.integral-input-group {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
  margin-top: 4px;
  justify-content: flex-start;
}
.integral-sign-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 38px;
  position: relative;
  min-width: 38px;
}
.integral-sign {
  font-size: 2.2em;
  line-height: 1;
  margin: 1px 0 12px 0;
  z-index: 1;
  background: transparent;
  color: #222;
}
.limit-input {
  width: 38px;
  text-align: center;
  font-size: 1em;
  border: 1.5px solid #bbb;
  border-radius: 4px;
  padding: 1px 0 1px 0;
  background: #fff;
  margin: 0 0 0 0;
  position: relative;
  z-index: 2;
  box-sizing: border-box;
  appearance: textfield;
  color: #222;
  font-weight: 500;
  height: 30px;
}
.limit-input.upper { margin-bottom: 2px;}
.limit-input.lower { margin-top: 0px;}
.limit-input::-webkit-outer-spin-button,
.limit-input::-webkit-inner-spin-button {
  -webkit-appearance: none !important;
  margin: 0;
}
.limit-input[type=number] { -moz-appearance: textfield; }
.integral-expression {
  flex: 1 1 180px;
  font-size: 1.1em;
  padding: 8px 12px;
  border-radius: var(--radius);
  border: 1px solid #e3e6ee;
  min-width: 120px;
}
.dx-label {
  margin-left: 7px;
  font-size: 1.1em;
  color: #888;
  font-weight: 500;
}