/* 全体 */
html {
    font-size: 62.5%;
}

:root {
    --page-image-color: #F9E36E; /*これ*/
}

body {
    border-top: 5px solid var(--page-image-color);
    font-family: 'ヒラギノ角ゴ Pro W3', 'Hiragino Kaku Gothic Pro', 'メイリオ', Meiryo, 'ヒラギノ角ゴ', sans-serif;
    color: black;
    -webkit-font-smoothing: antialiased; /*safari用*/
    font-size: 1.4rem;
}

/* 見出し */
h2, h3, h4 {
    font-weight: bold;
    text-rendering: optimizeLegibility;
    line-height: 1.1;
    margin-bottom: 1rem;
}

h2 {
    font-size: x-large;
    padding: 1rem 0;
}

h2:not(header h2) {
    position: relative;
    padding: 7px 10px 7px 45px;
    z-index: 1;
    text-shadow: 1px 1px 0 rgb(255 255 255);
    border-bottom: 1px solid #C0C0C0;
}

h2::before  {
    content: " ";
    position: absolute;
    top: 0;
    left: 0;
    width: 40px;
    height: 40px;
    border-right: #fff solid 1px;
    background-color: #F9E36E; /*これ*/
    background-image: linear-gradient(
        to bottom,
        transparent 20%,
        rgba(255, 255, 255, 0.1) 20%,
        rgba(255, 255, 255, 0.1) 40%,
        rgba(255, 255, 255, 0.3) 40%,
        rgba(255, 255, 255, 0.3) 60%,
        rgba(255, 255, 255, 0.5) 60%,
        rgba(255, 255, 255, 0.5) 80%,
        rgba(255, 255, 255, 0.6) 80%,
        rgba(255, 255, 255, 0.6) 100%
    );
    z-index: -1;
}

h2::after  {
    content: " ";
    position: absolute;
    top: 0;
    left: 0;
    width: 40px;
    height: 40px;
    background-image: linear-gradient(
        to right,
        transparent 20%,
        rgba(255, 255, 255, 0.1) 20%,
        rgba(255, 255, 255, 0.1) 40%,
        rgba(255, 255, 255, 0.3) 40%,
        rgba(255, 255, 255, 0.3) 60%,
        rgba(255, 255, 255, 0.5) 60%,
        rgba(255, 255, 255, 0.5) 80%,
        rgba(255, 255, 255, 0.6) 80%,
        rgba(255, 255, 255, 0.6) 100%
    );
    z-index: -1;
}

h3 {
    font-size: large;
    position: relative;
    margin: 2rem 0 1rem 1rem;
    padding: 1rem 0 0.5rem 1rem;
    border-bottom: 1px #C0C0C0 solid;
}

h3::before {
    content: "";
    position: absolute;
    background: #F9E36E; /*これ*/
    top: 0;
    left: -5px;
    height: 12px;
    width: 12px;
    transform: rotate(45deg);
}

h3::after {
    content: "";
    position: absolute;
    background: #FFCC00; /*これ*/
    top: 15px;
    left: -10px;
    height: 6px;
    width: 6px;
    transform: rotate(15deg);
}

h4 {
    padding: 1.5rem 0 0.5rem;
    border-bottom: 1px dotted #C0C0C0;
}

/* エラーページ */
.error_page > h1 {
    font-size: 5rem;
    font-weight: bolder;
}
.error_page > p {
    padding-left: 1rem;
    font-size: 1.5rem;
}