/* style.css */

/* 基本リセット */
body, h1, h2, h3, h4, h5, h6, p, ul, ol, pre, code, blockquote, table {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ==================================== */
/* Root Variables (Modern/Light Theme - Default) */
/* ==================================== */
:root {
    --font-family-base: 'Hiragino Sans', 'ヒラギノ角ゴシック ProN', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', '游ゴシック', 'Meiryo', 'メイリオ', sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    --font-family-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
    --font-family-classic: 'Press Start 2P', cursive, 'Hiragino Sans', 'ヒラギノ角ゴシック ProN', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', '游ゴシック', 'Meiryo', 'メイリオ', sans-serif;

    /* Body */
    --body-bg-color: #eef1f4; /* 既に修正済み */
    --body-bg-image: none; /* グリッド表示はなし */
    --body-color: #24292e;
    --body-line-height: 1.7;
    --body-padding-top-bottom: 60px;
    --body-padding-left-right: 30px;
    --body-text-shadow: none; /* ライトテーマでは影なし */

    /* Site Title */
    --site-title-font-size: 2.8em;
    --site-title-color: #0366d6;
    --site-title-margin-bottom: 60px;
    --site-title-font-weight: 700;
    --site-title-letter-spacing: 0.02em;
    --site-title-text-shadow: none;
    --site-title-padding: 10px 25px;
    --site-title-border: 1px solid #d1d5da;
    --site-title-bg-color: #ffffff;
    --site-title-border-radius: 4px;
    --site-title-box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);

    /* Cards */
    --card-gap: 25px;
    --card-bg-color: #ffffff;
    --card-border-radius: 6px;
    --card-border: 1px solid #e0e0e0;
    --card-box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05);
    --card-hover-transform: translateY(-2px);
    --card-hover-box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1); /* ここを調整！影を広げて少し濃く */
    --card-hover-border-color: #0366d6;
    --card-hover-bg-color: #fcfcfc; /* ここを調整！よりわずかな変化に */
    --card-padding: 25px;
    --card-h2-font-size: 1.25em;
    --card-h2-font-weight: 600;
    --card-h2-color: #24292e;
    --card-h2-letter-spacing: 0.01em;
    --card-h2-text-shadow: none;
    --card-meta-font-size: 0.85em;
    --card-meta-color: #586069;
    --card-meta-border-top: 1px solid #e0e0e0;
    --card-meta-text-shadow: none;
    --card-category-bg-color: #eef1f4;
    --card-category-border: 1px solid #d1d5da;
    --card-category-box-shadow: none;
    --card-category-letter-spacing: 0.01em;
    --card-category-color: #586069;

    /* Back Link */
    --back-link-color: #0366d6;
    --back-link-font-weight: 500;
    --back-link-padding: 10px 20px;
    --back-link-border: 1px solid #d1d5da;
    --back-link-border-radius: 4px;
    --back-link-bg-color: #ffffff;
    --back-link-box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --back-link-text-shadow: none;
    --back-link-letter-spacing: 0.02em;
    --back-link-hover-bg-color: #fdfdfd;
    --back-link-hover-color: #005cc5;
    --back-link-hover-box-shadow: 0 4px 10px rgba(0, 0, 0, 0.12);
    --back-link-hover-transform: translateY(-2px);

    /* Content Body */
    --content-body-line-height: 1.75;
    --content-body-font-size: 1.05em;
    --content-body-padding: 40px;
    --content-body-bg-color: #ffffff;
    --content-body-color: #24292e;
    --content-body-box-shadow: 0 6px 18px rgba(0, 0, 0, 0.06);
    --content-body-border-radius: 6px;
    --content-body-border: 1px solid #e0e0e0;
    --content-body-text-shadow: none;

    /* Content Headings */
    --content-h1-font-size: 2.5em;
    --content-h1-color: #24292e;
    --content-h1-margin-bottom: 1.0em;
    --content-h1-font-weight: 700;
    --content-h1-letter-spacing: 0.02em;
    --content-h1-text-shadow: none;
    --content-h1-border-bottom: none;
    --content-h1-padding-bottom: 0;
    --content-h-border-bottom: 1px solid #e0e0e0;
    --content-h-padding-bottom: 0.8em;
    --content-h-margin-top: 2.5em;
    --content-h-margin-bottom: 1.2em;
    --content-h-color: #24292e;
    --content-h-font-weight: 600;
    --content-h-text-shadow: none;
    --content-h-letter-spacing: 0.015em;
    --content-h2-font-size: 1.8em;
    --content-h3-font-size: 1.5em;
    --content-h4-font-size: 1.2em;

    /* Content Paragraphs & Lists */
    --content-p-margin-bottom: 1.5em;
    --content-list-margin-bottom: 1.5em;
    --content-list-padding-left: 2.5em;
    --content-ul-list-style: disc;
    --content-ul-before-content: none;

