:root {
  --accent: #8fd3ff;
  --ink: #eef4ff;
  --dim: rgba(230, 240, 255, 0.66);
  --panel: rgba(6, 10, 20, 0.58);
  --line: rgba(255, 255, 255, 0.14);
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: "Space Grotesk", system-ui, -apple-system, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { background: #02030a; scrollbar-width: none; }
html::-webkit-scrollbar { display: none; }
body {
  margin: 0; color: var(--ink); font-family: var(--sans);
  -webkit-font-smoothing: antialiased; overflow-x: hidden;
  -webkit-tap-highlight-color: transparent;
}
#scene { position: fixed; inset: 0; width: 100vw; height: 100vh; display: block; z-index: 0; }
#track { position: relative; width: 1px; z-index: -1; }

/* ---------- cards ---------- */
#cards { position: fixed; inset: 0; pointer-events: none; z-index: 2; overflow: hidden; }
.card {
  position: absolute; top: 0; width: min(350px, 31vw);
  padding: 14px 18px 16px; border-radius: 14px;
  background: linear-gradient(160deg, rgba(8, 12, 24, 0.78), rgba(8, 12, 24, 0.55));
  border: 1px solid var(--line);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
  will-change: transform, opacity; visibility: hidden;
  transition: border-color .4s, box-shadow .4s;
}
.card.L { left: 3.5vw; }
.card.R { right: 3.5vw; }
.card.on { visibility: visible; }
.card.active { border-color: color-mix(in srgb, var(--accent) 55%, transparent); box-shadow: 0 10px 50px rgba(0,0,0,.4), 0 0 0 1px color-mix(in srgb, var(--accent) 25%, transparent) inset; }
.card .idx { font: 500 11px/1.2 var(--mono); letter-spacing: .08em; color: var(--dim); text-transform: uppercase; }
.card h3 { margin: 6px 0 4px; font-size: 21px; line-height: 1.15; font-weight: 700; letter-spacing: -.01em; }
.card .fig { font: 600 15px/1.3 var(--mono); color: var(--accent); margin-bottom: 7px; }
.card p { margin: 0; font-size: 15px; line-height: 1.45; color: rgba(236, 242, 255, 0.86); }

/* ---------- HUD ---------- */
#hud {
  position: fixed; top: 18px; left: 22px; z-index: 5; pointer-events: none;
  padding: 12px 16px 12px; border-radius: 14px; background: var(--panel);
  border: 1px solid var(--line); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  min-width: 260px;
}
#hud .row1 { font: 500 11px/1 var(--mono); letter-spacing: .14em; color: var(--dim); text-transform: uppercase; white-space: nowrap; }
#hud #hLabel { color: var(--accent); }
#hud .dot { margin: 0 7px; opacity: .5; }
#hud .num { font: 600 44px/1.05 var(--mono); letter-spacing: -.03em; margin-top: 6px; font-variant-numeric: tabular-nums; white-space: nowrap; }
#hud #hSign { opacity: .7; }
#hud #hUnit { font-size: 18px; margin-left: 8px; color: var(--dim); letter-spacing: 0; }
#hud .env { font: 400 12px/1.3 var(--mono); color: var(--dim); margin-top: 4px; white-space: nowrap; }
#hud .sep { margin: 0 6px; opacity: .5; }

#controls { position: fixed; top: 18px; right: 22px; z-index: 6; display: flex; gap: 8px; }
#controls button, #stepper button, #noteBtn, #topBtn, #listClose {
  font: 500 13px/1 var(--sans); color: var(--ink); cursor: pointer;
  background: var(--panel); border: 1px solid var(--line); border-radius: 999px;
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
}
#controls button { display: flex; align-items: center; gap: 8px; height: 38px; padding: 0 14px; }
#controls button:hover, #stepper button:hover { border-color: var(--accent); }
#controls button:focus-visible, #stepper button:focus-visible, #noteBtn:focus-visible, #topBtn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
#soundBtn .waves { display: none; }
#soundBtn[aria-pressed="true"] .waves { display: inline; }
#soundBtn[aria-pressed="true"] .mute { display: none; }
#soundBtn[aria-pressed="true"] { border-color: color-mix(in srgb, var(--accent) 60%, transparent); }
#soundBtn.nudge { animation: nudge 2.4s ease-in-out 1.2s 3; }
@keyframes nudge { 0%,100% { box-shadow: 0 0 0 0 rgba(143,211,255,0); } 50% { box-shadow: 0 0 0 6px color-mix(in srgb, var(--accent) 30%, transparent); } }

