/* Layout: a chart-room hub — slim top bar, left-aligned hero with a coordinate line,
   then a "chart index" grid of sections. Navy night-chart by default, pale chart paper in light. */
:root{
  --bg:#eef2f4; --panel:#f8fafb; --ink:#14202d; --ink-2:#4a5a6b; --ink-3:#7a8898;
  --line:#cfd8df; --grid:#dfe6eb; --accent:#94651c; --accent-soft:#f1e4cc; --sea:#d7e3ea;
  --f-display:"Newsreader", "Iowan Old Style", Georgia, serif;
  --f-body:"IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --f-mono:"IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --wrap:1080px;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){ :root:not([data-theme="light"]){
  --bg:#111b28; --panel:#172435; --ink:#e7edf3; --ink-2:#a3b3c4; --ink-3:#6f8195;
  --line:#26374b; --grid:#1a2839; --accent:#d9ad62; --accent-soft:#2c2a24; --sea:#18293b;
  color-scheme:dark } }
:root[data-theme="dark"]{
  --bg:#111b28; --panel:#172435; --ink:#e7edf3; --ink-2:#a3b3c4; --ink-3:#6f8195;
  --line:#26374b; --grid:#1a2839; --accent:#d9ad62; --accent-soft:#2c2a24; --sea:#18293b;
  color-scheme:dark }

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.6;
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:64px 64px;background-position:-1px -1px}
a{color:inherit;text-underline-offset:3px;text-decoration-thickness:1px}
a:hover{color:var(--accent)}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px}
img,svg{max-width:100%}

.wrap{max-width:var(--wrap);margin:0 auto;padding-inline:clamp(16px,4vw,32px)}

/* top bar */
.topbar{border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(6px);
  position:sticky;top:env(safe-area-inset-top,0px);z-index:10}
.topbar .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px 24px;flex-wrap:wrap;padding-block:12px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-family:var(--f-display);font-size:20px;font-weight:500;letter-spacing:.01em}
.mark{display:inline-block;flex:none;background:var(--accent);
  -webkit-mask:url(../img/sailboat.svg) center/contain no-repeat;mask:url(../img/sailboat.svg) center/contain no-repeat}
.brand .mark{width:34px;height:34px;margin-block:-4px;-webkit-mask-image:url(../img/sailboat-small.svg);mask-image:url(../img/sailboat-small.svg)}
.nav{display:flex;flex-wrap:wrap;gap:4px 20px;font-size:14px;letter-spacing:.08em;text-transform:uppercase}
.nav a{text-decoration:none;color:var(--ink-2);padding-block:4px}
.nav a:hover,.nav a[aria-current="page"]{color:var(--ink)}
.nav a[aria-current="page"]{box-shadow:inset 0 -2px 0 var(--accent)}

/* type */
h1,h2,h3{font-family:var(--f-display);font-weight:500;line-height:1.1;text-wrap:balance;margin:0}
.eyebrow{font-family:var(--f-mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--accent);margin:0}
.lede{font-size:clamp(18px,2.2vw,21px);color:var(--ink-2);max-width:40ch;margin:0}
.prose{max-width:65ch}
.prose p{margin:0 0 1em}
.mono{font-family:var(--f-mono);font-size:13px;color:var(--ink-3);letter-spacing:.04em;font-variant-numeric:tabular-nums}

main{padding-block:clamp(40px,8vw,88px) 64px;display:flex;flex-direction:column;gap:clamp(48px,8vw,80px)}

/* hero */
.hero{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:24px 48px}
.hero-text{display:flex;flex-direction:column;gap:18px;min-width:0}
.hero .mark{width:clamp(200px,24vw,300px);aspect-ratio:1;max-width:100%}
@media (max-width: 760px){ .hero{grid-template-columns:minmax(0,1fr)} .hero .mark{display:none} }
.hero h1{font-size:clamp(48px,9vw,104px);letter-spacing:-.02em;font-weight:400}
.hero h1 em{font-style:italic;color:var(--accent)}
.page-head{display:flex;flex-direction:column;gap:14px}
.page-head h1{font-size:clamp(40px,6vw,64px);font-weight:400;letter-spacing:-.01em}

