<style>
  :root{
    --bg:#0b1020;
    --card:#111a33;
    --text:#e8ecff;
    --muted:#aab3d6;
    --accent:#6ea8ff;
    --danger:#ff6b6b;
  }
  body{
    margin:0;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
    background: linear-gradient(180deg, var(--bg), #070a14);
    color: var(--text);
  }
  .wrap{
    max-width: 900px;
    margin: 0 auto;
    padding: 24px 16px;
  }
  h1,h2{ margin: 8px 0 16px; }
  p{ color: var(--muted); line-height:1.6; }

  /* ボタン/リンクをボタン化 */
  .btn, a.btn, button{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    gap:8px;
    padding: 12px 14px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,.12);
    background: rgba(255,255,255,.06);
    color: var(--text);
    text-decoration:none;
    cursor:pointer;
    transition: transform .05s ease, background .2s ease;
  }
  .btn:hover, a.btn:hover, button:hover{
    background: rgba(255,255,255,.10);
  }
  .btn:active, a.btn:active, button:active{
    transform: translateY(1px);
  }
  .primary{
    background: rgba(110,168,255,.18);
    border-color: rgba(110,168,255,.35);
  }
  .primary:hover{ background: rgba(110,168,255,.26); }

  /* カード */
  .grid{
    display:grid;
    grid-template-columns: repeat(auto-fit, minmax(220px,1fr));
    gap: 12px;
    margin-top: 14px;
  }
  .card{
    background: rgba(255,255,255,.06);
    border:1px solid rgba(255,255,255,.10);
    border-radius:16px;
    padding:14px;
  }
  .card small{ color: var(--muted); }

  /* クイズ */
  #question{
    font-size: 20px;
    margin-bottom: 14px;
  }
  .choices{
    display:grid;
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .choice{
    width: 100%;
    text-align:left;
  }
  #result{
    margin-top: 12px;
    font-weight: 700;
  }
  #explain{
    margin-top: 10px;
    padding: 12px;
    border-radius: 12px;
    background: rgba(255,255,255,.06);
    border:1px solid rgba(255,255,255,.10);
  }
  .hidden{ display:none; }

  /* フッターリンク */
  .links{
    margin-top: 18px;
    display:flex;
    gap:10px;
    flex-wrap: wrap;
  }
</style>