/* ============================================
   EFFECT LAB — 共通スタイル
   ダークラボ基調 × ビビッドパープル × ミント
   ============================================ */
:root {
  --bg: #0a0a14;
  --bg2: #10101d;
  --panel: rgba(255, 255, 255, 0.04);
  --line: rgba(255, 255, 255, 0.1);
  --ink: #f2f2fa;
  --muted: #9d9db4;
  --purple: #8b5cf6;
  --purple-deep: #6c3ef5;
  --mint: #3ef5c0;
  --font-body: "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", sans-serif;
  --font-disp: "Space Grotesk", "Zen Kaku Gothic New", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

::selection { background: var(--purple); color: #fff; }

/* スクロールバー */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #2a2a40; border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--purple-deep); }

/* ============ 共通ヘッダー ============ */
.lab-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  background: linear-gradient(to bottom, rgba(10, 10, 20, 0.85), rgba(10, 10, 20, 0));
  pointer-events: none;
}
.lab-header > * { pointer-events: auto; }

.lab-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--muted);
  transition: color 0.3s;
}
.lab-back::before {
  content: "←";
  transition: transform 0.3s;
}
.lab-back:hover { color: var(--mint); }
.lab-back:hover::before { transform: translateX(-4px); }

.lab-brand {
  font-family: var(--font-disp);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--ink);
}
.lab-brand .dot { color: var(--mint); }

/* ============ デモ番号バッジ ============ */
.demo-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-disp);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.25em;
  color: var(--mint);
  text-transform: uppercase;
}
.demo-badge::before {
  content: "";
  width: 32px; height: 1px;
  background: var(--mint);
}

/* ============ 解説カード ============ */
.info-section {
  position: relative;
  z-index: 5;
  background: var(--bg);
  border-top: 1px solid var(--line);
  padding: 72px 24px 48px;
}
.info-inner { max-width: 880px; margin: 0 auto; }
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-top: 32px;
}
.info-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 24px;
}
.info-card h3 {
  font-size: 13px;
  letter-spacing: 0.15em;
  color: var(--mint);
  margin-bottom: 10px;
  font-weight: 700;
}
.info-card p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.9;
}
.info-title {
  font-size: clamp(22px, 3.4vw, 30px);
  font-weight: 700;
  letter-spacing: 0.04em;
  margin: 14px 0 8px;
}
.info-lead { font-size: 15px; color: var(--muted); }

/* ============ 前後ナビ ============ */
.demo-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  max-width: 880px;
  margin: 48px auto 0;
}
.demo-nav a {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px 24px;
  transition: border-color 0.3s, background 0.3s, transform 0.3s;
}
.demo-nav a:hover {
  border-color: var(--purple);
  background: rgba(139, 92, 246, 0.08);
  transform: translateY(-3px);
}
.demo-nav .nav-label {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--muted);
  font-family: var(--font-disp);
}
.demo-nav .nav-title {
  font-size: 15px;
  font-weight: 700;
  margin-top: 4px;
}
.demo-nav a.next { text-align: right; }
.demo-nav a.placeholder { visibility: hidden; }

/* ============ 操作ヒント ============ */
.hint-chip {
  position: fixed;
  bottom: 22px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 90;
  background: rgba(16, 16, 30, 0.8);
  backdrop-filter: blur(8px);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 9px 22px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
  white-space: nowrap;
  animation: hintIn 1s 0.8s both;
  pointer-events: none;
}
.hint-chip b { color: var(--mint); font-weight: 700; }
@keyframes hintIn {
  from { opacity: 0; translate: 0 12px; }
  to { opacity: 1; translate: 0 0; }
}

/* ============ ユーティリティ ============ */
.en { font-family: var(--font-disp); }

@media (max-width: 640px) {
  .info-section { padding: 56px 20px 40px; }
  .demo-nav { grid-template-columns: 1fr; }
  .demo-nav a.next { text-align: left; }
  .hint-chip { font-size: 11px; padding: 8px 16px; }
}

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