スクロール連動トップへ戻るボタン

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            <span class="d03-11-10-logo">UPWARD</span>
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              <a href="#" onclick="return false">サービス</a>
              <a href="#" onclick="return false">実績</a>
              <a href="#" onclick="return false">お問合せ</a>
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          </header>
          <div class="d03-11-10-scroll">
            <div class="d03-11-10-body">
              <p>↓ しばらくスクロールするとトップへ戻るボタンが現れます</p>
              <div class="d03-11-10-block"></div>
              <div class="d03-11-10-block"></div>
              <div class="d03-11-10-block"></div>
              <div class="d03-11-10-block"></div>
              <div class="d03-11-10-block"></div>
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          <button type="button" class="d03-11-10-top" aria-label="トップへ戻る">▲</button>
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