/* ===== Oceanic Civilization — base ===== */
:root{
  --paper: #f4ecd8;
  --paper-2: #e9dfc4;
  --paper-deep: #d8caa3;
  --ink: #102236;
  --ink-soft: #3a4f63;
  --rule: #a89b6e;
  --brass: #c89b3c;
  --brass-2: #a87a23;
  --coral: #c8513e;
  --teal: #2a8a8a;
  --deep: #143a52;
  --sea: #4a8aae;
}
[data-theme="dark"]{
  --paper: #0c1a26;
  --paper-2: #122230;
  --paper-deep: #1a2c3c;
  --ink: #e8eef3;
  --ink-soft: #9bb1c2;
  --rule: #3d5366;
  --brass: #d8b14a;
  --brass-2: #e8c266;
  --coral: #e36e58;
  --teal: #5cb1b1;
  --deep: #5c8aae;
  --sea: #7aaecf;
}

*{box-sizing:border-box}
html,body{margin:0;padding:0}
html{scroll-behavior:smooth; scroll-padding-top:72px}
body{
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 17px; line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  background-image:
    radial-gradient(900px 500px at 18% -8%, rgba(42,138,138,.12), transparent 60%),
    radial-gradient(700px 500px at 110% 20%, rgba(200,81,62,.07), transparent 60%),
    radial-gradient(700px 500px at 50% 110%, rgba(20,58,82,.06), transparent 60%);
}
[data-theme="dark"] body{
  background-image:
    radial-gradient(900px 500px at 18% -8%, rgba(92,177,177,.10), transparent 60%),
    radial-gradient(700px 500px at 110% 20%, rgba(227,110,88,.06), transparent 60%),
    radial-gradient(700px 500px at 50% 110%, rgba(122,174,207,.05), transparent 60%);
}

a{color:var(--ink); text-decoration: underline; text-decoration-color: var(--rule); text-underline-offset: 3px}
a:hover{text-decoration-color: var(--brass)}
em{font-style:italic; color: var(--coral)}

/* ===== Bilingual toggle ===== */
[lang="zh"]{display:none}
html[data-lang="zh"] [lang="en"]{display:none}
html[data-lang="zh"] [lang="zh"]{display:initial}
html svg [lang="zh"]{display:none}
html[data-lang="zh"] svg [lang="zh"]{display:inline}
html[data-lang="zh"] svg [lang="en"]{display:none}
html[data-lang="zh"]{
  font-family: "Noto Serif SC", "Source Han Serif SC", "Source Serif 4", Georgia, serif;
}

/* ===== Topbar ===== */
.topbar{
  position:sticky; top:0; z-index:50;
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}
.topbar-inner{
  max-width: 1320px; margin: 0 auto;
  padding: 12px 24px;
  display:flex; align-items:center; gap:18px;
}
.brand{
  display:flex; align-items:center; gap:10px;
  font-family: "Cormorant Garamond", serif;
  font-size: 22px; font-weight: 600; letter-spacing: .01em;
  text-decoration:none; color:var(--ink);
}
.brand .seal{
  display:inline-flex; align-items:center; justify-content:center;
  width:36px; height:36px; border-radius:50%;
  background: var(--deep); color: var(--paper);
  font-family: "Cormorant Garamond", serif; font-style:italic; font-size:18px;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.2), inset 0 0 0 3px var(--brass), 0 1px 0 rgba(255,255,255,.1);
}
[data-theme="dark"] .brand .seal{background: var(--brass); color: var(--deep); box-shadow: inset 0 0 0 1px rgba(0,0,0,.2), inset 0 0 0 3px var(--paper), 0 1px 0 rgba(0,0,0,.1);}
.nav{display:flex; gap:14px; flex-wrap:wrap; margin-left:8px}
.nav a{
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 12px; letter-spacing: .04em;
  text-transform: uppercase; text-decoration:none;
  color: var(--ink-soft);
  padding: 6px 0; border-bottom: 1px solid transparent;
}
.nav a:hover{color:var(--ink); border-bottom-color: var(--brass)}
.toolbar{margin-left:auto; display:flex; gap:10px; align-items:center}
.lang-toggle, .theme-toggle{display:inline-flex; gap:0; border:1px solid var(--rule); border-radius:3px; overflow:hidden}
.lang-toggle button, .theme-toggle button{
  font-family: "JetBrains Mono", monospace; font-size: 12px;
  background: transparent; color: var(--ink-soft);
  border:none; border-right:1px solid var(--rule); padding: 5px 10px;
  cursor: pointer; letter-spacing: .04em;
}
.lang-toggle button:last-child, .theme-toggle button:last-child{border-right:none}
.lang-toggle button.active, .theme-toggle button.active{background: var(--ink); color: var(--paper)}

