/*
  Bitcoin Essentials — Shared Stylesheet
  Designed for sophisticated, older audiences per cognitive load & UX research:
  - 17px base font, system sans-serif (screen legibility)
  - 820px max content width (~65 char line length)
  - 1.8 line height, generous section spacing
  - Max 4 bullets per list, max 3 columns in any grid
  - High contrast, minimal decorative noise
*/

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --orange:       #f7931a;
  --dark:         #12121f;
  --mid:          #181828;
  --panel:        #1c2538;
  --border:       #263044;
  --text:         #e2e2e2;
  --muted:        #8a96aa;
  --faint:        #4a5468;
  --green:        #4caf7d;
  --red:          #d95f52;
  --gold:         #e8c84a;
  --radius:       10px;
  --section-gap:  72px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  font-size: 17px;
  line-height: 1.8;
  background: var(--dark);
  color: var(--text);
  min-height: 100vh;
}

/* ── Navigation ── */
.site-nav {
  background: var(--mid);
  border-bottom: 1px solid var(--border);
  padding: 13px 32px;
  font-size: 0.82rem;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav a { color: var(--orange); text-decoration: none; }
.site-nav a:hover { text-decoration: underline; }
.site-nav .sep { color: var(--faint); }

/* ── Hero ── */
.hero {
  padding: 80px 32px 64px;
  text-align: center;
  border-bottom: 2px solid var(--orange);
}

.hero .eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.5px;
  margin-bottom: 18px;
  line-height: 1.2;
}

.hero h1 em {
  color: var(--orange);
  font-style: normal;
}

.hero .lead {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ── Main layout ── */
main {
  max-width: 820px;
  margin: 0 auto;
  padding: var(--section-gap) 24px 96px;
}

.section {
  margin-bottom: var(--section-gap);
}

/* ── Section headers ── */
.section-label {
  font-size: 0.72rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 8px;
}

.section-title {
  font-size: 1.55rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 6px;
  line-height: 1.25;
}

.section-lead {
  font-size: 1rem;
  color: var(--muted);
  margin-bottom: 28px;
  max-width: 620px;
}

/* ── Pull quote / intro box ── */
.pull-box {
  border-left: 3px solid var(--orange);
  padding: 20px 28px;
  background: var(--panel);
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: 40px;
}

.pull-box p {
  font-size: 1rem;
  color: var(--muted);
  margin-bottom: 10px;
}

.pull-box p:last-child { margin-bottom: 0; }
.pull-box strong { color: var(--text); }

.pull-box .attributed-quote {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-style: italic;
  font-size: 0.95rem;
  color: var(--muted);
}

.pull-box .attributed-quote cite {
  display: block;
  font-style: normal;
  font-size: 0.8rem;
  color: var(--orange);
  margin-top: 6px;
}

/* ── 3-column card grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 40px;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 22px;
}

.card .card-icon { font-size: 1.8rem; display: block; margin-bottom: 10px; }

.card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
}

.card p { font-size: 0.9rem; color: var(--muted); }

/* ── Numbered characteristic rows ── */
.char-list { display: flex; flex-direction: column; gap: 14px; margin-bottom: 40px; }

.char-row {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 0 16px;
  align-items: start;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 20px 20px 16px;
  transition: border-color 0.2s;
}

.char-row:hover { border-color: rgba(247,147,26,0.4); }

.char-num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid var(--orange);
  color: var(--orange);
  font-weight: 700;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 3px;
}

.char-row h3 {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.char-row p { font-size: 0.9rem; color: var(--muted); }
.char-row strong { color: var(--text); }

/* ── Stats ── */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 14px;
  margin-bottom: 40px;
}

.stat-block {
  background: var(--panel);
  border: 1px solid var(--border);
  border-top: 3px solid var(--orange);
  border-radius: var(--radius);
  padding: 20px 16px;
  text-align: center;
}

.stat-block .num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--orange);
  line-height: 1;
  margin-bottom: 8px;
}

.stat-block .lbl { font-size: 0.83rem; color: var(--muted); line-height: 1.4; }
.stat-block .sub { font-size: 0.72rem; color: var(--faint); margin-top: 4px; }

/* ── Tables ── */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.data-table thead tr { background: #1a2440; }

.data-table th {
  padding: 11px 14px;
  text-align: left;
  color: var(--muted);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.data-table th:first-child { border-radius: 8px 0 0 0; }
.data-table th:last-child  { border-radius: 0 8px 0 0; }

.data-table tbody tr {
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.data-table tbody tr:hover { background: #1f2e48; }

.data-table td {
  padding: 12px 14px;
  color: var(--muted);
  vertical-align: top;
  font-size: 0.9rem;
}

.data-table td:first-child { color: var(--text); font-weight: 600; }

.data-table td .sub {
  display: block;
  font-size: 0.77rem;
  color: var(--faint);
  margin-top: 2px;
}

