project-full-content {
  padding: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.project-meta-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.project-type-tag {
  font-family: var(--font-mono);
  font-size: var(--fs-xsmall);
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border-subtle);
  padding: 0.2em 0.6em;
  border-radius: 2px;
  text-transform: uppercase;
}

.project-full-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  color: var(--color-gold);
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.project-full-subtitle {
  font-family: var(--font-ja-serif);
  font-size: clamp(0.9rem, 2vw, 1.1rem);
  color: var(--color-text-secondary);
  font-weight: 400;
  letter-spacing: 0.12em;
}

.project-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-top: var(--space-sm);
}

.project-detail-item {
  display: flex;
  flex-direction: column;
  gap: 0.3em;
}

.detail-label {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  text-transform: uppercase;
}

.detail-value {
  font-size: var(--fs-small);
  color: var(--color-text-primary);
}

/* ===== スクロールアニメーション ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }
.reveal-delay-5 { transition-delay: 0.5s; }

/* ===== エンジンコアSVGアニメーション ===== */
#orbit-outer {
  animation: rotateOrbit 60s linear infinite;
}

#orbit-tilt1 {
  animation: rotateOrbit 45s linear infinite;
}

#orbit-tilt2 {
  animation: rotateOrbitReverse 50s linear infinite;
}

#orbit-mid {
  animation: rotateOrbitReverse 40s linear infinite;
}

#orbit-inner {
  animation: rotateOrbit 30s linear infinite;
}

#inner-structure {
  animation: rotateOrbitReverse 120s linear infinite;
}

@keyframes rotateOrbit {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

@keyframes rotateOrbitReverse {
  from { transform: rotate(0deg); }
  to   { transform: rotate(-360deg); }
}

/* エンジン起動時加速 */
.engine-boosting #orbit-outer {
  animation-duration: 8s;
}
.engine-boosting #orbit-tilt1 {
  animation-duration: 6s;
}
.engine-boosting #orbit-tilt2 {
  animation-duration: 7s;
}
.engine-boosting #orbit-mid {
  animation-duration: 5s;
}
.engine-boosting #orbit-inner {
  animation-duration: 4s;
}

/* ノードの点灯 */
.engine-node-lit circle:first-child {
  filter: url(#coreGlowStrong);
}

/* reduced motion 対応 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  html {
    scroll-behavior: auto;
  }
}

/* =============================================================================
   RESPONSIVE DESIGN — 全端末対応
   対応範囲: 320px (iPhone SE) 〜 3840px (4K UHD)
   breakpoints:
     xs:  〜 374px   (古いiPhone SE, Galaxy Mini 等)
     sm:  375px〜    (iPhone SE 3rd, 標準スマホ)
     md:  768px〜    (iPad mini, タブレット縦)
     lg:  1024px〜   (iPad Pro, タブレット横, 小型ノートPC)
     xl:  1280px〜   (一般ノートPC)
     2xl: 1440px〜   (ワイドノートPC, デスクトップ)
     3xl: 1920px〜   (Full HD デスクトップ)
     4k:  2560px〜   (2K / 4K ディスプレイ)
   ============================================================================= */

/* ===== ベースのモバイルファースト補正 ===== */

/* タッチ端末でのタップ領域を十分に確保 */
a, button, [role="button"] {
  min-height: 44px;
  min-width: 44px;
}
.nav-link, .mobile-nav-link, .footer-nav-link {
  min-height: unset; /* ナビリンクはデザイン優先 */
  min-width:  unset;
}

/* ===== xs: 〜374px (超小型スマートフォン) ===== */
@media (max-width: 374px) {
  :root {
    --space-xs:   0.35rem;
    --space-sm:   0.75rem;
    --space-md:   1.1rem;
    --space-lg:   1.75rem;
    --space-xl:   2.25rem;
    --space-2xl:  3.25rem;
    --space-3xl:  4rem;
    --header-height: 60px;
  }

  html { font-size: 14px; }

  .container {
    padding-inline: 0.85rem;
  }

  .header-logo-en {
    font-size: 0.78rem;
    letter-spacing: 0.08em;
  }

  .header-logo-ja { display: none; }

  .header-logo-mark {
    width: 28px;
    height: 28px;
  }

  .header-nav { display: none; }

  .hamburger-btn { display: flex; }

  .hero-content {
    grid-template-columns: 1fr;
    padding-block: var(--space-lg);
    gap: var(--space-md);
    text-align: center;
  }

