/*
Theme Name: Mitsune
Theme URI: https://github.com/mitsune
Author: Mitsune
Author URI: #
Description: Stable Diffusionプロンプト集・AIブログ向けクリーンモダンテーマ
Version: 1.0.0
Requires at least: 6.0
Tested up to: 6.5
Requires PHP: 8.0
License: GNU General Public License v2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: mitsune
Tags: blog, ai, clean, modern, responsive
*/

/* ===========================
   CSS Variables
   =========================== */
:root {
  --color-primary: #2563eb;
  --color-primary-light: #0ea5e9;
  --color-bg: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-header-bg: #0f172a;
  --color-header-text: #f8fafc;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --gradient-primary: linear-gradient(135deg, #0ea5e9, #2563eb);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.12);
  --shadow-hover: 0 8px 32px rgba(37,99,235,0.15);
  --radius: 10px;
  --font-sans: 'Inter', 'Noto Sans JP', sans-serif;
  --font-mono: 'Fira Code', 'Consolas', monospace;
}

/* ===========================
   Reset & Base
   =========================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-primary-light);
}

ul, ol {
  padding-left: 1.5em;
}

/* ===========================
   Layout
   =========================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.site-wrapper {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-main {
  flex: 1;
  padding: 2.5rem 0;
}

.content-area {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 2.5rem;
  align-items: start;
}

@media (max-width: 900px) {
  .content-area {
    grid-template-columns: 1fr;
  }
}

/* ===========================
   Header
   =========================== */
.site-header {
  background-color: var(--color-header-bg);
  color: var(--color-header-text);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 16px rgba(0,0,0,0.25);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.site-branding a {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}

.site-branding .custom-logo-link img,
.site-branding .custom-logo {
  max-height: 44px;
  max-width: 200px;
  width: auto;
  height: auto;
  display: block;
}

.site-title {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.site-tagline {
  font-size: 0.72rem;
  color: #94a3b8;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  display: block;
  margin-top: -2px;
}

/* ===========================
   Navigation
   =========================== */
.main-navigation ul {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.main-navigation a {
  color: #cbd5e1;
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.45rem 0.85rem;
  border-radius: 6px;
  transition: background 0.2s, color 0.2s;
  text-decoration: none;
}

.main-navigation a:hover,
.main-navigation .current-menu-item > a {
  background: rgba(14,165,233,0.15);
  color: var(--color-primary-light);
}

/* ===========================
   Hero / Archive Header
   =========================== */
.archive-header,
.page-header {
  background: var(--gradient-primary);
  color: #fff;
  padding: 3.5rem 1.5rem;
  text-align: center;
}

.archive-header h1,
.page-header h1 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.archive-header p,
.page-header p {
  font-size: 1rem;
  opacity: 0.85;
}

/* ===========================
   Post Grid
   =========================== */
.posts-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

@media (max-width: 900px) {
  .posts-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 560px) {
  .posts-grid {
    grid-template-columns: 1fr;
  }
}

/* ===========================
   Post Card
   =========================== */
.post-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
  display: flex;
  flex-direction: column;
}

.post-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}

.post-card-thumbnail {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16/9;
  background: var(--color-bg-secondary);
}

.post-card-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s;
}

.post-card:hover .post-card-thumbnail img {
  transform: scale(1.04);
}

.post-card-no-image {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  color: rgba(255,255,255,0.4);
  font-size: 2.5rem;
}

.post-card-body {
  padding: 1.15rem 1.2rem 1.4rem;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.category-badge {
  display: inline-block;
  background: var(--gradient-primary);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.2rem 0.65rem;
  border-radius: 999px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.post-date {
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

.post-card-title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--color-text);
  flex: 1;
}

.post-card-title a {
  color: inherit;
  text-decoration: none;
}

.post-card-title a:hover {
  color: var(--color-primary);
}

.post-card-excerpt {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.read-more {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-top: 0.25rem;
}

.read-more:hover {
  gap: 0.5rem;
}

/* ===========================
   Single Post
   =========================== */
.single-article {
  background: var(--color-bg);
  border-radius: var(--radius);
}

.single-header {
  margin-bottom: 2rem;
}

.single-thumbnail {
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 1.75rem;
  aspect-ratio: 16/6;
}

.single-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.single-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0.85rem;
}

.single-title {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: 1.5rem;
}

.single-divider {
  border: none;
  border-top: 2px solid var(--color-border);
  margin: 1.75rem 0;
}

/* ===========================
   Post Content
   =========================== */
.entry-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--color-text);
}

.entry-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 2.25rem 0 0.85rem;
  padding-left: 0.75rem;
  border-left: 4px solid var(--color-primary);
  color: var(--color-text);
}