    /* Code Blocks (pre) */
    --pre-bg-color: #f6f8fa;
    --pre-padding: 1.5em;
    --pre-border-radius: 4px;
    --pre-font-size: 0.9em;
    --pre-line-height: 1.5;
    --pre-margin-bottom: 2em;
    --pre-border: 1px solid #e0e0e0;
    --pre-box-shadow: inset 0 1px 3px rgba(0,0,0,0.03);
    --pre-color: #24292e;
    --pre-text-shadow: none;
    --pre-before-font-size: 0.65em;
    --pre-before-color: #586069;
    --pre-before-bg-color: #f6f8fa;
    --pre-before-padding: 0.1em 0.7em;
    --pre-before-border: 1px solid #e0e0e0;
    --pre-before-border-radius: 4px 4px 0 0;
    --pre-before-letter-spacing: 0.08em;
    --pre-before-text-shadow: none;

    /* Inline Code (code) */
    --code-bg-color: #eef1f4;
    --code-padding: 0.2em 0.5em;
    --code-border-radius: 3px;
    --code-font-size: 0.85em;
    --code-border: 1px solid #e0e0e0;
    --code-color: #0366d6;
    --code-text-shadow: none;

    /* Links (a) */
    --a-color: #0366d6;
    --a-border-bottom: 1px solid #0366d6;
    --a-hover-color: #005cc5;
    --a-hover-border-bottom-color: #005cc5;
    --a-text-shadow: none;
    --a-hover-text-shadow: none;

    /* Blockquotes */
    --blockquote-border-left: 4px solid #0366d6;
    --blockquote-padding-left: 2em;
    --blockquote-margin: 2em 0;
    --blockquote-color: #586069;
    --blockquote-bg-color: #eef1f4;
    --blockquote-border-radius: 4px;
    --blockquote-box-shadow: none;
    --blockquote-text-shadow: none;

    /* Tables */
    --table-margin-bottom: 2em;
    --table-box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    --table-border-radius: 4px;
    --table-border: 1px solid #e0e0e0;
    --table-th-td-border: 1px solid #f0f2f5;
    --table-th-td-padding: 12px;
    --table-th-td-color: #24292e;
    --table-th-td-text-shadow: none;
    --table-th-bg-color: #eef1f4;
    --table-th-font-weight: 600;
    --table-th-color: #24292e;
    --table-th-letter-spacing: 0.01em;
    --table-tr-even-bg-color: #fdfdfd;

    /* Theme Switcher specific styles */
    --theme-switcher-button-bg: rgba(255, 255, 255, 0.5);
    --theme-switcher-button-color: rgba(36, 41, 46, 0.5);
    --theme-switcher-button-border: 1px solid rgba(209, 213, 218, 0.5);
    --theme-switcher-button-opacity: 0.5;
    --theme-switcher-button-hover-bg: #d1d5da;
    --theme-switcher-button-hover-color: #24292e;
    --theme-switcher-button-hover-border: 1px solid #0366d6;
    --theme-switcher-button-hover-box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    --theme-switcher-button-hover-transform: scale(1.2) translateY(-1px);

    /* Info Message */
    --info-message-color: #7f8c8d;

    /* Media Query Variables (Defaults for smaller screens - can be overridden by classic theme) */
    --body-padding-top-bottom-mobile: 30px;
    --body-padding-left-right-mobile: 15px;
    --body-font-size-mobile: 0.95em;
    --site-title-font-size-mobile: 2.2em;
    --site-title-margin-bottom-mobile: 40px;
    --site-title-padding-mobile: 8px 20px;
    --card-gap-mobile: 15px;
    --card-padding-mobile: 20px;
    --card-h2-font-size-mobile: 1.15em;
    --card-h2-margin-bottom-mobile: 15px;
    --card-meta-font-size-mobile: 0.8em;
    --card-meta-padding-top-mobile: 12px;
    --back-link-margin-bottom-mobile: 30px;
    --back-link-padding-mobile: 8px 18px;
    --content-body-padding-mobile: 30px;
    --content-body-max-width-mobile: 95%;
    --content-body-font-size-mobile: 0.95em;
    --content-h1-font-size-mobile: 2.0em;
    --content-h1-margin-bottom-mobile: 0.8em;
    --content-h2-font-size-mobile-inner: 1.6em;
    --content-h3-font-size-mobile-inner: 1.3em;
    --content-h4-font-size-mobile-inner: 1.1em;
    --content-p-margin-bottom-mobile: 1.2em;
    --content-list-margin-bottom-mobile: 1.2em;
    --content-list-padding-left-mobile: 2em;
    --content-ul-before-margin-left-mobile: -1.2em;
    --pre-padding-mobile: 1.2em;
    --pre-margin-bottom-mobile: 1.8em;
    --pre-before-top-mobile: -0.9em;
    --pre-before-padding-mobile: 0.1em 0.5em;
    --pre-before-font-size-mobile: 0.6em;
    --code-padding-mobile: 0.15em 0.4em;
    --code-font-size-mobile: 0.8em;
    --blockquote-padding-left-mobile: 1.8em;
    --blockquote-margin-mobile: 1.8em 0;
    --table-margin-bottom-mobile: 1.8em;
    --table-th-td-padding-mobile: 10px;
    --body-padding-top-bottom-small-mobile: 20px;
    --body-padding-left-right-small-mobile: 10px;
    --body-font-size-small-mobile: 0.9em;
    --site-title-font-size-small-mobile: 1.8em;
    --site-title-margin-bottom-small-mobile: 25px;
    --site-title-padding-small-mobile: 6px 15px;
    --content-body-padding-small-mobile: 20px 15px;
    --content-body-max-width-small-mobile: 100%;
    --content-body-font-size-small-mobile: 0.9em;
    --content-h1-font-size-small-mobile: 1.6em;
    --content-h1-margin-bottom-small-mobile: 0.7em;
    --content-h2-font-size-small-mobile-inner: 1.4em;
    --content-h3-font-size-small-mobile-inner: 1.2em;
    --content-h4-font-size-small-mobile-inner: 1.0em;
}

