/* =============================================================
   Elegant personal site — design system
   ============================================================= */

:root {
  --bg: #faf8f5;
  --bg-elev: #ffffff;
  --ink: #1c1a17;
  --ink-soft: #4a463f;
  --ink-faint: #837c70;
  --line: #e7e1d8;
  --line-strong: #d8d0c4;
  --accent: #3a5a78;       /* refined slate-blue */
  --accent-ink: #2b4257;
  --accent-soft: #eef2f6;
  --shadow: 0 1px 2px rgba(28, 26, 23, 0.04), 0 8px 28px rgba(28, 26, 23, 0.06);
  --radius: 14px;
  --maxw: 720px;
  --maxw-wide: 1080px;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

[data-theme="dark"] {
  --bg: #14130f;
  --bg-elev: #1c1b16;
  --ink: #f1ece3;
  --ink-soft: #c9c2b5;
  --ink-faint: #908a7c;
  --line: #2c2a23;
  --line-strong: #3a372e;
  --accent: #8fb4d4;
  --accent-ink: #b6d2ea;
  --accent-soft: #1f2630;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 10px 32px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--ink);
}

a { color: var(--accent-ink); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

img { max-width: 100%; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.wrap-wide { max-width: var(--maxw-wide); margin: 0 auto; padding: 0 24px; }

/* ---------------- Header / nav ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(180%) blur(12px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.brand:hover { text-decoration: none; }
.nav-links { display: flex; align-items: center; gap: 26px; }
.nav-links a {
  color: var(--ink-soft);
  font-size: 0.95rem;
  font-weight: 500;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-links a.active { color: var(--accent-ink); }

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  background: var(--bg-elev);
  color: var(--ink-soft);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, transform 0.15s;
}
.theme-toggle:hover { color: var(--ink); border-color: var(--accent); transform: translateY(-1px); }
.theme-toggle svg { width: 18px; height: 18px; }
[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }

/* ---------------- Hero ---------------- */
.hero { padding: 92px 0 64px; }
.eyebrow {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin: 0 0 18px;
}
.hero h1 { font-size: clamp(2.4rem, 6vw, 3.6rem); margin: 0 0 8px; }
.hero .role {
  font-size: 1.05rem;
  color: var(--ink-faint);
  font-weight: 500;
  margin: 0 0 22px;
}
.hero .tagline {
  font-size: 1.25rem;
  color: var(--ink-soft);
  max-width: 38ch;
  margin: 0 0 32px;
  line-height: 1.55;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  gap: 52px;
  align-items: center;
}
.hero-photo { display: flex; justify-content: center; }
.hero-photo img {
  width: 100%;
  max-width: 300px;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  object-position: center 30%;
  border-radius: 50%;
  border: 4px solid var(--bg-elev);
  box-shadow: var(--shadow);
}

/* ---------------- Buttons ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: 10px;
  font-size: 0.96rem;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.15s ease, background 0.2s, border-color 0.2s, color 0.2s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #fff; }
[data-theme="dark"] .btn-primary { color: #11161c; }
.btn-primary:hover { background: var(--accent-ink); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent-ink); }

/* ---------------- Social row ---------------- */
.socials { display: flex; gap: 12px; margin-top: 28px; }
.socials a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid var(--line);
  color: var(--ink-soft);
  background: var(--bg-elev);
  transition: color 0.2s, border-color 0.2s, transform 0.15s;
}
.socials a:hover { color: var(--accent-ink); border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.socials svg { width: 19px; height: 19px; }

/* ---------------- Sections ---------------- */
section { padding: 56px 0; scroll-margin-top: 88px; }
.section-label {
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 20px;
}
.prose p { color: var(--ink-soft); margin: 0 0 18px; }
.prose a { font-weight: 600; text-decoration: underline; text-underline-offset: 3px; }
.prose p:last-child { margin-bottom: 0; }

.divider { border: none; border-top: 1px solid var(--line); margin: 0; }

/* ---------------- Focus cards ---------------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--line-strong); }
.card h3 { font-size: 1.18rem; margin: 0 0 10px; }
.card p { color: var(--ink-soft); font-size: 0.96rem; margin: 0; line-height: 1.6; }
.card .num {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--accent-ink);
  display: block;
  margin-bottom: 14px;
}

