/* P4 dossier. Visual language: NYC subway signage. Light paper, black sign bands, route colours as lines. */
@view-transition { navigation: auto; }

:root{
  --paper: oklch(97.6% 0.004 95);
  --paper-2: oklch(94.2% 0.006 95);
  --ink: oklch(18% 0.008 260);
  --ink-2: oklch(42% 0.01 260);
  --ink-3: oklch(60% 0.008 260);
  --rule: oklch(88% 0.006 95);
  --sign: oklch(16.5% 0.006 260);
  --sign-ink: oklch(97% 0.004 95);
  --sign-2: oklch(72% 0.008 260);
  --code-bg: oklch(19% 0.008 260);
  --code-ink: oklch(92% 0.006 95);
  --ease: cubic-bezier(.16, 1, .3, 1);
  --display: "Archivo", "Helvetica Neue", Arial, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, Consolas, monospace;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font:400 16.5px/1.6 var(--display);font-stretch:100%;-webkit-font-smoothing:antialiased}
a{color:inherit}
img{max-width:100%;display:block}
code{font-family:var(--mono);font-size:.86em;background:var(--paper-2);padding:.1em .38em;border-radius:4px}
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}
@media(min-width:760px){.wrap{padding:0 40px}}

/* ---------- top bar: a station sign ---------- */
.topbar{background:var(--sign);color:var(--sign-ink);position:sticky;top:0;z-index:20}
.topbar .wrap{display:flex;align-items:center;gap:24px;height:58px}
.mark{display:flex;align-items:center;gap:12px;text-decoration:none;font-weight:600;font-size:15px;letter-spacing:.01em;white-space:nowrap}
.mk{display:grid;place-items:center;width:32px;height:32px;border-radius:7px;background:var(--sign-ink);color:var(--sign);font-weight:800;font-size:14px;letter-spacing:-.02em}
.topbar nav{margin-left:auto;display:flex;gap:22px;font-size:14.5px;color:var(--sign-2);overflow-x:auto;scrollbar-width:none}
.topbar nav::-webkit-scrollbar{display:none}
.topbar nav a{text-decoration:none;white-space:nowrap;transition:color .2s}
.topbar nav a:hover{color:var(--sign-ink)}
@media(max-width:640px){.mark span:last-child{display:none}}

/* ---------- route bullets ---------- */
.bullet{display:inline-grid;place-items:center;flex:none;width:44px;height:44px;border-radius:50%;background:var(--c);color:var(--on);font-weight:700;font-size:19px;font-stretch:90%;line-height:1;font-variant-numeric:tabular-nums}
.bullet.xs{width:24px;height:24px;font-size:11.5px}
.bullet.sm{width:28px;height:28px;font-size:13px}
.bullet.xl{width:clamp(84px,11vw,120px);height:clamp(84px,11vw,120px);font-size:clamp(40px,5.2vw,58px);font-weight:800}

/* ---------- index: hero ---------- */
.hero{padding:clamp(48px,8vw,104px) 0 clamp(40px,6vw,72px)}
.hero-grid{display:grid;gap:clamp(32px,5vw,64px);align-items:end}
@media(min-width:980px){.hero-grid{grid-template-columns:1.05fr .95fr}}
.eyebrow{margin:0 0 22px;font-size:14px;color:var(--ink-2);font-weight:500}
.hero h1{margin:0;font-weight:800;font-stretch:72%;font-size:clamp(56px,10.5vw,140px);line-height:.86;letter-spacing:-.015em;text-wrap:balance}
.abstract{margin:28px 0 0;max-width:56ch;font-size:clamp(17px,1.5vw,19.5px);line-height:1.55;color:var(--ink-2)}
.authors{margin:20px 0 0;font-weight:600;font-size:15px}
.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:30px}
.cta{display:inline-flex;align-items:center;gap:8px;height:46px;padding:0 20px;border-radius:999px;background:var(--ink);color:var(--paper);text-decoration:none;font-weight:600;font-size:15px;transition:transform .35s var(--ease),background .2s}
.cta:hover{transform:translateY(-2px)}
.cta.ghost{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--ink)}
.hero-fig{margin:0;background:oklch(99.5% 0.002 95);border:1px solid var(--rule);border-radius:6px;padding:10px;overflow:hidden}
.hero-fig img{border-radius:3px}
.hero-fig figcaption{font-size:13px;color:var(--ink-3);padding:10px 4px 2px}

