.btnsForCrew-Common {
            border-radius:10px;
            font-size:xx-small;
            width:15%;

            }
  .CrewPrsntButtonsIdle {
            color:black;
            background:linear-gradient(to bottom, lightgreen 15%,  white
             10%);
           }
 .FontsForCrewPresents {
            font-size:40px
                      }

<button type="button" id="btnIdle" class="btnsForCrew-Common CrewPrsntButtonsIdle">
          <span style="color:black;font-weight:bold;">ERROR</span>
          <br><br>
          <span class="FontsForCrewPresents"> 254</span>
        </button>

        <button type="button" id="btnIdle1" class="btnsForCrew-Common CrewPrsntButtonsIdle">
          <span style="color:black;font-weight:bold;">IDLE</span>
          <br><br>
          <span class="FontsForCrewPresents"> 100</span>
        </button>

        <button type="button" id="btnIdle2" class="btnsForCrew-Common CrewPrsntButtonsIdle">
          <span style="color:black;font-weight:bold;">WAITING To RUN</span>
          <br><br>
          <span class="FontsForCrewPresents"> 600000</span>
        </button>