:root {
    /* Color Scheme */
    --bg-color: #ffffff;
    --text-color: #333333;
    --primary-color: #b10d0d;
    --secondary-color: #f5f5f5;
    --border-color: #ddd;
    --focus-color: #007bff;
    
    /* Typography */
    --font-size-base: 1rem;
    --line-height: 1.5;
    
    /* Spacing */
    --spacing-unit: 0.5rem;
    --spacing-xs: calc(var(--spacing-unit) * 0);
    --spacing-sm: var(--spacing-unit);
    --spacing-md: calc(var(--spacing-unit) * 1.5);
    --spacing-lg: calc(var(--spacing-unit) * 2);
    
    /* Borders */
    --border-radius: 4px;
    --border-width: 1px;
    
    /* Transitions */
    --transition-duration: 0.2s;
    --transition-timing: ease-in-out;
    
    /* Breakpoints */
    --breakpoint-sm: 480px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 1024px;

    /* Performance Optimization */
    --font-display: swap;
}

/* Utility Classes (必要なもののみ保持) */
/* 未使用のユーティリティクラスは削除してファイルサイズを削減 */

html {
    overflow-x: hidden;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: var(--spacing-md);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: var(--line-height);
    font-size: var(--font-size-base);
    transition: background-color var(--transition-duration) var(--transition-timing),
                color var(--transition-duration) var(--transition-timing);
}




/* 🚀 完全アニメーション無効化 - 初期描画時のチカツキを根絶 */
html.no-theme-transitions,
html.no-theme-transitions *,
html.no-theme-transitions *::before,
html.no-theme-transitions *::after {
    transition: none !important;
    animation: none !important;
    animation-delay: 0s !important;
    animation-duration: 0s !important;
    animation-fill-mode: none !important;
    animation-iteration-count: 0 !important;
    transform: none !important;
    -webkit-transition: none !important;
    -moz-transition: none !important;
    -o-transition: none !important;
    -ms-transition: none !important;
    -webkit-animation: none !important;
    -moz-animation: none !important;
    -o-animation: none !important;
    -ms-animation: none !important;
}

/* Accessibility Focus Styles */
:focus-visible {
    /* Provide a visible focus indicator for keyboard users */
    outline: 3px solid var(--focus-color);
    outline-offset: 2px;
}

/* Favicons: provide intrinsic size to avoid layout shifts */
.favicon {
    width: 32px;
    height: 32px;
    display: inline-block;
    object-fit: contain;
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-sm);
    z-index: 100;
    transition: top 0.3s;
}

.skip-link:focus {
    top: 0;
}

/* Responsive Breakpoints - 統合版 */
@media (max-width: 1024px) {
    :root {
        --font-size-base: 13px;
    }
}

@media (max-width: 768px) {
    :root {
        --font-size-base: 13px;
        --spacing-unit: 6px;
    }
}

@media (max-width: 480px) {
    :root {
        --font-size-base: 13px;
        --spacing-unit: 4px;
    }
}

a {
  text-decoration: none;
}

header {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    background-color: var(--primary-color);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    top: 0;
    z-index: 10;
}

h1 {
    color: white;
    margin-bottom: 15px;
    font-size: 1.8rem;
}

.search-form {
    max-width: 700px;
    width: 90%;
    margin: 0 auto;
    display: flex;
    gap: var(--spacing-unit);
}

#search-input {
    flex: 1;
    width: 100%;
    padding: var(--spacing-sm);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--text-color);
    background-color: var(--bg-color);
    font-size: var(--font-size-base);
    transition: all var(--transition-duration) var(--transition-timing);
}

#search-input:focus {
    border-color: var(--focus-color);
}

#search-input:focus-visible {
    outline: none;
}

#search-btn {
    padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
    background-color: var(--bg-color);
    color: var(--text-color);
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: var(--font-size-base);
    min-width: 70px;
    transition: all var(--transition-duration);
    white-space: nowrap;
}

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

.quick-search-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-unit);
    margin-top: calc(var(--spacing-unit) * 1.5);
    flex-wrap: nowrap;
    width: 100%;
    padding: 0 var(--spacing-unit);
}

.quick-search {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
    background-color: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-duration);
    min-width: 100px;
    text-align: center;
    white-space: nowrap;
    font-weight: bold;
}

.quick-search:hover {
    background-color: var(--secondary-color);
    transform: translateZ(0);
    will-change: transform;
}

@media (max-width: 768px) {
    .search-form {
        max-width: 100%;
        width: 90%;
        padding: 0 var(--spacing-md);
        gap: var(--spacing-md);
    }

    .quick-search-buttons {
        gap: var(--spacing-sm);
        padding: 0 var(--spacing-md);
        margin-top: var(--spacing-lg);
        margin: 10px 0;
    }
    
