/* ──────────────────────────────────────────────────────────────────────
   Direction B — Briefing.
   Reads like an institutional briefing paper or board memorandum.
   Two-column body: narrow left rail carries the section reference and
   a short marginal note, right column carries the prose.
   ────────────────────────────────────────────────────────────────────── */

.dir-b { background: var(--surface); }

/* ─── Header ─────────────────────────────────────────────────────── */
.dir-b .b-header {
  background: var(--warm);
  padding: 64px 96px 56px;
  border-bottom: 2px solid var(--brass);
}

.dir-b .b-doc-meta {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 24px;
  font-family: var(--fs);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-3);
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 48px;
}
.dir-b .b-doc-meta .ref { color: var(--ink); }
.dir-b .b-doc-meta .ref strong { color: var(--brass); font-weight: 500; }
.dir-b .b-doc-meta .right {
  display: flex;
  gap: 22px;
  align-items: center;
}
.dir-b .b-doc-meta .right .sep {
  width: 3px;
  height: 3px;
  background: var(--ink-3);
  opacity: 0.6;
  border-radius: 50%;
}

.dir-b .b-title {
  font-family: var(--fd);
  font-size: 56px;
  line-height: 1.04;
  color: var(--ink);
  letter-spacing: -0.022em;
  margin: 0 0 24px;
  max-width: 20ch;
}
.dir-b .b-deck {
  font-family: var(--fd);
  font-style: italic;
  font-size: 21px;
  line-height: 1.5;
  color: var(--ink-2);
  max-width: 42ch;
  margin: 0 0 56px;
}

.dir-b .b-glance {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 24px;
  align-items: baseline;
  padding-top: 22px;
  border-top: 1px solid var(--border);
}
.dir-b .b-glance-label {
  font-family: var(--fs);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.dir-b .b-glance-row {
  display: flex;
  gap: 18px;
  align-items: center;
  font-size: 13px;
  color: var(--ink-2);
  letter-spacing: 0.02em;
}
.dir-b .b-glance-row .sep {
  width: 1px;
  height: 11px;
  background: var(--border-strong);
}

/* ─── Body: two-column sections ──────────────────────────────────── */
.dir-b .b-main {
  padding: 64px 96px 88px;
}
.dir-b .b-section {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 56px;
  align-items: start;
  padding: 48px 0;
  border-top: 1px solid var(--border);
  scroll-margin-top: calc(var(--nav-h) + 24px);
}
.dir-b .b-section:first-of-type {
  border-top: none;
  padding-top: 24px;
}

.dir-b .b-sec-rail {
  position: sticky;
  top: 80px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.dir-b .b-sec-mark {
  font-family: var(--fs);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-3);
  display: flex;
  gap: 12px;
  align-items: center;
}
.dir-b .b-sec-mark .num {
  font-family: var(--fs);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--brass);
  text-transform: none;
}
.dir-b .b-sec-rule {
  width: 28px;
  height: 1px;
  background: var(--brass);
}
.dir-b .b-sec-key {
  font-family: var(--fs);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 500;
}

.dir-b .b-sec-body { max-width: 600px; }
.dir-b .b-h2 {
  font-family: var(--fd);
  font-size: 28px;
  line-height: 1.2;
  color: var(--ink);
  letter-spacing: -0.012em;
  margin-bottom: 24px;
  max-width: 22ch;
}
.dir-b .b-h2 em {
  font-style: italic;
  color: var(--brass);
}
.dir-b .b-sec-body p {
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink-2);
  font-weight: 400;
  margin-bottom: 16px;
}
.dir-b .b-sec-body p:last-child { margin-bottom: 0; }
.dir-b .b-sec-body p strong { font-weight: 500; color: var(--ink); }
.dir-b .b-sec-body a.inline {
  color: var(--ink);
  border-bottom: 1px solid var(--brass);
}
.dir-b .b-sec-body a.inline:hover { color: var(--brass-dk); }

/* ─── Continue block ─────────────────────────────────────────────── */
.dir-b .b-continue {
  padding: 48px 0 64px;
  background: var(--warm);
  border-top: 1px solid var(--border-strong);
}
.dir-b .b-continue-inner {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 96px;
}
.dir-b .b-continue-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
}
.dir-b .b-continue-label {
  font-family: var(--fs);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.dir-b .b-continue-meta {
  font-family: var(--fs);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--ink-3);
}
.dir-b .b-continue-row {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  gap: 24px;
  align-items: center;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
}
.dir-b .b-continue-row:last-child { border-bottom: none; }
.dir-b .b-continue-row:hover .arrow { transform: translateX(4px); }
.dir-b .b-cr-num {
  font-family: var(--fs);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--brass);
}
.dir-b .b-cr-title {
  font-family: var(--fd);
  font-size: 20px;
  color: var(--ink);
  letter-spacing: -0.01em;
}

@media (max-width: 900px) {
  .dir-b .b-header   { padding: 48px 32px 40px; }
  .dir-b .b-main     { padding: 48px 32px 64px; }
  .dir-b .b-continue { padding: 36px 0 48px; }
  .dir-b .b-continue-inner { padding-left: 32px; padding-right: 32px; }
  .dir-b .b-secmap   { padding-left: 32px; padding-right: 32px; }
  .dir-b .b-doc-meta { grid-template-columns: 1fr; }
  .dir-b .b-glance   { grid-template-columns: 1fr; gap: 8px; }
}

@media (max-width: 768px) {
  .dir-b .b-section  { grid-template-columns: 1fr; gap: 0; }
  .dir-b .b-sec-rail {
    position: static;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 24px;
  }
  .dir-b .b-sec-key  { display: none; }
}

@media (max-width: 600px) {
  .dir-b .b-header   { padding: 32px 24px; }
  .dir-b .b-main     { padding: 32px 24px 48px; }
  .dir-b .b-continue { padding: 28px 0 40px; }
  .dir-b .b-continue-inner { padding-left: 24px; padding-right: 24px; }
  .dir-b .b-secmap   { padding-left: 24px; padding-right: 24px; }
  .dir-b .b-title    { font-size: 40px; }
  .dir-b .b-deck     { font-size: 17px; }
  .dir-b .b-continue-row { grid-template-columns: 40px 1fr auto; gap: 16px; }
}