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

:root {
  --color-primary:    #3AAFA9;
  --color-primary-dk: #2B7A78;
  --color-accent:     #FBBF24;
  --color-bg:         #F7FBFC;
  --color-surface:    #FFFFFF;
  --color-border:     #DEF0F0;
  --color-text:       #2D3748;
  --color-muted:      #718096;
  --color-tag-bg:     #E6F6F5;
  --color-tag-text:   #2B7A78;

  --font-base: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  --font-heading: "Noto Serif JP", "Hiragino Mincho ProN", serif;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --shadow-card: 0 2px 12px rgba(58, 175, 169, 0.10);
  --shadow-hover: 0 6px 24px rgba(58, 175, 169, 0.18);

  --max-width: 1310px;
  --content-width: 860px;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-base);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.8;
  font-size: 16px;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ===========================
   Header
=========================== */
.site-header {
  background: var(--color-surface);
  border-bottom: 2px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dk));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
}

.logo-text {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-primary-dk);
  letter-spacing: 0.03em;
}

.logo-sub {
  font-size: 0.65rem;
  color: var(--color-muted);
  display: block;
  letter-spacing: 0.05em;
  margin-top: -2px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  padding: 6px 11px;
  border-radius: var(--radius-sm);
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--color-text);
  transition: background 0.2s, color 0.2s;
  white-space: nowrap;
}

.site-nav a:hover,
.site-nav a.active {
  background: var(--color-tag-bg);
  color: var(--color-primary-dk);
}

.nav-cta {
  background: var(--color-primary) !important;
  color: #fff !important;
  border-radius: var(--radius-sm) !important;
}

.nav-cta:hover {
  background: var(--color-primary-dk) !important;
  color: #fff !important;
}

/* ===========================
   Hero
=========================== */
.hero {
  background: linear-gradient(135deg, #EAF8F7 0%, #F0FFFE 40%, #FFF8ED 100%);
  padding: 48px 32px 56px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -80px; right: -80px;
  width: 320px; height: 320px;
  background: radial-gradient(circle, rgba(58,175,169,0.12) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -60px; left: -60px;
  width: 260px; height: 260px;
  background: radial-gradient(circle, rgba(251,191,36,0.10) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(58,175,169,0.12);
  color: var(--color-primary-dk);
  border: 1px solid rgba(58,175,169,0.3);
  border-radius: 100px;
  padding: 4px 14px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 20px;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1.4;
  color: var(--color-text);
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}

.hero-title em {
  font-style: normal;
  color: var(--color-primary);
}

.hero-desc {
  font-size: 1rem;
  color: var(--color-muted);
  max-width: 500px;
  margin: 0 auto 32px;
  line-height: 1.9;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-primary);
  font-family: var(--font-heading);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--color-muted);
  letter-spacing: 0.05em;
}

/* ===========================
   Category Bar
=========================== */
.category-bar {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.category-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  gap: 4px;
  height: 48px;
  align-items: center;
  white-space: nowrap;
}

.cat-btn {
  padding: 5px 16px;
  border-radius: 100px;
  font-size: 0.82rem;
  font-weight: 500;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: all 0.2s;
  background: transparent;
  color: var(--color-muted);
}

.cat-btn:hover {
  background: var(--color-tag-bg);
  color: var(--color-primary-dk);
}

.cat-btn.active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* ===========================
   Main Layout
=========================== */
.main-layout {
  max-width: var(--max-width);
  margin: 32px auto;
  padding: 0 32px;
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  align-items: start;
}

/* ===========================
   Post Grid
=========================== */
.section-heading {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
}

.section-heading h2 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text);
}

.section-heading .divider {
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

/* Featured Post */
.featured-post {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  margin-bottom: 20px;
  display: grid;
  grid-template-columns: 200px 1fr;
  transition: box-shadow 0.25s, transform 0.25s;
  cursor: pointer;
}

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

.featured-thumb {
  background: linear-gradient(135deg, #3AAFA9 0%, #2B7A78 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.8rem;
  min-height: 120px;
}

