div.sentence{
  font-size: 16px;
  line-height: 1.8em;
  margin-bottom: 20px;
}
p#policy{
  display: none;
  border: 2px solid;
  border-color: #6fb7a9;
  padding: 20px;
  margin: 20px 0;
}

/* ---- チェックボックス ----- */
.chk-input{
  display: none;
}
.chk-parts{
  padding-left: 20px;
  position:relative;
  margin-right: 20px;
  display: inline-block;
}
.chk-parts::before{
  content: "";
  display: block;
  position: absolute;
  top: 5px;
  left: 0;
  width: 15px;
  height: 15px;
  border: 1px solid #999;
  border-radius: 4px;
}
.chk-input:checked + .chk-parts{
  color: #009a9a;
}
.chk-input:checked + .chk-parts::after{
  content: "";
  display: block;
  position: absolute;
  top: 0;
  left: 5px;
  width: 7px;
  height: 14px;
  transform: rotate(40deg);
  border-bottom: 3px solid #009a9a;
  border-right: 3px solid #009a9a;
}