/* ========================================
   ITプロジェクト入門
   アカデミックスタイル（数学入門と統一）
   ======================================== */

/* ========================================
   基本設定
   ======================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Noto Serif JP", "Hiragino Mincho ProN", "Yu Mincho", serif;
    line-height: 2.0;
    color: #333;
    background: #fdfcf9;
    font-size: 16px;
}

/* ========================================
   レイアウト
   ======================================== */

main,
.main-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* テキストの両端揃え */
p {
    text-align: justify;
    margin-bottom: 1.5em;
    text-indent: 1em;
}

/* ========================================
   見出し
   ======================================== */

h1 {
    font-size: 1.75rem;
    font-weight: bold;
    margin-bottom: 1rem;
    color: #1a365d;
    border-bottom: 2px solid #1a365d;
    padding-bottom: 1rem;
}

h2 {
    font-size: 1.4rem;
    color: #1a365d;
    margin: 2.5rem 0 1rem 0;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid #d4c5a9;
}

h3 {
    font-size: 1.15rem;
    color: #2c5282;
    margin: 2rem 0 0.8rem 0;
}

h4 {
    font-size: 1rem;
    color: #333;
    margin: 1.5rem 0 0.5rem 0;
}

/* ========================================
   ヘッダー
   ======================================== */

header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid #1a365d;
}

header h1 {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0.5rem;
}

header .small {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 1rem;
}

header .lead,
.lead {
    background: #f8f6f1;
    padding: 1.5rem;
    border-left: 4px solid #1a365d;
    margin-top: 1rem;
    text-indent: 0;
}

/* ========================================
   パンくずリスト
   ======================================== */

.breadcrumb {
    background: #f8f6f1;
    padding: 0.75rem 1rem;
    font-size: 0.9rem;
    margin-bottom: 2rem;
    border-radius: 4px;
}

.breadcrumb a {
    color: #1a365d;
    text-decoration: none;
}

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

/* ========================================
   リンク
   ======================================== */

a {
    color: #1a365d;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* ========================================
   テーブル
   ======================================== */

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.95rem;
}

th, td {
    border: 1px solid #d4c5a9;
    padding: 0.75rem;
    text-align: left;
}

th {
    background: #f8f6f1;
    font-weight: bold;
    color: #1a365d;
}

/* ========================================
   コンポーネント（ボックス類）
   ======================================== */

/* 基本ノート */
.note {
    background: #f8f6f1;
    border-left: 4px solid #1a365d;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.note strong {
    display: block;
    color: #1a365d;
    margin-bottom: 0.5rem;
}

.note p {
    margin: 0;
    text-indent: 0;
}

/* 実践ボックス */
.practical-box {
    background: #f0f4f8;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-radius: 4px;
}

.practical-box h4 {
    color: #2c5282;
    margin-top: 0;
    margin-bottom: 1rem;
}

.practical-box p {
    margin-bottom: 0;
    text-indent: 0;
}

/* 警告ボックス */
.warning {
    background: #fffbeb;
    border-left: 4px solid #d97706;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.warning strong {
    display: block;
    color: #92400e;
    margin-bottom: 0.5rem;
}

.warning p {
    margin: 0;
    text-indent: 0;
}

/* 成功ボックス */
.success {
    background: #f0fdf4;
    border-left: 4px solid #16a34a;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.success strong {
    display: block;
    color: #166534;
    margin-bottom: 0.5rem;
}

.success p {
    margin: 0;
    text-indent: 0;
}

/* ========================================
   ページナビゲーション
   ======================================== */

.page-navigation {
    display: flex;
    justify-content: space-between;
    margin: 3rem 0 2rem 0;
    padding-top: 2rem;
    border-top: 1px solid #d4c5a9;
}

.page-navigation a {
    color: #1a365d;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border: 1px solid #d4c5a9;
    border-radius: 4px;
    transition: background 0.2s;
}

.page-navigation a:hover {
    background: #f8f6f1;
    text-decoration: none;
}

/* ========================================
   参考文献
   ======================================== */

.refs {
    background: #f8f6f1;
    padding: 1.5rem;
    margin-top: 2rem;
    font-size: 0.9rem;
    border-radius: 4px;
}

.refs strong {
    display: block;
    color: #1a365d;
    margin-bottom: 0.5rem;
}

/* ========================================
   コード
   ======================================== */

code {
    font-family: "Source Code Pro", Consolas, monospace;
    background: #f5f5f5;
    padding: 0.15rem 0.4rem;
    border-radius: 3px;
    font-size: 0.9em;
}

pre {
    background: #2d2d2d;
    color: #f8f8f2;
    padding: 1rem;
    overflow-x: auto;
    margin: 1.5rem 0;
    border-radius: 4px;
}

pre code {
    background: none;
    padding: 0;
    color: inherit;
}

/* ========================================
   レスポンシブ
   ======================================== */

@media (max-width: 768px) {
    body {
        font-size: 15px;
    }
    
    main,
    .main-content {
        padding: 1rem;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    h2 {
        font-size: 1.2rem;
    }
    
    h3 {
        font-size: 1.05rem;
    }
    
    .page-navigation {
        flex-direction: column;
        gap: 1rem;
    }
    
    .page-navigation a {
        text-align: center;
    }
}