/* ==================================== */
/* Classic/Dark Theme Overrides */
/* ==================================== */
html.classic-theme { /* html要素にclassic-themeクラスが付与された時に適用 */
    --body-bg-color: #000000;
    --body-bg-image: repeating-linear-gradient(0deg, #001a1a, #001a1a 1px, transparent 1px, transparent 20px), repeating-linear-gradient(90deg, #001a1a, #001a1a 1px, transparent 1px, transparent 20px);
    --body-color: #aaffff;
    --body-line-height: 1.6;
    --body-padding-top-bottom: 50px;
    --body-padding-left-right: 20px;
    --body-text-shadow: 2px 2px 0px #001a1a;
    --font-family-base: var(--font-family-classic);

    --site-title-font-size: 3.5em;
    --site-title-color: #aaffff;
    --site-title-margin-bottom: 50px;
    --site-title-font-weight: normal;
    --site-title-letter-spacing: 0.1em;
    --site-title-text-shadow: 4px 4px 0px #001a1a;
    --site-title-padding: 15px 30px;
    --site-title-border: 4px solid #006666;
    --site-title-bg-color: #003333;
    --site-title-border-radius: 8px;
    --site-title-box-shadow: 8px 8px 0px #001a1a;

    --card-gap: 30px;
    --card-bg-color: #003333;
    --card-border-radius: 10px;
    --card-border: 3px solid #006666;
    --card-box-shadow: 5px 5px 0px #001a1a;
    --card-hover-transform: translate(-3px, -3px);
    --card-hover-box-shadow: 8px 8px 0px #001a1a;
    --card-hover-border-color: #009999;
    --card-hover-bg-color: #004444;
    --card-h2-font-size: 1.3em;
    --card-h2-font-weight: normal;
    --card-h2-color: #aaffff;
    --card-h2-letter-spacing: 0.05em;
    --card-h2-text-shadow: 2px 2px 0px #001a1a;
    --card-meta-font-size: 0.85em;
    --card-meta-color: #00ffff;
    --card-meta-border-top: 1px dashed #006666;
    --card-meta-text-shadow: 1px 1px 0px #001a1a;
    --card-category-bg-color: #004d4d;
    --card-category-border: 1px solid #009999;
    --card-category-box-shadow: 2px 2px 0px #001a1a;
    --card-category-letter-spacing: 0.03em;
    --card-category-color: #aaffff;

    --back-link-color: #aaffff;
    --back-link-font-weight: normal;
    --back-link-padding: 10px 20px;
    --back-link-border: 3px solid #006666;
    --back-link-border-radius: 8px;
    --back-link-bg-color: #003333;
    --back-link-box-shadow: 5px 5px 0px #001a1a;
    --back-link-text-shadow: 2px 2px 0px #001a1a;
    --back-link-letter-spacing: 0.05em;
    --back-link-hover-bg-color: #004444;
    --back-link-hover-color: #ffffff;
    --back-link-hover-box-shadow: 8px 8px 0px #001a1a;
    --back-link-hover-transform: translate(-3px, -3px);

    --content-body-line-height: 1.6;
    --content-body-font-size: 1em;
    --content-body-padding: 40px;
    --content-body-bg-color: #003333;
    --content-body-color: #aaffff;
    --content-body-box-shadow: 8px 8px 0px #001a1a;
    --content-body-border-radius: 10px;
    --content-body-border: 3px solid #006666;
    --content-body-text-shadow: 2px 2px 0px #001a1a;
    --font-family-body-content: var(--font-family-classic);

    --content-h1-font-size: 2.5em;
    --content-h1-color: #ffffff;
    --content-h1-margin-bottom: 1.0em;
    --content-h1-font-weight: normal;
    --content-h1-letter-spacing: 0.05em;
    --content-h1-text-shadow: 3px 3px 0px #001a1a;
    --content-h1-border-bottom: 2px dashed #006666;
    --content-h1-padding-bottom: 0.5em;
    --content-h-border-bottom: 2px dashed #006666;
    --content-h-padding-bottom: 0.5em;
    --content-h-margin-top: 2.5em;
    --content-h-margin-bottom: 1.2em;
    --content-h-color: #00ffff;
    --content-h-font-weight: normal;
    --content-h-text-shadow: 2px 2px 0px #001a1a;
    --content-h-letter-spacing: 0.03em;
    --content-h2-font-size: 1.8em;
    --content-h3-font-size: 1.5em;
    --content-h4-font-size: 1.2em;