.featured-content {
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.post-category {
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 100px;
  letter-spacing: 0.04em;
}

.post-date {
  font-size: 0.75rem;
  color: var(--color-muted);
}

.featured-badge {
  background: var(--color-accent);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 100px;
  letter-spacing: 0.05em;
}

.featured-content h2 {
  font-family: var(--font-heading);
  font-size: 1rem;
  line-height: 1.5;
  margin-bottom: 6px;
  color: var(--color-text);
}

.featured-content p {
  font-size: 0.82rem;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 10px;
}

.read-more {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--color-primary);
  font-size: 0.85rem;
  font-weight: 600;
}

.read-more::after {
  content: "→";
  transition: transform 0.2s;
}

.featured-post:hover .read-more::after {
  transform: translateX(4px);
}

/* Post Grid */
.posts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 14px;
}

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

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

.card-thumb {
  aspect-ratio: 16/7;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
}

.card-thumb.teal    { background: linear-gradient(135deg, #EAF8F7, #C8EEEC); }
.card-thumb.green   { background: linear-gradient(135deg, #F0FDF4, #C6F6D5); }
.card-thumb.amber   { background: linear-gradient(135deg, #FFFBEB, #FDE68A); }
.card-thumb.blue    { background: linear-gradient(135deg, #EFF6FF, #BFDBFE); }
.card-thumb.rose    { background: linear-gradient(135deg, #FFF1F2, #FECDD3); }
.card-thumb.purple  { background: linear-gradient(135deg, #FAF5FF, #E9D5FF); }

.card-body {
  padding: 10px 12px;
}

.card-body h3 {
  font-family: var(--font-heading);
  font-size: 0.82rem;
  line-height: 1.5;
  margin-bottom: 4px;
  color: var(--color-text);
}

.card-footer {
  padding: 0 12px 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.read-time {
  font-size: 0.72rem;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ===========================
   Sidebar
=========================== */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
  position: sticky;
  top: 80px;
}

.sidebar-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 22px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--color-border);
}

.sidebar-card h3 {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-border);
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Profile */
.profile-avatar {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  margin: 0 auto 12px;
  overflow: hidden;
}

.profile-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.profile-name {
  text-align: center;
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.profile-title {
  text-align: center;
  font-size: 0.78rem;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.profile-bio {
  font-size: 0.82rem;
  color: var(--color-muted);
  line-height: 1.8;
  text-align: left;
}

/* Newsletter */
.newsletter-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.newsletter-desc {
  font-size: 0.82rem;
  color: var(--color-muted);
  line-height: 1.7;
}

.newsletter-form input[type="email"] {
  width: 100%;
  padding: 9px 12px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-family: var(--font-base);
  outline: none;
  transition: border-color 0.2s;
}

.newsletter-form input[type="email"]:focus {
  border-color: var(--color-primary);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
  font-family: var(--font-base);
  width: 100%;
}

.btn-primary:hover { background: var(--color-primary-dk); }

/* Tags */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  font-size: 0.78rem;
  padding: 4px 12px;
  border-radius: 100px;
  border: 1px solid rgba(58,175,169,0.2);
  cursor: pointer;
  transition: all 0.2s;
}

.tag:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* Popular posts */
.popular-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.popular-item {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  cursor: pointer;
}

.popular-rank {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-border);
  min-width: 24px;
  font-family: var(--font-heading);
  line-height: 1.3;
}

.popular-rank.gold   { color: #FBBF24; }
.popular-rank.silver { color: #9CA3AF; }
.popular-rank.bronze { color: #D97706; }

.popular-title {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--color-text);
}

.popular-item:hover .popular-title { color: var(--color-primary); }

/* ===========================
   Load More
=========================== */
.load-more {
  text-align: center;
  margin-top: 32px;
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
  background: transparent;
  border-radius: 100px;
  padding: 10px 32px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-base);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: #fff;
}