#scalebox {
  position: fixed; left: 22px; bottom: 18px; z-index: 5; width: 330px;
  padding: 12px 14px; border-radius: 14px; background: var(--panel);
  border: 1px solid var(--line); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
}
#scalebox .top { display: flex; gap: 12px; align-items: center; }
#globe { width: 96px; height: 96px; flex: none; }
#scalebox .k { font: 500 10px/1 var(--mono); letter-spacing: .14em; color: var(--dim); }
#pct { font: 600 14px/1.3 var(--mono); margin-top: 6px; color: var(--accent); }
#gauge { font: 400 12px/1.35 var(--mono); color: var(--dim); margin-top: 3px; }
#noteBtn { margin-top: 8px; padding: 6px 10px; font-size: 12px; }
#note { margin: 10px 0 0; font-size: 12.5px; line-height: 1.45; color: rgba(236,242,255,.8); display: none; }
#scalebox.open #note { display: block; }
#intro .scale-line { display: none; }
#note b { color: var(--ink); font-weight: 600; }

#stepper { position: fixed; right: 22px; bottom: 18px; z-index: 5; display: flex; flex-direction: column; gap: 8px; }
#stepper button { width: 46px; height: 46px; display: grid; place-items: center; border-radius: 50%; }

/* ---------- intro / outro ---------- */
#intro {
  position: fixed; left: 50%; top: 13vh; transform: translateX(-50%); z-index: 3;
  text-align: center; pointer-events: none; width: min(760px, 92vw);
}
#intro .kicker, #outro .kicker { font: 500 12px/1 var(--mono); letter-spacing: .28em; text-transform: uppercase; color: var(--accent); margin: 0; }
#intro h1 {
  margin: 12px 0 8px; font-size: clamp(64px, 11vw, 150px); line-height: .9; font-weight: 700; letter-spacing: -.045em;
  background: linear-gradient(180deg, #ffffff 0%, #cfe6ff 45%, #7fb9ff 100%); -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 30px rgba(120, 180, 255, 0.25));
}
#intro .sub { font-size: clamp(16px, 1.7vw, 20px); line-height: 1.4; color: rgba(236,242,255,.85); margin: 0 auto; max-width: 560px; }
#intro .hint { position: fixed; left: 50%; transform: translateX(-50%); top: calc(88vh - 13vh); white-space: nowrap; font: 400 12px/1 var(--mono); color: var(--dim); letter-spacing: .04em; }
#intro .chev { display: inline-block; width: 10px; height: 10px; border-right: 2px solid var(--accent); border-bottom: 2px solid var(--accent); transform: rotate(45deg); margin-right: 12px; position: relative; top: -3px; animation: bob 1.6s ease-in-out infinite; }
@keyframes bob { 0%,100% { top: -5px; } 50% { top: 1px; } }
kbd { font: 600 11px/1 var(--mono); padding: 3px 6px; border: 1px solid var(--line); border-radius: 5px; background: rgba(255,255,255,.06); color: var(--ink); }
#intro > * { animation: rise 1.1s cubic-bezier(.2,.7,.2,1) both; }
#intro h1 { animation-delay: .12s; }
#intro .sub { animation-delay: .28s; }
#intro .hint { animation: fade 1s ease 1s both; }
@keyframes rise { from { opacity: 0; transform: translateY(18px); filter: blur(6px); } to { opacity: 1; transform: none; filter: none; } }
#intro .hint { animation-name: fade; }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