    --content-p-margin-bottom: 1.5em;
    --content-list-margin-bottom: 1.5em;
    --content-list-padding-left: 2.5em;
    --content-ul-list-style: none;
    --content-ul-before-content: '→ ';

    --pre-bg-color: #001a1a;
    --pre-padding: 1.5em;
    --pre-border-radius: 5px;
    --pre-font-size: 0.9em;
    --pre-line-height: 1.5;
    --pre-margin-bottom: 2em;
    --pre-border: 2px solid #006666;
    --pre-box-shadow: 3px 3px 0px #000d0d;
    --pre-color: #aaffff;
    --pre-text-shadow: 1px 1px 0px #000a0a;
    --pre-before-font-size: 0.7em;
    --pre-before-color: #00ffff;
    --pre-before-bg-color: #001a1a;
    --pre-before-padding: 0.1em 0.7em;
    --pre-before-border: 1px solid #006666;
    --pre-before-border-radius: 5px 5px 0 0;
    --pre-before-letter-spacing: 0.08em;
    --pre-before-text-shadow: 1px 1px 0px #000d0d;

    --code-bg-color: #004d4d;
    --code-padding: 0.2em 0.5em;
    --code-border-radius: 3px;
    --code-font-size: 0.85em;
    --code-border: 1px solid #009999;
    --code-color: #aaffff;
    --code-text-shadow: 1px 1px 0px #001a1a;
    
    --a-color: #00ffff;
    --a-border-bottom: 2px solid #009999;
    --a-hover-color: #ffffff;
    --a-hover-border-bottom-color: #ffffff;
    --a-text-shadow: 1px 1px 0px #001a1a;
    --a-hover-text-shadow: 2px 2px 0px #001a1a;

    --blockquote-border-left: 5px solid #00ffff;
    --blockquote-padding-left: 2em;
    --blockquote-margin: 2em 0;
    --blockquote-color: #88ffff;
    --blockquote-bg-color: #002222;
    --blockquote-border-radius: 5px;
    --blockquote-box-shadow: 3px 3px 0px #001a1a;
    --blockquote-text-shadow: 1px 1px 0px #001a1a;

    --table-margin-bottom: 2em;
    --table-box-shadow: 3px 3px 0px #001a1a;
    --table-border-radius: 5px;
    --table-border: 2px solid #006666;
    --table-th-td-border: 1px solid #004d4d;
    --table-th-td-padding: 12px;
    --table-th-td-color: #aaffff;
    --table-th-td-text-shadow: 1px 1px 0px #001a1a;
    --table-th-bg-color: #004d4d;
    --table-th-font-weight: normal;
    --table-th-color: #ffffff;
    --table-th-letter-spacing: 0.03em;
    --table-tr-even-bg-color: #002222;

    /* Theme Switcher specific styles */
    --theme-switcher-button-bg: rgba(0, 51, 51, 0.2);
    --theme-switcher-button-color: rgba(170, 255, 255, 0.3);
    --theme-switcher-button-border: 1px solid rgba(0, 102, 102, 0.2);
    --theme-switcher-button-opacity: 0.2;
    --theme-switcher-button-hover-bg: #004444;
    --theme-switcher-button-hover-color: #ffffff;
    --theme-switcher-button-hover-border: 2px solid #006666;
    --theme-switcher-button-hover-box-shadow: 3px 3px 0px #001a1a;
    --theme-switcher-button-hover-transform: scale(1.2) translateY(-2px);

    /* Info Message */
    --info-message-color: #aaffff;

