/* 繝ェ繧ケ繝亥�菴薙r繝懊ャ繧ッ繧ケ縺ァ蝗イ繧€ */
ul.opt-intro-toc {
    list-style-type: none;
    padding: 10px;
	padding-top: 20px;
    margin: 0;
    border: 1px solid #ddd; /* 蜈ィ菴薙�譫�邱� */
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    background-color: #f8f8f8; /* 閭梧勹濶イ */
}

/* 蜷�い繧、繝�Β縺ョ繧ケ繧ソ繧、繝ォ */
ul.opt-intro-toc li {
    margin-bottom: 20px; /* 蜷�い繧、繝�Β縺ョ髢薙↓繧ケ繝壹�繧ケ繧貞�繧後k */
}

/* 繝ェ繝ウ繧ッ驛ィ蛻�シ医ち繧、繝医Ν�峨�繧ケ繧ソ繧、繝ォ */
ul.opt-intro-toc li a {
    text-decoration: none; /* 繝ェ繝ウ繧ッ縺ョ荳狗キ壹r縺ェ縺上☆ */
    color: #1a73e8; /* 繧ソ繧、繝医Ν縺ョ濶イ */
    font-weight: bold;
    font-size: 1.3em; /* 繧ソ繧、繝医Ν縺ョ繝輔か繝ウ繝医し繧、繧コ繧貞、ァ縺阪¥ */
    display: block; /* 繧ソ繧、繝医Ν繧堤峡遶九@縺溯。後↓ */
}

/* 隱ャ譏朱Κ蛻��繧ケ繧ソ繧、繝ォ */
ul.opt-intro-toc li .opt-intro-toc-summary {
    font-size: 1.1em; /* 隱ャ譏弱�繝輔か繝ウ繝医し繧、繧コ繧貞ー代@螟ァ縺阪¥ */
    margin-left: 20px; /* 隱ャ譏弱r繧、繝ウ繝�Φ繝� */
    color: #555; /* 隱ャ譏弱�譁�ュ苓牡 */
    line-height: 1.6; /* 陦碁俣繧貞コ�a縺ォ */
    padding-left: 10px; /* 霑ス蜉�繧、繝ウ繝�Φ繝医〒隱ャ譏弱r隕九d縺吶¥ */
}

/* 繝ェ繝ウ繧ッ驛ィ蛻�シ医ち繧、繝医Ν�峨�繧ケ繧ソ繧、繝ォ */
h2.opt-intro-toc-title {
    text-decoration: none; /* 繝ェ繝ウ繧ッ縺ョ荳狗キ壹r縺ェ縺上☆ */
    color: #1a73e8; /* 繧ソ繧、繝医Ν縺ョ濶イ */
    font-weight: bold;
    font-size: 1.5rem;
    text-align: center; /* 繝�く繧ケ繝医r荳ュ螟ョ謠�∴ */
    margin: 2px auto; /* 荳贋ク九�繝槭�繧ク繝ウ繧�20px縲∝キヲ蜿ウ縺ッ閾ェ蜍� */
    max-width: 80%; /* 譛€螟ァ蟷�r險ュ螳� */
    line-height: 1.2; /* 陦碁俣繧定ェソ謨エ */
    word-wrap: break-word; /* 髟キ縺�腰隱槭r謚倥j霑斐☆ */
}



.section-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    margin: 0px 0;
    padding: 1px 7px;
    background-color: #f0f0f0;
    border-radius: 5px;
    box-sizing: border-box;
	font-weight: bolder;
	font-size: 0.9rem;
}

.section-nav .prev-section,
.section-nav .next-section,
.section-nav .home-link {
    flex: 1;
    text-decoration: none;
    color: #333;
}

.section-nav .home-link {
    text-align: center;
}

.section-nav .next-section {
    text-align: right;
}