:root {
  --bg-deep: #f8fafc;
  --bg-main: #ffffff;
  --bg-card: #f1f5f9;
  --indigo: #6366f1;
  --indigo-light: #4f46e5;
  --text: #4b5563;
  --text-dim: #64748b;
  --text-bright: #111827;
  --border: #e2e8f0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  background: var(--bg-deep);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Nav */
nav {
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-main);
}

.nav-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--text-bright);
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  gap: 20px;
  list-style: none;
  margin-left: auto;
}

.nav-links a {
  font-size: 0.875rem;
  color: var(--text-dim);
  text-decoration: none;
  font-weight: 500;
}

.nav-links a:hover {
  color: var(--text-bright);
}

/* Header */
header {
  padding: 80px 0 40px;
  text-align: center;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-bottom: 16px;
}

.logo-text {
  font-size: 3rem;
  font-weight: 800;
  color: var(--text-bright);
  letter-spacing: -0.03em;
}

.tagline {
  font-size: 1.25rem;
  color: var(--text-dim);
  max-width: 480px;
  margin: 0 auto;
}

/* Hero section */
.hero {
  padding: 40px 0;
  text-align: center;
}

.hero p {
  font-size: 1.05rem;
  color: var(--text);
  max-width: 560px;
  margin: 0 auto 32px;
}

.cta-group {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.15s ease;
}

.btn-primary {
  background: var(--indigo);
  color: white;
}

.btn-primary:hover {
  background: #818cf8;
}

.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--text-dim);
  color: var(--text-bright);
}

/* Quickstart */
.quickstart {
  margin: 48px 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.quickstart-header {
  padding: 12px 20px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.quickstart pre {
  padding: 20px;
  font-family: 'SF Mono', 'Fira Code', 'Fira Mono', Menlo, monospace;
  font-size: 0.9rem;
  line-height: 1.8;
  overflow-x: auto;
  color: var(--text-bright);
}

.quickstart .comment { color: #9ca3af; }
.quickstart .cmd { color: var(--indigo); }

/* Features */
.features {
  padding: 48px 0;
}

.features h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 32px;
  text-align: center;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

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

.feature {
  padding: 20px;
  background: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.feature h3 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 6px;
}

.feature p {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.5;
}

/* The Insight */
.insight {
  padding: 48px 0;
  text-align: center;
}

.insight blockquote {
  font-size: 1.2rem;
  color: var(--text-bright);
  font-style: italic;
  max-width: 480px;
  margin: 0 auto;
  padding: 24px;
  border-left: 3px solid var(--indigo);
  text-align: left;
  background: #eef2ff;
  border-radius: 0 8px 8px 0;
}

/* Roadmap */
.roadmap {
  padding: 48px 0;
}

.roadmap h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 24px;
  text-align: center;
}

.step-list {
  list-style: none;
  position: relative;
}

.step-list::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
}

.step {
  display: flex;
  gap: 16px;
  padding: 12px 0;
  position: relative;
}

.step-dot {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 700;
}

.step-done .step-dot {
  background: var(--indigo);
  color: white;
}

.step-next .step-dot {
  background: white;
  border: 2px solid var(--indigo);
  color: var(--indigo);
}

.step-future .step-dot {
  background: white;
  border: 2px solid var(--border);
  color: var(--text-dim);
}

.step-content h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-bright);
}

.step-content p {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 2px;
}

.step-done .step-content h3 { color: var(--text-dim); }

/* Tech stack */
.stack {
  padding: 48px 0;
}

.stack h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 24px;
  text-align: center;
}

.stack-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.stack-tag {
  padding: 6px 14px;
  background: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--text-dim);
  font-weight: 500;
}

/* Built with */
.built-with {
  padding: 48px 0;
  text-align: center;
}

.built-with p {
  font-size: 0.95rem;
  color: var(--text-dim);
  max-width: 480px;
  margin: 0 auto;
}

.built-with a {
  color: var(--indigo-light);
  text-decoration: none;
}

.built-with a:hover {
  text-decoration: underline;
}

/* Logbook */
.log-header {
  padding: 60px 0 32px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0;
}

.log-header h1 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-bright);
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.log-header p {
  font-size: 0.9rem;
  color: var(--text-dim);
}

.log-entry {
  padding: 40px 0;
  border-bottom: 1px solid var(--border);
}

.log-entry:last-child {
  border-bottom: none;
}

.log-date {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--indigo);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.log-body p {
  font-size: 0.975rem;
  line-height: 1.75;
  color: var(--text);
  margin-bottom: 1.2em;
}

.log-body p:last-child {
  margin-bottom: 0;
}

.log-body strong {
  color: var(--text-bright);
  font-weight: 600;
}

.log-body em {
  font-style: italic;
}

/* Blog index */
.blog-list {
  padding: 48px 0;
}

.blog-list h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 24px;
  text-align: center;
}

.post-card {
  display: block;
  padding: 0;
  background: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: 10px;
  text-decoration: none;
  margin-bottom: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
  overflow: hidden;
}

.post-card:hover {
  border-color: var(--indigo);
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.12);
}

.post-card-image {
  width: 100%;
  height: 180px;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  background: var(--bg-raised);
}

.post-card-image img,
.post-card-image svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.post-card-body {
  padding: 20px 24px;
}

.post-card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 4px;
}

.post-card-meta {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.post-card-excerpt {
  font-size: 0.875rem;
  color: var(--text);
  line-height: 1.5;
}

/* Article / blog post */
.article-header {
  padding: 60px 0 32px;
}

.article-back {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-bottom: 24px;
}

.article-back:hover {
  color: var(--indigo-light);
}

.article-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-bright);
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 4px;
}

.article-date {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.article-authors {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.85rem;
  font-weight: 500;
  text-decoration: none;
}

/* Human authors: near-black */
.author-human {
  color: var(--text-bright);
}

/* AI authors: indigo — the primary human/AI distinction */
.author-ai {
  color: var(--indigo);
}

.author svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.article-body {
  padding-bottom: 80px;
}

.article-body p {
  margin-bottom: 1.4em;
  font-size: 1.05rem;
  line-height: 1.75;
}

.article-body h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-bright);
  margin: 2.5em 0 0.75em;
}

.article-body h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-bright);
  margin: 2em 0 0.5em;
}

.article-body ul, .article-body ol {
  margin: 0 0 1.4em 1.5em;
}

.article-body li {
  font-size: 1.05rem;
  line-height: 1.75;
  margin-bottom: 0.4em;
}

.article-body blockquote {
  font-size: 1.05rem;
  font-style: italic;
  color: var(--text-bright);
  margin: 1.5em 0;
  padding: 16px 20px;
  border-left: 3px solid var(--indigo);
  background: #eef2ff;
  border-radius: 0 8px 8px 0;
}

.article-body strong {
  color: var(--text-bright);
  font-weight: 600;
}

.article-body hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.5em 0;
}

/* Article illustrations */
.article-figure {
  margin: 2.5em 0;
}

.article-figure svg {
  width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
  display: block;
}

.article-figure figcaption {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-dim);
  font-style: italic;
  margin-top: 10px;
}

.placeholder {
  background: #fef9c3;
  border: 1px solid #fde047;
  border-radius: 6px;
  padding: 10px 14px;
  font-size: 0.85rem;
  color: #713f12;
  font-style: italic;
  margin: 1em 0;
}

/* Footer */
footer {
  padding: 32px 0;
  text-align: center;
  border-top: 1px solid var(--border);
  margin-top: 32px;
}

footer p {
  font-size: 0.8rem;
  color: var(--text-dim);
}

footer a {
  color: var(--indigo-light);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}