/* ==========================================================================
   Blog Stylesheet - Light Yield Co., Ltd.
   ========================================================================== */

/* --- Global Smooth Scroll --- */
html {
  scroll-behavior: smooth;
}

/* --- Navigation Header for Subpages (Logo Only, Left Aligned) --- */
.site_header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(44, 62, 80, 0.98);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.site_header .header_inner {
  max-width: 100%;
  padding: 16px 50px;
  display: flex;
  align-items: center;
}

.header_brand {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.header_brand:hover {
  opacity: 0.85;
  transform: scale(1.02);
}

.header_brand svg {
  width: 44px;
  height: auto;
}

/* --- Breadcrumbs (Left Aligned) --- */
.breadcrumb_container {
  background-color: var(--bg-light);
  border-bottom: 1px solid #eee;
  padding: 12px 50px;
  font-size: 0.85rem;
}

.breadcrumb_inner {
  max-width: 100%;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
}

.breadcrumb_inner a {
  color: var(--accent-color);
  text-decoration: none;
}

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

.breadcrumb_separator {
  color: #bbb;
  font-size: 0.75rem;
}

/* --- Blog Post Article Layout --- */
.blog_main {
  padding: 50px 20px 90px;
  background-color: #fff;
}

.article_container {
  max-width: 800px;
  margin: 0 auto;
}

.article_header {
  margin-bottom: 35px;
}

.article_meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.article_date {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.article_category {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background-color: #edf2f7;
  color: var(--accent-color);
  padding: 3px 10px;
  border-radius: 4px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.article_title {
  font-size: clamp(1.75rem, 4vw, 2.3rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--main-color);
  margin-bottom: 15px;
}

/* --- Table of Contents (TOC) --- */
.article_toc {
  background-color: #f8fafc;
  border: 1px solid #e2e8f0;
  border-left: 4px solid var(--accent-color);
  border-radius: 6px;
  padding: 24px 28px;
  margin: 30px 0 45px;
}

.toc_title {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  color: var(--main-color);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  letter-spacing: 0.05em;
}

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

.toc_list li {
  margin-bottom: 8px;
  font-size: 0.95rem;
}

.toc_list li a {
  color: var(--main-color);
  text-decoration: none;
  transition: color 0.15s ease;
  display: inline-block;
}

.toc_list li a:hover {
  color: var(--accent-color);
  text-decoration: underline;
}

/* --- Article Body Content --- */
.article_body {
  font-size: 1.05rem;
  line-height: 1.95;
  color: #2d3748;
}

.article_body p {
  margin-bottom: 28px;
}

.article_body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--main-color);
  margin: 55px 0 25px;
  padding-bottom: 12px;
  border-bottom: 2px solid #e2e8f0;
  position: relative;
  scroll-margin-top: 85px;
}

.article_body h2::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 50px;
  height: 2px;
  background-color: var(--accent-color);
}

.article_body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--main-color);
  margin: 35px 0 18px;
}

.article_body blockquote {
  background-color: #f8fafc;
  border-left: 4px solid #cbd5e1;
  padding: 18px 24px;
  margin: 30px 0;
  border-radius: 0 6px 6px 0;
  color: #475569;
  font-size: 0.98rem;
}

.article_body blockquote p:last-child {
  margin-bottom: 0;
}

.article_body strong {
  font-weight: 700;
  color: inherit;
}

.article_body a {
  color: var(--accent-color);
  text-decoration: underline;
}

.article_body a:hover {
  color: var(--main-color);
}

.article_body hr {
  border: 0;
  border-top: 1px solid #e2e8f0;
  margin: 50px 0;
}

/* 記事内図表 */
.article_figure {
  margin: 40px 0;
  text-align: center;
}

.article_figure img {
  width: auto;
  max-width: 480px;
  height: auto;
  border-radius: 6px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.07);
  border: 1px solid #e2e8f0;
  display: inline-block;
  cursor: zoom-in;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.article_figure img:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

/* 図1（タスク洗い出しリスト）専用のコンパクト表示 */
.article_figure.figure_sm img {
  max-width: 320px;
}

.article_figure figcaption {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 10px;
  font-style: italic;
}

/* --- Image Modal / Lightbox --- */
.image_modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(15, 23, 42, 0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 2000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 30px 20px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s ease;
  cursor: zoom-out;
}

.image_modal.is_active {
  opacity: 1;
  visibility: visible;
}

.image_modal_inner {
  max-width: 95vw;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  cursor: default;
}

