@media only screen and (max-width: 768px) {
  #background .logo {
    width: 100px;
    height: auto;
    left: 50px;
    top: 20px;
  }
  #background .box-left-runing {
    display: none;
  }
  #background .box-right-ultra {
    position: relative;
    top: -50px;
    right: 0;
    border-radius: 12px;
    padding: 12px;
    margin: 0 12px;
    display: flex;
    align-items: center;
    flex-direction: column;
  }
  #background .box-right-ultra .sub-title {
    font-size: 12px;
    line-height: 18px;
    letter-spacing: 3px;
    text-align: center;
  }

  #background .box-right-ultra .title {
    font-weight: 900;
    font-size: 32px;
    line-height: 46px;
    text-align: center;
  }
  #background .box-right-ultra .timeline {
    text-align: center;
    font-weight: 400;
    font-size: 32px;
    line-height: 46px;
  }

  #background .box-right-ultra .description {
    font-weight: 600;
    font-size: 16px;
    line-height: 169.68%;
  }
  #background .box-right-ultra .btn-join-now {
    padding: 8px 20px;
    margin: 0 auto;
    font-weight: 600;
    font-size: 20px;
    line-height: 30px;
    margin-top: 12px;
  }

  #introduce .row {
    margin-top: 0;
  }
  #introduce .row-reverse {
    flex-direction: column-reverse;
  }
  #introduce .row img {
    width: 100%;
  }
  #introduce .row .col-sm-6 {
    width: 100%;
  }
  #introduce .box-introduce .wrap-num-introduce {
    height: 110px;
    margin-bottom: 0;
    margin-top: 30px;
  }

  #introduce .box-introduce .wrap-num-introduce .num {
    top: 0;
    left: 0;
    font-size: 110px;
    line-height: 110px;
  }
  #introduce .box-introduce .wrap-num-introduce .box-text {
    position: absolute;
    width: max-content;
    left: 115px;
    bottom: 30px;
  }
  #introduce .box-introduce .wrap-num-introduce .text-introduce {
    position: relative;

    font-size: 16px;
    line-height: 24px;
    /* identical to box height */

    letter-spacing: 0.125rem;
  }

  #introduce .box-introduce .wrap-num-introduce .text-introduce:before {
    content: "";
    background: #fbd784;
    width: 40px;
    height: 2px;

    position: absolute;
    left: -50px;
    top: 10px;
  }

  #introduce .wrap-content {
    direction: rtl;
    margin-left: 15px;
    padding-left: 15px;
  }

  #introduce .wrap-content .title {
    font-size: 42px;
    line-height: 56px;
  }
  #introduce .wrap-content li {
    margin-top: 16px;
  }
  #introduce .wrap-content .li-title {
    font-size: 20px;
    line-height: 30px;
  }
  #introduce .wrap-content .li-description {
    font-size: 18px;
    line-height: 27px;
  }
  #introduce .col-sm-6 img {
    margin-top: 30px;
  }

  #introduce .box-introduce-2 .wrap-num-introduce {
    height: 110px;
    margin-bottom: 0;
  }
  #introduce .box-introduce-2 .wrap-num-introduce .num {
    position: relative;
    top: 0;
    left: 0;

    font-size: 110px;
    line-height: 110px;
  }
  #introduce .box-introduce-2 .wrap-num-introduce .box-text {
    position: absolute;
    width: max-content;
    left: 110px;
    bottom: 30px;
  }
  #introduce .box-introduce-2 .wrap-num-introduce .text-introduce {
    position: relative;

    font-size: 16px;
    line-height: 24px;
    /* identical to box height */

    letter-spacing: 0.125rem;
  }

  #introduce .box-introduce-2 .wrap-num-introduce .text-introduce:before {
    content: "";
    background: #fbd784;
    width: 40px;
    height: 2px;

    position: absolute;
    left: -50px;
    top: 10px;
  }
  #introduce .wrap-content-2 {
    max-height: 520px;
    position: relative;
    overflow-y: auto;
    margin-left: 15px;
    direction: rtl;
    padding-left: 15px;
  }
  #introduce .wrap-content-2::-webkit-scrollbar-track {
    padding: 2px 0;
    background-color: #d9d9d9;
  }
  #introduce .wrap-content-2::-webkit-scrollbar {
    width: 3px;
  }
  #introduce .wrap-content-2::-webkit-scrollbar-thumb {
    border-radius: 10px;
    box-shadow: inset 0 0 6px #fbd784;
    background-color: #fbd784;
  }
  #introduce .wrap-content-2 .title {
    font-size: 42px;
    line-height: 56px;
  }
  #introduce .wrap-content-2 .long-description {
    margin-top: 12px;
    font-size: 18px;
    line-height: 27px;
  }

