/* Model Studio — Structural & Strategic Lenses build brief · shared site chrome */
:root {
  --brand-primary: #0F6CBD;
  --accent-warm: #C05621;
  --ink: #1a1a1a;
  --ink-2: #555;
  --border: #e5e7eb;
  --bg: #fafafa;
  --card: #ffffff;
}

* { box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
}

.site-header {
  background: linear-gradient(120deg, var(--brand-primary), var(--accent-warm));
  color: #fff;
  padding: 18px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.site-header a {
  color: #fff;
  text-decoration: none;
}

.site-header__brand {
  font-weight: 800;
  font-size: 17px;
  letter-spacing: 0.01em;
}

.site-header__brand span {
  font-weight: 400;
  opacity: 0.85;
  margin-left: 6px;
}

.site-header__nav {
  display: flex;
  gap: 18px;
  font-size: 14px;
  font-weight: 600;
}

.site-header__nav a {
  opacity: 0.92;
}

.site-header__nav a:hover {
  opacity: 1;
  text-decoration: underline;
}

main.doc {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px 60px;
}

.doc-frame {
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: var(--card);
  margin-top: 24px;
  height: calc(100vh - 160px);
}

.doc-frame iframe {
  width: 100%;
  height: 100%;
  border: 0;
}

.back-link {
  display: inline-block;
  margin: 24px 0 0;
  font-size: 14px;
  color: var(--brand-primary);
  text-decoration: none;
  font-weight: 600;
}

.back-link:hover { text-decoration: underline; }

footer.site-footer {
  text-align: center;
  padding: 28px 16px 40px;
  color: #888;
  font-size: 12.5px;
}