/* chart index */
.index-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:10px;margin-bottom:20px}
.index-head h2{font-size:14px;font-family:var(--f-mono);font-weight:500;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-2)}
.tiles{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:16px}
.tile{position:relative;display:flex;flex-direction:column;gap:10px;min-width:0;padding:22px 22px 20px;background:var(--panel);border:1px solid var(--line);border-radius:6px;text-decoration:none;
  transition:border-color .2s, transform .2s}
.tile:hover{border-color:var(--accent);transform:translateY(-2px);color:inherit}
.tile .no{font-family:var(--f-mono);font-size:12px;color:var(--ink-3);letter-spacing:.1em}
.tile h3{font-size:clamp(26px,3vw,32px)}
.tile p{margin:0;color:var(--ink-2);max-width:48ch}
.tile .go{margin-top:auto;padding-top:8px;font-family:var(--f-mono);font-size:13px;letter-spacing:.06em;color:var(--accent)}
.tile.feature{grid-column:span 6;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);gap:24px;padding:0;overflow:hidden}
.tile.feature .body{display:flex;flex-direction:column;gap:10px;padding:28px}
.tile.feature h3{font-size:clamp(32px,4.4vw,48px)}
.tile.feature .art{background:var(--sea);border-left:1px solid var(--line);min-height:240px;display:block}
.tile.third{grid-column:span 2}
.tile.half{grid-column:span 3}
.badge{display:inline-flex;align-self:flex-start;font-family:var(--f-mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;padding:3px 8px;border-radius:3px;background:var(--accent-soft);color:var(--accent)}

/* route art */
.route-land{fill:var(--panel);stroke:var(--line);stroke-width:1.2}
.route-line{fill:none;stroke:var(--accent);stroke-width:2.2;stroke-dasharray:6 5;stroke-linecap:round}
.route-dot{fill:var(--bg);stroke:var(--ink);stroke-width:1.6}
.route-lbl{font-family:var(--f-mono);font-size:10px;letter-spacing:.08em;fill:var(--ink-2)}
@media (prefers-reduced-motion: no-preference){
  .tile.feature:hover .route-line{animation:sail 1.2s linear infinite}
}
@keyframes sail{to{stroke-dashoffset:-22}}

/* map cards (maps page) */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,320px),1fr));gap:16px}

/* resource links */
.links{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,300px),1fr));gap:0 32px}
.links li{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:baseline;gap:2px 12px;padding:16px 0;border-bottom:1px solid var(--line);min-width:0}
.links a{font-family:var(--f-display);font-size:22px;text-decoration:none}
.links a::after{content:" ↗";font-size:14px;color:var(--accent)}
.links .host{font-family:var(--f-mono);font-size:12px;color:var(--ink-3)}
.links p{grid-column:1/-1;margin:0;color:var(--ink-2);font-size:15px}
.links .badge{display:inline-block;margin-right:6px;vertical-align:1px}

/* empty state */
.empty{border:1px dashed var(--line);border-radius:6px;padding:28px;background:color-mix(in srgb,var(--panel) 70%,transparent);display:flex;flex-direction:column;gap:8px;max-width:640px}
.empty p{margin:0;color:var(--ink-2)}

/* about */
.facts{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,220px),1fr));gap:0;border-top:1px solid var(--line)}
.facts div{padding:14px 0;border-bottom:1px solid var(--line);display:flex;flex-direction:column;gap:2px;padding-right:16px}
.facts dt{font-family:var(--f-mono);font-size:12px;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-3)}
.facts dd{margin:0}

/* footer */
footer{border-top:1px solid var(--line)}
footer .wrap{display:flex;justify-content:space-between;gap:8px 24px;flex-wrap:wrap;padding-block:22px 28px}
footer a{color:var(--ink-2)}

@media (max-width: 760px){
  .tile.feature{grid-template-columns:minmax(0,1fr)}
  .tile.feature .art{border-left:none;border-top:1px solid var(--line);min-height:190px;order:-1}
  .tile.third,.tile.half{grid-column:span 6}
}
@media (prefers-reduced-motion: reduce){.tile{transition:none}.tile:hover{transform:none}}