/* ============================================================
   THE LONG WALK — deep-time field-notebook design system
   ============================================================ */
:root, [data-theme="light"]{
  --paper:#f1e9db; --paper-2:#f7f0e3; --surface:#fbf6ec; --surface-2:#fffaf1;
  --line:#ddd1bd; --line-strong:#c8ba9f;
  --ink:#241b12; --ink-muted:#6c5f4d; --ink-faint:#a3957f;
  --accent:#b4531f; --accent-hover:#963f15; --accent-soft:#e7d3c2;
  --gold:#a9791f; --gold-soft:#ece0c4;
  --teal:#2f6f6a;
  --strata-1:#caa86f; --strata-2:#bf8e57; --strata-3:#a9714a; --strata-4:#8a5a40; --strata-5:#6e4a3a;
  --shadow-sm:0 1px 2px rgba(60,40,20,.07);
  --shadow-md:0 6px 22px rgba(60,40,20,.10);
  --shadow-lg:0 18px 50px rgba(50,32,16,.16);
  --maxw:1180px;
  --font-display:"Fraunces","Georgia",serif;
  --font-body:"Work Sans","Helvetica Neue",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,monospace;
  --r-sm:6px; --r-md:12px; --r-lg:20px; --r-xl:28px;
  --t:200ms cubic-bezier(.16,1,.3,1);
}
[data-theme="dark"]{
  --paper:#16110b; --paper-2:#1b150e; --surface:#211a11; --surface-2:#271f14;
  --line:#3a2f20; --line-strong:#4a3c28;
  --ink:#ece1cd; --ink-muted:#a3957c; --ink-faint:#70634e;
  --accent:#d8753f; --accent-hover:#e88a53; --accent-soft:#3a2719;
  --gold:#d2a24e; --gold-soft:#34291a;
  --teal:#5fa39c;
  --strata-1:#7c6038; --strata-2:#6f5232; --strata-3:#5e432f; --strata-4:#4c3829; --strata-5:#3b2d22;
  --shadow-sm:0 1px 2px rgba(0,0,0,.3);
  --shadow-md:0 6px 22px rgba(0,0,0,.4);
  --shadow-lg:0 18px 50px rgba(0,0,0,.55);
}
@media (prefers-color-scheme:dark){:root:not([data-theme]){
  --paper:#16110b; --paper-2:#1b150e; --surface:#211a11; --surface-2:#271f14;
  --line:#3a2f20; --line-strong:#4a3c28; --ink:#ece1cd; --ink-muted:#a3957c; --ink-faint:#70634e;
  --accent:#d8753f; --accent-hover:#e88a53; --accent-soft:#3a2719; --gold:#d2a24e; --gold-soft:#34291a;
}}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;scroll-behavior:smooth;scroll-padding-top:90px}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{animation-duration:.01ms!important;transition-duration:.01ms!important}}
body{min-height:100dvh;overflow-x:hidden;line-height:1.65;font-family:var(--font-body);font-size:1rem;color:var(--ink);
  background:var(--paper);
  background-image:radial-gradient(1200px 600px at 80% -10%, color-mix(in oklab,var(--gold-soft),transparent 60%), transparent 60%);
  -webkit-font-smoothing:antialiased;transition:background-color var(--t),color var(--t)}
img,svg,canvas{display:block;max-width:100%;height:auto}
a{color:inherit;text-decoration:none}
button{cursor:pointer;background:none;border:none;color:inherit;font:inherit}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:560;line-height:1.1;text-wrap:balance;letter-spacing:-.01em}
p{text-wrap:pretty;max-width:70ch}
::selection{background:color-mix(in oklab,var(--accent),transparent 72%)}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-sm)}
.mono{font-family:var(--font-mono)}
.wrap{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:clamp(1.1rem,4vw,2.5rem)}

