/* 77th Street: one long page with a sticky contents column. */

@font-face {
  font-family: "PW Heros";
  src: url("fonts/pw-heros-regular.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "PW Heros";
  src: url("fonts/pw-heros-bold.woff2") format("woff2");
  font-weight: 700;
  font-display: swap;
}

/* ---- Tokens ---------------------------------------------------- */

:root {
  --paper:       #fbfaf7;
  --paper-sunk:  #f2f1ec;
  --ink:         #16181d;
  --ink-soft:    #4a4f5a;
  --ink-faint:   #6b7078;
  --rule:        #e0ddd6;
  --accent:      #1f4a43;   /* harbor green; 9.5:1 on the paper */
  --glass:       rgba(251, 250, 247, .88);

  --sans: "PW Heros", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, monospace;

  --measure: 40rem;
  --toc-w:   13rem;
  --gap:     4.5rem;
  --gutter:  clamp(1rem, 4vw, 2.5rem);
}

/* ---- Base ------------------------------------------------------ */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 1.5rem;
}
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 1.0625rem/1.6 var(--sans);
  font-feature-settings: "kern", "lnum";
}

a { color: var(--accent); text-underline-offset: .18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

img { display: block; max-width: 100%; height: auto; }

.skip {
  position: absolute; left: -999px; top: .5rem;
  background: var(--ink); color: var(--paper); padding: .5rem .75rem;
}
.skip:focus { left: .5rem; z-index: 10; }

/* ---- Masthead -------------------------------------------------- */

.masthead {
  max-width: calc(var(--toc-w) + var(--gap) + var(--measure) + 2 * var(--gutter));
  margin: 0 auto;
  padding: 1.25rem var(--gutter);
  border-bottom: 1px solid var(--rule);
}
.wordmark {
  color: var(--ink);
  font-weight: 700;
  font-size: .9375rem;
  letter-spacing: .01em;
  text-decoration: none;
}

/* ---- Layout ---------------------------------------------------- */

.layout {
  display: grid;
  grid-template-columns: var(--toc-w) minmax(0, var(--measure));
  gap: var(--gap);
  max-width: calc(var(--toc-w) + var(--gap) + var(--measure) + 2 * var(--gutter));
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ---- Contents -------------------------------------------------- */

.toc {
  position: sticky;
  top: 0;
  align-self: start;
  padding-top: 3.25rem;
  font-size: .875rem;
}
.toc-toggle { display: none; }
.toc-head {
  margin: 0 0 .75rem;
  color: var(--ink-faint);
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--rule);
}
.toc-list a {
  display: block;
  margin-left: -1px;
  padding: .3rem 0 .3rem .9rem;
  border-left: 2px solid transparent;
  color: var(--ink-soft);
  text-decoration: none;
  transition: color .15s, border-color .15s;
}
.toc-list a:hover { color: var(--ink); }
.toc-list a[aria-current="true"] {
  border-left-color: var(--accent);
  color: var(--ink);
  font-weight: 700;
}

/* ---- Report ---------------------------------------------------- */

.report { padding: 3rem 0 5rem; }

h1 {
  margin: 0;
  font-size: clamp(2rem, 1.4rem + 2.4vw, 2.75rem);
  line-height: 1.1;
  letter-spacing: -.015em;
}
.dateline {
  margin: .6rem 0 2rem;
  color: var(--ink-faint);
  font-size: .875rem;
}
.lede {
  margin: 0 0 1rem;
  font-size: 1.25rem;
  line-height: 1.5;
}

section { padding-top: 1.5rem; }

h2 {
  margin: 2rem 0 1rem;
  padding-bottom: .4rem;
  border-bottom: 1px solid var(--rule);
  font-size: 1.5rem;
  line-height: 1.25;
  letter-spacing: -.01em;
}
h3 {
  margin: 2rem 0 .5rem;
  font-size: 1.0625rem;
  line-height: 1.35;
}
p { margin: 0 0 1rem; }

sup { line-height: 0; font-size: .7em; }
sup a { padding: 0 .1em; text-decoration: none; }

code { font: .875em var(--mono); }

/* Key-value table for the program. */
.facts {
  width: 100%;
  margin: 1.5rem 0;
  border-collapse: collapse;
  font-size: .9375rem;
}
.facts th, .facts td {
  padding: .6rem 0;
  border-top: 1px solid var(--rule);
  text-align: left;
  vertical-align: top;
}
.facts tr:last-child th, .facts tr:last-child td { border-bottom: 1px solid var(--rule); }
.facts th { width: 8.5rem; padding-right: 1rem; color: var(--ink-faint); font-weight: 400; }

