body {
  background-color: #ffdd00;
  color: #000000;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.9;
}

@media (min-width: 961px) {
  body {
    font-size: 15px;
  }
}

a {
  -webkit-transition: 0.2s ease-in-out;
          transition: 0.2s ease-in-out;
}

h1 a, h1 a:hover, h2 a, h2 a:hover, h3 a, h3 a:hover, h4 a, h4 a:hover, h5 a, h5 a:hover, h6 a, h6 a:hover {
  color: #000000;
  text-decoration: none;
}

body {
  align-items: center;
  -webkit-box-align: center;
  -webkit-box-pack: center;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-align: center;
  -ms-flex-pack: center;
  justify-content: center;
}

.contents {
  margin-inline: auto;
  max-width: 1010px;
  padding-left: 15px;
  padding-right: 15px;
}

.contents .content-item {
  margin-top: 5vh;
  text-align: center;
}

.logo {
  margin-inline: auto;
  width: 200px;
}

@media (min-width: 961px) {
  .logo {
    width: 300px;
  }
}

.btn {
  position: relative;

  background-color: #000000;
  color: #ffffff;
  display: inline-block;
  line-height: 1.3;
  margin-bottom: 10px;
  padding: 15px 1em;
  text-align: center;
  text-decoration: none;
  width: 280px;
}

@media (min-width: 961px) {
  .btn {
    width: 320px;
  }
}

.btn:hover {
  background-color: #484848;
}

.btn:after {
  position: absolute;
  top: 50%;
  right: 1rem;

  border-color: transparent transparent transparent #ffffff;
  border-style: solid;
  border-width: 5px 0 5px 5px;
  content: "";
  display: block;
  height: 0;
  -webkit-transform: translateY(-50%);
          transform: translateY(-50%);
  width: 0;
}