/* -----------------------
  research
----------------------- */
.research {
  background: url(../img/research_bg.png) no-repeat center top / 100% auto;
  padding-bottom: calc(40/960 * 100vw);
  margin-top: max(calc(-110/960 * 100vw), -110px);
  padding-bottom: min(calc(70/960 * 100vw), 70px);
}

.research .ttl-box {
  position: relative;
}

.research .ttl-box img {
  position: relative;
}

.research .grid-box {
  position: relative;
}

.research .grid-box p {
  grid-column: 1 / 1;
  grid-row: 1 / 1;
}

.research .grid-01 {
  z-index: 1;
}

.research .grid-02 {
  z-index: 2;
}

.research .grid-03 {
  z-index: 3;
}

.research .grid-04 {
  z-index: 4;
}

.research .grid-05 {
  z-index: 5;
}

.research .grid-06 {
  z-index: 5;
}

.research .grid-04,
.research .grid-05,
.research .grid-06 {
  align-self: end;
}

.research .grid-box .grid-02 {
  position: absolute;
  top: 7%;
  left: 0;
  right: 0;
  animation: 15s linear infinite rotation;
  z-index: 2;
}

.research .grid-02 img {
  display: block;
  margin: 0 auto;
  width: min(calc(895/960 * 100vw), 895px);
}

@keyframes rotation {
  from {
    transform: rotateZ(0deg);
  }

  to {
    transform: rotateZ(360deg);
  }
}