/* ===== Hero ===== */
.hero{ max-width: 1320px; margin: 0 auto; padding: 80px 24px 48px; }
.hero-eyebrow{
  font-family: "JetBrains Mono", monospace;
  font-size: 12px; letter-spacing: .18em;
  color: var(--brass-2); text-transform: uppercase;
  margin-bottom: 24px;
}
.hero h1{
  font-family: "Cormorant Garamond", serif; font-weight: 600;
  font-size: clamp(40px, 6vw, 76px);
  line-height: 1.05; letter-spacing: -.01em;
  margin: 0 0 20px; max-width: 18ch;
}
.hero h1 em{color: var(--coral); font-style: italic}
.hero-lede{
  font-size: 20px; line-height: 1.55; max-width: 64ch;
  color: var(--ink-soft); margin: 0 0 28px;
}
.hero-thesis{
  display:grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px; margin-top: 36px;
}
.hero-thesis div{ border-left: 2px solid var(--brass); padding: 8px 0 8px 16px; }
.hero-thesis strong{
  font-family: "JetBrains Mono", monospace; font-weight:500;
  font-size: 11px; letter-spacing: .12em;
  color: var(--brass-2); text-transform: uppercase;
  display:block; margin-bottom: 4px;
}

/* ===== Section ===== */
section{ max-width: 1320px; margin: 0 auto; padding: 64px 24px; border-top: 1px solid var(--rule); }
section.no-rule{border-top:none}
.section-eyebrow{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .18em;
  color: var(--brass-2); text-transform: uppercase;
  margin: 0 0 12px;
}
.section-title{
  font-family: "Cormorant Garamond", serif; font-weight: 500;
  font-size: clamp(30px, 3.6vw, 44px);
  line-height: 1.15; margin: 0 0 16px;
}
.section-lede{
  font-size: 18px; line-height: 1.6; color: var(--ink-soft);
  max-width: 70ch; margin: 0 0 32px;
}

/* ===== Map ===== */
.map-wrap{
  border: 1px solid var(--rule); border-radius: 4px;
  background: var(--paper-2);
  background-image:
    repeating-linear-gradient(0deg, rgba(0,0,0,.02) 0 1px, transparent 1px 32px),
    repeating-linear-gradient(90deg, rgba(0,0,0,.02) 0 1px, transparent 1px 32px);
  overflow: hidden;
}
[data-theme="dark"] .map-wrap{
  background-image:
    repeating-linear-gradient(0deg, rgba(255,255,255,.02) 0 1px, transparent 1px 32px),
    repeating-linear-gradient(90deg, rgba(255,255,255,.02) 0 1px, transparent 1px 32px);
}
.map-wrap svg{display:block; width:100%; height:auto}
.map-controls{
  display:flex; gap:8px; flex-wrap:wrap; padding: 10px 12px;
  border-bottom: 1px solid var(--rule);
  background: color-mix(in oklab, var(--paper-deep) 60%, var(--paper));
}
.map-controls button{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .04em;
  background: transparent; color: var(--ink-soft);
  border: 1px solid var(--rule); padding: 4px 10px; border-radius: 3px;
  cursor: pointer; text-transform: uppercase;
}
.map-controls button.active{background: var(--ink); color: var(--paper); border-color: var(--ink)}
.map-controls button:hover:not(.active){border-color: var(--brass); color: var(--ink)}
.map-legend{
  display:flex; gap:18px; flex-wrap:wrap;
  padding: 10px 12px; border-top: 1px solid var(--rule);
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; color: var(--ink-soft);
}
.map-legend span{display:inline-flex; align-items:center; gap:6px}
.map-legend i{width:18px; height:3px; display:inline-block; border-radius:2px}

