:root {
  --paper: #f4efe4;
  --paper-2: #fbf8f0;
  --ink: #1d1b18;
  --ink-2: #3d3831;
  --muted: #756b5d;
  --line: #d9cfbf;
  --line-strong: #c4b6a0;
  --red: #9b2c1f;
  --red-2: #7e2117;
  --gold: #8a6a2f;
  --green: #3d5a45;
  --shadow: 0 10px 30px rgba(50, 40, 25, .06);
  --serif: "Noto Serif SC", "Songti SC", "STSong", "SimSun", "Source Han Serif SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --radius: 4px;
  --max: 820px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    radial-gradient(1200px 600px at 50% -10%, #fffdf8 0%, transparent 60%),
    var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: rgba(155, 44, 31, .16); }

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: var(--paper);
  padding: 8px 14px;
  z-index: 100;
}
.skip:focus { left: 12px; top: 12px; }

.topbar {
  max-width: var(--max);
  margin: 0 auto;
  padding: 22px 24px 8px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  font-family: var(--serif);
  font-size: 18px;
  letter-spacing: .16em;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
}
.brand::after {
  content: "";
  display: block;
  width: 22px;
  height: 2px;
  margin-top: 5px;
  background: var(--red);
}

.nav {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}
.nav button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  letter-spacing: .06em;
  padding: 7px 10px;
  cursor: pointer;
  border-radius: 999px;
}
.nav button:hover { color: var(--ink); background: rgba(29, 27, 24, .05); }
.nav button.is-on { color: var(--red); background: rgba(155, 44, 31, .07); }

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 20px 24px 80px;
}

.view { animation: fadeUp .45s ease both; }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .view { animation: none; }
}

.hero { padding: 54px 0 26px; }

.kicker {
  margin: 0 0 14px;
  color: var(--red);
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
}

h1 {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(32px, 6.2vw, 54px);
  line-height: 1.28;
  letter-spacing: -.02em;
  margin: 0 0 20px;
}

h2 {
  font-family: var(--serif);
  font-size: clamp(22px, 3.6vw, 30px);
  line-height: 1.4;
  margin: 0 0 12px;
}

h3 {
  font-family: var(--serif);
  font-size: 18px;
  margin: 0 0 8px;
}

.lead {
  color: var(--ink-2);
  font-size: 16px;
  max-width: 640px;
  margin: 0 0 28px;
}
.lead .muted { display: block; margin-top: 6px; }

.muted { color: var(--muted); }
.small { font-size: 13px; }
.tiny { font-size: 12px; }

.period-picker {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 26px;
}
.period-chip {
  appearance: none;
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, .55);
  color: var(--ink-2);
  font: inherit;
  font-size: 13px;
  padding: 7px 13px;
  border-radius: 999px;
  cursor: pointer;
  transition: .18s ease;
}
.period-chip:hover { border-color: var(--line-strong); background: #fffdf8; }
.period-chip.is-on {
  border-color: var(--red);
  background: var(--red);
  color: #fff8ee;
}
.period-chip .era { opacity: .65; margin-left: 4px; font-size: 11px; }

.hero-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

button.primary, button.ghost, button.again, button.share, .linklike {
  font-family: var(--sans);
  font-size: 14px;
  cursor: pointer;
  border-radius: var(--radius);
  transition: .18s ease;
}

button.primary {
  appearance: none;
  border: 1px solid var(--red);
  background: var(--red);
  color: #fff8ee;
  padding: 12px 22px;
  letter-spacing: .04em;
  box-shadow: 0 6px 18px rgba(155, 44, 31, .16);
}
button.primary:hover { background: var(--red-2); border-color: var(--red-2); transform: translateY(-1px); }
button.primary.big { padding: 14px 30px; font-size: 15px; }

button.ghost {
  appearance: none;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--ink-2);
  padding: 12px 18px;
}
button.ghost:hover { background: rgba(29, 27, 24, .04); }

button.again, button.share {
  appearance: none;
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, .6);
  color: var(--ink-2);
  padding: 10px 16px;
}
button.again:hover, button.share:hover { background: #fffdf8; border-color: var(--line-strong); }

button:disabled { opacity: .45; cursor: not-allowed; transform: none !important; }

.hint {
  color: var(--muted);
  font-size: 13px;
  margin: 14px 0 0;
}

.home-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 30px;
  margin-top: 34px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
.home-meta b { color: var(--ink); font-weight: 600; }

