/* ─── CSS CUSTOM PROPERTIES ─────────────────────────────── */
:root {
  --orange:         #F25E0D;
  --cool-white:     #F7F7FF;
  --slate:          #545E75;
  --navy:           #1A1A2E;
  --lavender:       #EEEEF8;
  --pale-border:    #D8D8EE;

  --bg:             var(--cool-white);
  --bg-surface:     var(--lavender);
  --text-primary:   var(--navy);
  --text-secondary: var(--slate);
  --border:         var(--pale-border);
  --accent:         var(--orange);
}

[data-theme="dark"] {
  --bg:             #1A1A2E;
  --bg-surface:     #242438;
  --text-primary:   #F7F7FF;
  --text-secondary: #8890A0;
  --border:         #32324A;
  --accent:         #F25E0D;
}

[data-theme="light"] {
  --bg:             #F7F7FF;
  --bg-surface:     #EEEEF8;
  --text-primary:   #1A1A2E;
  --text-secondary: #545E75;
  --border:         #D8D8EE;
  --accent:         #F25E0D;
}

/* ─── RESET & BASE ──────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.5;
  transition: background 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
}

/* ─── LAYOUT ────────────────────────────────────────────── */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ─── NAV ───────────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s ease;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 32px;
}

.nav-logo {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  text-decoration: none;
}

.nav-logo span { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 14px;
  font-weight: 400;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
}

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

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 14px;
  width: 32px;
  height: 32px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 0.15s, color 0.15s;
}

.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }

/* ─── FOOTER ────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 32px;
}

.footer-copy {
  font-size: 11px;
  color: var(--text-secondary);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
}

.footer-links a:hover { color: var(--accent); }

/* ─── SECTION HEADER ────────────────────────────────────── */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 40px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--text-primary);
}

.section-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
}

.section-link {
  font-size: 14px;
  color: var(--accent);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 6px;
}

.section-link:hover { opacity: 0.8; }

/* ─── HOMEPAGE: HERO ────────────────────────────────────── */
.hero {
  padding: 96px 0 80px;
  border-bottom: 1px solid var(--border);
}

.hero-headline {
  font-size: clamp(52px, 7vw, 88px);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 0.95;
  color: var(--text-primary);
  margin-bottom: 32px;
  max-width: 700px;
}

.hero-headline em {
  font-style: normal;
  color: var(--accent);
}

.hero-bio {
  font-size: 17px;
  line-height: 1.7;
  color: var(--text-secondary);
  max-width: 520px;
  margin-bottom: 16px;
}

.hero-bio a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.hero-aside {
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 520px;
  margin-bottom: 40px;
  opacity: 0.7;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--accent);
  color: #F7F7FF;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  padding: 14px 28px;
  text-decoration: none;
  transition: opacity 0.15s;
}

.hero-cta:hover { opacity: 0.88; }

/* ─── HOMEPAGE: POST CARDS ──────────────────────────────── */
.posts-section {
  padding: 72px 0;
  border-bottom: 1px solid var(--border);
}

.posts-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  background: var(--border);
}

.post-card {
  background: var(--bg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  text-decoration: none;
  transition: background 0.15s;
  position: relative;
}

.post-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent);
  transition: height 0.2s ease;
}

.post-card:hover { background: var(--bg-surface); }
.post-card:hover::before { height: 100%; }

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

.post-tag {
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 2px 8px;
}

.post-date {
  font-size: 12px;
  color: var(--text-secondary);
}

.post-title {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text-primary);
}

.post-excerpt {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
  flex: 1;
}

.post-readmore {
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: auto;
}

/* ─── HOMEPAGE: CONTACT STRIP ───────────────────────────── */
.contact-strip {
  padding: 80px 0;
}

.contact-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 40px;
}

.contact-headline {
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.05;
  color: var(--text-primary);
}

.contact-headline em {
  font-style: normal;
  color: var(--accent);
}

.contact-sub {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 12px;
  line-height: 1.6;
}

.contact-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: flex-end;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--accent);
  color: #F7F7FF;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  padding: 14px 28px;
  text-decoration: none;
  white-space: nowrap;
  transition: opacity 0.15s;
}

.btn-primary:hover { opacity: 0.88; }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 14px;
  padding: 13px 28px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.15s, color 0.15s;
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ─── BLOG INDEX ────────────────────────────────────────── */
.blog-header {
  padding: 64px 0 48px;
  border-bottom: 1px solid var(--border);
  max-width: 640px;
}

.blog-header h1 {
  font-size: clamp(40px, 5vw, 64px);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.0;
  margin-bottom: 16px;
}

.blog-header p {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.blog-list {
  padding: 56px 0 80px;
}

.blog-list-grid {
  display: flex;
  flex-direction: column;
  gap: 2px;
  background: var(--border);
}

.blog-list-item {
  background: var(--bg);
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: start;
  gap: 24px;
  padding: 28px 32px;
  text-decoration: none;
  transition: background 0.15s;
  position: relative;
}

.blog-list-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent);
  transition: height 0.2s ease;
}

.blog-list-item:hover { background: var(--bg-surface); }
.blog-list-item:hover::before { height: 100%; }

