:root {
  --paper: #f2ead4;
  --paper-deep: #e7dcbc;
  --ink: #10263a;
  --ink-soft: #3f5568;
  --ink-faint: #6e8091;
  --brass: #9c7a2e;
  --brass-deep: #7a5f22;
  --line: rgba(16, 38, 58, 0.18);
  --line-deep: rgba(16, 38, 58, 0.32);
  --water-1: #bcd7dd;
  --water-2: #6fa3ad;
  --water-3: #2f7183;
  --water-4: #144a5c;
  --water-5: #0a2f42;
  --ottoman: #7c2d24;
  --ottoman-bg: #f4e2dc;
  --austro: #4b5a72;
  --austro-bg: #e2e7ee;
  --romania: #1f5e42;
  --romania-bg: #dcece2;
  --danger: #8a2d24;
  --font-display: "Spectral", Georgia, "Times New Roman", serif;
  --font-body: "IBM Plex Sans", -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, monospace;
  --radius: 6px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0d2233;
    --paper-deep: #0a1a28;
    --ink: #ecdfc0;
    --ink-soft: #b9c7d2;
    --ink-faint: #7f93a2;
    --brass: #d9b464;
    --brass-deep: #b8892b;
    --line: rgba(236, 223, 192, 0.14);
    --line-deep: rgba(236, 223, 192, 0.26);
    --water-1: #163244;
    --water-2: #114256;
    --water-3: #0d5568;
    --water-4: #0a6e82;
    --water-5: #0ea5c4;
    --ottoman-bg: #3a1f1c;
    --austro-bg: #232b38;
    --romania-bg: #16301f;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --paper: #0d2233;
  --paper-deep: #0a1a28;
  --ink: #ecdfc0;
  --ink-soft: #b9c7d2;
  --ink-faint: #7f93a2;
  --brass: #d9b464;
  --brass-deep: #b8892b;
  --line: rgba(236, 223, 192, 0.14);
  --line-deep: rgba(236, 223, 192, 0.26);
  --water-1: #163244;
  --water-2: #114256;
  --water-3: #0d5568;
  --water-4: #0a6e82;
  --water-5: #0ea5c4;
  --ottoman-bg: #3a1f1c;
  --austro-bg: #232b38;
  --romania-bg: #16301f;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  background-image:
    repeating-linear-gradient(0deg, var(--line) 0, var(--line) 1px, transparent 1px, transparent 32px),
    repeating-linear-gradient(90deg, var(--line) 0, var(--line) 1px, transparent 1px, transparent 32px);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.visually-hidden:focus {
  position: static; width: auto; height: auto; margin: 0; padding: 0.5rem 1rem;
  background: var(--brass); color: var(--paper);
}

.shell { max-width: 760px; margin: 0 auto; padding: 0 1.5rem; }
.shell-wide { max-width: 980px; margin: 0 auto; padding: 0 1.5rem; }

.topbar {
  display: flex; justify-content: space-between; align-items: center;
  padding: 1.1rem 1.5rem; border-bottom: 1px solid var(--line-deep);
  font-family: var(--font-mono); font-size: 0.85rem; letter-spacing: 0.02em;
}
.brand { color: var(--ink); text-decoration: none; font-weight: 500; }
.brand:hover { color: var(--brass-deep); }
.langsw a { color: var(--ink-soft); text-decoration: none; padding: 0.2rem 0.3rem; }
.langsw a[aria-current="page"] { color: var(--ink); font-weight: 600; border-bottom: 2px solid var(--brass); }
.langsw a:hover { color: var(--brass-deep); }

.hero { padding: 3rem 0 2rem; }
.kicker {
  font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--brass-deep); margin: 0 0 1rem;
}
h1 {
  font-family: var(--font-display); font-weight: 600; font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.12; margin: 0 0 1.2rem; color: var(--ink);
}
.standfirst { font-size: 1.14rem; color: var(--ink-soft); max-width: 62ch; }

.coordbar {
  display: flex; flex-wrap: wrap; gap: 0.4rem 1.6rem; margin: 1.6rem 0 0;
  padding: 0.9rem 1.1rem; border: 1px solid var(--line-deep); border-radius: var(--radius);
  background: var(--paper-deep); font-family: var(--font-mono); font-size: 0.82rem; color: var(--ink-soft);
}
.coordbar strong { color: var(--ink); font-weight: 600; }

.block { padding: 2.6rem 0; }
.prose h2 {
  font-family: var(--font-display); font-size: 1.55rem; font-weight: 600;
  margin: 0 0 1.1rem; color: var(--ink); border-bottom: 1px solid var(--line-deep); padding-bottom: 0.6rem;
}
.prose p { margin: 0 0 1.1rem; max-width: 68ch; }
.prose p.lead { font-size: 1.08rem; color: var(--ink-soft); }
.prose strong { color: var(--ink); }

.callout {
  border-left: 3px solid var(--brass); background: var(--paper-deep);
  border-radius: var(--radius); padding: 1rem 1.2rem; margin: 1.4rem 0;
}
.callout-title { font-weight: 600; margin-bottom: 0.4rem; color: var(--ink); }
.callout p { margin: 0; max-width: none; }

