How to raise a div in email layout?

Question

Layout of letters

<div style="margin-top:-15px;background-color: #ffffff;border: 3px solid #b6c939; border-radius: 20px;  z-index: 1; position: relative; text-align: center; max-width: 384px; color: #4b4a4a;font-size: 12px;font-weight: 700; width: 100%; margin: -26px auto 0;">
                  <span style="padding: 10px 0; width: 52%; border-right: 1px dashed #b6c939;">НОМЕР СЕРТИФИКАТА</span>
                  <span style="padding: 10px 0; width: 45%;">000</span>
                </div>

margin for letters doesn't work position:relative either. How can a div be raised?