/* Roosevelt Island Chess Club: dusk on the East River, lit by club orange. */
:root {
  --canvas: #132029;
  --canvas-deep: #0d171e;
  --panel: #1b2c37;
  --line: #2f4655;
  --ivory: #f3ebdd;
  --muted: #a9b7bf;
  --orange: #ff5b1f;
  --orange-hover: #ff7440;
  --maple: #d9b98a;
  --display: "Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --body: "Atkinson Hyperlegible", "Segoe UI", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, Consolas, monospace;
  --gutter: max(20px, env(safe-area-inset-left, 0px));
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: auto; }
body {
  margin: 0;
  background: var(--canvas);
  color: var(--ivory);
  font: 16px/1.6 var(--body);
  -webkit-font-smoothing: antialiased;
}
h1, h2 { font-family: var(--display); margin: 0; text-wrap: balance; letter-spacing: -0.015em; }
p { margin: 0; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--orange); outline-offset: 3px; border-radius: 4px; }

.skip {
  position: fixed; left: 12px; top: -60px; z-index: 50;
  background: var(--ivory); color: var(--canvas); padding: 10px 14px; border-radius: 6px; font-weight: 700;
  transition: top 0.2s;
}
.skip:focus { top: calc(env(safe-area-inset-top, 0px) + 12px); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--orange); color: #1a0b04; text-decoration: none;
  font: 700 15px/1 var(--display); letter-spacing: 0.01em;
  padding: 13px 20px; border-radius: 999px;
  box-shadow: 0 10px 30px -10px #ff5b1f99;
  transition: background 0.2s, transform 0.2s;
}
.btn:hover { background: var(--orange-hover); transform: translateY(-1px); }
.btn-small { padding: 9px 15px; font-size: 13.5px; box-shadow: none; }
@media (pointer: coarse) { .btn, .btn-small { min-height: 44px; } }

/* ------------------------------------------------------------ top bar */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: calc(env(safe-area-inset-top, 0px) + 10px) max(20px, env(safe-area-inset-right, 0px)) 10px max(20px, env(safe-area-inset-left, 0px));
  pointer-events: none;
}
.topbar > * { pointer-events: auto; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font: 700 15px/1.1 var(--display); }
.brand img { border-radius: 50%; display: block; width: 30px; height: 30px; }
@media (max-width: 520px) { .brand span { display: none; } }

/* ------------------------------------------------------------ the story */
.story { position: relative; }
.js .story { height: 1400vh; }
.stage { position: relative; }
.js .stage { position: sticky; top: 0; height: 100vh; height: 100svh; overflow: hidden; }

.stage {
  background:
    radial-gradient(1100px 720px at 62% 42%, #2a4556 0%, transparent 70%),
    radial-gradient(800px 500px at 90% 0%, #ff5b1f17, transparent 60%),
    linear-gradient(180deg, #16262f 0%, var(--canvas-deep) 100%);
}
#scene { position: absolute; inset: 0; width: 100%; height: 100%; display: block; opacity: 0; transition: opacity 1.2s ease; }
.ready #scene { opacity: 1; }
.no-webgl #scene { display: none; }

/* Legibility scrim behind the captions: left side on wide screens, bottom on phones. */
.scrim { position: absolute; inset: 0; pointer-events: none; background: linear-gradient(90deg, #0f1a21e6 0%, #0f1a2199 28%, transparent 55%); }
@media (max-width: 899px) { .scrim { background: linear-gradient(0deg, #0f1a21f2 0%, #0f1a21b3 30%, transparent 58%); } }

.captions { position: relative; z-index: 2; padding: 120px var(--gutter) 80px; display: grid; gap: 40vh; }
.js .captions { position: absolute; left: clamp(20px, 5.5vw, 88px); top: 50%; transform: translateY(-50%); width: min(470px, 38vw); padding: 0; display: block; }
.js .cap { position: absolute; left: 0; right: 0; top: 50%; translate: 0 -50%; opacity: 0; will-change: opacity, transform; }
.js .cap-arrival { opacity: 1; }
@media (max-width: 899px) {
  .js .captions { left: var(--gutter); right: max(20px, env(safe-area-inset-right, 0px)); width: auto; top: auto; bottom: calc(env(safe-area-inset-bottom, 0px) + 84px); transform: none; }
  .js .cap { top: auto; bottom: 0; translate: none; }
}

