header {
  width: 100%;
  z-index: 5;
  position: fixed;
  top: 0;
  transition: background 0.3s ease, padding 0.3s ease, box-shadow 0.3s ease;
}

header .header_wrap {
  max-width: 1600px;
  min-width: 1100px;
  padding: 30px 2%;
  margin: auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  transition: padding 0.3s ease;
}
header a.logo {
  
  width: 300px;
  transition: opacity 0.3s ease;
}

header a.logo_blue {
  display: none;
  transition: opacity 0.3s ease;
}



.header_menu {
  display: flex;
  flex-wrap: wrap;
  width:calc(100% - 300px);
  padding-left:100px;
  justify-content: flex-end;
}
.header_menu ul{
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  
}
.header_menu ul li{

}
.header_menu ul li a {
  color: #FFF;
  font-weight: 700;
  transition: color 0.3s ease;
}
.header_menu ul li.contact a{
  background-color: #FFA500;
  padding:10px 20px;
  border-radius: 50px;
}
header.scrolled {
  background: #FFF;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1); /* フワッと感を強調 */
}

header.scrolled a.logo {
  display: none;
}

header.scrolled a.logo_blue {
  width: 200px !important;
  display: block !important;
  opacity: 1;
}
header.scrolled .header_menu {

  width:calc(100% - 200px);
}
header.scrolled .header_wrap {
  padding: 10px 4%;
  border-bottom: 1px solid #F9F9F9;
}

header.scrolled .header_menu ul li a {
  color: #000;
}
header.scrolled .header_menu ul li.contact a{
  background-color: #FFA500;
  padding:10px 20px;
  border-radius: 50px;
  color: #FFF;
}