텍스트 박스 배경 투명도 설정 관련 질문입니다

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            <div class="slider_txt filter"> <h2>To whom it may concern</h2> 
                 <p>I certify that I will be responsible for all expenses while my daughter So Young Kim is studying in the United States. I will cover all expenses including So Young Kim’s education, personal, medical and tuition expenses. I will also be responsible for So Young Kim’s travel expenses when she returns home from the United States after she completes your English program.</p> </div>
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