/* Headline sizes follow the screen's width and its height, so short laptop screens stay balanced. */
.cap { display: grid; gap: 12px; text-shadow: 0 2px 18px #0b141acc; }
.cap h1 { font-size: clamp(34px, min(4.4vw, 8.4vh), 64px); font-weight: 800; line-height: 1; }
.cap h2 { font-size: clamp(28px, min(3.1vw, 6.4vh), 46px); font-weight: 800; line-height: 1.05; }
.cap p { font-size: clamp(15px, 1.15vw, 18px); color: var(--ivory); max-width: 36ch; }
.cap .lede { font-size: clamp(17px, 1.45vw, 22px); font-family: var(--display); font-weight: 600; }
.kicker, .notation { font: 500 12px/1.3 var(--mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.notation { color: var(--maple); }
.cap .btn { justify-self: start; margin-top: 6px; }
.cap .credit { font: 400 14px/1.5 var(--body); color: var(--muted); max-width: 46ch; }
.cap .cue { max-width: none; }
.cue { display: inline-flex; align-items: center; gap: 10px; margin-top: 14px; font: 500 12px/1 var(--mono) !important; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted) !important; }
.cue svg { width: 18px; height: 18px; animation: nudge 2.2s ease-in-out infinite; }
@keyframes nudge { 50% { transform: translateY(5px); } }

/* Move readout: which move this is, and what happened, in plain words. */
.hud { position: absolute; z-index: 3; left: clamp(20px, 5.5vw, 88px); bottom: calc(env(safe-area-inset-bottom, 0px) + 28px); display: none; gap: 4px; margin: 0; max-width: 40ch; text-shadow: 0 2px 14px #0b141a; }
.js .hud { display: grid; }
.hud-move { font: 500 12px/1.3 var(--mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--maple); }
.hud-say { font: 700 15px/1.35 var(--display); color: var(--ivory); min-height: 1.35em; }
@media (max-width: 899px) {
  .hud { left: var(--gutter); right: max(20px, env(safe-area-inset-right, 0px)); bottom: auto; top: calc(env(safe-area-inset-top, 0px) + 72px); }
  .hud-say { font-size: 15px; }
}

/* Chapter rail: a readable panel of chapters on the right. */
.rail {
  position: absolute; z-index: 3; right: max(22px, env(safe-area-inset-right, 0px)); top: 50%; transform: translateY(-50%);
  display: none; flex-direction: column; gap: 1px; padding: 8px;
  background: #0f1a21c7; border: 1px solid #3a5566; border-radius: 16px;
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); box-shadow: 0 20px 50px -20px #000d;
}
.js .rail { display: flex; }
.rail::before {
  content: ""; position: absolute; right: 22px; top: 22px; bottom: 22px; width: 2px; background: #3a5566; border-radius: 2px;
}
.rail button {
  position: relative; appearance: none; border: 0; background: none; cursor: pointer; color: #c3ced4;
  display: flex; align-items: center; justify-content: flex-end; gap: 12px; padding: 8px 9px 8px 12px; border-radius: 10px;
  font: 700 13px/1 var(--display); letter-spacing: 0.01em; text-align: right; white-space: nowrap;
  transition: background 0.25s, color 0.25s;
}
.rail button:hover { background: #ffffff12; color: var(--ivory); }
.rail button::after {
  content: ""; flex: none; width: 12px; height: 12px; border-radius: 50%; border: 2px solid #c3ced4; background: #0f1a21;
  transition: background 0.3s, border-color 0.3s, transform 0.3s, box-shadow 0.3s;
}
.rail button[aria-current="step"] { color: var(--ivory); background: #ff5b1f24; }
.rail button[aria-current="step"]::after { background: var(--orange); border-color: var(--orange); transform: scale(1.15); box-shadow: 0 0 0 5px #ff5b1f33; }
/* Mid-size screens: dots only, with a large touch area; the label shows on hover or focus. */
@media (max-width: 1180px) {
  .rail button:not([aria-current="step"]):not(:hover):not(:focus-visible) span { display: none; }
}
@media (max-width: 899px) { .js .rail { display: none; } }

/* ------------------------------------------------------------ after the story */
.wrap { max-width: 1160px; margin: 0 auto; padding-left: var(--gutter); padding-right: max(20px, env(safe-area-inset-right, 0px)); }
.facts { display: grid; gap: 28px; margin: 0; width: 100%; }
.facts div { display: grid; gap: 8px; padding-top: 14px; border-top: 1px solid var(--line); }
.facts dt { font: 500 12px/1 var(--mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.facts dd { margin: 0; font-size: 16px; line-height: 1.45; }

@media (prefers-reduced-motion: reduce) {
  .cue svg { animation: none; }
  #scene { transition: none; }
  .btn { transition: none; }
}