html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

ul {
  padding: 0;
  margin: 0;
  list-style: none;
}

.view {
  width: 100%;
  height: 100vh;
  overflow: hidden;
  position: relative;
}

.content {
  width: 100%;
  transition: all .8s;
}

.content .item {
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.content .item:nth-child(1) {
  background-image: url("./1.png");
}

.content .item:nth-child(2) {
  background-image: url("./2.jpg");
}

.content .item:nth-child(3) {
  background-image: url("./3.jpg");
}

.content .item:nth-child(4) {
  background-image: url("./4.jpg");
}

.scrollbar {
  position: absolute;
  right: 3px;
  top: 1%;
  z-index: 50;
  width: 5px;
  height: 98%;
  background-color: rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

.scrollbar .scrollbar-drag {
  height: 125px;
  width: 100%;
  position: relative;
  background-color: rgba(0, 0, 0, 0.5);
  border-radius: 10px;
  left: 0;
  top: 0;
  transition: all .8s;
}

.btn-list {
  position: fixed;
  right: 50px;
  top: 50%;
  transform: translateY(-50%) scale(0.8);
  user-select: none;
  z-index: 40;
  transition: all .8s;
}

.btn-list.hide {
  right: -300px;
}

.btn-list .line {
  width: 2px;
  height: calc(100% + 80px);
  background-color: rgba(255, 255, 255, 0.2);
  position: absolute;
  top: -40px;
  right: 8px;
  user-select: none;
}

.btn-list .btn-item {
  margin-bottom: 20px;
  display: flex;
  cursor: pointer;
  position: relative;
  align-items: center;
  user-select: none;
}

.btn-list .btn-item p {
  width: 123px;
  height: 32px;
  line-height: 32px;
  font-size: 18px;
  color: #fff;
  padding: 0 12px;
  margin: 0 10px 0 0;
  text-align: right;
  user-select: none;
}

.btn-list .btn-item .icon {
  display: block;
  width: 18px;
  height: 18px;
  background-color: #fff;
  transform-origin: 50%;
  transition: all .4s ease;
  transform: rotate(45deg) scale(0.3);
  box-sizing: border-box;
  user-select: none;
}

.btn-list .btn-item.active p {
  background-color: #fff;
  color: #283849;
  user-select: none;
}

.btn-list .btn-item.active .icon {
  background-color: rgba(18, 51, 77, 0.4);
  border: 1px solid #fff;
  padding: 4px;
  transform: rotate(45deg) scale(1);
}

.btn-list .btn-item.active .icon::after {
  content: '';
  display: block;
  width: 8px;
  height: 8px;
  background-color: #fff;
  box-sizing: border-box;
}

.btn-list .btn-item.disable p {
  opacity: .5;
}