/* ---------- Header ---------- */
.nav{position:sticky;top:0;z-index:50;backdrop-filter:blur(10px);
  background:color-mix(in oklab,var(--paper),transparent 12%);
  border-bottom:1px solid var(--line);transition:background var(--t)}
.nav-in{display:flex;align-items:center;gap:1.2rem;height:64px}
.brand{display:flex;align-items:center;gap:.6rem;font-family:var(--font-display);font-size:1.12rem;font-weight:600;letter-spacing:-.02em}
.brand svg{width:30px;height:30px;color:var(--accent);flex:none}
.nav-links{margin-left:auto;display:flex;align-items:center;gap:.3rem}
.nav-links a{font-size:.84rem;letter-spacing:.03em;text-transform:uppercase;color:var(--ink-muted);padding:.5rem .7rem;border-radius:var(--r-sm)}
.nav-links a:hover,.nav-links a.active{color:var(--ink);background:color-mix(in oklab,var(--accent),transparent 90%)}
.icon-btn{width:38px;height:38px;display:grid;place-items:center;border-radius:var(--r-sm);color:var(--ink-muted)}
.icon-btn:hover{color:var(--accent);background:color-mix(in oklab,var(--accent),transparent 90%)}
@media(max-width:640px){
  .nav-in{gap:.5rem;height:auto;min-height:64px;flex-wrap:wrap;padding-block:.5rem;row-gap:.2rem}
  .brand span{font-size:1rem}
  .nav-links{gap:.05rem;margin-left:auto}
  .nav-links a:not(.btn){font-size:.7rem;padding:.45rem .5rem;letter-spacing:.02em}
}
@media(max-width:380px){.brand span{display:none}}

/* ---------- Hero ---------- */
.hero{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.hero-img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.9}
.hero-veil{position:absolute;inset:0;background:
  linear-gradient(to bottom, color-mix(in oklab,var(--paper),transparent 35%) 0%, color-mix(in oklab,var(--paper),transparent 55%) 40%, var(--paper) 100%)}
.hero-in{position:relative;padding-block:clamp(4rem,13vw,9rem);max-width:780px}
.eyebrow{font-family:var(--font-mono);font-size:.78rem;letter-spacing:.22em;text-transform:uppercase;color:var(--accent);margin-bottom:1.1rem}
.hero h1{font-size:clamp(2.7rem,7vw,5.4rem);font-weight:540;line-height:.98}
.hero h1 em{font-style:italic;color:var(--accent)}
.hero .lede{font-size:clamp(1.05rem,2.2vw,1.32rem);color:var(--ink-muted);margin-top:1.4rem;max-width:60ch}
.hero-cta{display:flex;flex-wrap:wrap;gap:.8rem;margin-top:2.2rem}
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.78rem 1.3rem;border-radius:var(--r-sm);font-size:.92rem;font-weight:600;
  background:var(--accent);color:#fff;box-shadow:var(--shadow-sm);transition:all var(--t)}
.btn:hover{background:var(--accent-hover);transform:translateY(-1px);box-shadow:var(--shadow-md)}
.btn.ghost{background:transparent;color:var(--ink);border:1px solid var(--line-strong)}
.btn.ghost:hover{background:var(--surface);border-color:var(--accent);color:var(--accent)}

/* ---------- Section scaffolding ---------- */
section{padding-block:clamp(3rem,7vw,6rem)}
.sec-head{max-width:62ch;margin-bottom:clamp(2rem,5vw,3.4rem)}
.sec-head .kicker{font-family:var(--font-mono);font-size:.76rem;letter-spacing:.2em;text-transform:uppercase;color:var(--accent);display:block;margin-bottom:.8rem}
.sec-head h2{font-size:clamp(1.9rem,4.2vw,3rem);font-weight:520}
.sec-head p{color:var(--ink-muted);margin-top:.9rem;font-size:1.06rem}

/* ---------- Timeline ---------- */
.era-band{display:flex;align-items:baseline;gap:1rem;padding:.5rem 0 .3rem;margin-top:1.5rem;
  border-top:2px solid var(--line-strong)}
.era-band .era-name{font-family:var(--font-display);font-size:1.15rem;color:var(--ink)}
.era-band .era-span{font-family:var(--font-mono);font-size:.78rem;color:var(--ink-faint);margin-left:auto}

.timeline{position:relative;margin-top:1rem}
.timeline::before{content:"";position:absolute;left:25px;top:0;bottom:0;width:2px;
  background:linear-gradient(var(--strata-1),var(--strata-3),var(--strata-5));opacity:.5}
@media(min-width:780px){.timeline::before{left:140px}}

.tl-item{position:relative;display:grid;grid-template-columns:1fr;gap:0;padding-left:62px;margin-bottom:1.5rem}
@media(min-width:780px){.tl-item{grid-template-columns:120px 1fr;padding-left:0;gap:48px;align-items:center}}
.tl-date{font-family:var(--font-mono);font-size:.8rem;color:var(--ink-faint);text-align:left;padding-top:.2rem}
@media(min-width:780px){.tl-date{text-align:right}}
.tl-node{position:absolute;left:16px;top:1.6rem;width:20px;height:20px;border-radius:50%;
  background:var(--surface);border:3px solid var(--accent);z-index:2;box-shadow:0 0 0 4px var(--paper)}
@media(min-width:780px){.tl-node{left:131px}}