    /* Media Query Variables (Classic specific overrides for smaller screens) */
    --body-padding-top-bottom-mobile: 25px; /* Classic specific */
    --body-padding-left-right-mobile: 10px; /* Classic specific */
    --body-font-size-mobile: 0.9em; /* Classic specific */
    --site-title-font-size-mobile: 2.5em; /* Classic specific */
    --site-title-margin-bottom-mobile: 30px; /* Classic specific */
    --site-title-padding-mobile: 10px 25px; /* Classic specific */
    --card-gap-mobile: 20px; /* Classic specific */
    --card-padding-mobile: 20px; /* Classic specific */
    --card-h2-font-size-mobile: 1.2em; /* Classic specific */
    --card-h2-margin-bottom-mobile: 15px; /* Classic specific */
    --card-meta-font-size-mobile: 0.8em; /* Classic specific */
    --card-meta-padding-top-mobile: 12px; /* Classic specific */
    --back-link-margin-bottom-mobile: 30px; /* Classic specific */
    --back-link-padding-mobile: 8px 18px; /* Classic specific */
    --content-body-padding-mobile: 30px; /* Classic specific */
    --content-body-max-width-mobile: 95%; /* Classic specific */
    --content-body-font-size-mobile: 0.9em; /* Classic specific */
    --content-h1-font-size-mobile: 2.0em; /* Classic specific */
    --content-h1-margin-bottom-mobile: 0.8em; /* Classic specific */
    --content-h2-font-size-mobile-inner: 1.5em; /* Classic specific */
    --content-h3-font-size-mobile-inner: 1.2em; /* Classic specific */
    --content-h4-font-size-mobile-inner: 1.0em; /* Classic specific */
    --content-p-margin-bottom-mobile: 1.2em; /* Classic specific */
    --content-list-margin-bottom-mobile: 1.2em; /* Classic specific */
    --content-list-padding-left-mobile: 2em; /* Classic specific */
    --content-ul-before-margin-left-mobile: -1.2em; /* Classic specific */
    --pre-padding-mobile: 1.2em; /* Classic specific */
    --pre-margin-bottom-mobile: 1.8em; /* Classic specific */
    --pre-before-top-mobile: -0.9em; /* Classic specific */
    --pre-before-padding-mobile: 0.1em 0.5em; /* Classic specific */
    --pre-before-font-size-mobile: 0.6em; /* Classic specific */
    --code-padding-mobile: 0.15em 0.4em; /* Classic specific */
    --code-font-size-mobile: 0.8em; /* Classic specific */
    --blockquote-padding-left-mobile: 1.8em; /* Classic specific */
    --blockquote-margin-mobile: 1.8em 0; /* Classic specific */
    --table-margin-bottom-mobile: 1.8em; /* Classic specific */
    --table-th-td-padding-mobile: 10px; /* Classic specific */
    --body-padding-top-bottom-small-mobile: 15px; /* Classic specific */
    --body-padding-left-right-small-mobile: 8px; /* Classic specific */
    --body-font-size-small-mobile: 0.85em; /* Classic specific */
    --site-title-font-size-small-mobile: 1.5em; /* Classic specific */
    --site-title-margin-bottom-small-mobile: 20px; /* Classic specific */
    --site-title-padding-small-mobile: 5px 10px; /* Classic specific */
    --content-body-padding-small-mobile: 15px 10px; /* Classic specific */
    --content-body-max-width-small-mobile: 100%; /* Classic specific */
    --content-body-font-size-small-mobile: 0.85em; /* Classic specific */
    --content-h1-font-size-small-mobile: 1.4em; /* Classic specific */
    --content-h1-margin-bottom-small-mobile: 0.6em; /* Classic specific */
    --content-h2-font-size-small-mobile-inner: 1.3em; /* Classic specific */
    --content-h3-font-size-small-mobile-inner: 1.1em; /* Classic specific */
    --content-h4-font-size-small-mobile-inner: 0.9em; /* Classic specific */
}

/* ==================================== */
/* General Body Styles (using variables) */
/* ==================================== */
body {
    background-color: var(--body-bg-color);
    background-image: var(--body-bg-image);
    background-size: 20px 20px; /* grid size for classic */
    background-position: 0 0;
    font-family: var(--font-family-base);
    font-size: 1em;
    color: var(--body-color);
    line-height: var(--body-line-height);
    padding: var(--body-padding-top-bottom) var(--body-padding-left-right);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-shadow: var(--body-text-shadow);
    transition: background-color 0.3s ease, color 0.3s ease, text-shadow 0.3s ease;
}

h1.site-title {
    font-size: var(--site-title-font-size);
    color: var(--site-title-color);
    text-align: center;
    margin-bottom: var(--site-title-margin-bottom);
    font-weight: var(--site-title-font-weight);
    letter-spacing: var(--site-title-letter-spacing);
    text-shadow: var(--site-title-text-shadow);
    padding: var(--site-title-padding);
    border: var(--site-title-border);
    background-color: var(--site-title-bg-color);
    border-radius: var(--site-title-border-radius);
    box-shadow: var(--site-title-box-shadow);
    transition: all 0.3s ease;
}

.card-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--card-gap);
    max-width: 1300px;
    width: 100%;
    margin: 0 auto;
    padding: 0 20px;
}

/* .card は<a>タグになったため、スタイルを調整 */
.card {
    background-color: var(--card-bg-color);
    border-radius: var(--card-border-radius);
    border: var(--card-border);
    box-shadow: var(--card-box-shadow);
    text-decoration: none; /* リンクの下線を削除 */
    color: inherit; /* テキスト色を親から継承 */
    display: flex;
    flex-direction: column;
    transition: transform 0.1s ease-out, box-shadow 0.1s ease-out, background-color 0.2s ease-out, border-color 0.2s ease-out;
    position: relative;
    padding: var(--card-padding);
}

.card:hover {
    transform: var(--card-hover-transform);
    box-shadow: var(--card-hover-box-shadow);
    border-color: var(--card-hover-border-color);
    background-color: var(--card-hover-bg-color);
}