  .hero-text { align-items: center; }

  .engine-core-wrapper {
    width: min(220px, 70vw);
  }

  .hero-buttons {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
  }

  .btn {
    width: 100%;
    justify-content: center;
    padding: 0.9em 1em;
  }

  .btn-sub-label { font-size: 0.6rem; }

  .flow-grid {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }

  .flow-grid::after { display: none; }

  .about-grid { grid-template-columns: 1fr; }

  .principles-grid { grid-template-columns: 1fr; }

  .footer-upper {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .footer-lower {
    flex-direction: column;
    align-items: flex-start;
  }

  .policies-grid {
    grid-template-columns: 1fr;
  }

  .project-card-header {
    flex-direction: column;
    padding: var(--space-sm) var(--space-md);
  }

  .project-card-body {
    padding: var(--space-sm) var(--space-md);
  }

  .project-detail-grid {
    grid-template-columns: 1fr;
  }

  .project-full-content {
    padding: var(--space-md);
  }

  .system-modules-grid { grid-template-columns: 1fr; }

  .safety-arch-grid { grid-template-columns: 1fr; }

  .youtube-policy-box {
    padding: var(--space-md);
  }
}

/* ===== sm: 375px〜767px (標準スマートフォン) ===== */
@media (min-width: 375px) and (max-width: 767px) {
  :root {
    --space-xl:  2.5rem;
    --space-2xl: 4rem;
    --space-3xl: 5rem;
    --header-height: 64px;
  }

  .header-nav { display: none; }

  .hamburger-btn { display: flex; }

  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--space-lg);
    padding-block: var(--space-xl);
  }

  .hero-text { align-items: center; }

  .hero-description {
    text-align: left;
    max-width: 100%;
  }

  .hero-buttons { justify-content: center; }

  .hero-visual { order: -1; }

  .engine-core-wrapper {
    width: min(280px, 72vw);
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  .about-visual-block { order: -1; }

  .flow-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
  }

  .flow-grid::after { display: none; }

  .principles-grid { grid-template-columns: 1fr; }

  .footer-upper {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  .footer-lower {
    flex-direction: column;
    align-items: flex-start;
  }

  .project-card-header {
    flex-direction: column;
    padding: var(--space-md) var(--space-lg);
  }

  .project-card-body {
    padding: var(--space-md) var(--space-lg);
  }

  .project-detail-grid {
    grid-template-columns: 1fr;
  }

  .project-full-content {
    padding: var(--space-lg) var(--space-md);
  }

  .system-modules-grid { grid-template-columns: 1fr; }

  .safety-arch-grid { grid-template-columns: 1fr 1fr; }

  .policies-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== md: 768px〜1023px (タブレット) ===== */
@media (min-width: 768px) and (max-width: 1023px) {
  :root {
    --header-height: 68px;
  }

  .header-nav { display: none; }

  .hamburger-btn { display: flex; }

  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--space-xl);
  }

  .hero-text { align-items: center; }

  .hero-description {
    text-align: left;
    max-width: 600px;
  }

  .hero-buttons { justify-content: center; }

  .hero-visual { order: -1; }

  .engine-core-wrapper {
    width: min(360px, 60vw);
  }

  .about-grid { grid-template-columns: 1fr; }

  .about-visual-block { order: -1; }

  .flow-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
  }

  .flow-grid::after { display: none; }

  .footer-upper {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
  }

  .project-detail-grid {
    grid-template-columns: 1fr 1fr;
  }

  .safety-arch-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .policies-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ===== lg: 1024px〜1279px (小型ノートPC・タブレット横) ===== */
@media (min-width: 1024px) and (max-width: 1279px) {
  .header-nav { display: flex; }
  .hamburger-btn { display: none; }