.card{position:relative;background:var(--surface);border:1px solid var(--line);border-radius:var(--r-lg);
  overflow:hidden;box-shadow:var(--shadow-sm);transition:transform var(--t),box-shadow var(--t),border-color var(--t);display:block}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:color-mix(in oklab,var(--card-accent,var(--accent)),transparent 50%)}
.card-row{display:grid;grid-template-columns:96px 1fr;gap:0;align-items:stretch}
@media(min-width:560px){.card-row{grid-template-columns:150px 1fr}}
.card-thumb{position:relative;overflow:hidden;background:var(--paper-2)}
.card-thumb img{width:100%;height:100%;object-fit:cover;min-height:130px;transition:transform 600ms cubic-bezier(.16,1,.3,1)}
.card:hover .card-thumb img{transform:scale(1.05)}
.card-thumb::after{content:"";position:absolute;inset:0;background:linear-gradient(120deg,transparent 55%,color-mix(in oklab,var(--card-accent,var(--accent)),transparent 80%))}
.card-body{padding:1.1rem 1.3rem 1.2rem;min-width:0}
.card-genus{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--card-accent,var(--accent));font-weight:600}
.card h3{font-size:1.4rem;font-style:italic;margin:.15rem 0 .1rem;font-weight:500}
.card .common{font-size:.86rem;color:var(--ink-faint);margin-bottom:.55rem}
.card .tag{font-size:.95rem;color:var(--ink-muted);line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.card-meta{display:flex;flex-wrap:wrap;gap:.4rem .9rem;margin-top:.8rem}
.chip{font-family:var(--font-mono);font-size:.72rem;color:var(--ink-muted);background:color-mix(in oklab,var(--gold-soft),transparent 35%);
  padding:.22rem .5rem;border-radius:var(--r-sm);border:1px solid var(--line)}
.card-go{position:absolute;right:1rem;bottom:1rem;color:var(--card-accent,var(--accent));opacity:0;transform:translateX(-4px);transition:all var(--t)}
.card:hover .card-go{opacity:1;transform:translateX(0)}

/* reveal on scroll */
.reveal{opacity:0;transform:translateY(22px)}
.reveal.in{opacity:1;transform:none;transition:opacity .7s ease,transform .7s cubic-bezier(.16,1,.3,1)}

/* ---------- Brain-size mini bar ---------- */
.bw{position:relative;height:6px;border-radius:99px;background:var(--line);overflow:hidden;margin-top:.5rem}
.bw>span{position:absolute;inset:0 auto 0 0;border-radius:99px;background:linear-gradient(90deg,var(--gold),var(--accent))}

/* ---------- Species detail ---------- */
.sp-hero{position:relative;border-bottom:1px solid var(--line);overflow:hidden}
.sp-hero-grid{display:grid;grid-template-columns:1fr;gap:2rem;align-items:center;padding-block:clamp(2rem,5vw,3.5rem)}
@media(min-width:860px){.sp-hero-grid{grid-template-columns:340px 1fr;gap:3.2rem}}
.sp-portrait{border-radius:var(--r-lg);overflow:hidden;box-shadow:var(--shadow-lg);border:1px solid var(--line);aspect-ratio:3/4;background:var(--paper-2)}
.sp-portrait img{width:100%;height:100%;object-fit:cover}
.sp-hero h1{font-size:clamp(2.2rem,5vw,3.6rem);font-style:italic;font-weight:520}
.sp-hero .sp-genus{font-family:var(--font-mono);letter-spacing:.16em;text-transform:uppercase;color:var(--sp-accent,var(--accent));font-size:.82rem;font-weight:600}
.sp-hero .sp-common{font-size:1.05rem;color:var(--ink-faint);margin-top:.2rem}
.sp-hero .sp-tag{font-size:1.18rem;color:var(--ink-muted);margin-top:1.1rem;max-width:52ch;line-height:1.5}
.fact-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:.8rem;margin-top:1.6rem}
@media(min-width:560px){.fact-grid{grid-template-columns:repeat(3,1fr)}}
.fact{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-md);padding:.7rem .85rem}
.fact .k{font-family:var(--font-mono);font-size:.68rem;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-faint)}
.fact .v{font-size:.96rem;font-weight:600;margin-top:.15rem}

