/* common */

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}

h1,
h2,
h3 {
  margin: 0;
  font-weight: normal;
  line-height: 1.6;
}

p {
  margin: 32px;
}

img {
  vertical-align: bottom;
}

.container {
  margin: 0 16px;
}

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

a {
  text-decoration: none;
  color: inherit;
  transition: opacity 0.3s;
}

a:hover {
  opacity: 0.5;
}

button {
  background: inherit;
  transition: opacity 0.3s;
  cursor: pointer;
}

button:hover {
  opacity: 0.5;
}


/* header */

header {
  background: white;
  padding: 16px 0;
  position: fixed;
  top: 0;
  width: 100%;
  transition: background-color 0.3s, box-shadow 0.3s;
  z-index: 1;
}

header.scrolled {
  background-color: rgba(255, 255, 255, 0.95);
  box-shadow: 0 0 4px rgba(0, 0, 0, 0.3);
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header ul {
  display: flex;
}

header li a {
  display: flex;
  flex-direction: column;
  font-size: 12px;
  text-align: center;
}

header li a i {
  font-size: 18px;
}

header li + li {
  margin-left: 8px;
}

header form {
  display: none;
}

header input,
header button {
  all: unset;
}

header input {
  border-bottom: 1px solid #aaa;
  padding: 4px;
  width: 300px;
}

header button {
  cursor: pointer;
}

#to_top {
  position: fixed;
  bottom: 16px;
  right: 16px;
  opacity: 0;
  transition: opacity 0.3s;
}

/* main */

main {
  margin: 83px auto 0;
  width: 800px;
}

h2 {
  font-size: 18px;
  border-left: 8px solid #20b2aa;
  padding: 8px 16px;
  margin-bottom: 16px;
}

dl {
  margin: 0;
}

dl > div {
  margin-bottom: 8px;
}

dt {
  padding: 8px;
  cursor: pointer;
  user-select: none;
  position: relative;
  border-bottom: 2px solid #20b2aa;
}

dt:hover {
  background: #d4e7e6;
}

dt::before {
  content: "★ ";
  color: #20b2aa;
}

dt::after {
  content: "+";
  position: absolute;
  top: 8px;
  right: 16px;
  transition: transform 0.3s;
}

dl > div.appear dt::after {
  transform: rotate(45deg);
}

dd {
  padding: 8px;
  margin: 0;
  display: none;
}

dd::before {
  content: "・ ";
}

dl > div.appear dd {
  display: block;
  animation: 0.3s fadeIn;
}


/* footer */

footer {
  margin-top: 80px;
  background: #4c4948;
  padding: 16px 0;
  color: #eee;
}

footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

footer small {
  font-size: 16px;
}

footer li i {
  font-size: 24px;
}

footer ul {
  display: flex;
}

footer li + li {
  margin-left: 8px;
}
.list-item{
    opacity: 1;
}
.list-item.is-hidden {
    opacity: 0;
    height: 0;
    margin: 0;
}
.list-btn {
    margin-top: 20px;
}
.list-btn.is-btn-hidden{
  display:none;
}
.list-btn button {
    background-color: #333;
  color:#fff;
    border: none;
    cursor: pointer;
    outline: none;
    padding: 0;
    height: 32px;
    line-height: 32px;
    width: 120px;
}

@keyframes fadeIn {
  0% {
    opacity: 0;
    transform: translateY(-10px);
  }
  100% {
    opacity: 1;
    transform: none;
  }
}