.home-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 26px;
}
.home-card {
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, .5);
  padding: 18px;
  border-radius: var(--radius);
}
.home-card h3 { font-size: 15px; margin-bottom: 6px; }
.home-card p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.65; }
@media (max-width: 680px) {
  .home-cards { grid-template-columns: 1fr; }
}

/* progress */
.progress {
  list-style: none;
  display: flex;
  gap: 6px;
  padding: 0;
  margin: 8px 0 30px;
  counter-reset: step;
}
.progress li {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 7px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .04em;
  padding-bottom: 9px;
  border-bottom: 2px solid var(--line);
}
.progress li span {
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  font-size: 11px;
}
.progress li.is-done { color: var(--ink-2); border-bottom-color: var(--line-strong); }
.progress li.is-on { color: var(--red); border-bottom-color: var(--red); }
.progress li.is-on span { border-color: var(--red); color: var(--red); }

/* cards */
.card {
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, .62);
  border-radius: var(--radius);
  padding: 26px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.card.flush { padding: 0; overflow: hidden; }

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 14px;
}
.card-head .tag {
  flex: none;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--red);
  border: 1px solid rgba(155, 44, 31, .28);
  padding: 3px 8px;
  border-radius: 999px;
  background: rgba(155, 44, 31, .04);
}
.card-head .tag.low { color: var(--gold); border-color: rgba(138, 106, 47, .3); background: rgba(138, 106, 47, .05); }
.card-head .tag.mid { color: var(--green); border-color: rgba(61, 90, 69, .3); background: rgba(61, 90, 69, .05); }

.era-line {
  font-family: var(--serif);
  font-size: clamp(26px, 5vw, 40px);
  line-height: 1.25;
  margin: 0 0 6px;
}
.era-sub { color: var(--muted); font-size: 14px; margin: 0 0 18px; }

.place-name {
  font-family: var(--serif);
  font-size: clamp(28px, 5.4vw, 44px);
  line-height: 1.2;
  margin: 0 0 6px;
}
.place-modern { color: var(--ink-2); font-size: 15px; margin: 0 0 16px; }
.place-modern b { color: var(--red); }

.standard-loc {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  border: 1px dashed var(--line-strong);
  padding: 8px 12px;
  border-radius: var(--radius);
  color: var(--muted);
  font-size: 13px;
  background: rgba(255, 253, 248, .6);
}
.standard-loc .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 0 3px rgba(155, 44, 31, .12);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 18px 0;
}
.stat {
  background: var(--paper-2);
  padding: 14px 12px;
}
.stat .k { color: var(--muted); font-size: 11px; letter-spacing: .06em; display: block; margin-bottom: 4px; }
.stat .v { font-family: var(--serif); font-size: 22px; line-height: 1.2; }
.stat .u { color: var(--muted); font-size: 11px; margin-left: 2px; }
@media (max-width: 620px) {
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
}

.origin-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 6px 0 14px;
}
.pill {
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, .65);
  padding: 6px 11px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--ink-2);
}
.pill b { color: var(--red); font-weight: 600; }

/* story */
.story {
  font-family: var(--serif);
  font-size: 18px;
  line-height: 2.05;
  color: var(--ink);
}
.story p { margin: 0 0 1.1em; }
.story p:first-letter { font-size: 1.05em; }
.story .refs {
  font-family: var(--sans);
  font-size: 10px;
  vertical-align: super;
  color: var(--red);
  margin-left: 2px;
  cursor: pointer;
  white-space: nowrap;
}
.story .refs:hover { text-decoration: underline; }
.story .fact {
  border-bottom: 1px dotted rgba(155, 44, 31, .35);
  cursor: help;
}

.timeline {
  list-style: none;
  padding: 0;
  margin: 24px 0 0;
  border-left: 1px solid var(--line-strong);
  margin-left: 8px;
}
.timeline li {
  position: relative;
  padding: 0 0 18px 22px;
}
.timeline li::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 7px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--paper);
  border: 1px solid var(--red);
}
.timeline .age {
  color: var(--red);
  font-size: 12px;
  letter-spacing: .06em;
  display: block;
  margin-bottom: 2px;
}
.timeline .what { color: var(--ink-2); font-size: 14px; }