/* hero entrance */
.is-hub .hero h1,.is-hub .eyebrow,.is-hub .abstract,.is-hub .authors,.is-hub .actions,.is-hub .hero-fig{animation:rise .9s var(--ease) both}
.is-hub .eyebrow{animation-delay:.02s}.is-hub .hero h1{animation-delay:.08s}.is-hub .abstract{animation-delay:.18s}
.is-hub .authors{animation-delay:.24s}.is-hub .actions{animation-delay:.3s}.is-hub .hero-fig{animation-delay:.22s}
@keyframes rise{from{opacity:0;transform:translateY(22px)}}

/* ---------- index: the line diagram ---------- */
.map{padding:clamp(36px,6vw,72px) 0 clamp(64px,9vw,120px);border-top:1px solid var(--rule)}
.map-head{display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;gap:8px 24px;margin-bottom:clamp(28px,4vw,48px)}
.map-head h2{margin:0;font-weight:800;font-stretch:75%;font-size:clamp(34px,4.6vw,56px);line-height:1;letter-spacing:-.01em}
.map-head p{margin:0;color:var(--ink-2)}
.routes{display:grid;gap:clamp(28px,4vw,44px)}
@media(min-width:1000px){.routes{grid-template-columns:1fr 1fr;column-gap:72px}}
.route-name{display:flex;align-items:center;gap:12px;margin:0 0 14px;font-size:15px;font-weight:700;letter-spacing:.01em}
.route-swatch{width:30px;height:10px;border-radius:5px;background:var(--c)}
.stops{list-style:none;margin:0;padding:0;position:relative}
.stops::before{content:"";position:absolute;left:17px;top:22px;bottom:22px;width:10px;border-radius:5px;background:var(--c);transform-origin:top;animation:draw 1.1s var(--ease) both;animation-delay:calc(var(--g) * .14s + .3s)}
@keyframes draw{from{transform:scaleY(0)}}
.stop{position:relative;animation:stopin .8s var(--ease) both;animation-delay:calc(var(--i) * .055s + .45s)}
@keyframes stopin{from{opacity:0;transform:translateX(-12px)}}
.stop a{display:grid;grid-template-columns:44px 1fr;column-gap:20px;align-items:center;padding:12px 0;text-decoration:none;position:relative}
.stop .bullet{grid-row:span 2;box-shadow:0 0 0 3px var(--paper);transition:transform .4s var(--ease)}
.st-name{font-weight:700;font-stretch:88%;font-size:clamp(21px,2.1vw,26px);line-height:1.1;letter-spacing:-.005em;transition:transform .4s var(--ease)}
.st-sum{color:var(--ink-2);font-size:15px;line-height:1.45;transition:color .2s}
.stop a:hover .bullet,.stop a:focus-visible .bullet{transform:scale(1.12)}
.stop a:hover .st-name,.stop a:focus-visible .st-name{transform:translateX(4px)}
.stop a:hover .st-sum{color:var(--ink)}
.stop a:focus-visible{outline:2px solid var(--ink);outline-offset:4px;border-radius:8px}

/* ---------- detail: sign band ---------- */
.band{background:var(--sign);color:var(--sign-ink)}
.band-inner{display:grid;grid-template-columns:auto 1fr;gap:clamp(20px,3.5vw,44px);align-items:center;padding:clamp(40px,6vw,76px) 0 clamp(36px,5vw,60px)}
.band-bullet .bullet{box-shadow:0 0 0 6px var(--sign)}
.line-name{margin:0 0 10px;color:var(--sign-2);font-size:14px;font-weight:500}
.band h1{margin:0;font-weight:800;font-stretch:72%;font-size:clamp(46px,8vw,104px);line-height:.88;letter-spacing:-.015em}
.lede{margin:20px 0 0;max-width:66ch;color:oklch(86% 0.006 95);font-size:clamp(16.5px,1.4vw,18.5px);line-height:1.55}
.lede code{background:oklch(28% 0.008 260);color:var(--sign-ink)}
.band-rule{height:12px;background:var(--line);transform-origin:left;animation:sweep 1s var(--ease) both .1s}
@keyframes sweep{from{transform:scaleX(0)}}
.band h1,.line-name,.lede{animation:rise .8s var(--ease) both}
.line-name{animation-delay:.05s}.band h1{animation-delay:.1s}.lede{animation-delay:.2s}
@media(max-width:560px){.band-inner{grid-template-columns:1fr}}