    .quick-search {
        min-width: 80px;
        font-size: calc(var(--font-size-base) * 0.9);
        font-weight: bold;
        padding: calc(var(--spacing-sm) * 1.4) calc(var(--spacing-md) * 1.4);
    }

    #search-input {
        padding: calc(var(--spacing-sm) * 1.4);
    }

    #search-btn {
        padding: calc(var(--spacing-sm) * 1.4) calc(var(--spacing-md) * 1.4);
    }
}

.categories-container {
    display: grid;
    place-content: center;
    justify-content: center;
    grid-template-columns: repeat(auto-fill, [col-start] 320px [col-end]); 
}

/* --- モナんてな風（色は変更しない）: クイックサーチ表示調整 --- */
.quick-search-buttons {
    gap: 0.5rem;           /* モナんてなと揃えた間隔 */
    margin-top: 1rem;      /* 見た目の距離感 */
    padding: 0 0.5rem;
    justify-content: center;
    flex-wrap: nowrap;
}

.quick-search {
    padding: 0.6rem 1rem;  /* ボタンのサイズをモナんてな寄せに */
    font-size: 1rem;
    min-width: 100px;      /* ボタン幅を揃える */
    font-weight: 700;      /* 太文字で印象を近づける */
    border: 1px solid var(--border-color); /* 色は既存変数を使用 */
    border-radius: 4px;
    box-shadow: 0 1px 0 rgba(0,0,0,0.03); /* 立体感（色を変えない） */
    white-space: nowrap;
    transition: transform 0.12s ease, box-shadow 0.12s ease;
}

.quick-search:hover {
    transform: translateY(-2px); /* 軽い持ち上げ効果で視覚一致 */
    box-shadow: 0 6px 12px rgba(0,0,0,0.06);
}

/* レスポンシブ微調整（スマホ） */
@media (max-width: 768px) {
    .quick-search { min-width: 80px; font-size: 0.9rem; padding: 0.5rem 0.8rem; }
    .quick-search-buttons { gap: 0.35rem; margin-top: 0.9rem; }
}

/* 追加: スマホ幅 <=480px の細かい調整（クイックサーチだけに限定） */
@media (max-width: 480px) {
    .quick-search-buttons {
        gap: 0.25rem;           /* ボタン間隔を狭める */
        margin-top: 0.6rem;
        padding: 0 0.4rem;
        justify-content: center;
        flex-wrap: wrap;        /* 必要時は折り返しを許可（クイックサーチのみ影響） */
    }

    .quick-search {
        min-width: 68px;       /* 小さい端末でも押しやすく */
        font-size: 0.82rem;    /* テキストを少し小さく */
        padding: 0.42rem 0.68rem;
        line-height: 1;        /* 高さを揃える */
    }
}

.category {
    margin: 0 5px 10px 5px;
    background-color: var(--secondary-color);
    padding: auto;
    border-radius: 4px;
    transition: all 0.2s;
    width: auto;
    min-width: 100px;
    display: inline-block;
    vertical-align: top;
    white-space: nowrap;
}

.category h2 {
    color: #333333;
    border-bottom: 2px solid #bf0000;
    padding: 2px 0;
    margin: 3px 0 2px 0;
    font-size: 1rem;
}

.site-list {
    margin: 10px 0;
    columns: 1;
    column-gap: 4px;
}

.site-item {
    background: var(--bg-color);
    padding: 3px 8px;
    border-radius: 4px;
    box-shadow: 0 1px 1px rgba(0,0,0,0.1);
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 3px;
    break-inside: avoid;
    border: 1px solid var(--border-color);
    transition: all 0.2s;
    text-align: left;
    min-height: 32px;
    contain: content;
    overflow: hidden;
}

/* Loading states */
.favicon.loading {
    background-color: var(--secondary-color);
    border-radius: 50%;
    animation: pulse 1.5s infinite;
}

.favicon.error {
    filter: grayscale(1);
    opacity: 0.7;
}

@keyframes pulse {
    0% { opacity: 0.5; }
    50% { opacity: 1; }
    100% { opacity: 0.5; }
}

.favicon {
    width: 16px;
    height: 16px;
    margin-right: 6px;
}

.site-name {
    font-weight: normal;
    color: #333333;
    font-size: 0.9rem;
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: clip;
    min-width: 0;
    cursor: pointer;
}

.search-site {
    padding: calc(var(--spacing-unit) * 0.625) calc(var(--spacing-unit) * 1.25);
    background-color: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: calc(var(--font-size-base) * 0.916);
    width: 50px;
    flex-shrink: 0;
    text-align: center;
    transition: all var(--transition-duration);
}

.search-site:hover {
    background-color: var(--secondary-color);
    transform: translateZ(0);
    will-change: transform;
}

/* Icon styles */
.category h2 i {
    display: inline-block;
    width: 20px;
    height: 1em;
    line-height: 1;
    margin-right: 6px;
    color: var(--primary-color);
    text-align: center;
    font-style: normal !important;
    font-variant: normal !important;
    font-weight: 900 !important;
    speak: none;
}

