/* baotrinh.com — minimal, text-first */
:root {
  --text: #1a1a1a;
  --muted: #666;
  --rule: #ddd;
  --bg: #ffffff;
  --link: #2456a4;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.075rem;
  line-height: 1.65;
}

.page {
  max-width: 42rem;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

/* header / nav */
.site-header {
  margin-bottom: 3rem;
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.site-header .brand { color: var(--text); text-decoration: none; font-weight: 600; }
.site-header nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 1rem;
}
.site-header nav a:hover { color: var(--text); text-decoration: underline; }

h1 {
  font-size: 1.75rem;
  line-height: 1.25;
  font-weight: 600;
  margin: 0 0 0.5rem;
}
h2 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 2.5rem 0 0.75rem;
}
.subtitle {
  color: var(--muted);
  font-style: italic;
  margin: 0 0 2rem;
}

a { color: var(--link); }
a:hover { text-decoration-thickness: 2px; }

p { margin: 0 0 1.1rem; }

figure { margin: 2rem 0; }
figure img { max-width: 100%; height: auto; display: block; border: 1px solid var(--rule); }
figcaption {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 0.5rem;
}

hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 3rem 0;
}

/* home — full-bleed bands, subtle alternation */
.container {
  max-width: 60rem;
  margin: 0 auto;
  padding: 0 1.25rem;
}
.container .site-header { padding-top: 2.5rem; }

.band { padding: 3rem 0; }
.band-alt { background: #f7f6f3; }
.band-hero { padding-top: 4rem; }

.intro {
  text-align: center;
  margin: 0 auto 2.5rem;
}
.intro-name { margin: 0 0 0.5rem; font-size: 1.35rem; }
.intro p { margin: 0; }

.map-root {
  text-align: center;
  margin: 0 auto;
}
.map-root p { margin: 0 0 1rem; }
.map-root p:last-child { margin-bottom: 0; }
.hero-title {
  font-size: 2rem;
  line-height: 1.2;
  margin: 0 0 0.5rem;
}
.hero-for {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 1.05rem;
  color: var(--muted);
  margin: 0;
}
.map-root .hero-pair { line-height: 1.9; }
.map-root .hero-motto {
  font-size: 1.45rem;
  font-weight: 600;
  margin: 1.5rem 0;
}

/* seven-title list inside the essay card */
a.card-name { display: block; text-decoration: none; color: inherit; }
a.card-name:hover { text-decoration: underline; }
.card-chain {
  margin: 0 auto 0.25rem;
  padding: 0;
  list-style: decimal;
  display: inline-block;
  text-align: left;
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.85rem;
  line-height: 1.9;
}
.card-chain li { margin-left: 1.4rem; }
.card-chain a { color: var(--link); text-decoration: none; }
.card-chain a:hover { text-decoration: underline; }
.card-chain li::marker { color: var(--muted); }
.proof-line {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
  margin: 0.85rem 0 0;
}
.read-essay {
  display: block;
  margin-top: 0.85rem;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(0,0,0,0.08);
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.85rem;
  color: var(--link);
  text-decoration: none;
}
.read-essay:hover { text-decoration: underline; }
.map-root-title {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

.map-branches {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}
.branch { display: flex; flex-direction: column; }
.branch .card-essay { flex: 1; }
.branch-title {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 1rem;
}

.card {
  display: block;
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 0.85rem 1rem;
  text-align: center;
  text-decoration: none;
  color: var(--text);
}
a.card:hover .card-name { text-decoration: underline; }
.card-name { font-weight: 600; line-height: 1.35; }
.card-sub {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.78rem;
  color: var(--muted);
  margin-top: 0.2rem;
}
.card-plain { background: none; }
.card-arrow {
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1;
  padding: 0.4rem 0;
}

.branch-risk .card-essay,
.branch-risk a.card:not(.card-plain) {
  background: #faf1ef;
  border-color: #e5cfc9;
}
.branch-speed .card-essay,
.branch-speed a.card:not(.card-plain) {
  background: #eef6f1;
  border-color: #cfe0d5;
}
.card-plain { background: none; border-color: var(--rule); }
.card-plain .card-name { color: var(--muted); font-weight: 600; }

.map-layer {
  text-align: center;
}
.map-layer .card-name { font-size: 1.45rem; }
.map-layer .card-sub {
  font-size: 0.95rem;
  margin-top: 0.6rem;
  line-height: 1.7;
}
.map-layer .card-sub { max-width: 38rem; margin-left: auto; margin-right: auto; }

.map-tail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  margin-top: 0;
}
.map-tail .card-name { color: var(--text); }

.forthcoming {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.75rem;
  color: var(--muted);
  border: 1px solid var(--rule);
  border-radius: 2px;
  padding: 0.1rem 0.4rem;
  margin-left: 0.5rem;
  vertical-align: middle;
  white-space: nowrap;
}
.principle {
  margin: 1.25rem 0 0;
  text-align: center;
  font-size: 1.1rem;
}
.principle em { font-weight: 600; }

/* seven-step chain (home, risk column) */
.chain {
  margin: 0.75rem 0 0;
  padding: 0 0 0 1.5rem;
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.82rem;
  line-height: 1.9;
  color: var(--muted);
}
.chain a { color: var(--muted); text-decoration: none; }
.chain a:hover { color: var(--text); text-decoration: underline; }
.branch-risk .chain { margin-bottom: 0.75rem; }

/* table of contents (essay page) */
.toc {
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: #faf9f6;
  padding: 1rem 1.25rem;
  margin: 0 0 2.5rem;
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.9rem;
}
.toc-title {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 0.5rem;
}
.toc ol { margin: 0; padding-left: 1.4rem; line-height: 2; }
.toc a { text-decoration: none; }
.toc a:hover { text-decoration: underline; }

/* essay */
.essay h2 { scroll-margin-top: 1.5rem; }
.byline {
  border-top: 1px solid var(--rule);
  margin-top: 3rem;
  padding-top: 1.25rem;
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.85rem;
  color: var(--muted);
}
.byline a { color: var(--muted); }

/* footer */
.site-footer {
  margin-top: 4rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.8rem;
  color: var(--muted);
}
.site-footer a { color: var(--muted); }

@media (max-width: 600px) {
  body { font-size: 1rem; }
  h1 { font-size: 1.5rem; }
  .hero-title { font-size: 1.5rem; }
  .map-branches, .map-tail { grid-template-columns: 1fr; }
  .site-header { flex-direction: column; align-items: flex-start; gap: 0.25rem; }
}