header {
  position: fixed;
  width: 100%;
  top: 0;
  padding: 10px 0px;
  z-index: 10;
  background-color: #ff7f00;
}

header h1 a img {
  width: 180px;
}

header .menu ul li {
  padding: 0px 30px;
  line-height: 60px;
  color: #fff;
  cursor: pointer;
  font-size: 16px;
}

header .menu.mobile .button i{
  color: #fff;
  font-size: 24px;
  cursor: pointer;
}

header .menu.mobile > ul{
  position: fixed;
  top: 0;
  left: 0;
  max-width: 0px;
  width: 250px;
  height: 100vh;
  background-color: #fff;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  transition: max-width .5s;
}

header.on .menu.mobile > ul{
  max-width: 250px;
}

header .menu.mobile > ul > li{
  color: #000;
  line-height: 60px;
  font-size: 20px;
  white-space: nowrap;
}

header .menu.mobile > div:not(.button){
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background-color: #00000077;
  opacity: 0;
  visibility: hidden;
}

header.on .menu.mobile > div:not(.button){
  opacity: 1;
  visibility: visible;
}