/* ---------------- Connect / Contact ---------------- */
.connect {
  background: var(--accent-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 40px 36px;
}
.connect-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 40px;
  align-items: start;
}
.connect-follow h2 { font-size: 1.7rem; margin: 0 0 8px; }
.connect-follow p { color: var(--ink-soft); margin: 0 0 22px; max-width: 36ch; }
.follow-btns { display: flex; flex-direction: column; gap: 12px; align-items: stretch; }
.follow-btn { background: var(--bg-elev); justify-content: flex-start; }
.follow-ico { display: inline-flex; }
.follow-ico svg { width: 17px; height: 17px; }

.contact-form { display: flex; flex-direction: column; gap: 12px; }
.contact-form h3 { font-size: 1.25rem; margin: 0 0 4px; }
.field-row { display: flex; gap: 12px; flex-wrap: wrap; }
.field-row input { flex: 1 1 160px; }
.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid var(--line-strong);
  background: var(--bg-elev);
  color: var(--ink);
  font-size: 0.96rem;
  font-family: inherit;
  resize: vertical;
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent);
}
.contact-form .btn-primary { align-self: flex-start; }
.contact-msg { margin-top: 4px; font-size: 0.92rem; min-height: 1.2em; }
.contact-msg.ok { color: #2f7d4f; }
.contact-msg.err { color: #b4452f; }
[data-theme="dark"] .contact-msg.ok { color: #7fd0a0; }
[data-theme="dark"] .contact-msg.err { color: #e7937f; }

@media (max-width: 760px) {
  .connect { padding: 32px 22px; }
  .connect-grid { grid-template-columns: 1fr; gap: 30px; }
}

/* ---------------- Post feedback (below articles) ---------------- */
.post-feedback-section {
  padding: 0 0 56px;
  border-top: 1px solid var(--line);
}
.post-feedback {
  max-width: 640px;
  padding-top: 40px;
}
.post-feedback h2 {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 600;
  margin: 0 0 8px;
}
.post-feedback-lead {
  color: var(--ink-soft);
  margin: 0 0 20px;
  font-size: 0.96rem;
  max-width: 42ch;
}
.hp-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

/* ---------------- Blog list ---------------- */
.page-head { padding: 72px 0 24px; }
.page-head h1 { font-size: clamp(2rem, 5vw, 2.8rem); margin: 0 0 10px; }
.page-head p { color: var(--ink-faint); font-size: 1.1rem; margin: 0; }

/* ---------------- Category chips ---------------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 28px;
}
.chip {
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  padding: 7px 15px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: var(--bg-elev);
  color: var(--ink-soft);
  cursor: pointer;
  transition: color 0.18s, border-color 0.18s, background 0.18s, transform 0.12s;
}
.chip:hover { color: var(--ink); border-color: var(--accent); transform: translateY(-1px); }
.chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
[data-theme="dark"] .chip.active { color: #11161c; }

.post-list { list-style: none; padding: 0; margin: 0; }
.post-item { border-top: 1px solid var(--line); }
.post-item:last-child { border-bottom: 1px solid var(--line); }
.post-link {
  display: block;
  padding: 26px 4px;
  transition: padding-left 0.2s, background 0.2s;
  border-radius: 8px;
}
.post-link:hover { text-decoration: none; padding-left: 14px; }
.post-link:hover .post-title { color: var(--accent-ink); }
.post-meta {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  margin-bottom: 8px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.post-title { font-size: 1.5rem; margin: 0 0 8px; color: var(--ink); transition: color 0.2s; }
.post-excerpt { color: var(--ink-soft); margin: 0; font-size: 1rem; }
.tag {
  display: inline-block;
  padding: 2px 9px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.03em;
}

/* ---------------- Article ---------------- */
.article { padding: 56px 0 40px; }
.article-head { margin-bottom: 36px; }
.article-head h1 { font-size: clamp(2rem, 5vw, 2.9rem); margin: 12px 0 14px; }
.article-content { font-size: 1.08rem; line-height: 1.8; }
.article-content > *:first-child { margin-top: 0; }
.article-content h2 { font-size: 1.6rem; margin: 44px 0 16px; }
.article-content h3 { font-size: 1.3rem; margin: 34px 0 12px; }
.article-content p { margin: 0 0 22px; color: var(--ink-soft); }
.article-content ul, .article-content ol { color: var(--ink-soft); padding-left: 1.3em; margin: 0 0 22px; }
.article-content li { margin: 0 0 8px; }
.article-content a { color: var(--accent-ink); text-decoration: underline; text-underline-offset: 3px; }
.article-content blockquote {
  margin: 0 0 22px;
  padding: 6px 20px;
  border-left: 3px solid var(--accent);
  color: var(--ink-faint);
  font-style: italic;
}
.article-content code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--accent-soft);
  padding: 2px 6px;
  border-radius: 6px;
}
.article-content pre {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  overflow-x: auto;
  margin: 0 0 22px;
}
.article-content pre code { background: none; padding: 0; font-size: 0.9rem; line-height: 1.6; }
.article-content img { border-radius: var(--radius); margin: 8px 0 22px; }
.article-content hr { border: none; border-top: 1px solid var(--line); margin: 36px 0; }