.report{display:grid;grid-template-columns:1fr;gap:2.5rem;padding-block:clamp(2.5rem,6vw,4.5rem)}
@media(min-width:920px){.report{grid-template-columns:210px 1fr;gap:4rem;align-items:start}}
.report-nav{position:sticky;top:84px;display:none;flex-direction:column;gap:.1rem}
@media(min-width:920px){.report-nav{display:flex}}
.report-nav a{font-size:.86rem;color:var(--ink-muted);padding:.45rem .7rem;border-left:2px solid var(--line);transition:all var(--t)}
.report-nav a:hover,.report-nav a.active{color:var(--sp-accent,var(--accent));border-left-color:var(--sp-accent,var(--accent));background:color-mix(in oklab,var(--accent),transparent 93%)}
.report-body{max-width:none}
.rsec{padding-top:.5rem;margin-bottom:2.6rem;scroll-margin-top:90px}
.rsec h2{font-size:1.55rem;font-weight:520;margin-bottom:.9rem;display:flex;align-items:center;gap:.7rem}
.rsec h2::before{content:"";width:26px;height:2px;background:var(--sp-accent,var(--accent))}
.rsec p{color:var(--ink);margin-bottom:1rem;font-size:1.04rem;max-width:68ch}
.rsec p em{color:var(--ink-muted)}
.rsec ul{list-style:none;display:flex;flex-direction:column;gap:.7rem;margin:.3rem 0 1rem}
.rsec li{position:relative;padding-left:1.4rem;color:var(--ink);max-width:68ch}
.rsec li::before{content:"";position:absolute;left:0;top:.62em;width:7px;height:7px;border-radius:50%;background:var(--sp-accent,var(--accent))}
.sources{border-top:1px solid var(--line);padding-top:1.3rem;margin-top:1rem}
.sources h4{font-family:var(--font-mono);font-size:.74rem;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-faint);margin-bottom:.6rem}
.sources a{display:inline-block;font-size:.88rem;color:var(--teal);border-bottom:1px solid color-mix(in oklab,var(--teal),transparent 60%);margin-right:1.1rem;margin-bottom:.4rem}
.sources a:hover{color:var(--accent)}
.sp-foot{display:flex;justify-content:space-between;gap:1rem;border-top:1px solid var(--line);padding-block:2rem;flex-wrap:wrap}
.sp-foot a{display:flex;flex-direction:column;gap:.2rem;padding:.8rem 1.1rem;border:1px solid var(--line);border-radius:var(--r-md);transition:all var(--t);min-width:200px}
.sp-foot a:hover{border-color:var(--accent);background:var(--surface)}
.sp-foot .dir{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-faint)}
.sp-foot .nm{font-style:italic;font-size:1.05rem;color:var(--ink)}
.sp-foot a.next{text-align:right;margin-left:auto}

/* ---------- Migration page ---------- */
.banner{background:linear-gradient(135deg,color-mix(in oklab,var(--accent),transparent 88%),color-mix(in oklab,var(--gold),transparent 90%));
  border-bottom:1px solid var(--line)}
#map{height:min(70vh,620px);width:100%;border-radius:var(--r-lg);border:1px solid var(--line-strong);box-shadow:var(--shadow-md);background:#dfe8ee;z-index:1;overflow:hidden}
.leaflet-container{overflow:hidden}
[data-theme="dark"] #map{background:#10171c}
.map-toolbar{display:flex;flex-wrap:wrap;gap:.5rem;margin-bottom:1rem;align-items:center}
.toggle{display:inline-flex;align-items:center;gap:.45rem;font-size:.85rem;font-weight:600;color:var(--ink-muted);
  border:1px solid var(--line-strong);background:var(--surface);padding:.5rem .85rem;border-radius:99px;transition:all var(--t)}
.toggle .dot{width:11px;height:11px;border-radius:50%}
.toggle[aria-pressed="true"]{color:var(--ink);border-color:var(--accent);background:color-mix(in oklab,var(--accent),transparent 90%)}
.toggle:hover{border-color:var(--accent)}
.legend{display:flex;flex-wrap:wrap;gap:.4rem .9rem;margin-top:.9rem;font-size:.78rem;color:var(--ink-muted)}
.legend span{display:inline-flex;align-items:center;gap:.35rem}
.legend i{width:11px;height:11px;border-radius:50%;display:inline-block}
.leaflet-popup-content-wrapper{border-radius:var(--r-md)!important;font-family:var(--font-body)}
.leaflet-popup-content{margin:.7rem .9rem!important;font-size:.84rem;line-height:1.5}
.pp-t{font-family:var(--font-display);font-style:italic;font-size:1rem;color:var(--accent);display:block;margin-bottom:.2rem}
.pp-d{font-family:var(--font-mono);font-size:.74rem;color:#666}