  .hero-content {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
  }

  .engine-core-wrapper {
    width: min(400px, 45vw);
  }

  .flow-grid {
    grid-template-columns: repeat(5, 1fr);
  }

  .footer-upper {
    grid-template-columns: 1fr 1fr 1fr;
  }
}

/* ===== xl: 1280px〜1439px (一般ノートPC) ===== */
@media (min-width: 1280px) and (max-width: 1439px) {
  .header-nav { display: flex; }
  .hamburger-btn { display: none; }

  .hero-content {
    grid-template-columns: 1fr 1fr;
  }

  .footer-upper {
    grid-template-columns: 1fr 1fr 1fr;
  }
}

/* ===== 2xl: 1440px〜1919px (ワイドノートPC・デスクトップ) ===== */
@media (min-width: 1440px) {
  :root {
    --max-width: 1360px;
  }

  .header-nav { display: flex; }
  .hamburger-btn { display: none; }
}

/* ===== 3xl: 1920px〜2559px (Full HD デスクトップ) ===== */
@media (min-width: 1920px) {
  :root {
    --max-width:   1600px;
    --space-xl:    5rem;
    --space-2xl:   7rem;
    --space-3xl:  10rem;
  }

  html { font-size: 17px; }

  .engine-core-wrapper {
    width: min(560px, 100%);
  }
}

/* ===== 4K: 2560px〜 (2K/4K ディスプレイ) ===== */
@media (min-width: 2560px) {
  :root {
    --max-width:   2000px;
    --space-xl:    6rem;
    --space-2xl:   8rem;
    --space-3xl:  12rem;
    --header-height: 88px;
  }

  html { font-size: 19px; }

  .engine-core-wrapper {
    width: min(700px, 100%);
  }

  .header-logo-mark {
    width: 48px;
    height: 48px;
  }

  .nav-link {
    font-size: 0.9rem;
    padding: 0.6em 1em;
  }
}

/* ===== 横向き低背スマートフォン (landscape/short) ===== */
@media (max-height: 500px) and (orientation: landscape) {
  .hero {
    min-height: unset;
    padding-top: calc(var(--header-height) + var(--space-md));
    padding-bottom: var(--space-md);
  }

  .hero-content {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
    padding-block: var(--space-md);
    text-align: left;
  }

  .hero-text { align-items: flex-start; }

  .hero-visual { order: 0; }

  .engine-core-wrapper {
    width: min(200px, 40vw);
  }

  .hero-buttons { justify-content: flex-start; }
}

/* ===== 高解像度 Retina / HiDPI ===== */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .header-logo-mark,
  .footer-logo-mark {
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
  }
}

/* ===== Print ===== */
@media print {
  .site-header,
  .hamburger-btn,
  .mobile-menu,
  .engine-boot-overlay,
  .hero-visual,
  .hero-bg,
  .hero-grid {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  .container {
    max-width: 100%;
    padding-inline: 1.5cm;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.75em;
    color: #555;
  }
}

/* ===== reduced motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  html {
    scroll-behavior: auto;
  }
}

/* ===== 後方互換: max-width のみのフォールバック ===== */

/* 768px以下で確実にハンバーガーを出す */
@media (max-width: 767px) {
  .header-nav { display: none !important; }
  .hamburger-btn { display: flex !important; }
}

/* 1024px以上で確実にデスクトップナビを出す */
@media (min-width: 1024px) {
  .header-nav { display: flex !important; }
  .hamburger-btn { display: none !important; }
}

/* ===== ユーティリティ ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border-width: 0;
}

.text-center { text-align: center; }
.text-gold   { color: var(--color-gold); }
.text-cyan   { color: var(--color-cyan); }
.text-muted  { color: var(--color-text-muted); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }

/* ===== プロジェクト視覚装飾（Paws用） ===== */
.paws-visual {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(ellipse at 50% 50%, #0c1e38 0%, #080e1c 100%);
}