:root {
  --frog-green: #2d6a4f;
  --frog-light: #95d5b2;
  --frog-bg: #f0f7f4;
  --frog-accent: #1b4332;
  --frog-warm: #d8f3dc;
  --text-dark: #1a1a2e;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--frog-bg);
  color: var(--text-dark);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  background-image:
    radial-gradient(circle at 10% 90%, rgba(45, 106, 79, 0.06) 0%, transparent 50%),
    radial-gradient(circle at 90% 10%, rgba(149, 213, 178, 0.08) 0%, transparent 50%);
}

.container {
  max-width: 720px;
  width: 100%;
  padding: 2rem 1.5rem;
}

.back-link {
  display: inline-block;
  margin-bottom: 1rem;
  color: var(--frog-green);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}
.back-link:hover { text-decoration: underline; }

/* Blog Header */
.blog-header {
  text-align: center;
  padding: 2.5rem 1rem 2rem;
  background: white;
  border-radius: 20px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}
.blog-header::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--frog-green), var(--frog-light), var(--frog-green));
}
.blog-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--frog-accent);
  margin-bottom: 0.25rem;
}
.blog-subtitle {
  font-size: 1rem;
  color: var(--frog-green);
  font-weight: 500;
}
.blog-desc {
  font-size: 0.9rem;
  color: #6b7280;
  line-height: 1.6;
  max-width: 500px;
  margin: 1rem auto 0;
}

/* Post Card */
.post-card {
  background: white;
  border-radius: 16px;
  padding: 1.5rem 1.75rem;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
  margin-bottom: 1.25rem;
  border: 1px solid rgba(149, 213, 178, 0.3);
  transition: transform 0.15s, box-shadow 0.15s;
  display: block;
  text-decoration: none;
  color: inherit;
}
.post-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: #9ca3af;
  margin-bottom: 0.5rem;
}
.post-tag {
  background: var(--frog-warm);
  color: var(--frog-green);
  padding: 0.15rem 0.6rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.post-title {
  font-size: 1.2rem;
  color: var(--frog-accent);
  margin-bottom: 0.4rem;
  line-height: 1.3;
}
.post-excerpt {
  font-size: 0.9rem;
  color: #6b7280;
  line-height: 1.6;
}
.read-more {
  display: inline-block;
  margin-top: 0.6rem;
  color: var(--frog-green);
  font-weight: 600;
  font-size: 0.85rem;
}

.coming-soon {
  background: white;
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
  border: 1px dashed rgba(149, 213, 178, 0.5);
  text-align: center;
  color: #9ca3af;
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ── Post Article Styles ── */
article {
  background: white;
  border-radius: 20px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}
article::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--frog-green), var(--frog-light), var(--frog-green));
}

.article-header {
  padding: 2.5rem 2rem 1.5rem;
  text-align: center;
  border-bottom: 1px solid rgba(149, 213, 178, 0.2);
}
.article-header h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--frog-accent);
  line-height: 1.3;
  margin-bottom: 1rem;
}
.article-header .byline {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  color: #6b7280;
}
.article-header .byline .avatar-sm {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--frog-light);
}
.article-header .byline .author-name {
  font-weight: 600;
  color: var(--frog-accent);
}

.article-body {
  padding: 2rem;
  font-size: 1.05rem;
  line-height: 1.8;
  color: #374151;
}
.article-body h2 {
  font-size: 1.4rem;
  color: var(--frog-accent);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid rgba(149, 213, 178, 0.3);
}
.article-body h3 {
  font-size: 1.15rem;
  color: var(--frog-green);
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}
.article-body p {
  margin-bottom: 1rem;
}
.article-body ul, .article-body ol {
  margin: 0.5rem 0 1rem 1.5rem;
}
.article-body li {
  margin-bottom: 0.4rem;
}
.article-body code {
  background: #e8f5e9;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: 'JetBrains Mono', 'Cascadia Code', monospace;
}
.article-body pre {
  background: #1b4332;
  color: #d8f3dc;
  padding: 1rem 1.25rem;
  border-radius: 10px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
  margin: 1rem 0 1.5rem;
  font-family: 'JetBrains Mono', 'Cascadia Code', monospace;
}
.article-body pre code {
  background: transparent;
  padding: 0;
  color: inherit;
  font-size: inherit;
}
.article-body blockquote {
  border-left: 3px solid var(--frog-green);
  background: var(--frog-bg);
  padding: 0.75rem 1.25rem;
  margin: 1rem 0 1.5rem;
  border-radius: 0 10px 10px 0;
  font-style: italic;
  color: #555;
}
.article-body blockquote cite {
  display: block;
  margin-top: 0.4rem;
  font-style: normal;
  font-size: 0.85rem;
  color: var(--frog-green);
}
.article-body .notebook-note {
  background: #fefce8;
  border: 1px dashed #eab308;
  border-radius: 10px;
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  color: #92400e;
  margin: 1rem 0;
}
.article-body .notebook-note strong { color: #713f12; }
.article-body .frog-diagram {
  margin: 1.5rem 0;
  text-align: center;
}
.article-body .frog-diagram svg {
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  background: #fafcfb;
  padding: 0.5rem;
}

.article-footer {
  padding: 1.5rem 2rem;
  border-top: 1px solid rgba(149, 213, 178, 0.2);
  text-align: center;
  font-size: 0.85rem;
  color: #9ca3af;
}
.article-footer .tags {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.75rem;
}
.article-footer .tags span {
  background: var(--frog-warm);
  color: var(--frog-green);
  padding: 0.2rem 0.7rem;
  border-radius: 10px;
  font-size: 0.75rem;
  font-weight: 500;
}

footer {
  text-align: center;
  padding: 2rem 0 1rem;
  color: #9ca3af;
  font-size: 0.8rem;
}
footer span { color: var(--frog-green); }
footer a { color: var(--frog-green); text-decoration: none; border-bottom: 2px solid var(--frog-light); }

@media (max-width: 600px) {
  .container { padding: 1rem 0.75rem; }
  .blog-header { padding: 1.5rem 0.75rem; }
  .blog-header h1 { font-size: 1.3rem; }
  .post-card { padding: 1rem; }
  .article-header { padding: 1.5rem 1rem; }
  .article-header h1 { font-size: 1.4rem; }
  .article-body { padding: 1.25rem; font-size: 0.95rem; }
  .article-footer { padding: 1rem; }
}