:root {
  --green-900: #064e3b;
  --green-800: #065f46;
  --green-700: #047857;
  --green-600: #059669;
  --green-100: #d1fae5;
  --green-50: #ecfdf5;
  --ink-900: #111827;
  --ink-700: #374151;
  --ink-500: #6b7280;
  --ink-100: #f3f4f6;
  --ink-50: #f9fafb;
  --white: #ffffff;
  --amber-700: #b45309;
  --amber-100: #fef3c7;
  --red-700: #b91c1c;
  --red-50: #fef2f2;
  --blue-700: #1d4ed8;
  --blue-50: #eff6ff;
  --shadow: 0 1px 3px rgba(17, 24, 39, 0.08), 0 4px 12px rgba(17, 24, 39, 0.06);
  --shadow-lg: 0 8px 30px rgba(17, 24, 39, 0.12);
  --radius: 12px;
  --maxw: 1160px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink-700);
  line-height: 1.65;
  background: var(--white);
}

h1, h2, h3, h4 {
  color: var(--ink-900);
  line-height: 1.25;
  font-weight: 700;
}

a { color: var(--green-700); text-decoration: none; }
a:hover { text-decoration: underline; }

img, svg { max-width: 100%; height: auto; }

/* ---------- Layout ---------- */
.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}

.wrap-flex { display: flex; gap: 32px; flex-wrap: wrap; }
.wrap-main { flex: 2 1 640px; min-width: 0; }
.wrap-side { flex: 1 1 280px; min-width: 0; }

/* ---------- Header ---------- */
.site-header {
  background: var(--green-900);
  padding: 14px 0;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow);
}

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.02em;
}
.brand:hover { text-decoration: none; }
.brand svg { flex: none; }

.nav { display: flex; gap: 22px; align-items: center; }
.nav a {
  color: #a7f3d0;
  font-size: 0.95rem;
  font-weight: 600;
}
.nav a:hover { color: var(--white); text-decoration: none; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, var(--green-900) 0%, var(--green-600) 100%);
  color: var(--white);
  padding: 72px 0;
}

.hero-grid {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: center;
}

.hero h1 {
  color: var(--white);
  font-size: 2.5rem;
  margin: 0 0 16px;
  letter-spacing: -0.02em;
}

.hero p { font-size: 1.1rem; color: #d1fae5; margin: 0 0 28px; }

.hero-badges { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 28px; }
.hero-badges span {
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
}

.hero-art { background: rgba(255, 255, 255, 0.1); border-radius: var(--radius); padding: 20px; }

.btn {
  display: inline-block;
  background: var(--white);
  color: var(--green-800);
  font-weight: 700;
  padding: 12px 24px;
  border-radius: 10px;
  font-size: 0.98rem;
}
.btn:hover { text-decoration: none; background: var(--green-50); }

.btn-ghost {
  background: transparent;
  color: var(--white);
  border: 1.5px solid rgba(255, 255, 255, 0.6);
  margin-left: 12px;
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.12); }

.btn-primary { background: var(--green-600); color: var(--white); }
.btn-primary:hover { background: var(--green-700); }

.btn-sm { padding: 8px 16px; font-size: 0.9rem; }

/* ---------- Sections ---------- */
.section { padding: 56px 0; }
.section-alt { background: var(--ink-50); }
.section-head { max-width: var(--maxw); margin: 0 auto 36px; padding: 0 20px; }
.section-head h2 { font-size: 1.9rem; margin: 0 0 8px; }
.section-head p { margin: 0; color: var(--ink-500); }

.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: var(--white);
  border: 1px solid var(--ink-100);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }
.card-body { padding: 22px; display: flex; flex-direction: column; flex: 1; }
.card-title { font-size: 1.15rem; margin: 0 0 8px; }
.card-title a { color: var(--ink-900); }
.card-title a:hover { color: var(--green-700); text-decoration: none; }
.card-text { font-size: 0.92rem; color: var(--ink-500); flex: 1; margin: 0 0 14px; }
.card-meta { font-size: 0.82rem; color: var(--ink-500); }

