/* THL Theme — "What is Biomimetic Dentistry?" page (page-biomimetic-dentistry.php).
   SEO landing page. Reuses .card (course grid), .speakers-strip/.speaker-rail/.scard
   and .membership from home.css (enqueued alongside this file); bd.css adds the hero,
   the definition + etymology block, section chrome, the Six Lessons links and the
   glossary callout. Solid nav (not over a hero). */

/* ---- Hero / intro ------------------------------------------------------ */
.bd-hero {
  padding: 88px 48px 64px;
  background:
    radial-gradient(ellipse 70% 130% at 82% 0%, rgba(122,175,201,0.12) 0%, transparent 60%),
    linear-gradient(180deg, #16202e 0%, var(--bg-deep) 100%);
  border-bottom: 1px solid var(--line);
}
.bd-inner { max-width: 1040px; margin: 0 auto; }
.bd-hero .crumb { font-size: 12.5px; color: var(--t-soft); margin-bottom: 18px; }
.bd-hero .crumb a { color: var(--t-mid); text-decoration: none; transition: color .2s; }
.bd-hero .crumb a:hover { color: var(--blue-bright); }
.bd-hero .crumb .sep { margin: 0 8px; }
.bd-kicker { display: inline-flex; align-items: center; gap: 10px; font-size: 11px; font-weight: 700; letter-spacing: 0.22em; text-transform: uppercase; color: var(--blue-bright); margin-bottom: 16px; }
.bd-kicker::before { content: ''; width: 26px; height: 1px; background: var(--blue); }
.bd-hero h1 { font-size: clamp(34px, 5vw, 58px); font-weight: 800; letter-spacing: -0.025em; line-height: 1.05; margin-bottom: 18px; max-width: 16ch; }
.bd-hero h1 .accent { color: var(--blue-bright); }
.bd-hero .bd-lede { font-size: clamp(16px, 1.7vw, 19px); color: var(--t-mid); line-height: 1.65; max-width: 680px; }

/* ---- Definition + etymology ------------------------------------------- */
.bd-define { padding: 64px 48px; background: var(--bg); }
.bd-define-grid { max-width: 1040px; margin: 0 auto; display: grid; grid-template-columns: 1.5fr 1fr; gap: 48px; align-items: start; }
.bd-prose h2, .bd-prose .bd-h2 { font-size: clamp(23px, 2.5vw, 31px); font-weight: 700; letter-spacing: -0.02em; line-height: 1.15; color: var(--t-strong); margin-bottom: 18px; }
.bd-prose p { font-size: 16px; color: var(--t-mid); line-height: 1.78; }
.bd-prose p + p { margin-top: 1.1em; }
.bd-prose strong { color: var(--t-strong); font-weight: 600; }

/* Etymology card. */
.bd-ety { background: rgba(255,255,255,0.03); border: 1px solid var(--line); border-radius: 18px; padding: 28px 26px; position: sticky; top: calc(var(--nav-h) + 20px); }
.bd-ety h2 { font-size: 12px; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase; color: var(--blue-bright); margin-bottom: 6px; }
.bd-ety .ety-from { font-size: 13px; color: var(--t-soft); margin-bottom: 20px; line-height: 1.5; }
.bd-ety dl { margin: 0; }
.bd-ety .ety-row { display: flex; align-items: baseline; gap: 14px; padding: 14px 0; border-top: 1px solid var(--line); }
.bd-ety .ety-row:first-of-type { border-top: 0; }
.bd-ety dt { font-size: 26px; font-weight: 700; color: var(--t-strong); line-height: 1; min-width: 92px; }
.bd-ety dd { margin: 0; font-size: 14px; color: var(--t-mid); }
.bd-ety dd .en { display: block; font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--t-soft); margin-bottom: 2px; }

/* ---- Generic section --------------------------------------------------- */
.bd-section { padding: 64px 48px; }
.bd-section--deep { background: var(--bg-deep); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.bd-sec-head { max-width: 1040px; margin: 0 auto 30px; }
.bd-sec-head .bd-kicker { margin-bottom: 12px; }
.bd-sec-head h2 { font-size: clamp(24px, 2.6vw, 34px); font-weight: 700; letter-spacing: -0.02em; line-height: 1.12; margin-bottom: 12px; }
.bd-sec-head p { font-size: 15.5px; color: var(--t-soft); line-height: 1.65; max-width: 640px; }

/* ---- Course grid (reuses .card from home.css) -------------------------- */
.bd-grid { max-width: var(--wrap); margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px 18px; }
.bd-section--lib .bd-sec-head { max-width: var(--wrap); }
.bd-grid .card { flex: none; width: auto; scroll-snap-align: none; }

/* ---- Action row -------------------------------------------------------- */
.bd-actions { max-width: var(--wrap); margin: 34px auto 0; display: flex; flex-wrap: wrap; gap: 14px; }
.bd-btn, .bd-btn-ghost { display: inline-flex; align-items: center; gap: 9px; font-size: 14px; font-weight: 700; border-radius: 10px; padding: 13px 24px; transition: background .2s, transform .15s, border-color .2s, color .2s; }
.bd-btn { background: var(--blue); color: var(--navy-deeper); }
.bd-btn:hover { background: var(--blue-bright); transform: translateY(-1px); }
.bd-btn-ghost { background: transparent; color: var(--t-strong); border: 1px solid var(--line-2); }
.bd-btn-ghost:hover { border-color: var(--blue); color: var(--blue-bright); }
.bd-btn svg, .bd-btn-ghost svg { width: 17px; height: 17px; }

/* ---- Six Lessons links ------------------------------------------------- */
.bd-lessons { max-width: 1040px; margin: 0 auto; display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.bd-lesson { display: flex; align-items: center; gap: 14px; padding: 16px 18px; background: rgba(255,255,255,0.03); border: 1px solid var(--line); border-radius: 12px; text-decoration: none; transition: border-color .25s var(--ease-out), background .25s var(--ease-out), transform .25s var(--ease-out); }
.bd-lesson:hover { border-color: rgba(122,175,201,0.4); background: rgba(122,175,201,0.06); transform: translateY(-2px); }
.bd-lesson .num { flex-shrink: 0; width: 34px; height: 34px; border-radius: 9px; background: rgba(122,175,201,0.12); border: 1px solid rgba(122,175,201,0.25); color: var(--blue-bright); font-size: 13px; font-weight: 800; display: flex; align-items: center; justify-content: center; }
.bd-lesson .ltxt { font-size: 14px; color: var(--t-mid); line-height: 1.4; font-weight: 500; }
.bd-lesson:hover .ltxt { color: var(--t-strong); }

/* ---- Glossary callout -------------------------------------------------- */
.bd-glossary { max-width: 1040px; margin: 22px auto 0; display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap; padding: 22px 26px; background: rgba(255,255,255,0.03); border: 1px solid var(--line); border-radius: 14px; }
.bd-glossary .gtxt { font-size: 14.5px; color: var(--t-mid); line-height: 1.5; }
.bd-glossary .gtxt strong { color: var(--t-strong); font-weight: 700; display: block; font-size: 16px; margin-bottom: 3px; }

/* ---- Responsive -------------------------------------------------------- */
@media (max-width: 900px) {
  .bd-define-grid { grid-template-columns: 1fr; gap: 30px; }
  .bd-ety { position: static; }
}
@media (max-width: 720px) {
  .bd-hero { padding: 60px 24px 44px; }
  .bd-define, .bd-section { padding: 48px 24px; }
  .bd-lessons { grid-template-columns: 1fr; }
}