:root {
      --main-color: #2c3e50;
      --accent-color: #e74c3c;
      --bg-color: #f4f6f7;
    }
    p {
        line-height: 1.4;
    }
    body {
      font-family: 'Helvetica Neue', Arial, sans-serif;
      background-color: var(--bg-color);
      color: #333;
      margin: 0;
      padding: 0;
      
    }
    header {
      background: linear-gradient(135deg, #111, #333);
      color: #fff;
      padding: 2rem;
      text-align: center;
      border-bottom: 5px solid var(--accent-color);
    }

    .透明化 {
  background-image: linear-gradient(45deg, #000, #fff,#fff);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent; /* フォールバック用 */
}
    header h1 {
      margin: 0;
      font-size: 2rem;
      letter-spacing: 2px;
    }
    header p {
      color: #bbb;
      margin-top: 0.5rem;
      font-size: 0.9rem;
    }
    .container {
      max-width: 900px;
      margin: 2rem auto;
      padding: 0 1rem;
    }
    .alert-banner {
      background-color: #ffed4a;
      border-left: 6px solid #f2d024;
      padding: 1rem;
      margin-bottom: 2rem;
      font-weight: bold;
      border-radius: 4px;
    }
    .grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 1.5rem;
    }
    .card {
      background: #fff;
      border-radius: 8px;
      box-shadow: 0 4px 6px rgba(0,0,0,0.1);
      padding: 1.5rem;
      transition: transform 0.2s;
    }
    .card:hover {
      transform: translateY(-5px);
    }
    .card h2 {
      margin-top: 0;
      color: var(--main-color);
      border-bottom: 2px solid var(--bg-color);
      padding-bottom: 0.5rem;
    }
    .badge {
      display: inline-block;
      background: var(--accent-color);
      color: #fff;
      padding: 0.2rem 0.5rem;
      font-size: 0.75rem;
      border-radius: 3px;
      margin-bottom: 0.5rem;
    }
    .btn {
      display: inline-block;
      background: var(--main-color);
      color: #fff;
      padding: 0.6rem 1.2rem;
      text-decoration: none;
      border-radius: 4px;
      margin-top: 1rem;
      cursor: pointer;
      border: none;
    }
    .btn:hover {
      background: #34495e;
    }
    footer {
      text-align: center;
      padding: 2rem;
      color: #777;
      font-size: 0.85rem;
      border-top: 1px solid #ccc;
      margin-top: 3rem;
    }