/* ===== PHYSICS FUNDAMENTALS — CALCULATOR "PRO" LAYER =====
   Additive styles for gold-standard calculator pages (Density onward).
   Loaded AFTER calc.css, so it inherits the :root design tokens.
   Existing 20 pages do not load this file and are unaffected. */

/* ---- Author byline / E-E-A-T ---- */
.pf-byline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: 'Manrope', sans-serif;
  font-size: 13px;
  color: var(--mist-text);
  margin: 0 0 28px;
  padding: 12px 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
.pf-byline a { color: var(--gold-text); font-weight: 700; text-decoration: none; }
.pf-byline a:hover { text-decoration: underline; }
.pf-byline-sep { color: var(--mist-2); }
.pf-byline-rev { color: var(--ink-3); }

/* ---- Copy-result button (injected into .pfc-result) ---- */
.pfc-copy {
  margin-top: 16px;
  font-family: 'Manrope', sans-serif;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--gold);
  background: var(--ink-2);
  border: 1px solid var(--gold);
  border-radius: 3px;
  padding: 8px 16px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.pfc-copy:hover { background: var(--gold); color: var(--ink); }
.pfc-copy:focus-visible { outline: 2px solid var(--gold-bright); outline-offset: 2px; }

/* ---- Generic pro button (embed copy etc.) ---- */
.pf-btn {
  font-family: 'Manrope', sans-serif;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--ink);
  background: var(--gold);
  border: 1px solid var(--gold);
  border-radius: 3px;
  padding: 10px 18px;
  cursor: pointer;
  transition: background 0.15s;
}
.pf-btn:hover { background: var(--gold-bright); }
.pf-btn:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }

/* ---- Related calculators ---- */
.pf-related { margin: 56px 0 0; }
.pf-related h2 {
  font-size: 26px;
  margin: 0 0 18px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--gold);
  display: inline-block;
}
.pf-related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 14px;
}
.pf-related-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: var(--cream);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 16px 18px;
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
}
a.pf-related-card:hover { border-color: var(--gold); transform: translateY(-2px); box-shadow: var(--shadow); }
.pf-related-card strong { font-family: 'Spectral', Georgia, serif; font-size: 17px; color: var(--ink); font-weight: 600; }
.pf-related-card em { font-style: normal; font-size: 13px; color: var(--mist-text); }
.pf-related-card.is-soon { opacity: 0.6; }
.pf-related-card.is-soon em { color: var(--mist-2); text-transform: uppercase; letter-spacing: 0.1em; font-size: 11px; font-weight: 700; }

/* ---- References ---- */
.pf-refs { margin: 48px 0 0; }
.pf-refs h2 {
  font-size: 20px;
  margin: 0 0 12px;
}
.pf-refs ul { margin: 0; padding-left: 20px; }
.pf-refs li { font-size: 14px; color: var(--ink-3); line-height: 1.7; }

/* ---- Embed box ---- */
.pf-embed { margin: 48px 0 0; }
.pf-embed h2 { font-size: 20px; margin: 0 0 8px; }
.pf-embed p { font-size: 15px; color: var(--ink-3); margin: 0 0 14px; }
.pf-embed-box { display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.pf-embed-box textarea {
  width: 100%;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 12px 14px;
  resize: vertical;
}

/* ---- Embed (iframe) mode ---- */
.pf-embed-body { margin: 0; background: var(--cream); }
.pf-embed-credit {
  font-family: 'Manrope', sans-serif;
  font-size: 12px;
  text-align: center;
  color: var(--mist-text);
  margin: 14px 0 0;
}
.pf-embed-credit a { color: var(--gold-text); font-weight: 700; }

/* ---- "Read more" blog link ---- */
.calc-readmore { margin: 32px 0 0; font-size: 15px; color: var(--ink-3); }
.calc-readmore a { color: var(--gold-text); font-weight: 600; }