.ad-container {
            max-width: 500px;
            margin: 40px auto;
            background: #fff;
            border-radius: 12px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            padding: 32px 24px;
            text-align: center;
        }

        .ad-container h1 {
            color: #1a4d8f;
            margin-bottom: 16px;
        }

        .ad-container p {
            color: #333;
            font-size: 1.1em;
            margin-bottom: 24px;
        }

        .join-btn {
            background: #1a4d8f;
            color: #fff;
            border: none;
            border-radius: 6px;
            padding: 14px 32px;
            font-size: 1.1em;
            cursor: pointer;
            transition: background 0.2s;
        }

        .join-btn:hover {
            background: #15507a;
        }

        .logo {
            width: 80px;
            margin-bottom: 18px;
        }