.pass  { color: var(--green); font-weight: 600; }
.fail  { color: var(--red);   font-weight: 600; }
.mixed { color: var(--gold);  font-weight: 600; }

/* ── Callout ── */
.callout {
  background: rgba(247,147,26,0.05);
  border: 1px solid rgba(247,147,26,0.25);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-bottom: 40px;
}

.callout h3 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--orange);
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 0.8rem;
}

.callout ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }

.callout ul li {
  font-size: 0.92rem;
  color: var(--muted);
  padding-left: 22px;
  position: relative;
}

.callout ul li::before { content: '→'; position: absolute; left: 0; color: var(--orange); }
.callout ul li strong { color: var(--text); }

/* ── Big cap callout ── */
.cap-callout {
  background: rgba(247,147,26,0.05);
  border: 1px solid rgba(247,147,26,0.3);
  border-radius: 12px;
  padding: 36px;
  text-align: center;
  margin-bottom: 40px;
}

.cap-callout .cap-number {
  font-size: clamp(2.8rem, 6vw, 4.2rem);
  font-weight: 700;
  color: var(--orange);
  display: block;
  margin-bottom: 8px;
  line-height: 1;
}

.cap-callout h2 {
  font-size: 1.2rem;
  color: #fff;
  margin-bottom: 18px;
}

.cap-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
  text-align: left;
  margin-top: 20px;
}

.cap-fact {
  background: rgba(0,0,0,0.2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
}

.cap-fact .cf-label {
  font-size: 0.7rem;
  color: var(--orange);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 3px;
}

.cap-fact .cf-value { font-size: 0.88rem; color: var(--text); }

/* ── Insight box (centered) ── */
.insight {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 36px;
  text-align: center;
  margin-bottom: 40px;
}

.insight h2 { font-size: 1.3rem; color: #fff; margin-bottom: 14px; }

.insight p {
  font-size: 0.97rem;
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto 12px;
}

.insight p:last-child { margin-bottom: 0; }
.insight .hi  { color: var(--orange); font-weight: 700; }
.insight .neg { color: var(--red);    font-weight: 700; }

/* ── Quote card ── */
.quote-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 24px 20px;
}

.quote-card .qmark {
  font-size: 2.5rem;
  color: var(--orange);
  opacity: 0.25;
  line-height: 1;
  margin-bottom: -8px;
}

.quote-card blockquote {
  font-size: 0.95rem;
  font-style: italic;
  color: var(--text);
  line-height: 1.65;
  margin-bottom: 14px;
}

.quote-card .attr {
  border-top: 1px solid var(--border);
  padding-top: 12px;
}

.quote-card .attr .name {
  font-size: 0.87rem;
  font-weight: 700;
  color: var(--orange);
}

.quote-card .attr .role { font-size: 0.77rem; color: var(--muted); }

/* ── Digital Gold comparison ── */
.dg-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 20px;
}

@media (max-width: 560px) { .dg-compare { grid-template-columns: 1fr; } }

.dg-col {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.dg-col-head {
  padding: 13px 18px;
  font-weight: 700;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.dg-col-head.gold { background: rgba(232,200,74,0.08); border-bottom: 1px solid rgba(232,200,74,0.2); color: var(--gold); }
.dg-col-head.btc  { background: rgba(247,147,26,0.08); border-bottom: 1px solid rgba(247,147,26,0.2); color: var(--orange); }

.dg-col ul { list-style: none; padding: 16px 18px; display: flex; flex-direction: column; gap: 9px; }

.dg-col ul li {
  font-size: 0.88rem;
  color: var(--muted);
  padding-left: 16px;
  position: relative;
}

.dg-col.gold-side ul li::before { content: '•'; position: absolute; left: 0; color: var(--gold); }
.dg-col.btc-side  ul li::before { content: '•'; position: absolute; left: 0; color: var(--orange); }
.dg-col ul li strong { color: var(--text); }

/* ── Drawdown bars ── */
.drawdown-box {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  margin-bottom: 24px;
}

.drawdown-box h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--muted);
  margin-bottom: 22px;
}

.dd-item { margin-bottom: 18px; }

.dd-item-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
}

.dd-item-name { font-size: 0.9rem; font-weight: 700; color: var(--text); }
.dd-item-note { font-size: 0.78rem; color: var(--muted); }

.dd-bar-row { display: flex; align-items: center; gap: 10px; margin-bottom: 5px; }

.dd-bar-yr { font-size: 0.72rem; color: var(--faint); width: 36px; text-align: right; flex-shrink: 0; }

.dd-track { flex: 1; background: rgba(255,255,255,0.04); border-radius: 3px; height: 20px; overflow: hidden; }

.dd-fill {
  height: 100%;
  border-radius: 3px;
  display: flex;
  align-items: center;
  padding: 0 8px;
  font-size: 0.7rem;
  font-weight: 700;
  color: rgba(255,255,255,0.85);
}