  #register img {
    margin-top: 30px;
  }
  #rules .list-equipment .item-equipment {
    width: 90%;
    margin-left: 5%;
    max-height: 300px;
  }
  /* Rules of games */
  #rules .rules-of-game .box-rules {
    width: 100%;
    height: auto;
    background: rgba(255, 239, 227, 0.9);
    padding: 20px;
    display: flex;
    flex-direction: column;
  }
  .slider-item .content .wrap-content {
    overflow-y: auto;
    margin-left: 15px;
    direction: rtl;
    padding-left: 15px;
    width: auto;
  }

  #rules .rules-of-game .box-rules .box-top {
    display: flex;
    flex-direction: column;
    margin-bottom: 20px;
  }

  .box-top .top-image {
    position: relative;
  }

  .box-top .top-image .image-core {
    width: 100%;
    height: auto;
  }

  .box-top .top-image .image-sub {
    position: absolute;
    top: 150px;
    left: -10px;
    width: 100%;
  }

  .box-top .top-content {
    padding-top: 100px;
    padding-left: 0;
  }

  .box-top .top-content .top-text {
    font-weight: 400;
    font-size: 20px;
    line-height: 28px;
    color: #000000;
  }

  .box-top .top-content .top-rules {
    margin-top: 16px;
  }

  .box-top .top-content .top-rules .item {
    font-weight: 400;
    font-size: 20px;
    line-height: 28px;
    color: #000000;
    margin-bottom: 12px;
  }

  .box-top .top-content .top-rules .item img {
    margin-right: 10px;
  }

  .box-top .top-content .top-text.sub {
    margin-top: 16px;
  }

  #rules .rules-of-game .box-rules .box-year {
    display: flex;
    flex-direction: column;
    margin-top: 30px;
  }

  .box-year .title {
    font-weight: 700;
    font-size: 32px;
    line-height: 36px;
    color: #000000;
  }

  .box-year .list {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    margin-top: 32px;
  }

  .box-year .list .list-item {
    margin: 10px auto;
    width: 47%;
    border: none;
    background: linear-gradient(180deg, #000000 0%, #50241e 100%);
    border-radius: 8px;
    color: #fff;
    text-align: center;
    letter-spacing: 0.2em;
  }

  #rules .rules-of-game .box-rules .box-apply {
    display: flex;
    flex-direction: column;
    margin-top: 30px;
  }

  .box-apply .title {
    font-weight: 700;
    font-size: 32px;
    line-height: 36px;
    color: #000000;
  }

  .box-apply .list {
    display: flex;
    flex-direction: column;
    margin-top: 16px;
  }

  .box-apply .list .item {
    display: flex;
    flex-direction: row;
    margin-bottom: 12px;
    font-weight: 400;
    font-size: 19px;
    line-height: 36px;
    color: #000000;
  }

  .box-apply .list .item b {
    font-weight: 800;
    color: #000000;
  }

  .box-apply .list .item img {
    margin-right: 5px;
  }

  #rules .rules-of-game .box-rules .box-rules-2 {
    display: flex;
    flex-direction: column;
    margin-top: 16px;
  }

  .box-rules-2 .item {
    font-weight: 400;
    font-size: 20px;
    line-height: 36px;
    color: #000000;
    margin-bottom: 8px;
  }

  .box-rules-2 .item b {
    font-weight: 800;
    font-size: 20px;
    line-height: 36px;
    color: #000000;
    margin-bottom: 8px;
  }

  #rules .rules-of-game .box-rules .box-button {
    display: flex;
    flex-direction: row;
    margin-top: 16px;
    font-weight: 700;
    font-size: 20px;
    line-height: 27px;
    text-align: center;
    letter-spacing: 0.25px;
    text-transform: uppercase;
    color: #ffa343;
  }

  #rules .rules-of-game .box-rules .box-button img {
    margin-left: 10px;
  }

  #rules .rules-of-game .text-rules {
    font-size: 42px;
    line-height: 56px;
    color: #000000;
    margin-bottom: 30px;
  }

  #footer {
    margin-top: 60px;
  }
  #footer .box-footer {
    padding: 0 30px;
  }
  #footer .box-footer img {
    width: 80px;
  }
  #footer .box-footer .text-footer {
    font-size: 14px;
    line-height: 20px;
  }

  #rules .equipment .text-equipment {
    font-size: 42px;
    line-height: 56px;
    color: #000000;
  }

  #register .title {
    font-size: 42px;
    line-height: 56px;
  }
}