/* ---------- detail: layout ---------- */
.layout{display:grid;gap:48px;padding-top:clamp(36px,5vw,64px);padding-bottom:40px}
@media(min-width:1040px){.layout{grid-template-columns:220px minmax(0,1fr);gap:64px}}
.layout aside{display:none}
@media(min-width:1040px){.layout aside{display:block}}
.miniline{position:sticky;top:84px}
.miniline ol{list-style:none;margin:0;padding:0}
.mgroup{font-size:12.5px;font-weight:700;color:var(--ink-3);margin:16px 0 4px}
.mgroup:first-child{margin-top:0}
.miniline a{display:flex;align-items:center;gap:10px;padding:5px 8px;margin-left:-8px;border-radius:7px;text-decoration:none;font-size:14.5px;color:var(--ink-2);transition:background .2s,color .2s}
.miniline a:hover{background:var(--paper-2);color:var(--ink)}
.miniline a[aria-current]{color:var(--ink);font-weight:700;background:var(--paper-2)}
.content{min-width:0;max-width:880px}

.facts{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));margin:0 0 8px;border-top:2px solid var(--ink)}
.facts>div{padding:14px 18px 16px 0;border-bottom:1px solid var(--rule)}
.facts>div:has(.filelink){grid-column:1/-1}
.facts dt{font-size:13px;font-weight:600;color:var(--ink-3)}
.facts dd{margin:4px 0 0;font-size:16px;line-height:1.45}
.facts a{text-decoration-thickness:1px;text-underline-offset:3px}
.block{margin-top:clamp(40px,5vw,64px)}
.block>h2{margin:0 0 16px;font-weight:800;font-stretch:80%;font-size:clamp(26px,2.8vw,34px);line-height:1.05;letter-spacing:-.005em}
.note{color:var(--ink-2);font-size:14.5px}
.filelink{display:inline-block;margin:2px 4px 2px 0;font-family:var(--mono);font-size:13px;padding:2px 8px;border-radius:5px;background:var(--paper-2);text-decoration:none;transition:background .2s}
.filelink:hover{background:var(--rule)}

.term-wrap{border-radius:8px;overflow:hidden;background:var(--code-bg);margin:0}
.term-label{font-family:var(--mono);font-size:12px;color:oklch(68% 0.01 260);padding:10px 16px;border-bottom:1px solid oklch(28% 0.008 260)}
.term{margin:0;color:var(--code-ink);padding:14px 16px 16px;font:12.5px/1.65 var(--mono);overflow:auto;max-height:560px;white-space:pre}

.tablewrap{overflow-x:auto;margin:0}
table{width:100%;border-collapse:collapse;font-size:14.5px;font-variant-numeric:tabular-nums}
th,td{text-align:left;padding:10px 14px 10px 0;border-bottom:1px solid var(--rule);vertical-align:top}
thead th{font-size:13px;font-weight:600;color:var(--ink-3);border-bottom:2px solid var(--ink)}
td.num,th.num{text-align:right;padding-right:0}
.prose{max-width:76ch}
.prose h1,.prose h2,.prose h3{font-weight:800;font-stretch:82%;line-height:1.1;margin:32px 0 10px}
.prose h2{font-size:24px}.prose h3{font-size:19px}
.prose p,.prose li{line-height:1.65}
.prose table{display:block;overflow-x:auto;margin:14px 0}
.prose pre{background:var(--code-bg);color:var(--code-ink);padding:14px 16px;border-radius:8px;overflow-x:auto;font:12.5px/1.65 var(--mono)}
.prose pre code{background:none;padding:0;color:inherit}
.prose a{text-underline-offset:3px}

.fig{margin:0 0 20px;background:oklch(99.5% 0.002 95);border:1px solid var(--rule);border-radius:6px;padding:10px}
.fig img{border-radius:3px}
.fig figcaption{font-size:13.5px;color:var(--ink-3);padding:10px 4px 2px}
.grid2{display:grid;gap:20px}
@media(min-width:860px){.grid2{grid-template-columns:1fr 1fr}}
.grid2>*{min-width:0}

