/* ========== CSS Variables ========== */
    :root {
      --primary-color: #000000; /* Orange */
      --accent-color: #333333; /* Dark Gray for text */
      --light-bg: #ffffff; /* White background */
      --gray-bg: #f5f5f5; /* Light gray background */
      --border-radius: 8px;
      --font-family: "Noto Sans JP", "Helvetica Neue", Arial, sans-serif;
    }

    /* ========== Global Styles ========== */
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      padding: 0;
      font-family: var(--font-family);
      background-color: var(--gray-bg);
      color: var(--text-color);
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: var(--primary-color);
      text-decoration: none;
    }

    /* ========== Header ========== */
    header {
      background-color: var(--primary-color);
      color: #ffffff;
      padding: 16px 24px;
      display: flex;
      align-items: center;
      gap: 16px;
    }
    header .logo {
      height: 40px; /* Placeholder for logo */
      width: auto;
    }
    header h1 {
      font-size: 1.5rem;
      margin: 0;
      font-weight: normal;
    }

    /* ========== Main Chat Container ========== */
    main {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 24px;
    }
    .chat-container {
      background-color: var(--light-bg);
      border-radius: var(--border-radius);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
      width: 100%;
      max-width: 680px;
      display: flex;
      flex-direction: column;
      overflow: hidden;
    }

    /* ========== Chat Messages ========== */
    .chat-messages {
      flex: 1;
      padding: 16px;
      overflow-y: auto;
      background-color: #fafafa;
    }
    .message {
      margin-bottom: 12px;
      max-width: 80%;
      padding: 12px 16px;
      border-radius: var(--border-radius);
      line-height: 1.4;
      word-break: break-word;
    }
    .message.ai {
      background-color: #fff7f0; /* Light orange background */
      border-left: 4px solid var(--primary-color);
      color: var(--accent-color);
    }
    .message.user {
      background-color: var(--primary-color);
      color: #ffffff;
      align-self: flex-end;
    }
    .message.thinking {
      color: #888;
      font-style: italic;
      padding: 10px 14px;
      background-color: #f7f7f7;
      border-left: 3px solid #ccc;
      border-radius: 4px;
    }

    /* Typing Indicator Styles */
    .typing-indicator {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 60px;
      height: 30px;
      background-color: #fff7f0;
      border-radius: var(--border-radius);
      margin-bottom: 12px;
    }
    .dot {
      height: 10px;
      width: 10px;
      margin: 0 3px;
      background-color: var(--accent-color);
      border-radius: 50%;
      animation: blink 1.5s infinite;
    }
    .dot:nth-child(2) {
      animation-delay: 0.2s;
    }
    .dot:nth-child(3) {
      animation-delay: 0.4s;
    }
    @keyframes blink {
      0%, 80%, 100% {
        opacity: 0;
      }
      40% {
        opacity: 1;
      }
    }

    /* ========== Input Area ========== */
    .chat-input-area {
      border-top: 1px solid #dddddd;
      padding: 12px 16px;
      display: flex;
      gap: 8px;
      background-color: var(--light-bg);
    }
    .chat-input-area input[type="text"] {
      flex: 1;
      padding: 10px 14px;
      border: 1px solid #cccccc;
      border-radius: var(--border-radius);
      font-size: 1rem;
      outline: none;
    }
    .chat-input-area input[type="text"]:focus {
      border-color: var(--primary-color);
      box-shadow: 0 0 0 2px rgba(0, 100, 0, 0.2);
    }
    .chat-input-area button {
      padding: 0 20px;
      background-color: var(--primary-color);
      color: #ffffff;
      border: none;
      border-radius: var(--border-radius);
      font-size: 1rem;
      cursor: pointer;
      transition: background-color 0.2s ease;
    }
    .chat-input-area button:disabled {
      opacity: 0.6;
      cursor: not-allowed;
    }
    .chat-input-area button:not(:disabled):hover {
      background-color: #004d00;
    }
    .disclaimer {
      font-size: 0.8rem; /* 12-13px */
      color: #999; /* Muted gray text */
      text-align: center;
      padding: 8px 0 0 0;
      margin: 0;
    }

    /* ========== Responsive ========== */
    @media (max-width: 600px) {
      header {
        flex-direction: column;
        align-items: flex-start;
      }
      .chat-container {
        border-radius: 0;
        height: 100%;
      }
    }