.tag {
  display: inline-block;
  background: var(--green-100);
  color: var(--green-800);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}
.tag-blue { background: var(--blue-50); color: var(--blue-700); }
.tag-amber { background: var(--amber-100); color: var(--amber-700); }
.tag-red { background: var(--red-50); color: var(--red-700); }

.card-art {
  height: 168px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--green-50), var(--green-100));
  padding: 16px;
}
.card-art svg { width: 110px; height: 110px; }

/* ---------- Hero art / step diagram ---------- */
.step-row { display: flex; flex-direction: column; gap: 6px; }
.step {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--white);
  color: var(--ink-700);
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 0.88rem;
  font-weight: 600;
}
.step b {
  background: var(--green-600);
  color: var(--white);
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  flex: none;
}
.step-arrow { text-align: center; color: #a7f3d0; font-weight: 800; font-size: 0.85rem; }

/* ---------- Callout / disclaimer ---------- */
.callout {
  border-left: 4px solid var(--green-600);
  background: var(--green-50);
  padding: 16px 20px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 24px 0;
}
.callout-warn { border-color: var(--amber-700); background: var(--amber-100); }
.callout-info { border-color: var(--blue-700); background: var(--blue-50); }
.callout p { margin: 0; }
.callout strong { color: var(--ink-900); }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; margin: 20px 0; border: 1px solid var(--ink-100); border-radius: var(--radius); }
table { border-collapse: collapse; width: 100%; font-size: 0.92rem; }
th, td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--ink-100); }
th { background: var(--green-50); color: var(--green-900); font-weight: 700; white-space: nowrap; }
tbody tr:last-child td { border-bottom: none; }
tr.hl td { background: var(--green-100); font-weight: 600; }

/* ---------- Flowchart ---------- */
.fc {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.fc-node {
  background: var(--white);
  border: 2px solid var(--green-600);
  border-radius: var(--radius);
  padding: 14px 22px;
  text-align: center;
  font-weight: 600;
  color: var(--ink-900);
  box-shadow: var(--shadow);
  max-width: 420px;
  width: 100%;
}
.fc-node.start { background: var(--green-600); color: var(--white); border-color: var(--green-700); }
.fc-node.question { border-style: dashed; }
.fc-node.leaf-ok { background: var(--green-50); border-color: var(--green-700); }
.fc-node.leaf-no { background: var(--red-50); border-color: var(--red-700); }
.fc-node.leaf-warn { background: var(--amber-100); border-color: var(--amber-700); }
.fc-node small { display: block; font-weight: 500; color: var(--ink-500); margin-top: 4px; }
.fc-node.start small { color: #d1fae5; }

.fc-branch {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  width: 100%;
  margin-top: 8px;
}
.fc-col { display: flex; flex-direction: column; align-items: center; text-align: center; }
.fc-col-left { align-items: flex-start; text-align: left; }
.fc-col-right { align-items: flex-end; text-align: right; }

.fc-link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10px 0;
  color: var(--ink-500);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.fc-link::after {
  content: "";
  width: 2px;
  height: 26px;
  background: var(--ink-300, #d1d5db);
  display: block;
  margin-top: 8px;
}
.fc-link.yes { color: var(--green-700); }
.fc-link.no { color: var(--red-700); }
.fc-link.warn { color: var(--amber-700); }

.fc-column-center { display: flex; flex-direction: column; align-items: center; }

/* Simple vertical chain when not branching */
.fc-chain { display: flex; flex-direction: column; align-items: center; width: 100%; }
.fc-chain .fc-link { width: 100%; }

/* ---------- Blog ---------- */
.article { max-width: 760px; margin: 0 auto; }
.article h1 { font-size: 2.1rem; margin: 0 0 6px; }
.article h2 { font-size: 1.45rem; margin: 36px 0 12px; }
.article h3 { font-size: 1.15rem; margin: 26px 0 10px; }
.article p { margin: 0 0 16px; }
.article ul, .article ol { margin: 0 0 18px; padding-left: 22px; }
.article li { margin-bottom: 6px; }
.article figure { margin: 28px 0; }
.article figcaption { text-align: center; font-size: 0.82rem; color: var(--ink-500); margin-top: 8px; }

