* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: YuGothic, "Yu Gothic Medium", "Yu Gothic", sans-serif;
  background-color: #FFF;
}

header {
  height: 90px;
  width: 100%;
  padding: 0px 15px;
  background-color: #FFF;
  position: fixed;
  top: 0;
  z-index: 10;
  display: flex;
  opacity: 1;
  box-shadow: 3px 2px 7px #b2b2b2;
}

.logo {
  font-size: 25px;
  width: 45%;
  margin:25px 0 0 70px;
}


.logo  a{padding: 0;}

nav {
  margin: 0 0 0 auto;
}

ul {
  display: flex;
  list-style: none;
  padding: 0;
  margin: 0;
  float: right;
}

a {
  color: #444;
  text-decoration: none;
  display: block;
  padding: 40px 20px 20px 20px;
  font-weight: bold;
}

.sm {
  display: none;
}

.pc{margin: 0 0 0 80px; width: 55%;}



/**********************************　
以下、ハンバーガーメニューの設定　
************************************/

@media (max-width: 900px) {

  .pc {
    display: none;
  }

  #hamburger {
    background-color: transparent;
    position: relative;
    cursor: pointer;
    margin: 0 0 0 auto;
    height: 60px;
    width: 60px;
  }

  .icon span {
    position: absolute;
    left: 15px;
    width: 30px;
    height: 4px;
    background-color: #333;
    border-radius: 8px;
    transition: ease 0.75s;
  }

  .icon span:nth-of-type(1) {
    top: 16px;
  }
  .icon span:nth-of-type(2) {
    top: 28px;
  }
  .icon span:nth-of-type(3) {
    bottom: 16px;
  }

  .close span:nth-of-type(1) {
    transform: rotate(45deg);
    top: 28px;
  }

  .close span:nth-of-type(2) {
    opacity: 0;
  }

  .close span:nth-of-type(3) {
      transform: rotate(-45deg);
      top: 28px;
  }

  .sm {
      top: 60px;
      left: 0px;
      position: absolute;
      z-index: 10;
      width: 100%;
      background-color: rgba(34, 49, 52, 0.9);
  }

  ul {
    flex-direction: column;
  }

  a {
    text-align: center; 
    border-top: solid 0.5px rgba(255, 255, 255, 0.6);
  }
}

#header_box{width: 100%; margin: 0 auto;}