.image_modal_img {
  max-width: 92vw;
  max-height: 82vh;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: 6px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
  background: #fff;
  cursor: zoom-out;
  transform: scale(0.95);
  transition: transform 0.25s ease;
}

.image_modal.is_active .image_modal_img {
  transform: scale(1);
}

.image_modal_caption {
  margin-top: 14px;
  color: #f1f5f9;
  font-size: 0.95rem;
  text-align: center;
  max-width: 800px;
  line-height: 1.5;
  font-family: var(--font-main);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.8);
}

.image_modal_close {
  position: absolute;
  top: 20px;
  right: 24px;
  width: 44px;
  height: 44px;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  color: #fff;
  font-size: 24px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease;
  z-index: 2010;
}

.image_modal_close:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.08);
}

/* --- Article Author --- */
.article_author {
  margin: 40px 0 20px;
  padding: 16px 22px;
  background-color: #f8fafc;
  border: 1px solid #e2e8f0;
  border-left: 4px solid var(--accent-color);
  border-radius: 6px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.author_label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
}

.author_name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--main-color);
}

/* --- Post Footer Actions --- */
.article_footer_nav {
  margin-top: 50px;
  display: flex;
  justify-content: flex-start;
  align-items: center;
}

.btn_back_list {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--main-color);
  background-color: #fff;
  border: 1px solid var(--main-color);
  padding: 10px 24px;
  border-radius: 4px;
  text-decoration: none;
  transition: all 0.2s ease;
}

.btn_back_list:hover {
  background-color: var(--main-color);
  color: #fff;
}

/* --- Blog List Page & Top Page Blog Cards --- */
.blog_grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 30px;
}

.blog_card {
  background: #fff;
  border-radius: 8px;
  border: 1px solid #e2e8f0;
  border-top: 3px solid var(--accent-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
}

.blog_card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
  border-top-color: var(--main-color);
}

.blog_card_body {
  padding: 28px 26px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.blog_card_meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.blog_card_date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.blog_card_tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  background-color: #edf2f7;
  color: var(--accent-color);
  padding: 2px 8px;
  border-radius: 3px;
  font-weight: 700;
}

.blog_card_title {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--main-color);
  margin-bottom: 14px;
}

.blog_card_excerpt {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.blog_card_more {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-color);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap 0.2s ease;
}

.blog_card:hover .blog_card_more {
  gap: 8px;
}

.blog_section_footer {
  margin-top: 65px;
  text-align: center;
}

.btn_view_all {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  background-color: var(--main-color);
  padding: 12px 32px;
  border-radius: 4px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.btn_view_all:hover {
  background-color: var(--accent-color);
  transform: translateY(-2px);
}

/* --- Section Lead & Category Block Styles --- */
.section_lead {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.7;
  max-width: 640px;
  margin: -35px auto 45px;
}

.category_block {
  margin-bottom: 70px;
}

.category_block:last-child {
  margin-bottom: 0;
}

.category_block_header {
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 2px solid #e2e8f0;
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.category_block_title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--main-color);
  margin: 0;
}

.category_block_en {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-color);
  font-weight: 700;
  letter-spacing: 0.05em;
}

.category_block_desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-top: 0;
  margin-bottom: 28px;
}

.blog_card_tag.tag_peek {
  background-color: rgba(30, 144, 255, 0.12);
  color: #0066cc;
}

/* --- Responsive Adjustments --- */
@media (max-width: 768px) {
  .site_header .header_inner {
    padding: 12px 20px;
  }

  .breadcrumb_container {
    padding: 12px 20px;
  }
  
  .header_brand svg {
    width: 38px;
  }
  
  .blog_main {
    padding: 35px 15px 60px;
  }
  
  .article_title {
    font-size: 1.55rem;
  }
  
  .article_body {
    font-size: 1rem;
    line-height: 1.85;
  }
  
  .article_body h2 {
    font-size: 1.25rem;
    margin: 40px 0 20px;
  }

  .article_figure img,
  .article_figure.figure_sm img {
    width: 100%;
    max-width: 100%;
  }

  .blog_card_body {
    padding: 22px 20px;
  }

  .section_lead {
    font-size: 0.9rem;
    margin: -25px auto 35px;
    padding: 0 10px;
  }

  .category_block_header {
    flex-direction: column;
    gap: 4px;
    align-items: flex-start;
  }

  .category_block_title {
    font-size: 1.25rem;
  }

  .article_author {
    padding: 12px 16px;
    gap: 10px;
  }

  .author_name {
    font-size: 0.98rem;
  }
}