.tests3{display:grid;gap:28px;margin-top:40px}
@media(min-width:900px){.tests3{grid-template-columns:repeat(3,1fr)}}
.tests3 h3{margin:0 0 10px;font-size:18px;font-weight:800;font-stretch:85%}
ul.tests{list-style:none;margin:0;padding:0;border-top:2px solid var(--ink)}
ul.tests li{display:flex;flex-direction:column;gap:2px;padding:9px 0;border-bottom:1px solid var(--rule)}
ul.tests code{background:none;padding:0;font-size:12.5px;overflow-wrap:anywhere}
ul.tests span{font-size:12.5px;color:var(--ink-3)}

.pdf{height:82vh;min-height:520px;border:1px solid var(--rule);border-radius:6px;overflow:hidden;margin-top:28px;background:var(--paper-2)}
.pager{display:flex;justify-content:space-between;gap:16px;margin-top:72px;padding-top:24px;border-top:2px solid var(--ink)}
.pg{display:flex;align-items:center;gap:12px;text-decoration:none;font-weight:700;font-stretch:88%;font-size:19px;transition:transform .35s var(--ease)}
.pg.prev:hover{transform:translateX(-4px)}.pg.next:hover{transform:translateX(4px)}
.pg.next{margin-left:auto;text-align:right}

/* ---------- source viewer ---------- */
.band-file .wrap{padding-top:36px;padding-bottom:32px}
.back{display:inline-flex;align-items:center;gap:10px;color:var(--sign-2);text-decoration:none;font-size:14.5px}
.back:hover{color:var(--sign-ink)}
.band-file h1{margin:18px 0 6px;font-weight:800;font-stretch:78%;font-size:clamp(38px,6vw,72px);line-height:.95}
.band-file .sub{margin:0;color:var(--sign-2);font-size:14.5px}
.band-file .path{font-family:var(--mono);font-size:13px}
.file-main{padding-top:28px;padding-bottom:56px}
.code{margin:0;background:var(--code-bg);color:var(--code-ink);border-radius:8px;padding:14px 0;font:12.5px/1.7 var(--mono);overflow-x:auto;white-space:pre}
.code .ln{display:block;padding-right:20px}
.code .ln a{display:inline-block;width:56px;margin-right:16px;text-align:right;color:oklch(52% 0.01 260);text-decoration:none;user-select:none}
.code .ln:target{background:oklch(30% 0.04 70)}

/* ---------- 404: a service notice ---------- */
.notice{padding:clamp(56px,10vw,128px) 0}
.notice-inner{max-width:860px}
.sign{background:var(--sign);color:var(--sign-ink);border-radius:10px;overflow:hidden;animation:rise .9s var(--ease) both}
.sign-top{display:flex;align-items:center;gap:14px;padding:14px 24px;background:#FCCC0A;color:#1a1a1a;font-weight:700;font-size:15px}
.sign-code{font-stretch:75%;font-weight:800;font-size:22px}
.sign-body{display:grid;grid-template-columns:auto 1fr;gap:clamp(20px,4vw,40px);align-items:center;padding:clamp(28px,5vw,52px) clamp(24px,4vw,44px)}
.sign-body .bullet{box-shadow:0 0 0 6px var(--sign);animation:blink 2.4s var(--ease) infinite 1s}
@keyframes blink{0%,100%{opacity:1}50%{opacity:.35}}
.sign h1{margin:0;font-weight:800;font-stretch:72%;font-size:clamp(40px,6.4vw,76px);line-height:.92}
.sign p{margin:16px 0 0;color:oklch(84% 0.006 95);max-width:46ch;font-size:17px;line-height:1.55}
.notice-links{display:flex;flex-wrap:wrap;gap:10px;margin-top:28px;animation:rise .9s var(--ease) both .15s}
@media(max-width:560px){.sign-body{grid-template-columns:1fr}}

/* ---------- footer ---------- */
.foot{border-top:1px solid var(--rule);margin-top:24px}
.foot .wrap{display:flex;flex-wrap:wrap;justify-content:space-between;gap:8px 24px;padding-top:26px;padding-bottom:40px;font-size:13.5px;color:var(--ink-3)}

