body {
      font-family: "Hiragino Sans", "Meiryo", sans-serif;
      background-color: #f5f8fb;
      color: #333;
      margin: 20;
      padding: 0;
      line-height: 1.8;
    }

    header, footer {
      color: #000;
      padding: 10px;
      text-align: center;
    }

    main {
      max-width: 800px;
      margin: 10px auto;
      background: #fff;
      padding: 20px;
      border-radius: 8px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    }

    h1, h2, h3 {
      color: #1e3a5f;
      line-height: 1.4;
    }

    h1 {
      font-size: 1.8em;
      margin-bottom: 0.5em;
    }

    h1 {
      color: #1a1a1a;   /* 背景と被らない濃い色 */
      text-shadow: 1px 1px 2px rgba(255,255,255,0.6); /* 読みやすさ補助 */
      margin-top: 0.5em;
    }

    h2 {
      margin-top: 1.5em;
      font-size: 1.4em;
      border-left: 5px solid #1e3a5f;
      padding-left: 10px;
    }

    h3 {
      margin-top: 1em;
      font-size: 1.2em;
    }

    a {
      color: #1a73e8;
      text-decoration: none;
    }

    a:hover {
      text-decoration: underline;
    }

    p, ul, ol {
      margin-bottom: 1.2em;
    }

    ul, ol {
      padding-left: 1.5em;
    }

hr { margin-top: 1em;
    }

    iframe {
      border: none;
      border-radius: 6px;
    }

    footer {
      font-size: 0.9em;
    }

/* ボタンsolid015 */
.button_solid015 {
    text-align: center;
}
.button_solid015 p {
    margin-bottom: 5px;
    font-weight: 600;
    color: #6bb6ff;
    letter-spacing: 0.04rem;
    display: inline-block;
    position: relative;
}
.button_solid015 p:before, .button_solid015 p:after {
    display: inline-block;
    position: absolute;
    top: 45%;
    width: 20px;
    height: 3px;
    border-radius: 5px;
    background-color: #6bb6ff;
    content: "";
}
.button_solid015 p:before {
    left: -30px;
    -webkit-transform: rotate( 50deg );
    transform: rotate( 50deg );
}
.button_solid015 p:after {
    right: -30px;
    -webkit-transform: rotate( -50deg );
    transform: rotate( -50deg );
}
.button_solid015 a {
    position: relative;
    display: flex;
    justify-content: space-around;
    align-items: center;
    margin: 0 auto;
    max-width: 240px;
    padding: 10px 25px;
    color: #FFF;
    transition: 0.3s ease-in-out;
    font-weight: 600;
    background: #6bb6ff;
    filter: drop-shadow(0px 2px 4px #ccc);
    border-radius: 50px;
}
.button_solid015 a:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px -5px rgb(0 0 0 / 15%), 0 0 5px rgb(0 0 0 / 10%);
}
.button_solid015 a:after {
    position: absolute;
    top: 50%;
    right: 20px;
    transition: 0.2s ease-in-out;
    content: "\f0da";
    font-family: "Font Awesome 5 Free";
    font-weight: 900;
    transform: translateY(-54%);
}