/* ===========================
   Footer
=========================== */
.site-footer {
  background: var(--color-text);
  color: rgba(255,255,255,0.75);
  margin-top: 80px;
}

.footer-top {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 32px 40px;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand .logo-text { color: #fff; }
.footer-brand .logo-sub  { color: rgba(255,255,255,0.5); }

.footer-tagline {
  font-size: 0.82rem;
  margin-top: 12px;
  line-height: 1.8;
  color: rgba(255,255,255,0.55);
}

.footer-col h4 {
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: 0.05em;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col ul li a {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.55);
  transition: color 0.2s;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
}

.footer-bottom-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.4);
}

/* ===========================
   Single Post Page
=========================== */
.post-hero {
  background: linear-gradient(135deg, #EAF8F7 0%, #F7FBFC 100%);
  padding: 48px 24px 0;
  text-align: center;
}

.post-hero-inner {
  max-width: var(--content-width);
  margin: 0 auto;
}

.post-hero .post-meta {
  justify-content: center;
  margin-bottom: 16px;
}

.post-hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.5;
  color: var(--color-text);
  margin-bottom: 16px;
}

.post-hero-thumb {
  max-width: 600px;
  margin: 32px auto 0;
  aspect-ratio: 2/1;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dk) 100%);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 6rem;
}

.post-layout {
  max-width: var(--max-width);
  margin: 32px auto;
  padding: 0 32px;
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 48px;
  align-items: start;
}

.post-content {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 40px 44px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--color-border);
}

.post-content h2 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  margin: 36px 0 14px;
  color: var(--color-text);
  padding-left: 14px;
  border-left: 4px solid var(--color-primary);
}

.post-content h3 {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  margin: 28px 0 10px;
  color: var(--color-text);
}

.post-content p {
  font-size: 0.95rem;
  line-height: 2;
  margin-bottom: 18px;
  color: var(--color-text);
}

.post-content ul, .post-content ol {
  margin: 0 0 18px 1.5em;
}

.post-content li {
  font-size: 0.95rem;
  line-height: 1.9;
  margin-bottom: 6px;
}

.post-content blockquote {
  background: var(--color-tag-bg);
  border-left: 4px solid var(--color-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px;
  margin: 20px 0;
  color: var(--color-primary-dk);
  font-size: 0.92rem;
  line-height: 1.9;
}

.post-content .tip-box {
  background: #FFFBEB;
  border: 1.5px solid #FDE68A;
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin: 20px 0;
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 0.9rem;
  line-height: 1.8;
}

.tip-icon { font-size: 1.2rem; flex-shrink: 0; margin-top: 2px; }

/* ===========================
   Table of Contents (TOC)
=========================== */
.toc-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--color-border);
  position: sticky;
  top: 80px;
}

.toc-card h3 {
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 6px;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toc-list a {
  display: block;
  font-size: 0.82rem;
  color: var(--color-muted);
  padding: 5px 8px;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: all 0.2s;
  line-height: 1.5;
}

.toc-list a:hover,
.toc-list a.active {
  color: var(--color-primary-dk);
  background: var(--color-tag-bg);
  border-left-color: var(--color-primary);
}

/* ===========================
   Responsive
=========================== */
@media (max-width: 900px) {
  .main-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .footer-top { grid-template-columns: 1fr 1fr; }
  .featured-post { grid-template-columns: 1fr; }
  .post-layout { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .header-inner { gap: 12px; padding: 0 16px; }
  .site-nav a:not(.nav-cta) { display: none; }
  .posts-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { gap: 20px; }
  .footer-top { grid-template-columns: 1fr; gap: 24px; padding: 32px 16px 24px; }
  .footer-bottom-inner { flex-direction: column; gap: 8px; text-align: center; padding: 16px; }
  .post-content { padding: 24px 20px; }
  .logo-text { font-size: 1rem; }
  .main-layout { padding: 0 16px; }
  .post-layout { padding: 0 16px; }
  .hero { padding: 48px 16px 56px; }
}