.blog-list-content { min-width: 0; }

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

.blog-list-title {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.blog-list-excerpt {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.blog-list-arrow {
  font-size: 18px;
  color: var(--text-secondary);
  align-self: center;
  flex-shrink: 0;
  transition: color 0.15s, transform 0.15s;
}

.blog-list-item:hover .blog-list-arrow {
  color: var(--accent);
  transform: translateX(4px);
}

/* ─── ARTICLE ───────────────────────────────────────────── */
.article-wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 32px;
}

.article-header {
  padding: 64px 0 48px;
  border-bottom: 1px solid var(--border);
  max-width: 740px;
}

.article-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  margin-bottom: 40px;
  transition: color 0.15s;
}

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

.article-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 2px 10px;
  margin-bottom: 20px;
}

.article-title {
  font-size: clamp(32px, 4.5vw, 56px);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.0;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.article-lede {
  font-size: 19px;
  line-height: 1.65;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 13px;
  color: var(--text-secondary);
}

.article-meta-divider {
  width: 1px;
  height: 14px;
  background: var(--border);
}

.article-body-wrap {
  display: grid;
  grid-template-columns: 1fr 220px;
  gap: 64px;
  padding: 56px 0 80px;
  align-items: start;
}

.article-body { min-width: 0; }

.article-body p {
  font-size: 17px;
  line-height: 1.75;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.article-body h2 {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin: 48px 0 16px;
  padding-top: 48px;
  border-top: 1px solid var(--border);
}

.article-body h3 {
  font-size: 19px;
  font-weight: 700;
  color: var(--text-primary);
  margin: 32px 0 12px;
}

.article-body ul,
.article-body ol {
  margin: 0 0 24px 0;
  padding-left: 0;
  list-style: none;
}

.article-body ul li,
.article-body ol li {
  font-size: 17px;
  line-height: 1.65;
  color: var(--text-primary);
  padding: 8px 0 8px 20px;
  border-bottom: 1px solid var(--border);
  position: relative;
}

.article-body ul li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

.article-body ol { counter-reset: ol-counter; }
.article-body ol li { counter-increment: ol-counter; }
.article-body ol li::before {
  content: counter(ol-counter, decimal-leading-zero);
  position: absolute;
  left: 0;
  font-size: 11px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.9;
}

.pullquote {
  margin: 48px 0;
  padding: 32px 32px 32px 28px;
  border-left: 4px solid var(--accent);
  background: var(--bg-surface);
}

.pullquote p {
  font-size: 22px !important;
  font-weight: 700 !important;
  letter-spacing: -0.01em;
  line-height: 1.4 !important;
  color: var(--text-primary) !important;
  margin-bottom: 0 !important;
  font-style: italic;
}

/* ─── SIDEBAR ───────────────────────────────────────────── */
.article-sidebar {
  position: sticky;
  top: 80px;
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.sidebar-block {
  border-top: 2px solid var(--text-primary);
  padding-top: 20px;
}

.sidebar-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.sidebar-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.sidebar-tag {
  font-size: 12px;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 3px 10px;
  text-decoration: none;
  transition: border-color 0.15s, color 0.15s;
}

.sidebar-tag:hover { border-color: var(--accent); color: var(--accent); }

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

.toc-list a {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 6px 0;
  border-bottom: 1px solid var(--border);
  transition: color 0.15s;
  line-height: 1.4;
}

.toc-list a:hover,
.toc-list a.active { color: var(--accent); }
.toc-list a.active { font-weight: 600; }

/* ─── ARTICLE FOOTER NAV ────────────────────────────────── */
.article-footer {
  border-top: 1px solid var(--border);
  padding: 48px 0 80px;
}

.article-footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  background: var(--border);
}

.next-prev-card {
  background: var(--bg);
  padding: 28px 32px;
  text-decoration: none;
  display: block;
  transition: background 0.15s;
}

.next-prev-card:hover { background: var(--bg-surface); }

.next-prev-direction {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.next-prev-title {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  line-height: 1.3;
}

/* ─── CONTACT FORM ──────────────────────────────────────── */
.contact-form {
  max-width: 560px;
  padding: 48px 0 80px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.form-group input,
.form-group textarea {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 15px;
  padding: 12px 16px;
  outline: none;
  transition: border-color 0.15s;
  width: 100%;
  box-sizing: border-box;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
}

.form-group textarea {
  resize: vertical;
  line-height: 1.6;
}

.contact-form .btn-primary {
  align-self: flex-start;
}

/* ─── RESPONSIVE ────────────────────────────────────────── */
@media (max-width: 768px) {
  .container,
  .nav-inner,
  .footer-inner,
  .article-wrap { padding-left: 20px; padding-right: 20px; }
  .hero { padding: 56px 0 48px; }
  .posts-grid { grid-template-columns: 1fr; }
  .contact-inner { grid-template-columns: 1fr; }
  .contact-actions { align-items: flex-start; }
  .footer-inner { flex-direction: column; gap: 16px; align-items: flex-start; }
  .article-body-wrap { grid-template-columns: 1fr; }
  .article-sidebar { position: static; }
  .article-footer-inner { grid-template-columns: 1fr; }
  .blog-list-item { grid-template-columns: 1fr; }
}