.canonical-note {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 6px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.02em;
}
.canonical-note:hover { border-color: var(--accent); text-decoration: none; }

.back-link {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--ink-faint);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.back-link:hover { color: var(--accent-ink); text-decoration: none; }

/* ---------------- Series (multi-part posts) ---------------- */
.series-eyebrow {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin: 0 0 10px;
  text-decoration: none;
}
a.series-eyebrow:hover { text-decoration: underline; text-underline-offset: 3px; }
.series-eyebrow--static { cursor: default; }

.series-blurb {
  font-size: 1.08rem;
  line-height: 1.7;
  color: var(--ink-soft);
  margin: 4px 0 16px;
}

/* Series cards on the blog index */
.series-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}
.series-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-elev);
  text-decoration: none;
}
.series-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  text-decoration: none;
}
.series-card-kicker {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent-ink);
}
.series-card-title {
  font-family: var(--serif);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.3;
}
.series-card-blurb { color: var(--ink-soft); font-size: 0.96rem; line-height: 1.6; }
.series-card-cta {
  margin-top: 2px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-ink);
}

/* Ordered lesson list on the series landing page */
.series-list { list-style: none; padding: 0; margin: 8px 0 0; counter-reset: none; }
.series-item { margin: 0 0 14px; }
.series-item-link {
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-areas:
    "num title meta"
    "num excerpt meta";
  align-items: baseline;
  column-gap: 16px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-elev);
  text-decoration: none;
}
a.series-item-link:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  text-decoration: none;
}
.series-item-num {
  grid-area: num;
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent-ink);
  white-space: nowrap;
}
.series-item-title { grid-area: title; font-weight: 600; color: var(--ink); line-height: 1.4; }
.series-item-excerpt { grid-area: excerpt; color: var(--ink-faint); font-size: 0.92rem; line-height: 1.6; margin-top: 4px; }
.series-item-meta {
  grid-area: meta;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  white-space: nowrap;
}
.series-item.is-upcoming .series-item-link {
  opacity: 0.62;
  background: transparent;
  border-style: dashed;
}
@media (max-width: 560px) {
  .series-item-link {
    grid-template-columns: 1fr;
    grid-template-areas: "num" "title" "excerpt" "meta";
    row-gap: 4px;
  }
}

.series-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}
.series-nav-link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-elev);
  text-decoration: none;
}
.series-nav-link:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  text-decoration: none;
}
.series-nav-link.next { text-align: right; }
.series-nav-link.is-empty {
  border: none;
  background: none;
  pointer-events: none;
}
.series-nav-dir {
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
}
.series-nav-title {
  font-weight: 600;
  color: var(--ink);
  line-height: 1.4;
}
@media (max-width: 560px) {
  .series-nav { grid-template-columns: 1fr; }
  .series-nav-link.next { text-align: left; }
  .series-nav-link.is-empty { display: none; }
}

/* ---------------- Footer ---------------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 44px 0;
  margin-top: 40px;
  color: var(--ink-faint);
  font-size: 0.9rem;
}
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 20px; flex-wrap: wrap; }
.footer-inner .socials { margin: 0; }
.footer-inner .socials a { width: 34px; height: 34px; }

/* ---------------- States ---------------- */
.loading, .empty { color: var(--ink-faint); padding: 40px 0; font-family: var(--mono); font-size: 0.9rem; }

.fade-in { opacity: 0; transform: translateY(12px); animation: fadeUp 0.6s ease forwards; }
@keyframes fadeUp { to { opacity: 1; transform: none; } }

/* ---------------- Responsive ---------------- */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero-photo { max-width: 360px; }
}

@media (max-width: 760px) {
  body { font-size: 16px; }
  .cards { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 48px; }
  .nav-links { gap: 18px; }
  .nav-links a.hide-sm { display: none; }
}