Making dropdown selection to fill element without gaps

I use menu that was created by other developer in our company. I add to the first item of the menu dropdown selection, but the problem that the dropdown box not fully fill the all the item and I can't make it fill.

here is HTML:

<div class="top-menu-item-container">
  <div class="inactive-border-bottom">
      <p class="control has-icons-left is-expanded">
      <span class="select is-fullwidth ">
        <select class="full-height">
          <option>dropdown</option>
          <option>options 1</option>
        </select>                  
      </span>
      <span class="icon is-small is-left"><i class="far fa-building"></i></span>
    </p> 
    
    
  </div>
</div>

 <div class="top-menu-item-container" >
    <div>
      <div class="top-menu-item">2. Lot and Model</div>
    </div>
</div>   

<div class="top-menu-item-container" >
  <div [className]="ishpExpanded?'active-border-bottom':'inactive-border-bottom'">
    <div class="top-menu-item">3. Home Plan</div>
  </div>
</div>

<div class="top-menu-item-container">
  <div [className]="isupgExpanded?'active-border-bottom':'inactive-border-bottom'">
    <div class="top-menu-item">4. Upgrades</div>
  </div>
</div>

<div class="top-menu-item-container">
  <div [className]="isnextExpanded?'active-border-bottom':'inactive-border-bottom'">
    <div class="top-menu-item">5. Next Steps</div>
  </div>
</div>
<div class="top-menu-icon-container">
  <i class="fas fa-print top-menu-icon"></i>
  <i class="fas fa-share-alt top-menu-icon"></i>
</div>

And her is CSS:

.scroll1::-webkit-scrollbar {
    width: 0px;
    height: 3px;
  }
  
  .scroll1::-webkit-scrollbar-track {
    background: #eff0f0;
  }
  
  .scroll1::-webkit-scrollbar-thumb {
    background: #666;
  }
  .main-container-top-menu {
    scrollbar-width: auto;
    display: flex;
    flex-direction: row;
    justify-content: space-between;
 
  }
  
  .top-menu-item-container-empty {
    border-bottom: 2px solid #eff0f0;
    font-family: "Roboto", sans-serif;
    border-right: 2px solid #eff0f0;
    box-sizing: border-box;
    color: #626262;
    font-size: 14px;
    font-weight: 350;
    user-select: none;
    justify-content: space-between;
  }
  .top-menu-item-container {
    border-bottom: 2px solid #eff0f0;
    font-family: "Roboto", sans-serif;
    border-right: 2px solid #eff0f0;
    box-sizing: border-box;
    color: #626262;
    font-size: 14px;
    font-weight: 350;
    user-select: none;
    flex: 1;
    justify-content: space-between;
  }
  .active-border-bottom {
    align-items: center;
    display: flex;
    padding-left: 20px;
    padding-right: 20px;
    height: 100%;
    border-bottom: 3px solid #eb2028;
    box-sizing: border-box;
  }
  .inactive-border-bottom {
    align-items: center;
    display: flex;
    padding-left: 20px;
    padding-right: 20px;
    height: 100%;
  }
  .top-menu-item-active {
    cursor: pointer;
    font-family: "Roboto", sans-serif;
    padding: 5px;
    font-family: "Roboto", sans-serif;
    box-sizing: border-box;
    color: #1d1d1d;
    font-size: 14px;
    font-weight: 350;
    user-select: none;
    align-items: center;
    justify-content: center;
    display: flex;
    stroke-width: 0.6px;
    -webkit-text-stroke-width: 0.6px;
    flex: 1;
  }
  .top-menu-item {
    cursor: pointer;
    padding: 10px;
    font-family: "Roboto", sans-serif;
    box-sizing: border-box;
    color: #626262;
    font-size: 14px;
    user-select: none;
    align-items: center;
    justify-content: center;
    display: flex;
    flex: 1;
  }
  
  .top-menu-item-first {
    cursor: default;
    border-right: 2px solid #eff0f0;
    font-size: 14px;
    padding-right: 20px;
    font-weight: 800;
    border-bottom: 2px solid #eff0f0;
    border-left: none;
    text-align: left;
    justify-content: left;
    flex: 1;
  }
  
  .top-right-menu-item {
    /* margin-right: 50px; */
    border-bottom: 2px solid #eff0f0;
    height: 100%;
    display: inline-flex;
    justify-content: flex-end;
    align-items: center;
  }
  
  .top-item-logo {
    height: 55px;
    z-index: 100;
    width: 55px;
    object-fit: contain;
  }
  
  .top-menu-icon-container{
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .top-menu-icon {
    cursor: pointer;
    margin-right: 25px;
    margin-left: 25px;
    cursor: pointer;
    width: 14px;
    padding-top: 25px;
    padding-bottom: 25px;
  }
  
  .left-arrow,
  .right-arrow {
    display: none;
  }
  
  @media screen and (max-width: 768px) {
    .constructor-top-container {
      justify-content: center;
      padding-left: 3%;
    }
  }
  
  @media screen and (max-width: 1088px) {
    .top-right-menu-item {
      padding-left: 10px;
      margin-right: 0px;
      border-bottom: 2px solid #eff0f0;
      flex: 1;
      height: 100%;
      display: inline-flex;
      justify-content: flex-end;
      align-items: center;
    }
  
    .main-container-top-menu {
      padding-left: 0;
      padding-right: 0;
      padding-bottom: 3px;
    }
  }
  
  @media screen and (max-width: 414px) {
    .top-menu-icon {
      margin-right: 15px;
      cursor: pointer;
      width: 14px;
      padding-top: 12px;
    }
    .scroll1::-webkit-scrollbar {
      width: 0px;
      height: 0px;
    }
  
    .scroll1::-webkit-scrollbar-track {
      background: #eff0f0;
    }
  
    .scroll1::-webkit-scrollbar-thumb {
      background: #666;
    }
    .top-menu-item-first {
      padding-left: 35px;
    }
  
    .main-container-top-menu {
      transition: 0.2s all;
      min-height: 62px;
    }
    .top-item-logo {
      position: absolute;
      top: 0;
      right: 0px;
      margin: 0;
      padding: 0;
      z-index: 100;
      height: 62px;
      width: 62px;
      object-fit: contain;
    }
  
    .left-arrow {
      height: 60px;
      padding-left: 5px;
      padding-right: 5px;
      background: white;
      display: flex;
      align-items: center;
      position: absolute;
      cursor: pointer;
      color: #d1d1d1;
      top: 0px;
      font-size: 1.6rem;
      left: 0;
      z-index: 5;
      padding-left: 7px;
    }
  
    .right-arrow {
      height: 60px;
      padding-left: 5px;
      padding-right: 5px;
      background: white;
      display: flex;
      align-items: center;
      position: absolute;
      cursor: pointer;
      color: #b1b1b1;
      font-size: 1.6rem;
      left: calc(100% - 88px);
    }
  }
  @media screen and (max-width: 1088px) {
    .main-container-top-menu {
      overflow-x: auto;
      overflow-y: hidden;
      /* display: block; */
      width: 100%;
      white-space: nowrap !important;
    }
  }
  
  @media screen and (max-width: 414px) {
    .main-container {
      padding-left: 0px;
      padding-right: 0px;
    }
  }
  
  .no-suite-title {
    text-transform: uppercase;
    font-size: 1.3em;
    font-weight: 300;
    position: absolute;
    left: 10%;
    top: 50%;
    z-index: 1000;
  }

Workink jsFiddle!

Please help me to make dropdown to fill the menuc without gaps.

Thank you in advance.