#outro {
  position: fixed; left: 50%; top: 50%; transform: translate(-50%, -50%); z-index: 4; text-align: center;
  width: min(620px, 90vw); padding: 28px 28px 30px; border-radius: 18px;
  background: rgba(46, 16, 2, 0.74); border: 1px solid rgba(255, 230, 180, 0.35);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  opacity: 0; pointer-events: none; transition: opacity .6s;
}
#outro.show { opacity: 1; pointer-events: auto; }
#outro h2 { font-size: clamp(30px, 4.4vw, 48px); margin: 10px 0; letter-spacing: -.02em; color: #fff; }
#outro p { font-size: 16px; line-height: 1.5; color: rgba(255, 246, 230, .9); margin: 0 0 18px; }
#outro .kicker { color: #fff3c4; }
#topBtn { padding: 11px 18px; font-size: 15px; }

/* ---------- list ---------- */
#list { position: fixed; inset: 0; z-index: 10; background: rgba(0,0,0,.45); display: flex; justify-content: flex-end; }
#list[hidden] { display: none; }
#list .panel { width: min(420px, 100vw); height: 100%; overflow: auto; background: rgba(8, 12, 22, 0.94); border-left: 1px solid var(--line); padding: 16px 16px 30px; }
#list .head { display: flex; justify-content: space-between; align-items: center; font: 600 13px/1 var(--mono); letter-spacing: .14em; text-transform: uppercase; padding: 6px 4px 14px; }
#listClose { width: 36px; height: 36px; font-size: 20px; }
#listItems { list-style: none; margin: 0; padding: 0; }
#listItems button {
  width: 100%; text-align: left; display: flex; justify-content: space-between; gap: 12px; align-items: baseline;
  background: none; border: 0; border-top: 1px solid rgba(255,255,255,.07); color: var(--ink);
  padding: 11px 6px; font: 500 15px/1.25 var(--sans); cursor: pointer;
}
#listItems button:hover, #listItems button:focus-visible { background: rgba(255,255,255,.06); outline: none; }
#listItems .f { font: 400 12px/1.2 var(--mono); color: var(--dim); white-space: nowrap; }
#listItems .n { font: 400 11px/1 var(--mono); color: var(--dim); margin-right: 8px; }

/* ---------- phones ---------- */
@media (max-width: 760px) {
  #hud { top: 10px; left: 10px; min-width: 0; padding: 9px 12px 9px; border-radius: 12px; }
  #hud .num { font-size: 30px; margin-top: 4px; }
  #hud #hUnit { font-size: 14px; margin-left: 5px; }
  #hud .row1 { font-size: 10px; letter-spacing: .1em; }
  #hud .env { font-size: 10.5px; }
  #controls { top: 10px; right: 10px; flex-direction: column; gap: 6px; }
  #controls button { height: 36px; padding: 0 11px; }
  #controls .t { display: none; }
  #scalebox { left: 10px; right: 76px; bottom: 10px; width: auto; padding: 8px 10px; border-radius: 12px; }
  #globe { width: 58px; height: 58px; }
  #scalebox .top { gap: 10px; }
  #scalebox .k { font-size: 9px; letter-spacing: .1em; }
  #pct { font-size: 12px; margin-top: 3px; }
  #gauge { font-size: 10.5px; }
  #noteBtn { display: inline-block; margin-top: 5px; padding: 5px 9px; font-size: 11px; }
  #note { font-size: 12px; }
  #intro .scale-line { display: block; margin: 14px auto 0; max-width: 320px; font: 400 12px/1.45 var(--mono); color: var(--dim); }
  #stepper { right: 10px; bottom: 10px; gap: 6px; }
  #stepper button { width: 50px; height: 44px; border-radius: 14px; }
  body.arrived .card { visibility: hidden !important; }
  .card { width: auto; left: 12px !important; right: 12px !important; padding: 11px 14px 13px; border-radius: 12px; }
  .card h3 { font-size: 18px; }
  .card .fig { font-size: 13.5px; }
  .card p { font-size: 14px; }
  #intro { top: 17vh; }
  #intro .kicker { letter-spacing: .16em; font-size: 11px; }
  #intro .hint .wide { display: none; }
  #intro .hint { top: calc(78vh - 17vh); font-size: 11px; }
  #intro .sub { font-size: 15.5px; max-width: 330px; }
}
@media (max-width: 760px) and (max-height: 700px) {
  #intro { top: 14vh; }
  #intro h1 { font-size: 58px; }
}
@media (prefers-reduced-motion: reduce) {
  #intro > *, #intro .chev, #soundBtn.nudge { animation: none !important; }
}