html { scroll-behavior: smooth; }
  body { margin: 0; background: #212b40; color: #fff; font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif; line-height: 1.6; }
  * { box-sizing: border-box; }
  a { color: #d9ec2b; }
  a:hover { color: #eaf95f; }

  /* ---- ハンバーガーメニュー ---- */
  .hamburger {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 26px;
    height: 18px;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
    z-index: 1100;
  }
  .hamburger span {
    display: block;
    width: 100%;
    height: 2px;
    background: #fff;
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease;
  }
  .hamburger.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
  .hamburger.active span:nth-child(2) { opacity: 0; }
  .hamburger.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

  .mobile-menu {
    display: none;
    flex-direction: column;
    background: #212b40;
    border-top: 1px solid rgba(255,255,255,0.1);
  }
  .mobile-menu a {
    padding: 16px 40px;
    color: #ccc;
    text-decoration: none;
    font-size: 0.95rem;
    border-bottom: 1px solid rgba(255,255,255,0.08);
  }
  .mobile-menu a:hover { color: #fff; }
  .mobile-menu.active { display: flex; }

  @media (max-width: 768px) {
    .header-nav { display: none !important; }
    .hamburger { display: flex; }
  }