/* ============================================================
   PERIOD PAGE — shared layout for all era longreads
   Depends on: styles.css (tokens, nav, img-slot, footer, reveal)
   ============================================================ */

/* ====== Reading progress bar ====== */
.progress-bar {
  position: fixed;
  top: 57px; left: 0; /* sits directly under the fixed nav */
  height: 3px;
  width: 0%;
  z-index: 200;
  transition: width 0.1s linear;
  /* accent inherits from body.<era> { --rus-gold }, falls back to lime */
  background: var(--rus-gold, var(--lime));
}
@media (prefers-reduced-motion: reduce) {
  .progress-bar { transition: none; }
}

/* ====== Period hero ====== */
.p-hero {
  padding-top: 57px; /* nav height */
  position: relative;
  overflow: hidden;
}
.p-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  /* default gradient — overridden per period */
  background:
    radial-gradient(circle at 70% 30%, rgba(124,107,255,0.12), transparent 55%),
    radial-gradient(circle at 20% 80%, rgba(212,255,79,0.05), transparent 60%);
}

.p-hero-top {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding-top: 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--hairline);
  position: relative;
  z-index: 2;
}

.p-crumb {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.p-crumb a { color: var(--ink-muted); transition: color 0.2s; }
.p-crumb a:hover { color: var(--ink); }
.p-crumb .sep {
  width: 4px; height: 4px;
  background: var(--ink-dim);
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}
.p-crumb span:last-child { color: var(--ink); }

.p-toc {
  display: flex;
  gap: 20px;
  justify-content: flex-end;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}
.p-toc a { color: var(--ink-muted); transition: color 0.2s; }
.p-toc a:hover { color: var(--ink); }

.p-hero-title {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 60px;
  align-items: end;
  padding: 80px 0 60px;
  position: relative;
  z-index: 2;
}
.p-hero-title > div:first-child {
  min-width: 0;
  overflow: hidden;
}
.p-hero-title .number {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 20px;
}
.p-hero-title h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(48px, 7vw, 120px);
  line-height: 0.88;
  letter-spacing: -0.03em;
  margin: 0;
  text-transform: uppercase;
}
.p-hero-title h1 .em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  text-transform: none;
  letter-spacing: -0.01em;
}

.p-hero-title .meta dl { margin: 0; }
.p-hero-title .meta dl > div {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 12px;
  padding: 14px 0;
  border-top: 1px solid var(--hairline);
  align-items: baseline;
}
.p-hero-title .meta dl > div:last-child { border-bottom: 1px solid var(--hairline); }
.p-hero-title .meta dt {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.p-hero-title .meta dd {
  margin: 0;
  font-size: 14px;
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.p-hero-bottom {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  padding-bottom: 80px;
  align-items: start;
  position: relative;
  z-index: 2;
}
.p-hero-lede {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(22px, 2.2vw, 32px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin: 0;
}
.p-hero-running {
  display: flex;
  flex-direction: column;
}
.p-hero-running .row {
  display: grid;
  grid-template-columns: 80px 1fr auto;
  gap: 20px;
  align-items: baseline;
  padding: 14px 0;
  border-top: 1px solid var(--hairline);
  font-size: 14px;
}
.p-hero-running .row:last-child { border-bottom: 1px solid var(--hairline); }
.p-hero-running .yr {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.02em;
}
.p-hero-running .ev { color: var(--ink); }
.p-hero-running .row > span:last-child {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

@media (max-width: 1100px) {
  .p-hero-title { grid-template-columns: 1fr; gap: 32px; padding: 48px 0 40px; }
}

@media (max-width: 900px) {
  .p-hero-top { grid-template-columns: 1fr; gap: 12px; }
  .p-toc { display: none; }
  .p-hero-bottom { grid-template-columns: 1fr; gap: 40px; }
}

/* ====== Lead / intro ====== */
.lead {
  padding: var(--section-pad) 0;
  border-top: 1px solid var(--hairline);
}
.lead-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 80px;
  align-items: start;
}
.lead-side {
  position: sticky;
  top: 140px;
}
.lead-side .kicker { margin-bottom: 20px; }
.lead-side h2 {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  font-size: clamp(28px, 3.2vw, 48px);
  line-height: 1.08;
  margin: 0;
  letter-spacing: -0.01em;
}
.lead-body p {
  font-size: 18px;
  line-height: 1.6;
  margin: 0 0 22px;
  max-width: 680px;
}
.lead-body p:first-child::first-letter {
  font-family: var(--font-serif);
  font-size: 4.5em;
  line-height: 0.75;
  float: left;
  margin: 0.06em 0.1em 0 0;
  font-weight: 700;
}

@media (max-width: 900px) {
  .lead-grid { grid-template-columns: 1fr; gap: 32px; }
  .lead-side { position: static; }
}

/* ====== Chapter sections ====== */
.chapter {
  padding: var(--section-pad) 0;
  border-top: 1px solid var(--hairline);
}
.chapter-header {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 40px;
  align-items: start;
  margin-bottom: 64px;
}
.chapter-header .num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(40px, 4.5vw, 72px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--ink-dim);
}
.chapter-header .kicker { margin-bottom: 12px; }
.chapter-header h3 {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  font-size: clamp(26px, 3vw, 44px);
  line-height: 1.1;
  margin: 0;
  letter-spacing: -0.01em;
}

.chapter-body {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 64px;
  align-items: start;
}
.chapter-text p {
  font-size: 18px;
  line-height: 1.6;
  margin: 0 0 20px;
  max-width: 680px;
}

.chapter-side {
  position: sticky;
  top: 120px;
}
.chapter-side .img-slot { aspect-ratio: 3/4; }

/* absolute badge inside img-slot */
.img-slot .tag {
  position: absolute;
  top: 16px; left: 16px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 5px 10px;
  border-radius: 4px;
  z-index: 2;
  /* colour set inline per item */
}

@media (max-width: 1100px) {
  .chapter-body { grid-template-columns: 1fr; }
  .chapter-side { position: static; }
}
@media (max-width: 900px) {
  .chapter-header { grid-template-columns: 60px 1fr; gap: 20px; }
}

/* ====== Inline helpers ====== */
.em { font-style: italic; }
.kicker {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.serif {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
}

/* ====== Next-period teaser ====== */
.next-period {
  padding: var(--section-pad) 0;
  border-top: 1px solid var(--hairline);
}
.next-period-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}
.next-period h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(36px, 5vw, 80px);
  text-transform: uppercase;
  letter-spacing: -0.025em;
  line-height: 0.9;
  margin: 12px 0 20px;
}
.next-period h3 .em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  text-transform: none;
}
.next-cta {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding: 16px 28px;
  border-radius: 999px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #0a0a0a;
  transition: transform 0.2s;
}
.next-cta:hover { transform: translateX(6px); }

@media (max-width: 900px) {
  .next-period-inner { grid-template-columns: 1fr; gap: 40px; }
}