/* card-title は <h2> に付与される */
.card-title {
    font-size: var(--card-h2-font-size);
    font-weight: var(--card-h2-font-weight);
    margin-top: 0;
    margin-bottom: 20px;
    color: var(--card-h2-color); /* h2の色を適用 */
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
    flex-grow: 1;
    text-shadow: var(--card-h2-text-shadow);
    letter-spacing: var(--card-h2-letter-spacing);
    /* <a>タグから継承される下線をリセット */
    text-decoration: none;
    transition: color 0.3s ease, text-shadow 0.3s ease; /* 追加 */
}

.card-meta {
    font-size: var(--card-meta-font-size);
    color: var(--card-meta-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
    padding-top: 15px;
    border-top: var(--card-meta-border-top);
    text-shadow: var(--card-meta-text-shadow);
    transition: color 0.3s ease, border-color 0.3s ease, text-shadow 0.3s ease; /* 追加 */
}

.card-date {
    color: inherit;
    white-space: nowrap;
}

.card-category {
    background-color: var(--card-category-bg-color);
    padding: 5px 10px;
    border-radius: 3px;
    border: var(--card-category-border);
    box-shadow: var(--card-category-box-shadow);
    letter-spacing: var(--card-category-letter-spacing);
    color: var(--card-category-color);
    white-space: nowrap;
    transition: all 0.3s ease;
}

/* info-message のスタイル */
.info-message {
    text-align: center;
    margin-top: 30px;
    font-size: 1.1em;
    color: var(--info-message-color); /* 変数を使用 */
    transition: color 0.3s ease;
}

.back-link {
    display: block;
    width: fit-content;
    margin: 0 auto 50px auto;
    text-decoration: none;
    color: var(--back-link-color);
    font-weight: var(--back-link-font-weight);
    padding: var(--back-link-padding);
    border: var(--back-link-border);
    border-radius: var(--back-link-border-radius);
    transition: all 0.2s ease;
    background-color: var(--back-link-bg-color);
    box-shadow: var(--back-link-box-shadow);
    text-shadow: var(--back-link-text-shadow);
    letter-spacing: var(--back-link-letter-spacing);
}

.back-link:hover {
    background-color: var(--back-link-hover-bg-color);
    color: var(--back-link-hover-color);
    box-shadow: var(--back-link-hover-box-shadow);
    transform: var(--back-link-hover-transform);
}

.content-body {
    font-family: var(--font-family-base);
    line-height: var(--content-body-line-height);
    font-size: var(--content-body-font-size);
    padding: var(--content-body-padding);
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
    background: var(--content-body-bg-color);
    color: var(--content-body-color);
    box-shadow: var(--content-body-box-shadow);
    border-radius: var(--content-body-border-radius);
    border: var(--content-body-border);
    text-shadow: var(--content-body-text-shadow);
    transition: all 0.3s ease;
}

.content-body > h1:first-child,
.content-body > h2:first-child,
.content-body > h3:first-child,
.content-body > h4:first-child,
.content-body > h5:first-child,
.content-body > h6:first-child {
    margin-top: 0;
}

.content-body h1 {
    font-size: var(--content-h1-font-size);
    color: var(--content-h1-color);
    margin-top: 0;
    margin-bottom: var(--content-h1-margin-bottom);
    font-weight: var(--content-h1-font-weight);
    letter-spacing: var(--content-h1-letter-spacing);
    text-align: left;
    text-shadow: var(--content-h1-text-shadow);
    border-bottom: var(--content-h1-border-bottom);
    padding-bottom: var(--content-h1-padding-bottom);
    transition: all 0.3s ease;
}

.content-body h2, .content-body h3, .content-body h4, .content-body h5, .content-body h6 {
    border-bottom: var(--content-h-border-bottom);
    padding-bottom: var(--content-h-padding-bottom);
    margin-top: var(--content-h-margin-top);
    margin-bottom: var(--content-h-margin-bottom);
    color: var(--content-h-color);
    line-height: 1.3;
    font-weight: var(--content-h-font-weight);
    text-shadow: var(--content-h-text-shadow);
    letter-spacing: var(--content-h-letter-spacing);
    transition: all 0.3s ease;
}

.content-body h2 { font-size: var(--content-h2-font-size); }
.content-body h3 { font-size: var(--content-h3-font-size); }
.content-body h4 { font-size: var(--content-h4-font-size); }

.content-body p {
    margin-bottom: var(--content-p-margin-bottom);
}

.content-body ul {
    list-style: var(--content-ul-list-style);
    margin-bottom: var(--content-list-margin-bottom);
    padding-left: var(--content-list-padding-left);
}

.content-body ul li::before {
    content: var(--content-ul-before-content);
    color: var(--content-h-color);
    display: inline-block;
    width: 1em;
    margin-left: -1.5em;
    font-family: sans-serif;
    font-size: 0.9em;
    transition: color 0.3s ease;
}

.content-body ol {
    list-style: decimal;
    margin-bottom: var(--content-list-margin-bottom);
    padding-left: var(--content-list-padding-left);
}