.entry-content h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 1.75rem 0 0.65rem;
  color: var(--color-text);
}

.entry-content p {
  margin-bottom: 1.3rem;
}

.entry-content ul,
.entry-content ol {
  margin-bottom: 1.3rem;
}

.entry-content li {
  margin-bottom: 0.4rem;
}

.entry-content blockquote {
  border-left: 4px solid var(--color-primary-light);
  background: var(--color-bg-secondary);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--color-text-muted);
  font-style: italic;
}

/* ===========================
   Code & Prompt Blocks
   =========================== */
.entry-content code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: #1e293b;
  color: #7dd3fc;
  padding: 0.15em 0.45em;
  border-radius: 4px;
}

.entry-content pre {
  background: #0f172a;
  color: #e2e8f0;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.5rem 0;
  position: relative;
  border: 1px solid #1e293b;
}

.entry-content pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: inherit;
}

/* Prompt Block */
.prompt-block {
  background: #0f172a !important;
  border: 1px solid #0ea5e9 !important;
  border-left: 4px solid #0ea5e9 !important;
  color: #bfdbfe !important;
  font-family: var(--font-mono) !important;
  font-size: 0.9rem !important;
  padding: 1.25rem 1.5rem !important;
  border-radius: var(--radius) !important;
  margin: 1.75rem 0 !important;
  position: relative !important;
  overflow-x: auto !important;
  white-space: pre-wrap !important;
  word-break: break-word !important;
}

.prompt-block::before {
  content: "PROMPT";
  display: block;
  font-size: 0.65rem;
  font-weight: 700;
  color: #0ea5e9;
  letter-spacing: 0.1em;
  margin-bottom: 0.6rem;
  font-family: var(--font-sans);
}

.copy-btn {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  background: rgba(14,165,233,0.15);
  border: 1px solid rgba(14,165,233,0.4);
  color: #0ea5e9;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.2s;
  font-family: var(--font-sans);
}

.copy-btn:hover {
  background: rgba(14,165,233,0.3);
}

.copy-btn.copied {
  color: #22c55e;
  border-color: rgba(34,197,94,0.4);
  background: rgba(34,197,94,0.1);
}

/* ===========================
   Post Navigation
   =========================== */
.post-navigation {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.nav-previous,
.nav-next {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  transition: box-shadow 0.2s;
}

.nav-previous:hover,
.nav-next:hover {
  box-shadow: var(--shadow-md);
}

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

.nav-label {
  display: block;
  font-size: 0.72rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.nav-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-primary);
}

/* ===========================
   Sidebar
   =========================== */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.widget {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.widget-title {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin-bottom: 0.85rem;
  padding-bottom: 0.65rem;
  border-bottom: 2px solid var(--color-border);
}

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

.widget ul li {
  padding: 0.4rem 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.88rem;
}

.widget ul li:last-child {
  border-bottom: none;
}

.widget ul li a {
  color: var(--color-text);
  transition: color 0.2s;
}

.widget ul li a:hover {
  color: var(--color-primary);
}

/* ===========================
   Pagination
   =========================== */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.4rem;
  margin-top: 3rem;
  flex-wrap: wrap;
}

.pagination .page-numbers {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text);
  transition: all 0.2s;
  background: var(--color-bg);
}

.pagination .page-numbers:hover,
.pagination .page-numbers.current {
  background: var(--gradient-primary);
  color: #fff;
  border-color: transparent;
}

/* ===========================
   Footer
   =========================== */
.site-footer {
  background-color: var(--color-header-bg);
  color: #94a3b8;
  padding: 2.5rem 0 1.5rem;
  margin-top: 3rem;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  text-align: center;
}

.footer-logo {
  font-size: 1.4rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
  display: inline-block;
}

.footer-tagline {
  font-size: 0.82rem;
  color: #64748b;
  margin-bottom: 1.5rem;
}

.footer-nav ul {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
  flex-wrap: wrap;
}

.footer-nav a {
  color: #94a3b8;
  font-size: 0.85rem;
  transition: color 0.2s;
  text-decoration: none;
}

.footer-nav a:hover {
  color: var(--color-primary-light);
}

.footer-divider {
  border: none;
  border-top: 1px solid #1e293b;
  margin: 1.25rem 0;
}

.footer-copy {
  font-size: 0.8rem;
  color: #475569;
}

/* ===========================
   Page
   =========================== */
.page-article {
  background: var(--color-bg);
  border-radius: var(--radius);
}

.page-title {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  color: var(--color-text);
}

/* ===========================
   404
   =========================== */
.error-404 {
  text-align: center;
  padding: 5rem 1.5rem;
}