.dd-fill.s1 { background: #9b2020; }
.dd-fill.s2 { background: #b03828; }
.dd-fill.s3 { background: #c0501a; }
.dd-fill.btc-bar { background: #8a3a00; }

.dd-recovery { font-size: 0.72rem; color: var(--green); white-space: nowrap; flex-shrink: 0; min-width: 90px; text-align: right; }
.dd-divider { border: none; border-top: 1px solid var(--border); margin: 16px 0; }

/* ── Profitability bars ── */
.prof-box { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; margin-bottom: 16px; }
.prof-box h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.5px; color: var(--muted); margin-bottom: 20px; }

.prof-row { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; }
.prof-label { font-size: 0.83rem; color: var(--muted); width: 90px; flex-shrink: 0; }
.prof-track { flex: 1; background: rgba(255,255,255,0.05); border-radius: 4px; height: 22px; overflow: hidden; }
.prof-fill { height: 100%; border-radius: 4px; display: flex; align-items: center; padding: 0 10px; font-size: 0.75rem; font-weight: 700; color: #fff; }
.p1y  { background: #b03020; width: 61%; }
.p2y  { background: #c07020; width: 78%; }
.p3y  { background: #c0a020; width: 95%; }
.p4y  { background: var(--green); width: 100%; }

.prof-note { font-size: 0.78rem; color: var(--faint); margin-top: 12px; font-style: italic; }

/* ── Market cap bars ── */
.cap-bars { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; margin-bottom: 14px; }
.cap-bars h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.5px; color: var(--muted); margin-bottom: 20px; }

.cap-bar-row { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; }
.cap-bar-label { font-size: 0.83rem; color: var(--muted); width: 150px; flex-shrink: 0; text-align: right; }
.cap-bar-track { flex: 1; background: rgba(255,255,255,0.04); border-radius: 3px; height: 24px; overflow: hidden; }
.cap-bar-fill { height: 100%; border-radius: 3px; display: flex; align-items: center; padding: 0 10px; font-size: 0.75rem; font-weight: 700; color: #fff; white-space: nowrap; }
.cb-btc     { background: var(--orange); width: 11%; }
.cb-apple   { background: #4a5a7a; width: 22%; }
.cb-sp500   { background: #3a5888; width: 30%; }
.cb-gold    { background: #7a6010; width: 92%; }

/* ── Page footer nav ── */
.page-nav { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

.nav-btn {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 22px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
  min-width: 180px;
  transition: border-color 0.2s;
}

.nav-btn:hover { border-color: var(--orange); }
.nav-btn .lbl { font-size: 0.73rem; text-transform: uppercase; letter-spacing: 0.5px; color: var(--muted); }
.nav-btn .ttl { font-size: 0.95rem; font-weight: 600; color: var(--text); }
.nav-btn.next { text-align: right; }
.nav-btn.next .lbl { color: var(--orange); }

/* ── Site footer ── */
.site-footer {
  background: var(--mid);
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 24px;
  font-size: 0.8rem;
  color: var(--faint);
}

/* ── Disclaimer ── */
.disclaimer {
  background: rgba(0,0,0,0.25);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 18px;
  font-size: 0.77rem;
  color: var(--faint);
  line-height: 1.5;
  margin-bottom: 56px;
}

/* ── CAGR grid ── */
.cagr-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px; margin-bottom: 24px; }

.cagr-card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; text-align: center; }
.cagr-card .period { font-size: 0.77rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 8px; }
.cagr-card .rate { font-size: 2rem; font-weight: 700; color: var(--green); line-height: 1; margin-bottom: 6px; }
.cagr-card .ctx { font-size: 0.77rem; color: var(--faint); }

/* ── Quote grid ── */
.quote-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; margin-bottom: 40px; }

/* ── Holders grid ── */
.holder-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin-bottom: 40px; }

.holder-card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; }
.holder-card .cat { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 1px; color: var(--orange); margin-bottom: 6px; }
.holder-card h4 { font-size: 0.95rem; font-weight: 700; color: #fff; margin-bottom: 10px; }
.holder-card ul { list-style: none; display: flex; flex-direction: column; gap: 5px; }
.holder-card ul li { font-size: 0.83rem; color: var(--muted); padding-left: 14px; position: relative; }
.holder-card ul li::before { content: '•'; position: absolute; left: 0; color: var(--orange); }

/* ── ETF table badge ── */
.badge-rec { display: inline-block; font-size: 0.67rem; padding: 1px 7px; border-radius: 4px; background: rgba(247,147,26,0.12); border: 1px solid rgba(247,147,26,0.35); color: var(--orange); text-transform: uppercase; letter-spacing: 0.3px; }

/* ── Responsive ── */
@media (max-width: 600px) {
  .hero { padding: 56px 20px 44px; }
  main { padding: 48px 16px 72px; }
  .dg-compare { grid-template-columns: 1fr; }
}