.content-body pre {
    background: var(--pre-bg-color);
    padding: var(--pre-padding);
    overflow-x: auto;
    border-radius: var(--pre-border-radius);
    font-family: var(--font-family-mono);
    font-size: var(--pre-font-size);
    line-height: var(--pre-line-height);
    margin-bottom: var(--pre-margin-bottom);
    border: var(--pre-border);
    box-shadow: var(--pre-box-shadow);
    color: var(--pre-color);
    text-shadow: var(--pre-text-shadow);
    position: relative;
    transition: all 0.3s ease;
}

.content-body pre::before {
    content: "CODE";
    position: absolute;
    top: -1em;
    left: 0;
    font-size: var(--pre-before-font-size);
    color: var(--pre-before-color);
    background-color: var(--pre-before-bg-color);
    padding: var(--pre-before-padding);
    border: var(--pre-before-border);
    border-bottom: none;
    border-radius: var(--pre-before-border-radius);
    text-transform: uppercase;
    letter-spacing: var(--pre-before-letter-spacing);
    text-shadow: var(--pre-before-text-shadow);
    transition: all 0.3s ease;
}
.content-body pre.language-html::before { content: "HTML"; }
.content-body pre.language-css::before { content: "CSS"; }
.content-body pre.language-javascript::before { content: "JS"; }
.content-body pre.language-python::before { content: "PYTHON"; }

.content-body code {
    background: var(--code-bg-color);
    padding: var(--code-padding);
    border-radius: var(--code-border-radius);
    font-family: var(--font-family-mono);
    font-size: var(--code-font-size);
    border: var(--code-border);
    color: var(--code-color);
    text-shadow: var(--code-text-shadow);
    transition: all 0.3s ease;
}

.content-body pre code {
    background: none;
    padding: 0;
    font-size: 1em;
    border: none;
    color: inherit;
    text-shadow: inherit;
}

.content-body a {
    text-decoration: none;
    color: var(--a-color);
    border-bottom: var(--a-border-bottom);
    transition: color 0.2s ease, border-bottom-color 0.2s ease, text-shadow 0.2s ease;
    text-shadow: var(--a-text-shadow);
}

.content-body a:hover {
    color: var(--a-hover-color);
    border-bottom-color: var(--a-hover-border-bottom-color);
    text-decoration: none;
    text-shadow: var(--a-hover-text-shadow);
}

.content-body blockquote {
    border-left: var(--blockquote-border-left);
    padding-left: var(--blockquote-padding-left);
    margin: var(--blockquote-margin);
    color: var(--blockquote-color);
    background-color: var(--blockquote-bg-color);
    border-radius: var(--blockquote-border-radius);
    box-shadow: var(--blockquote-box-shadow);
    text-shadow: var(--blockquote-text-shadow);
    transition: all 0.3s ease;
}

.content-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--table-margin-bottom);
    box-shadow: var(--table-box-shadow);
    border-radius: var(--table-border-radius);
    overflow: hidden;
    border: var(--table-border);
    transition: all 0.3s ease;
}

.content-body th, .content-body td {
    border: var(--table-th-td-border);
    padding: var(--table-th-td-padding);
    text-align: left;
    color: var(--table-th-td-color);
    text-shadow: var(--table-th-td-text-shadow);
    transition: all 0.3s ease;
}

.content-body th {
    background-color: var(--table-th-bg-color);
    font-weight: var(--table-th-font-weight);
    color: var(--table-th-color);
    text-shadow: var(--table-th-text-shadow);
    letter-spacing: var(--table-th-letter-spacing);
    transition: all 0.3s ease;
}

.content-body tr:nth-child(even) {
    background-color: var(--table-tr-even-bg-color);
    transition: background-color 0.3s ease;
}

/* ==================================== */
/* Media Queries (Responsive Design) - Variables Overridden */
/* ==================================== */
@media screen and (max-width: 1440px) {
    .card-container {
        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
        max-width: 1100px;
        gap: var(--card-gap);
    }
}

@media screen and (max-width: 1024px) {
    .card-container {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        max-width: 600px;
        gap: var(--card-gap);
        padding: 0 10px;
    }
}

@media screen and (max-width: 768px) {
    body {
        padding: var(--body-padding-top-bottom-mobile) var(--body-padding-left-right-mobile);
        font-size: var(--body-font-size-mobile);
    }

    h1.site-title {
        font-size: var(--site-title-font-size-mobile);
        margin-bottom: var(--site-title-margin-bottom-mobile);
        padding: var(--site-title-padding-mobile);
        border: var(--site-title-border);
        box-shadow: var(--site-title-box-shadow);
    }

    .card-container {
        grid-template-columns: 1fr;
        gap: var(--card-gap-mobile);
        padding: 0;
    }

    .card {
        padding: var(--card-padding-mobile);
        border: var(--card-border);
        box-shadow: var(--card-box-shadow);
    }
    .card:hover {
        transform: var(--card-hover-transform);
        box-shadow: var(--card-hover-box-shadow);
    }

    .card-title {
        font-size: var(--card-h2-font-size-mobile);
        margin-bottom: var(--card-h2-margin-bottom-mobile);
    }