/* --- Chronoscope instrument --- */
.instrument { padding: 2rem 0 3rem; }
.instrument-box {
  border: 1px solid var(--line-deep); border-radius: 10px; overflow: hidden;
  background: var(--paper-deep);
}
.chrono-stage {
  position: relative; min-height: 210px; padding: 1.6rem 1.6rem 1.2rem;
  background: linear-gradient(to bottom, var(--paper) 0%, var(--paper) 100%);
  transition: background 0.4s ease;
}
.chrono-flag {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.05em;
  text-transform: uppercase; padding: 0.3rem 0.7rem; border-radius: 999px;
  border: 1px solid currentColor;
}
.chrono-flag.f-ottoman { color: var(--ottoman); background: var(--ottoman-bg); }
.chrono-flag.f-austro { color: var(--austro); background: var(--austro-bg); }
.chrono-flag.f-romania { color: var(--romania); background: var(--romania-bg); }
.chrono-flag.f-submerged { color: var(--water-5); background: var(--water-1); }

.chrono-year {
  font-family: var(--font-display); font-size: 2.6rem; font-weight: 600;
  margin: 0.6rem 0 0.2rem; color: var(--ink);
}
.chrono-status { font-size: 1.06rem; color: var(--ink); max-width: 62ch; min-height: 3.2em; }
.chrono-pop { font-family: var(--font-mono); font-size: 0.85rem; color: var(--ink-soft); margin-top: 0.5rem; }

.chrono-water-overlay {
  position: absolute; left: 0; right: 0; bottom: 0; height: 0%;
  background: linear-gradient(to top, var(--water-5), var(--water-3) 60%, transparent 100%);
  opacity: 0; transition: height 0.5s ease, opacity 0.5s ease; pointer-events: none;
}
.chrono-water-overlay.visible { opacity: 0.85; }

.chrono-controls { padding: 1.1rem 1.6rem 1.5rem; border-top: 1px solid var(--line); background: var(--paper); }
.chrono-slider {
  -webkit-appearance: none; appearance: none; width: 100%; height: 6px;
  border-radius: 3px; background: var(--line-deep); outline: none; margin: 0.6rem 0 0.9rem;
}
.chrono-slider::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; width: 20px; height: 20px; border-radius: 50%;
  background: var(--brass); border: 2px solid var(--paper); cursor: pointer;
  box-shadow: 0 0 0 1px var(--brass-deep);
}
.chrono-slider::-moz-range-thumb {
  width: 20px; height: 20px; border-radius: 50%; background: var(--brass);
  border: 2px solid var(--paper); cursor: pointer; box-shadow: 0 0 0 1px var(--brass-deep);
}
.chrono-ticks {
  display: flex; justify-content: space-between; font-family: var(--font-mono);
  font-size: 0.68rem; color: var(--ink-faint); padding: 0 2px;
}
.chrono-ticks span { display: none; }
.chrono-ticks span.show { display: inline; }

.chrono-legend {
  display: flex; flex-wrap: wrap; gap: 1rem 1.4rem; margin-top: 1rem;
  font-family: var(--font-mono); font-size: 0.76rem; color: var(--ink-soft);
}
.chrono-legend .dot { display: inline-block; width: 9px; height: 9px; border-radius: 50%; margin-right: 0.4rem; }
.dot.f-ottoman { background: var(--ottoman); }
.dot.f-austro { background: var(--austro); }
.dot.f-romania { background: var(--romania); }
.dot.f-submerged { background: var(--water-4); }

/* --- Depth ruler --- */
.depth-ruler {
  display: flex; align-items: flex-end; gap: 1.6rem; height: 220px;
  padding: 1.5rem 1.5rem 0; border: 1px solid var(--line-deep); border-radius: var(--radius);
  background: var(--paper-deep); overflow-x: auto;
}
.depth-bar-wrap { display: flex; flex-direction: column; align-items: center; justify-content: flex-end; height: 100%; min-width: 90px; }
.depth-bar {
  width: 46px; border-radius: 3px 3px 0 0; background: linear-gradient(to top, var(--water-4), var(--water-2));
  position: relative;
}
.depth-bar-val { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink); margin-bottom: 0.4rem; font-weight: 600; }
.depth-bar-label { font-size: 0.8rem; color: var(--ink-soft); text-align: center; margin: 0.5rem 0 1rem; max-width: 100px; }
.depth-bar.marker { background: repeating-linear-gradient(45deg, var(--brass), var(--brass) 6px, var(--brass-deep) 6px, var(--brass-deep) 12px); }

/* --- Numbered ledger --- */
.ledgerline { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem 1.6rem; margin-top: 2rem; }
.ledger-item {
  padding: 0.9rem 1rem; border: 1px solid var(--line-deep); border-radius: var(--radius);
  background: var(--paper-deep);
}
.ledger-item .n { display: block; font-family: var(--font-mono); font-weight: 700; font-size: 1.3rem; color: var(--brass-deep); }
.ledger-item .l { font-size: 0.86rem; color: var(--ink-soft); }
@media (max-width: 640px) { .ledgerline { grid-template-columns: 1fr; } }

.sources-section { padding: 2.2rem 0 3rem; border-top: 1px solid var(--line-deep); }
.sources-list { padding-left: 1.2rem; font-size: 0.88rem; color: var(--ink-soft); }
.sources-list li { margin-bottom: 0.6rem; }
.sources-list strong { color: var(--ink); }
.sources-list a { color: var(--brass-deep); text-decoration: underline; text-underline-offset: 2px; }
.sources-list a:hover { color: var(--ink); }

footer { padding: 2rem 0 3rem; font-size: 0.85rem; color: var(--ink-faint); }
footer a { color: var(--ink-soft); }

@media (max-width: 900px) {
  .depth-ruler { height: 180px; }
}
@media (max-width: 600px) {
  body { font-size: 16px; }
  .hero { padding: 2rem 0 1.4rem; }
  .chrono-year { font-size: 2rem; }
  .depth-ruler { height: 160px; gap: 1rem; }
}