/* ===== Grid cards ===== */
.grid{ display:grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid.two{grid-template-columns: repeat(auto-fit, minmax(380px, 1fr))}
.card{
  border: 1px solid var(--rule);
  background: color-mix(in oklab, var(--paper-2) 70%, var(--paper));
  border-radius: 4px; padding: 22px;
}
.card h3{
  font-family: "Cormorant Garamond", serif; font-weight: 600;
  font-size: 22px; margin: 0 0 8px; line-height: 1.2;
}
.card .meta{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .08em;
  color: var(--brass-2); text-transform: uppercase;
  margin-bottom: 10px;
}
.card p{margin: 0 0 10px; line-height:1.55}
.card ul{margin: 8px 0 0; padding-left: 18px; color: var(--ink-soft); font-size: 14px}
.card ul li{margin-bottom: 4px}

/* ===== Timeline ===== */
.timeline-wrap{
  border: 1px solid var(--rule); background: var(--paper-2);
  border-radius: 4px; padding: 20px 16px 24px; overflow: hidden;
}
.timeline-axis{
  display:flex; justify-content: space-between;
  font-family: "JetBrains Mono", monospace; font-size: 11px;
  color: var(--ink-soft); padding: 0 8px 6px;
  border-bottom: 1px solid var(--rule);
}
.timeline-rows{position:relative; margin-top: 12px}
.timeline-row{
  position: relative; height: 38px; margin-bottom: 6px;
  display:flex; align-items:center;
}
.timeline-label{
  position: absolute; left: 0; top: 0; height: 100%;
  width: 200px;
  display:flex; flex-direction: column; justify-content: center;
  padding-right: 12px; border-right: 1px solid var(--rule);
  font-family: "Cormorant Garamond", serif; font-size: 16px; font-weight: 600;
}
.timeline-label small{
  font-family: "JetBrains Mono", monospace;
  font-size: 10px; color: var(--ink-soft); font-weight: 400;
}
.timeline-bar-track{
  margin-left: 212px; position: relative; flex: 1; height: 22px;
}
.timeline-bar{
  position: absolute; top: 0; height: 100%;
  border-radius: 2px; cursor: pointer;
  transition: filter .15s, transform .15s;
  display:flex; align-items:center; padding: 0 8px;
  font-family: "JetBrains Mono", monospace; font-size: 10px;
  color: rgba(255,255,255,.9); white-space: nowrap; overflow:hidden;
}
.timeline-bar:hover{filter: brightness(1.15); transform: translateY(-1px)}
.timeline-detail{
  margin-top: 24px; border: 1px solid var(--rule);
  border-radius: 4px; padding: 22px; background: var(--paper);
}
.timeline-detail h3{
  font-family: "Cormorant Garamond", serif; font-weight: 600;
  font-size: 28px; margin: 0 0 6px; line-height: 1.1;
}
.timeline-detail .meta{
  font-family: "JetBrains Mono", monospace; font-size: 11px;
  letter-spacing: .1em; text-transform: uppercase;
  color: var(--brass-2); margin-bottom: 14px;
}
.timeline-detail .keys{
  display:flex; gap: 8px; flex-wrap: wrap; margin-top: 12px;
}
.timeline-detail .keys span{
  background: var(--paper-deep); border: 1px solid var(--rule);
  font-family: "JetBrains Mono", monospace; font-size: 11px;
  padding: 4px 10px; border-radius: 3px;
}

/* ===== Contrasts table ===== */
.contrasts{
  width:100%; border-collapse: collapse;
  border: 1px solid var(--rule); border-radius: 4px; overflow: hidden;
}
.contrasts th, .contrasts td{
  text-align:left; vertical-align: top;
  padding: 14px 16px; border-bottom: 1px solid var(--rule);
  font-size: 15px;
}
.contrasts th{
  background: var(--paper-deep);
  font-family: "JetBrains Mono", monospace; font-weight: 500;
  font-size: 11px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--brass-2);
}
.contrasts td:first-child{
  font-family: "Cormorant Garamond", serif;
  font-size: 18px; font-weight: 600; width: 22%;
}

