body {
      margin: 0;
      font-family: 'Noto Sans JP', sans-serif;
      background-color: #fff;
      color: #222;
      overflow-x: hidden;
      transition: background-color 0.6s ease, color 0.6s ease;
    }
    h1, h2, h3 {
      font-family: 'Oswald', sans-serif;
      text-transform: uppercase;
      letter-spacing: 2px;
      transition: color 0.6s ease;
    }
    a { text-decoration: none; color: inherit; transition: color 0.6s ease; }

    header {
      background-color: darkred;
      color: #eef0f6;
      display: flex;
      justify-content: center;
      padding: 15px 40px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.1);
      position: relative;
      z-index: 100;
    }
    .header-left {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 900px;
      gap: 20px;
    }
    .logo { 
      font-size: 28px;
      font-weight: bold;
      color: #eef0f6;
      letter-spacing: 4px;
      cursor: pointer;
      flex-shrink: 0;
      transition: transform 0.5s ease;
    }
    .menu-button {
      font-size: 28px;
      background: none;
      border: none;
      color: #eef0f6;
      cursor: pointer;
      flex-shrink: 0;
      transition: transform 0.2s, opacity 0.4s ease;
      opacity: 1;
    }
    .menu-button.hidden { opacity: 0; pointer-events: none; }
    .menu-button:hover { transform: scale(1.2); }

    .menu-box {
      position: fixed;
      top: 0;
      left: -250px;
      width: 250px;
      height: 100vh;
      background: darkred;
      color: #eef0f6;
      box-shadow: 3px 0 15px rgba(0,0,0,0.3);
      display: flex;
      flex-direction: column;
      padding-top: 20px;
      transition: left 0.6s cubic-bezier(0.68, -0.55, 0.27, 1.55);
      z-index: 105;
    }
    .menu-box.active { left: 0; }
    .menu-logo-placeholder {
      height: 60px;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      margin-bottom: 30px;
    }
    .menu-box a {
      padding: 15px 20px;
      font-weight: 600;
      border-bottom: 1px solid rgba(255,255,255,0.2);
      color: #eef0f6;
      transition: background 0.2s, color 0.2s;
    }
    .menu-box a:hover { background: rgba(255,255,255,0.1); color: #ffcccc; }

    .faq-container {
      max-width: 900px;
      margin: 50px auto;
      padding: 0 20px;
      line-height: 1.8;
    }
    .faq-container h1 { font-size: 48px; margin-bottom: 20px; color: #ff2e3c; }
    .faq-item { border-bottom: 1px solid #ccc; margin-bottom: 10px; }
    .faq-question {
      font-size: 24px;
      margin: 0;
      padding: 15px;
      cursor: pointer;
      background: rgba(179,0,0,0.1);
      transition: background 0.3s ease;
    }
    .faq-question:hover { background: rgba(179,0,0,0.2); }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      padding: 0 15px;
      transition: max-height 0.4s ease, padding 0.4s ease;
    }
    .faq-answer p { margin: 10px 0; }
    .faq-item.active .faq-answer {
      max-height: 500px; /* enough for most answers */
      padding: 10px 15px 15px 15px;
    }

    body.dark-mode {
      background-color: #121212;
      color: #e0e0e0;
    }
    body.dark-mode header { background-color: #1f1f1f; color: #fff; }
    body.dark-mode .faq-container h1, body.dark-mode .faq-question { color: #ff2e3c; }
    body.dark-mode .menu-box { background-color: #1f1f1f; color: #fff; }
    body.dark-mode .menu-box a:hover { color: #ff9999; }
    body.dark-mode .faq-question { background: rgba(255,85,85,0.1); }
    body.dark-mode .faq-question:hover { background: rgba(255,85,85,0.2); }

    footer {
      background: #111;
      color: #bbb;
      text-align: center;
      padding: 15px;
      font-size: 14px;
      margin-top: 40px;
    }

    .theme-switch {
      position: absolute;
      bottom: 20px;
      right: 20px;
      width: 50px;
      height: 28px;
      background-color: rgba(255,255,255,0.2);
      border-radius: 14px;
      cursor: pointer;
      display: flex;
      align-items: center;
      padding: 2px;
      transition: background-color 0.4s ease;
    }
    .switch-thumb {
      width: 24px;
      height: 24px;
      background-color: var(--panel);
      border-radius: 50%;
      transition: transform 0.4s ease, background-color 0.4s ease;
      box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    }
    body.dark-mode .theme-switch {
      background-color: rgba(255,255,255,0.4);
    }
    body.dark-mode .switch-thumb {
      transform: translateX(22px);
      background-color: #ffcc00;
    }

    @media (max-width: 600px) {
      .logo { font-size: 24px; }
      .menu-button { font-size: 26px; }
      .faq-question { font-size: 20px; }
    }