.article-meta { color: var(--ink-500); font-size: 0.9rem; margin-bottom: 24px; display: flex; gap: 16px; flex-wrap: wrap; }

.article-img {
  background: linear-gradient(135deg, var(--green-50), var(--green-100));
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  border: 1px solid var(--green-100);
}

.article-nav {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin: 40px 0;
  padding-top: 24px;
  border-top: 1px solid var(--ink-100);
}
.article-nav a { font-weight: 600; }

.prose-toc { background: var(--ink-50); border-radius: var(--radius); padding: 18px 24px; margin: 24px 0; }
.prose-toc h4 { margin: 0 0 8px; font-size: 0.95rem; text-transform: uppercase; letter-spacing: 0.05em; }
.prose-toc ol { margin: 0; padding-left: 20px; }
.prose-toc li { margin: 4px 0; font-size: 0.92rem; }

/* ---------- Sidebar ---------- */
.side-card {
  background: var(--ink-50);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 24px;
}
.side-card h3 { font-size: 1rem; margin: 0 0 12px; }
.side-card ul { margin: 0; padding-left: 18px; }
.side-card li { margin-bottom: 6px; font-size: 0.9rem; }

/* ---------- Compare table (regime) ---------- */
.pill-row { display: flex; gap: 10px; margin: 18px 0; flex-wrap: wrap; }
.pill { flex: 1; min-width: 200px; border: 2px solid var(--green-600); border-radius: var(--radius); padding: 16px; text-align: center; font-weight: 700; color: var(--green-800); background: var(--green-50); }
.pill.alt { border-color: var(--amber-700); background: var(--amber-100); color: var(--amber-700); }

/* ---------- Footer ---------- */
.site-footer { background: var(--green-900); color: #a7f3d0; padding: 48px 0 24px; margin-top: 48px; }
.footer-grid {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
}
.footer-grid h4 { color: var(--white); font-size: 1rem; margin: 0 0 12px; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: #a7f3d0; font-size: 0.92rem; }
.footer-grid a:hover { color: var(--white); }
.footer-brand { font-size: 1.2rem; font-weight: 800; color: var(--white); }
.footer-desc { font-size: 0.92rem; margin: 12px 0 0; }
.footer-bottom {
  max-width: var(--maxw);
  margin: 32px auto 0;
  padding: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  font-size: 0.82rem;
  color: #6ee7b7;
  text-align: center;
}

/* ---------- Page hero (inner pages) ---------- */
.page-hero { background: var(--green-900); color: var(--white); padding: 44px 0; }
.page-hero .container { max-width: 860px; }
.page-hero h1 { color: var(--white); font-size: 2rem; margin: 0 0 10px; }
.page-hero p { margin: 0; color: #d1fae5; }
.crumbs { font-size: 0.82rem; color: #a7f3d0; margin-bottom: 14px; }
.crumbs a { color: #a7f3d0; }
.crumbs a:hover { color: var(--white); }

/* ---------- Utilities ---------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.mt-16 { margin-top: 16px; }
.mb-16 { margin-bottom: 16px; }
.muted { color: var(--ink-500); }
.small { font-size: 0.85rem; }

.breadcrumb { max-width: 860px; margin: 0 auto; padding: 18px 20px 0; font-size: 0.85rem; color: var(--ink-500); }
.breadcrumb a { color: var(--ink-500); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 28px; }
  .hero h1 { font-size: 1.9rem; }
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .nav-toggle { display: block; }
  .nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--green-900);
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 24px 24px;
    gap: 14px;
    box-shadow: var(--shadow-lg);
  }
  .nav.open { display: flex; }
}

@media (max-width: 560px) {
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .fc-branch { grid-template-columns: 1fr; }
  .fc-col-left, .fc-col-right { align-items: center; text-align: center; }
  .section-head h2 { font-size: 1.5rem; }
  .hero { padding: 48px 0; }
}