/* Column table: headers on top, figures right-aligned. */
.crossings th { width: auto; font-size: .8125rem; vertical-align: bottom; }
.crossings td { padding-right: 1rem; }
.crossings td:first-child { font-weight: 700; }
.crossings .num { padding-right: 0; padding-left: .75rem; text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.crossings th.num { white-space: normal; }
.table-note { margin-top: -.75rem; color: var(--ink-soft); font-size: .875rem; line-height: 1.45; }

figure { margin: 2rem 0; }
figure img {
  width: 100%;
  background: #f5f2e9;
  border: 1px solid var(--rule);
}
figcaption {
  margin-top: .6rem;
  color: var(--ink-soft);
  font-size: .875rem;
  line-height: 1.45;
}

/* Room held for a photo or video. */
.media-placeholder {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: .25rem;
  min-height: 12rem;
  padding: 1.25rem;
  background: var(--paper-sunk);
  border: 1px dashed var(--rule);
  color: var(--ink-soft);
  font-size: .9375rem;
}
.media-placeholder strong {
  color: var(--ink);
  font-size: .75rem;
  letter-spacing: .06em;
  text-transform: uppercase;
}
figure video { display: block; width: 100%; height: auto; background: var(--ink); }

.plain-list { margin: 0 0 1rem; padding: 0; list-style: none; }
.plain-list li { margin-bottom: 1rem; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: 0;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  border: 0;
}

/* A study that hasn't been done yet. */
.pending {
  margin: 1.5rem 0;
  padding: .9rem 1.1rem;
  background: var(--paper-sunk);
  border-left: 2px solid var(--accent);
  font-size: .9375rem;
}
.pending p { margin: 0; }
.pending .pending-head {
  margin-bottom: .25rem;
  color: var(--accent);
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.sources {
  margin: 0;
  padding-left: 1.6rem;
  font-size: .875rem;
  line-height: 1.5;
}
.sources li { margin-bottom: .5rem; padding-left: .25rem; }
.sources li:target { background: var(--paper-sunk); }

/* ---- Footer ---------------------------------------------------- */


/* ---- Narrow screens -------------------------------------------- */

/* The contents fold into a bar that sticks to the top and names the current section. */
@media (max-width: 60rem) {
  .layout { display: block; }

  .toc {
    z-index: 5;
    margin: 0 calc(-1 * var(--gutter));
    padding: 0;
    background: var(--glass);
    -webkit-backdrop-filter: saturate(140%) blur(12px);
    backdrop-filter: saturate(140%) blur(12px);
    border-bottom: 1px solid var(--rule);
  }
  .toc-head { display: none; }
  .toc-toggle {
    display: flex;
    gap: .75rem;
    align-items: baseline;
    width: 100%;
    min-height: 2.75rem;
    padding: .7rem var(--gutter);
    border: 0;
    background: none;
    color: var(--ink);
    font: inherit;
    text-align: left;
    cursor: pointer;
  }
  .toc-label {
    color: var(--ink-faint);
    font-size: .75rem;
    font-weight: 700;
    letter-spacing: .06em;
    text-transform: uppercase;
  }
  .toc-current { overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
  .toc-toggle::after {
    content: "";
    margin-left: auto;
    width: .45rem; height: .45rem;
    border-right: 1.5px solid var(--ink-soft);
    border-bottom: 1.5px solid var(--ink-soft);
    transform: translateY(-.15rem) rotate(45deg);
  }
  .toc-toggle[aria-expanded="true"]::after { transform: translateY(.1rem) rotate(-135deg); }

  .toc-list {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    padding: .25rem var(--gutter) .75rem;
    background: var(--paper);
    border-left: 0;
    border-bottom: 1px solid var(--rule);
    box-shadow: 0 8px 16px rgba(20, 22, 28, .06);
  }
  .toc.open .toc-list { display: block; }
  .toc-list a { padding: .55rem 0 .55rem .75rem; border-left-width: 2px; margin-left: 0; }

  .report { padding-top: 2rem; }
  html { scroll-padding-top: 4rem; }
}

/* Without the script the bar can't open, so show the list in place. */
@media (max-width: 60rem) {
  html:not(.js) .toc { position: static; }
  html:not(.js) .toc-toggle { display: none; }
  html:not(.js) .toc-list { display: block; position: static; padding-top: 1rem; box-shadow: none; }
}

figure.hero { margin: 0 0 2rem; }
figure.hero img { border: 0; }

.cta {
  display: inline-block;
  padding: .7rem 1.2rem;
  background: var(--ink);
  border: 0;
  color: var(--paper);
  font: inherit;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}
.cta:hover { background: var(--accent); }
.cta[hidden] { display: none; }


@media print {
  @page { margin: .6in; }
  body { background: #fff; font-size: 11pt; line-height: 1.35; }
  .skip, .masthead, .toc { display: none; }
}