/* ---------- scroll reveal ---------- */
[data-reveal]{opacity:0;transform:translateY(18px);transition:opacity .9s var(--ease),transform .9s var(--ease)}
[data-reveal].in{opacity:1;transform:none}

/* ---------- page transitions ---------- */
::view-transition-old(root),::view-transition-new(root){animation-duration:.35s;animation-timing-function:var(--ease)}
::view-transition-group(*){animation-duration:.55s;animation-timing-function:var(--ease)}

@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation:none !important;transition:none !important}
  [data-reveal]{opacity:1;transform:none}
  @view-transition{navigation:none}
}

/* ---------- touch targets ---------- */
.topbar nav a{display:inline-flex;align-items:center;min-height:44px}
.pg,.back,.sec-stop{min-height:44px}
@media(max-width:640px){
  .topbar .wrap{gap:12px}
  .topbar nav{gap:16px}
  .pager{flex-direction:column;gap:6px}
  .pg.next{margin-left:0;justify-content:flex-end}
  .term{font-size:11.5px}
  .facts{grid-template-columns:1fr}
}

/* ---------- Headway brand ---------- */
.hw-mark{width:30px;height:30px;flex:none;display:block}
.mark .wordmark{font-weight:800;font-stretch:78%;font-size:21px;letter-spacing:-.01em}
.mark .mk{display:none}
.foot-brand{display:inline-flex;align-items:center;gap:8px}
.foot-brand .hw-mark{width:18px;height:18px}
.foot-brand b{color:var(--ink);font-weight:800;font-stretch:80%}
.hero h1{font-size:clamp(84px,15vw,200px);line-height:.8;letter-spacing:-.03em;font-stretch:66%}
.tagline{margin:22px 0 0;font-weight:700;font-stretch:84%;font-size:clamp(22px,2.4vw,30px);line-height:1.15;max-width:22ch;animation:rise .9s var(--ease) both .14s}
.abstract{font-size:clamp(16px,1.3vw,18px)}
@media(min-width:980px){.hero-grid{grid-template-columns:.92fr 1.08fr;align-items:center}}

/* departure board */
.board{background:#121212;color:#FCCC0A;border-radius:12px;padding:18px 18px 14px;box-shadow:0 30px 60px -30px oklch(18% 0.01 260 / .55);font-family:var(--mono);animation:rise 1s var(--ease) both .2s;min-width:0}
.board-head{display:flex;justify-content:space-between;align-items:center;gap:12px;color:#f3f1ea;font:700 15px/1 var(--display);font-stretch:88%;padding:2px 2px 14px}
.board-head>span:first-child{display:inline-flex;align-items:center;gap:10px}
.board-head .hw-mark{width:24px;height:24px}
.board-clock{color:#8f8b82;font-weight:500;font-size:13px}
.board-cols,.board li{display:grid;grid-template-columns:4.2em minmax(0,1fr) 2.8em 3.2em 5.6em;gap:10px;align-items:center}
.board-cols{color:#6f6c64;font:600 11px var(--display);padding:0 10px 6px;border-bottom:1px solid #2a2a2a}
.board ol{list-style:none;margin:0;padding:0}
.board li{padding:8px 10px;border-bottom:1px solid #1e1e1e;font-size:13.5px;letter-spacing:.02em;white-space:nowrap}
.board li:nth-child(odd){background:#171717}
.board .b-time{color:#f3f1ea}
.board .b-dest{overflow:hidden;text-overflow:ellipsis}
.board .b-van{display:inline-flex;align-items:center;gap:6px;color:#f3f1ea}
.board .b-van i{width:10px;height:10px;border-radius:50%;display:inline-block}
.board .b-ord{color:#8f8b82}
.board .b-stat{color:#7BE0A6;font-size:12px}
.board-foot{color:#8f8b82;font:500 12.5px var(--display);padding:12px 2px 0}
@media(max-width:560px){
  .board-cols,.board li{grid-template-columns:3.9em minmax(0,1fr) 2.6em 5.4em}
  .board .b-ord,.board-cols span:nth-child(4){display:none}
  .board li{font-size:12px;padding:7px 6px}
}