.error-404 .error-code {
  font-size: 7rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.error-404 h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--color-text);
}

.error-404 p {
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

.btn-primary {
  display: inline-block;
  background: var(--gradient-primary);
  color: #fff;
  font-weight: 700;
  padding: 0.75rem 2rem;
  border-radius: 8px;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.2s;
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
  color: #fff;
}

/* ===========================
   No Posts
   =========================== */
.no-results {
  text-align: center;
  padding: 4rem 1.5rem;
  color: var(--color-text-muted);
}

/* ===========================
   Breadcrumb
   =========================== */
.breadcrumb {
  margin: 0.5rem 0 1.75rem;
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.25rem;
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "›";
  margin-right: 0.25rem;
  color: var(--color-border);
}

.breadcrumb-item a {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

.breadcrumb-item a:hover {
  color: var(--color-primary);
}

.breadcrumb-item.current {
  color: var(--color-text);
  font-weight: 500;
  /* 長いタイトルをトリム */
  max-width: 30ch;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ===========================
   Related Posts
   =========================== */
.related-posts {
  margin-top: 3.5rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--color-border);
}

.related-posts-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.related-posts-title::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 1.1em;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.related-posts-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 700px) {
  .related-posts-grid {
    grid-template-columns: 1fr;
  }
}

.related-post-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
  background: var(--color-bg);
}

.related-post-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.related-post-link {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  height: 100%;
}

.related-post-thumbnail {
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--color-bg-secondary);
}

.related-post-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s;
}

.related-post-card:hover .related-post-thumbnail img {
  transform: scale(1.04);
}

.related-post-no-image {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  color: rgba(255,255,255,0.4);
  font-size: 2rem;
}

.related-post-body {
  padding: 0.85rem 1rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  flex: 1;
}

.related-post-title {
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--color-text);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.related-post-card:hover .related-post-title {
  color: var(--color-primary);
}

/* ===========================
   Responsive Utilities
   =========================== */
@media (max-width: 560px) {
  .single-title {
    font-size: 1.5rem;
  }

  .post-navigation {
    grid-template-columns: 1fr;
  }
}

/* ===========================
   Hero Section
   =========================== */
.hero {
  position: relative;
  background: #0f172a;
  overflow: hidden;
  padding: 100px 0 80px;
  text-align: center;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(37,99,235,0.25) 0%, transparent 70%),
              radial-gradient(ellipse 50% 40% at 80% 100%, rgba(14,165,233,0.15) 0%, transparent 60%);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 700px;
  margin: 0 auto;
  padding: 0 1.5rem;
}
.hero-badge {
  display: inline-block;
  background: rgba(37,99,235,0.2);
  border: 1px solid rgba(37,99,235,0.4);
  color: #60a5fa;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.35rem 1rem;
  border-radius: 999px;
  margin-bottom: 1.5rem;
}
.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800;
  color: #f8fafc;
  line-height: 1.15;
  margin: 0 0 1.25rem;
}
.hero-title-accent {
  background: linear-gradient(135deg, #0ea5e9, #2563eb);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 1.1rem;
  color: #94a3b8;
  line-height: 1.8;
  margin: 0 0 2rem;
}
.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}
.btn-hero-primary {
  background: linear-gradient(135deg, #0ea5e9, #2563eb);
  color: #fff;
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.2s;
}
.btn-hero-primary:hover { opacity: 0.9; transform: translateY(-2px); }
.btn-hero-secondary {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  color: #e2e8f0;
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  transition: background 0.2s;
}
.btn-hero-secondary:hover { background: rgba(255,255,255,0.13); }

/* ===========================
   Category Feature Grid
   =========================== */
.category-feature {
  padding: 3rem 0;
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
}
.section-title {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-text);
  margin: 0 0 1.5rem;
}
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}
.section-more {
  font-size: 0.9rem;
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
}
.section-more:hover { text-decoration: underline; }
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1rem;
}
.category-grid ul { list-style: none; padding: 0; margin: 0; display: contents; }
.category-grid li { list-style: none; }
.category-grid li a {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.25rem 1rem;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 600;
  font-size: 0.9rem;
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
  text-align: center;
}
.category-grid li a:hover {
  border-color: var(--color-primary);
  box-shadow: 0 4px 16px rgba(37,99,235,0.12);
  transform: translateY(-2px);
}