.stat-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:1rem}
@media(min-width:720px){.stat-grid{grid-template-columns:repeat(4,1fr)}}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-md);padding:1.2rem}
.stat .n{font-family:var(--font-display);font-size:2rem;color:var(--accent);line-height:1}
.stat .l{font-size:.82rem;color:var(--ink-muted);margin-top:.4rem}

.events{display:grid;grid-template-columns:1fr;gap:1.2rem}
.event{display:grid;grid-template-columns:auto 1fr;gap:1.1rem;background:var(--surface);border:1px solid var(--line);
  border-radius:var(--r-lg);padding:1.3rem 1.5rem;box-shadow:var(--shadow-sm)}
.event .rank{font-family:var(--font-display);font-size:2.1rem;color:var(--accent-soft);line-height:1;width:1.6em;text-align:center}
[data-theme="dark"] .event .rank{color:color-mix(in oklab,var(--accent),transparent 40%)}
.event h3{font-size:1.25rem;font-weight:540}
.event .when{font-family:var(--font-mono);font-size:.78rem;color:var(--gold);margin:.2rem 0 .6rem}
.event p{font-size:.98rem;color:var(--ink-muted);margin-bottom:.5rem}
.event .conf{display:inline-flex;align-items:center;gap:.4rem;font-family:var(--font-mono);font-size:.72rem;text-transform:uppercase;letter-spacing:.08em;
  padding:.25rem .6rem;border-radius:99px;border:1px solid var(--line-strong);color:var(--ink-muted)}
.conf.high{color:var(--teal);border-color:color-mix(in oklab,var(--teal),transparent 50%)}
.conf.mod{color:var(--gold);border-color:color-mix(in oklab,var(--gold),transparent 50%)}

.fig{margin:1.5rem 0;border:1px solid var(--line);border-radius:var(--r-md);overflow:hidden;background:var(--surface-2)}
.fig img{width:100%}
.fig figcaption{font-size:.82rem;color:var(--ink-muted);padding:.7rem 1rem;border-top:1px solid var(--line)}

.callout{border-left:3px solid var(--accent);background:color-mix(in oklab,var(--accent),transparent 92%);
  padding:1.1rem 1.3rem;border-radius:0 var(--r-md) var(--r-md) 0;margin:1.4rem 0}
.callout strong{color:var(--accent)}
.narrative p{font-size:1.06rem;max-width:68ch;margin-bottom:1.05rem;color:var(--ink)}
.narrative h3{font-size:1.35rem;margin:.4rem 0 1rem}

.dl-row{display:flex;flex-wrap:wrap;gap:.7rem;margin-top:1rem}
.dl{display:inline-flex;align-items:center;gap:.5rem;font-family:var(--font-mono);font-size:.8rem;color:var(--ink);
  border:1px solid var(--line-strong);border-radius:var(--r-sm);padding:.5rem .8rem;transition:all var(--t)}
.dl:hover{border-color:var(--accent);color:var(--accent);background:var(--surface)}

.method-table{width:100%;border-collapse:collapse;margin-top:1rem;font-size:.9rem}
.method-table th,.method-table td{text-align:left;padding:.6rem .7rem;border-bottom:1px solid var(--line);vertical-align:top}
.method-table th{font-family:var(--font-mono);font-size:.72rem;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-faint)}
.method-table td:first-child{font-weight:600}

/* ---------- Footer ---------- */
.site-foot{border-top:1px solid var(--line);background:var(--paper-2);padding-block:2.6rem;margin-top:2rem}
.site-foot .wrap{display:flex;flex-wrap:wrap;gap:1.4rem;justify-content:space-between;align-items:center}
.site-foot p{font-size:.84rem;color:var(--ink-faint);max-width:60ch}
.site-foot .brand{font-size:1rem}

/* progress bar */
.scroll-prog{position:fixed;top:0;left:0;height:3px;background:var(--accent);width:0;z-index:60;transition:width 80ms linear}