.knowledge-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 16px;
}
.knowledge {
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, .55);
  padding: 18px 20px;
  border-radius: var(--radius);
}
.knowledge h3 { font-size: 16px; margin-bottom: 6px; }
.knowledge p { margin: 0; color: var(--ink-2); font-size: 14px; line-height: 1.8; }
.knowledge .src { margin-top: 8px; font-size: 11px; color: var(--muted); }

.source-list {
  margin: 10px 0 0;
  padding: 0;
  list-style: none;
  columns: 1;
}
.source-list li {
  font-size: 13px;
  color: var(--ink-2);
  padding: 8px 0;
  border-top: 1px solid var(--line);
  display: flex;
  gap: 10px;
  align-items: baseline;
}
.source-list li:first-child { border-top: 0; }
.source-list li.is-hit { background: rgba(155, 44, 31, .06); }
.source-list .id {
  color: var(--red);
  font-size: 11px;
  flex: none;
  font-family: ui-monospace, Menlo, Consolas, monospace;
}
.source-list a { color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--line-strong); }
.source-list a:hover { color: var(--red); border-bottom-color: var(--red); }
.source-list .type { color: var(--muted); font-size: 11px; margin-left: auto; flex: none; }

.detail {
  margin-top: 10px;
  border-top: 1px solid var(--line);
  padding-top: 10px;
}
.detail summary {
  cursor: pointer;
  color: var(--muted);
  font-size: 13px;
  list-style: none;
}
.detail summary::-webkit-details-marker { display: none; }
.detail summary::before { content: "＋ "; color: var(--red); }
.detail[open] summary::before { content: "－ "; }
.detail .body { padding-top: 10px; }

.stage-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 22px;
}
.stage-actions .spacer { flex: 1; }

.note {
  border-left: 2px solid var(--red);
  padding: 4px 0 4px 14px;
  color: var(--muted);
  font-size: 13px;
  margin: 16px 0;
}

.warn {
  border: 1px solid rgba(138, 106, 47, .3);
  background: rgba(138, 106, 47, .05);
  color: #5f4b25;
  padding: 12px 14px;
  border-radius: var(--radius);
  font-size: 13px;
  margin: 14px 0;
}

/* about */
.page-head { padding: 34px 0 18px; }
.page-head h1 { font-size: clamp(28px, 5vw, 44px); }

.about-section { margin: 26px 0; }
.about-section h2 { font-size: 22px; }
.about-section p { color: var(--ink-2); }

.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  background: rgba(255, 253, 248, .5);
}
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--muted); font-weight: 500; font-size: 11px; letter-spacing: .06em; background: rgba(29, 27, 24, .03); }
tr:last-child td { border-bottom: 0; }
td.num { font-variant-numeric: tabular-nums; white-space: nowrap; }
.badge {
  display: inline-block;
  font-size: 11px;
  padding: 2px 7px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--muted);
  white-space: nowrap;
}
.badge.high { color: var(--green); border-color: rgba(61, 90, 69, .35); background: rgba(61, 90, 69, .05); }
.badge.low { color: var(--gold); border-color: rgba(138, 106, 47, .35); background: rgba(138, 106, 47, .05); }
.badge.mid { color: var(--ink-2); }

/* footer */
.footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 24px 24px 50px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}
.footer p { margin: 6px 0; }
.footer strong { color: var(--ink); }
.linklike {
  border: 0; background: none; padding: 0; color: var(--red);
  font-size: inherit; text-decoration: underline; text-underline-offset: 3px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 26px;
  transform: translate(-50%, 16px);
  background: var(--ink);
  color: var(--paper);
  padding: 10px 16px;
  border-radius: var(--radius);
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transition: .25s ease;
  z-index: 50;
  max-width: calc(100vw - 40px);
  text-align: center;
}
.toast.is-on { opacity: 1; transform: translate(-50%, 0); }

/* loading */
.loading {
  display: grid;
  place-items: center;
  min-height: 40vh;
  color: var(--muted);
  font-size: 14px;
}
.loading .spin {
  width: 24px; height: 24px;
  border: 2px solid var(--line);
  border-top-color: var(--red);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: 12px;
}
@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 560px) {
  .topbar { padding: 18px 18px 6px; }
  main { padding: 8px 18px 60px; }
  .card { padding: 20px 18px; }
  .story { font-size: 17px; line-height: 1.95; }
  .progress li { font-size: 10px; gap: 4px; }
  .progress li span { width: 18px; height: 18px; font-size: 10px; }
  .stat .v { font-size: 19px; }
}