/* ===========================
   Post Card Enhanced
   =========================== */
.post-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 14px;
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
  display: flex;
  flex-direction: column;
}
.post-card:hover {
  box-shadow: 0 8px 32px rgba(15,23,42,0.12);
  transform: translateY(-4px);
}
.post-card-thumbnail {
  overflow: hidden;
  aspect-ratio: 16/9;
  background: #0f172a;
}
.post-card-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.post-card:hover .post-card-thumbnail img { transform: scale(1.05); }
.post-card-no-image {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  font-size: 2rem;
  color: #334155;
  background: linear-gradient(135deg, #0f172a, #1e293b);
  text-decoration: none;
}
.post-card-body { padding: 1.25rem; flex: 1; display: flex; flex-direction: column; }
.post-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.5;
  margin: 0.5rem 0;
}
.post-card-title a { color: var(--color-text); text-decoration: none; }
.post-card-title a:hover { color: var(--color-primary); }
.post-card-excerpt { font-size: 0.875rem; color: var(--color-text-muted); flex: 1; }

/* ===========================
   Footer 3-Column
   =========================== */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 3rem 0 1.5rem;
  margin-top: 4rem;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}
.footer-cols {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}
@media (max-width: 640px) {
  .footer-cols { grid-template-columns: 1fr; }
}
.footer-col-title {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #e2e8f0;
  margin: 0 0 1rem;
}
.footer-logo {
  font-size: 1.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, #0ea5e9, #2563eb);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.75rem;
}
.footer-cols ul { list-style: none; padding: 0; margin: 0; }
.footer-cols ul li a { color: #94a3b8; text-decoration: none; font-size: 0.875rem; }
.footer-cols ul li a:hover { color: #e2e8f0; }

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

/* タブレット（〜768px） */
@media (max-width: 768px) {
  /* ヘッダー：縦積み */
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
  }
  .main-navigation ul {
    flex-wrap: wrap;
    gap: 0.5rem;
  }

  /* ヒーロー */
  .hero { padding: 60px 0 50px; }
  .hero-title { font-size: 2rem; }
  .hero-actions { flex-direction: column; align-items: center; }
  .btn-hero-primary, .btn-hero-secondary { width: 100%; max-width: 280px; text-align: center; }

  /* 記事グリッド：2列 */
  .posts-grid { grid-template-columns: repeat(2, 1fr); }

  /* サイドバー：下に */
  .content-area { flex-direction: column; }
  .sidebar { width: 100%; }

  /* 記事ページ */
  .single-title { font-size: 1.5rem; }
}

/* スマホ（〜480px） */
@media (max-width: 480px) {
  .container { padding: 0 1rem; }

  /* ヒーロー */
  .hero { padding: 48px 0 40px; }
  .hero-title { font-size: 1.6rem; }
  .hero-badge { font-size: 0.7rem; }

  /* 記事グリッド：1列 */
  .posts-grid { grid-template-columns: 1fr; }

  /* カテゴリグリッド */
  .category-grid { grid-template-columns: repeat(2, 1fr); }

  /* ナビ非表示（ハンバーガー未実装のため） */
  .main-navigation { display: none; }

  /* フッター */
  .footer-cols { grid-template-columns: 1fr; gap: 1.5rem; }

  /* 関連記事 */
  .related-posts-grid { grid-template-columns: 1fr; }

  /* パンくず */
  .breadcrumb { font-size: 0.75rem; }
  
  /* コピーボタン */
  .copy-btn { font-size: 0.7rem; padding: 0.2rem 0.5rem; }
}

/* ===========================
   プロンプト集スタイル
   =========================== */
.prompt-list {
  margin: 0;
  padding: 0;
}
.prompt-entry {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--color-border);
  flex-wrap: wrap;
}
.prompt-entry:last-child { border-bottom: none; }
.prompt-entry-ja {
  flex: 1;
  min-width: 200px;
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.6;
}
.prompt-entry-ja .note {
  display: block;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-top: 0.2rem;
}
.prompt-entry-en {
  position: relative;
  background: #0f172a;
  color: #e2e8f0;
  padding: 0.4rem 9rem 0.4rem 0.75rem;
  border-radius: 6px;
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 0.9rem;
  white-space: nowrap;
  min-width: 180px;
}
.copy-btn {
  position: absolute;
  top: 50%;
  right: 0.4rem;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  color: #cbd5e1;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  font-size: 0.7rem;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}
.copy-btn:hover { background: rgba(255,255,255,0.22); }
.copy-btn.copied { color: #4ade80; }

/* 旧prompt-block互換（記事1等で使用） */
pre.prompt-block {
  position: relative;
  background: #0f172a;
  color: #e2e8f0;
  padding: 0.75rem 1rem 0.75rem 1rem;
  padding-right: 9rem;
  border-radius: 8px;
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 0.9rem;
  margin: 0.5rem 0;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
}