/* ===== Trade flow ===== */
.flow{ display:grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.flow-card{
  border: 1px solid var(--rule);
  border-left: 4px solid var(--brass);
  padding: 18px 20px;
  border-radius: 0 4px 4px 0;
  background: color-mix(in oklab, var(--paper-2) 70%, var(--paper));
}
.flow-card h3{font-family: "Cormorant Garamond", serif; margin: 0 0 4px; font-size: 22px}
.flow-card .period{
  font-family: "JetBrains Mono", monospace; font-size: 11px;
  letter-spacing: .08em; color: var(--brass-2); text-transform: uppercase;
  margin-bottom: 10px;
}
.flow-card .route{
  font-family: "JetBrains Mono", monospace; font-size: 12px;
  color: var(--ink-soft); margin-bottom: 10px; line-height: 1.6;
}
.flow-card p{margin:0; font-size: 14px; line-height: 1.55}

/* ===== Simulator ===== */
.sim{
  display:grid; grid-template-columns: 320px 1fr; gap: 24px;
  border: 1px solid var(--rule); border-radius: 4px;
  background: var(--paper-2); padding: 24px;
}
.sim-controls .ctrl{margin-bottom: 18px}
.sim-controls label{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink-soft); display:block; margin-bottom: 6px;
}
.sim-controls input[type="range"]{ width: 100%; accent-color: var(--coral); }
.sim-controls .val{
  font-family: "JetBrains Mono", monospace; font-size: 12px;
  color: var(--brass-2); float: right;
}
.sim-output{display:flex; flex-direction: column; gap: 16px;}
.sim-meter{
  display:grid; grid-template-columns: 160px 1fr 60px;
  gap: 12px; align-items: center;
  font-family: "JetBrains Mono", monospace; font-size: 12px;
}
.sim-meter .bar{
  height: 8px; background: var(--paper-deep);
  border-radius: 4px; overflow: hidden;
}
.sim-meter .bar-fill{
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--brass), var(--coral));
  transition: width .25s ease;
}
.sim-meter .num{text-align:right; color: var(--brass-2)}
.sim-summary{
  margin-top: 8px; padding: 16px;
  background: var(--paper); border: 1px dashed var(--rule); border-radius: 3px;
  font-style: italic; color: var(--ink-soft); font-size: 15px; line-height: 1.55;
}

/* ===== AI Q&A ===== */
.ai-panel{
  border: 1px solid var(--rule); border-radius: 4px;
  background: var(--paper-2); padding: 24px;
}
.ai-q{
  font-family: "Cormorant Garamond", serif;
  font-size: 22px; font-weight: 500;
  margin: 0 0 8px;
}
.ai-q::before{content:"⚓ "; color: var(--brass-2)}
.ai-a{
  margin: 0 0 24px;
  padding-left: 22px; border-left: 2px solid var(--rule);
  font-size: 16px; line-height: 1.65; color: var(--ink-soft);
}
.ai-a:last-child{margin-bottom: 0}

/* ===== Footer ===== */
footer{
  max-width: 1320px; margin: 0 auto; padding: 48px 24px 64px;
  border-top: 1px solid var(--rule);
  font-size: 14px; color: var(--ink-soft);
  display:flex; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
footer a{color:var(--ink-soft)}

/* ===== Responsive ===== */
@media (max-width: 900px){
  .nav{display:none}
  .sim{grid-template-columns: 1fr}
  .timeline-label{width:140px; font-size:13px}
  .timeline-bar-track{margin-left: 152px}
}
@media (max-width: 600px){
  .topbar-inner{padding: 10px 16px; gap: 10px}
  .hero{padding: 56px 16px 36px}
  section{padding: 48px 16px}
  .timeline-label{width:108px; font-size: 12px}
  .timeline-bar-track{margin-left: 120px}
  .timeline-bar{font-size: 9px; padding: 0 4px}
}