:root {
  --ink: #10231f;
  --muted: #52645f;
  --line: #dbe7e2;
  --green: #047857;
  --green-dark: #064e3b;
  --indigo: #4338ca;
  --paper: #ffffff;
  --wash: #f3faf7;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: linear-gradient(145deg, #f3faf7, #f7f7ff 55%, #f8fafc);
  font-family: "Noto Sans KR", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.75;
}
a { color: inherit; }
.insight-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 64px;
  padding: 10px max(20px, calc((100vw - 1120px) / 2));
  color: #fff;
  background: rgba(5, 46, 38, 0.96);
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.16);
  backdrop-filter: blur(12px);
}
.brand { font-size: 19px; font-weight: 900; text-decoration: none; }
.insight-nav { display: flex; gap: 16px; font-size: 13px; font-weight: 700; }
.insight-nav a { color: #d1fae5; text-decoration: none; }
.insight-nav a:hover { color: #fff; }
.insight-shell { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.insight-hero {
  margin: 42px 0 24px;
  padding: 44px;
  border: 1px solid rgba(4, 120, 87, 0.15);
  border-radius: 28px;
  background: linear-gradient(135deg, rgba(255,255,255,.98), rgba(236,253,245,.82));
  box-shadow: 0 24px 60px rgba(6, 78, 59, 0.10);
}
.eyebrow {
  display: inline-flex;
  padding: 6px 11px;
  border-radius: 999px;
  color: var(--green-dark);
  background: #d1fae5;
  font-size: 12px;
  font-weight: 900;
}
h1 { max-width: 850px; margin: 16px 0 12px; font-size: clamp(30px, 5vw, 48px); line-height: 1.2; letter-spacing: -1.4px; }
.lead { max-width: 820px; margin: 0; color: var(--muted); font-size: 17px; }
.meta { margin-top: 20px; color: #64748b; font-size: 12px; }
.article-layout { display: grid; grid-template-columns: minmax(0, 1fr) 250px; gap: 28px; align-items: start; }
.article, .toc, .insight-card {
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--paper);
  box-shadow: 0 12px 34px rgba(15, 23, 42, 0.06);
}
.article { padding: 38px; }
.article h2 { margin: 42px 0 12px; font-size: 25px; line-height: 1.35; }
.article h2:first-child { margin-top: 0; }
.article h3 { margin: 26px 0 8px; font-size: 18px; }
.article p { margin: 0 0 16px; color: #334155; }
.article ul, .article ol { margin: 10px 0 22px; padding-left: 22px; color: #334155; }
.article li { margin: 7px 0; }
.toc { position: sticky; top: 84px; padding: 20px; }
.toc strong { display: block; margin-bottom: 10px; }
.toc a { display: block; padding: 6px 0; color: #475569; font-size: 13px; text-decoration: none; }
.toc a:hover { color: var(--green); }
.callout {
  margin: 24px 0;
  padding: 18px 20px;
  border-left: 4px solid var(--green);
  border-radius: 12px;
  color: #23443a;
  background: #ecfdf5;
}
.callout.warn { border-left-color: #d97706; background: #fffbeb; color: #713f12; }
.data-table { width: 100%; margin: 18px 0 24px; border-collapse: collapse; font-size: 14px; }
.data-table th, .data-table td { padding: 12px; border: 1px solid #dfe8e4; text-align: left; vertical-align: top; }
.data-table th { background: #f0fdf4; }
.formula { margin: 18px 0; padding: 16px; border-radius: 12px; background: #0f172a; color: #e2e8f0; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; overflow-x: auto; }
.tool-link {
  display: inline-flex;
  margin-top: 8px;
  padding: 11px 16px;
  border-radius: 12px;
  color: #fff;
  background: var(--green);
  font-weight: 800;
  text-decoration: none;
}
.tool-link:hover { background: var(--green-dark); }
.insight-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin: 24px 0 56px; }
.insight-card { padding: 24px; text-decoration: none; transition: transform .15s, box-shadow .15s; }
.insight-card:hover { transform: translateY(-3px); box-shadow: 0 18px 40px rgba(15, 23, 42, 0.11); }
.insight-card small { color: var(--green); font-weight: 900; }
.insight-card h2 { margin: 8px 0; font-size: 21px; line-height: 1.4; }
.insight-card p { margin: 0; color: var(--muted); font-size: 14px; }
.insight-footer { margin-top: 48px; padding: 32px 20px; color: #64748b; background: #eaf3ef; text-align: center; font-size: 12px; }
@media (max-width: 820px) {
  .article-layout { grid-template-columns: 1fr; }
  .toc { position: static; order: -1; }
  .insight-hero, .article { padding: 24px; }
  .insight-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .insight-header { align-items: flex-start; flex-direction: column; gap: 4px; padding: 12px 16px; }
  .insight-nav { gap: 12px; }
  .insight-shell { width: min(100% - 20px, 1120px); }
  .insight-hero { margin-top: 20px; }
  .article { padding: 20px; }
  .data-table { font-size: 12px; }
}