/* リセットとベーススタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', 'Meiryo', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-light);
}

.container {
    max-width: 1200px;
    margin: 20px auto;
    padding: 0 20px;
}

/* ヘッダー */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 2rem 0;
    box-shadow: var(--shadow-lg);
}

header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.tagline {
    font-size: 1rem;
    opacity: 0.9;
}

/* ナビゲーション */
nav {
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.nav-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.3s ease;
    display: inline-block;
}

.nav-link:hover {
    background-color: var(--bg-light);
    color: var(--primary-color);
}

.nav-link.active {
    background-color: var(--primary-color);
    color: white;
}

/* メインコンテンツ */
main {
    padding: 2rem 0;
    min-height: calc(100vh - 300px);
}

/* 検索セクション */
.search-section {
    margin-bottom: 2rem;
}

.search-box {
    display: flex;
    gap: 0.5rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

#searchInput {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

#searchInput:focus {
    outline: none;
    border-color: var(--primary-color);
}

#searchButton {
    padding: 0.75rem 2rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#searchButton:hover {
    background-color: var(--secondary-color);
}

.search-results {
    margin-top: 1rem;
    padding: 1rem;
    background-color: var(--bg-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
    display: none;
}

.search-results.active {
    display: block;
}

.search-results h3 {
    margin-bottom: 1rem;
    color: var(--text-color);
}

/* 記事セクション */
.articles-section h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.articles-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

/* 記事カード */
.article-card {
    background-color: var(--bg-color);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.article-thumbnail {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background-color: var(--bg-light);
}

.article-content {
    padding: 1.5rem;
}

.article-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--bg-light);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.875rem;
    margin-bottom: 0.75rem;
    font-weight: 500;
}

.article-category.category-link {
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.article-category.category-link:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.article-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    line-height: 1.4;
}

.article-description {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.article-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--text-light);
}

/* 記事詳細ページ */
.article-detail {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--bg-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.article-detail-header {
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 8px;
}

.article-detail-title {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
    line-height: 1.3;
}

.article-detail-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
    color: var(--text-light);
    font-size: 0.9rem;
}

.article-detail-thumbnail {
    width: 100%;
    max-height: 400px;
    object-fit: cover;
    border-radius: 8px;
}

.article-section {
    margin-bottom: 2rem;
}

.article-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.article-section p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-color);
}

/* 記事内の見出しスタイル */
.article-section h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.article-section h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--secondary-color);
}

.article-section pre {
    background-color: var(--bg-light);
    padding: 1rem;
    border-radius: 6px;
    overflow-x: auto;
    margin: 1rem 0;
}

.article-section code {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

.back-button {
    display: inline-block;
    margin-bottom: 2rem;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    transition: background-color 0.3s ease;
}

.back-button:hover {
    background-color: var(--secondary-color);
}

/* 前後の記事ナビゲーション */
.article-navigation {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.nav-article-link {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1rem;
    background-color: var(--bg-light);
    border-radius: 8px;
    text-decoration: none;
    color: var(--text-color);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.nav-article-link:hover {
    background-color: var(--bg-color);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.nav-article-link.nav-article-prev {
    text-align: left;
}

.nav-article-link.nav-article-next {
    text-align: right;
}

.nav-article-link.nav-article-disabled {
    opacity: 0;
    pointer-events: none;
}

.nav-article-label {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.nav-article-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary-color);
    line-height: 1.4;
}

.nav-article-link:hover .nav-article-title {
    color: var(--secondary-color);
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .article-navigation {
        flex-direction: column;
    }

    .nav-article-link.nav-article-next {
        text-align: left;
    }
}

/* フッター */
footer {
    background-color: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

/* ローディング */
.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-light);
}

/* エラー */
.error {
    background-color: #fee2e2;
    color: #991b1b;
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
}

/* 用語集ページ */
.glossary-section {
    max-width: 1000px;
    margin: 0 auto;
}

.glossary-intro {
    margin-bottom: 2rem;
    color: var(--text-light);
    font-size: 1rem;
    line-height: 1.6;
}

.glossary-search {
    margin-bottom: 2rem;
}

#glossarySearchInput {
    width: 100%;
    max-width: 600px;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

#glossarySearchInput:focus {
    outline: none;
    border-color: var(--primary-color);
}

.glossary-category {
    margin-bottom: 3rem;
}

.glossary-category h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.glossary-terms {
    display: grid;
    gap: 1rem;
}

.glossary-term {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.glossary-term:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.glossary-term-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.glossary-term-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
    margin: 0;
}

.glossary-term-reading {
    font-size: 0.875rem;
    color: var(--text-light);
    background-color: var(--bg-light);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
}

.glossary-term-description {
    color: var(--text-color);
    line-height: 1.7;
    margin-bottom: 0.75rem;
}

.glossary-term-example {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border-color);
}

.glossary-term-example strong {
    color: var(--primary-color);
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.5rem;
    }

    .articles-container {
        grid-template-columns: 1fr;
    }

    .search-box {
        flex-direction: column;
    }

    #searchButton {
        width: 100%;
    }

    .article-detail {
        padding: 1rem;
    }

    .article-detail-title {
        font-size: 1.5rem;
    }

    .glossary-term-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .glossary-term-name {
        font-size: 1.1rem;
    }
}