* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    background-color: #fafafa;
}

h1, h2, h3, h4 {
    color: #2c3e50;
    margin-top: 2em;
    margin-bottom: 0.5em;
}

h1 {
    border-bottom: 3px solid #3498db;
    padding-bottom: 10px;
}

h2 {
    border-bottom: 1px solid #ecf0f1;
    padding-bottom: 5px;
}

a {
    color: #3498db;
}

.space-list > li {
    margin-top: 10px;
}

/* ナビゲーション */
.nav {
    background-color: #fff;
    padding: 15px;
    margin-bottom: 30px;
    border: 1px solid #ddd;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav a {
    margin-right: 20px;
    color: #3498db;
    text-decoration: none;
    font-weight: bold;
    vertical-align: middle;
}

.nav a:hover {
    text-decoration: underline;
}

/* 目次 */
.toc {
    background-color: #fff;
    border: 1px solid #ddd;
    padding: 20px;
    margin-bottom: 30px;
}

.toc h2 {
    margin-top: 0;
    border: none;
}

.toc ol {
    margin: 0;
    padding-left: 30px;
}

.toc a {
    color: #3498db;
    text-decoration: none;
}

.toc a:hover {
    text-decoration: underline;
}

/* コードブロック */
pre {
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    font-size: 14px;
    line-height: 1.4;
}

code {
    background-color: #ecf0f1;
    color: #e74c3c;
    padding: 2px 4px;
    border-radius: 3px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9em;
}

pre code {
    background-color: transparent;
    color: inherit;
    padding: 0;
}

/* 出力例 */
.output {
    background-color: #ecf8ff;
    border-left: 4px solid #3498db;
    padding: 10px 15px;
    margin: 10px 0;
    font-family: 'Courier New', Courier, monospace;
}

/* テーブル */
table {
    border-collapse: collapse;
    width: 100%;
    margin: 20px 0;
    background-color: #fff;
}

th, td {
    border: 1px solid #ddd;
    padding: 8px 12px;
    text-align: left;
}

th {
    background-color: #3498db;
    color: white;
}

tr:nth-child(even) {
    background-color: #f9f9f9;
}

/* 特徴リスト */
.features {
    list-style: none;
    padding: 0;
}

.features li {
    padding: 5px 0;
    padding-left: 25px;
    position: relative;
}

.features li:before {
    content: "✅";
    position: absolute;
    left: 0;
}

/* エラー例 */
.error-example {
    background-color: #ffe6e6;
    border-left: 4px solid #e74c3c;
    padding: 10px 15px;
    margin: 10px 0;
}

.error-example:before {
    content: "❌ ";
    font-weight: bold;
}

/* 正しい例 */
.correct-example {
    background-color: #e6ffe6;
    border-left: 4px solid #27ae60;
    padding: 10px 15px;
    margin: 10px 0;
}

.correct-example:before {
    content: "✅ ";
    font-weight: bold;
}

/* セクション */
section {
    background-color: #fff;
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid #eee;
}

/* モバイル対応 */
@media (max-width: 600px) {
    body {
        padding: 10px;
    }
    
    .nav {
        padding: 10px;
    }
    
    .nav a {
        /* display: block; */
        margin-bottom: 5px;
    }
    
    pre {
        padding: 10px;
        font-size: 12px;
    }
    
    table {
        font-size: 14px;
    }
}