    .card-meta {
        font-size: var(--card-meta-font-size-mobile);
        padding-top: var(--card-meta-padding-top-mobile);
    }

    .back-link {
        margin-bottom: var(--back-link-margin-bottom-mobile);
        padding: var(--back-link-padding-mobile);
        border: var(--back-link-border);
        box-shadow: var(--back-link-box-shadow);
    }
    .back-link:hover {
        box-shadow: var(--back-link-hover-box-shadow);
        transform: var(--back-link-hover-transform);
    }

    .content-body {
        padding: var(--content-body-padding-mobile);
        max-width: var(--content-body-max-width-mobile);
        font-size: var(--content-body-font-size-mobile);
        border: var(--content-body-border);
        box-shadow: var(--content-body-box-shadow);
    }

    .content-body h1 {
        font-size: var(--content-h1-font-size-mobile);
        margin-bottom: var(--content-h1-margin-bottom-mobile);
    }
    .content-body h2 { font-size: var(--content-h2-font-size-mobile-inner); margin-top: 2em; margin-bottom: 1em;}
    .content-body h3 { font-size: var(--content-h3-font-size-mobile-inner); margin-top: 2em; margin-bottom: 1em;}
    .content-body h4 { font-size: var(--content-h4-font-size-mobile-inner); margin-top: 2em; margin-bottom: 1em;}
    .content-body p { margin-bottom: var(--content-p-margin-bottom-mobile); }
    .content-body ul, .content-body ol { margin-bottom: var(--content-list-margin-bottom-mobile); padding-left: var(--content-list-padding-left-mobile); }
    .content-body ul li::before { margin-left: var(--content-ul-before-margin-left-mobile); }
    .content-body pre {
        padding: var(--pre-padding-mobile);
        margin-bottom: var(--pre-margin-bottom-mobile);
        border: var(--pre-border);
        box-shadow: var(--pre-box-shadow);
    }
    .content-body pre::before { top: var(--pre-before-top-mobile); padding: var(--pre-before-padding-mobile); font-size: var(--pre-before-font-size-mobile); }
    .content-body code { padding: var(--code-padding-mobile); font-size: var(--code-font-size-mobile);}
    .content-body blockquote {
        border-left: var(--blockquote-border-left);
        padding-left: var(--blockquote-padding-left-mobile);
        margin: var(--blockquote-margin-mobile);
    }
    .content-body table {
        margin-bottom: var(--table-margin-bottom-mobile);
        box-shadow: var(--table-box-shadow);
        border: var(--table-border);
    }
    .content-body th, .content-body td {
        padding: var(--table-th-td-padding-mobile);
        border: var(--table-th-td-border);
    }
}

@media screen and (max-width: 480px) {
    body {
        padding: var(--body-padding-top-bottom-small-mobile) var(--body-padding-left-right-small-mobile);
        font-size: var(--body-font-size-small-mobile);
    }

    h1.site-title {
        font-size: var(--site-title-font-size-small-mobile);
        margin-bottom: var(--site-title-margin-bottom-small-mobile);
        padding: var(--site-title-padding-small-mobile);
    }

    .content-body {
        padding: var(--content-body-padding-small-mobile);
        max-width: var(--content-body-max-width-small-mobile);
        margin-left: 0;
        margin-right: 0;
        font-size: var(--content-body-font-size-small-mobile);
    }
    .content-body pre::before {
        content: none;
    }

    .content-body h1 {
        font-size: var(--content-h1-font-size-small-mobile);
        margin-bottom: var(--content-h1-margin-bottom-small-mobile);
    }
    .content-body h2 { font-size: var(--content-h2-font-size-small-mobile-inner); }
    .content-body h3 { font-size: var(--content-h3-font-size-small-mobile-inner); }
    .content-body h4 { font-size: var(--content-h4-font-size-small-mobile-inner); }
}

/* ==================================== */
/* Theme Switcher Styles (using variables) */
/* ==================================== */
.theme-switcher {
    position: fixed;
    bottom: 10px;
    left: 10px;
    z-index: 1000;
}

.theme-switcher button {
    background-color: var(--theme-switcher-button-bg);
    color: var(--theme-switcher-button-color);
    border: var(--theme-switcher-button-border);
    border-radius: 50%;
    width: 30px;
    height: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    box-shadow: none;
    transition: all 0.3s ease;
    font-size: 1.2em;
    opacity: var(--theme-switcher-button-opacity);
    font-family: sans-serif;
}

.theme-switcher button:hover {
    background-color: var(--theme-switcher-button-hover-bg);
    color: var(--theme-switcher-button-hover-color);
    border: var(--theme-switcher-button-hover-border);
    box-shadow: var(--theme-switcher-button-hover-box-shadow);
    transform: var(--theme-switcher-button-hover-transform);
    opacity: 1;
}

.theme-switcher button span {
    display: block;
    line-height: 1;
}

@media screen and (max-width: 480px) {
    .theme-switcher {
        bottom: 5px;
        left: 5px;
    }
    .theme-switcher button {
        width: 25px;
        height: 25px;
        font-size: 1em;
    }
}