/* Fallback: if pseudo-element is missing, ensure font-based icons show */
.category h2 .fa, .category h2 .fas {
    display: inline-block;
    width: 20px;
    text-align: center;
}

/* Footer styles */
footer {
    background-color: var(--primary-color);
    padding: 8px;
    margin-top: 12px;
    border-radius: 4px;    
    font-weight: bold;
    color: white;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: space-between;
}

.footer-section {
    flex: 1;
    min-width: 180px;
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.legal-links-container {
    display: flex;
    gap: 12px;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.legal-links-container a {
    color: white;
    text-decoration: none;
    padding: 7px 8px;
    border-radius: 4px;
    transition: background-color 0.2s;
}

.legal-links-container a:hover {
    text-decoration: underline;
    background-color: rgba(255, 255, 255, 0.1);
}

.sitemap-links-container {
    display: flex;    
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.sitemap-links-container a {
    white-space: nowrap;
    color: white;
    text-decoration: none;
    padding: 2px 4px 8px ;
    border-radius: 4px;
    transition: background-color 0.2s;
}

.sitemap-links-container a:hover {
    text-decoration: underline;
    background-color: rgba(255, 255, 255, 0.1);
}

.footer-bottom {
    text-align: center;
    margin-top: 8px;
    padding-top: 8px;
    font-size: 0.8rem;
}

@media (max-width: 768px) {
    body {
        padding: 0;
        overflow-x: hidden;
        display: flex;
        flex-direction: column;
        justify-content: center;
        min-height: 100vh;
    }

    .content-container {        
        width: 95%;
        box-sizing: content-box;
        justify-content: center;
    }

    .categories-container {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
        width: 100%;
        padding: 0 8px;
        box-sizing: border-box;
    }

    .category {
        margin: 0;
        padding: 8px;
        width: 100%;
        box-sizing: border-box;
    }

    .site-item {
        text-align: left;
        padding: 8px 12px;
        margin: 4px 0;
        width: 100%;
        box-sizing: border-box;
        display: flex;
        align-items: center;
        gap: 8px;
    }

    .site-name {
        white-space: nowrap;
        overflow: hidden;
        text-overflow: clip;
        max-width: none;
    }

    header {
        padding: 10px 0;
        margin: 0;
        border-radius: 0;
        width: auto;
        max-width: 100%;
    }

    h1 {
        font-size: 1.6rem;
        margin: 0 0 10px 0;
    }

    .search-form {
        flex-direction: row;
        gap: 8px;
        margin: 0 10px;
    }

    #search-input {
        padding: 8px;
        font-size: 1rem;
    }

    #search-btn {
        padding: 8px 16px;
        font-size: 1rem;
    }

    .site-list {
        columns: 1;
    }

    .footer-content {
        flex-direction: column;
        gap: 8px;
    }

    .footer-bottom {
        padding: 8px;
    }
}

/* Performance Optimization */
img {
    font-display: var(--font-display);
    width: auto;
    height: auto;
}

/* Animation Optimization */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* 🎯 ダークテーマシステム */
.dark-theme {
    --bg-color: #22272e;
    --text-color: #e0e0e0;
    --secondary-color: #2d333b;
    --border-color: #3a4049;
    --primary-color-dark: #b33a3a;
    color-scheme: dark;
}

.dark-theme a {
    color: #9ACEEB;
}

/* ヘッダー内のリンクは白色 */
.dark-theme header a {
    color: var(--text-color) !important;
}

/* フッター内のリンクは白色 */
.dark-theme footer a {
    color: white !important;
}

.dark-theme header,
.dark-theme footer {
    background-color: var(--primary-color-dark);
}

.dark-theme .category h2 {
    border-bottom-color: var(--primary-color-dark);
}

.dark-theme .category h2 i {
    color: var(--primary-color-dark);
}

.dark-theme h1,
.dark-theme h2,
.dark-theme .site-name {
    color: var(--text-color);
}

.dark-theme #search-input,
.dark-theme #search-btn,
.dark-theme .quick-search,
.dark-theme .site-item,
.dark-theme .search-site {
    background-color: var(--secondary-color);
    color: var(--text-color);
    border-color: var(--border-color);
}

.dark-theme #search-btn:hover,
.dark-theme .quick-search:hover,
.dark-theme .search-site:hover {
    background-color: var(--border-color);
}

.dark-theme .category {
    background-color: var(--secondary-color);
}

/* Theme Switcher */
.header-top {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    max-width: 700px;
    margin: 0 auto;
}

#theme-toggle {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    border: none;
    color: white;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 5px;
}

#theme-toggle:hover {
    opacity: 0.8;
}

#install-pwa-btn {
    display: none;
    padding: 10px 20px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    margin-top: 10px;
}