/* The Idea Engine hero: full screen, under a transparent header. Accent follows the tube's phosphor. */
.hero-engine { --phos: #ffb347; --phos-rgb: 255,179,71; --phos-hi: #ffc46b; --phos-ink: #2a1600; }
.hero-engine[data-phosphor="green"] { --phos: #54ff80; --phos-rgb: 84,255,128; --phos-hi: #86ffa6; --phos-ink: #02240d; }
.hero-engine { position: relative; padding: 0; background: #0b0d12; color: #f3efe6; height: 100svh; min-height: 640px; overflow: hidden; }
.hero-engine .stage { position: absolute; inset: 0; cursor: pointer; }
.hero-engine .stage canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.hero-engine .ui { position: absolute; inset: 0; pointer-events: none; }
.hero-engine .copy { position: absolute; left: max(24px, calc((100% - var(--w)) / 2)); right: 52%; top: 50%; transform: translateY(-50%); }
.hero-engine .eyebrow { color: var(--phos); margin-bottom: 18px; }
.hero-engine h1 { font-family: var(--display); font-weight: 700; font-size: clamp(38px, 4.4vw, 62px); line-height: 1.0; letter-spacing: -0.035em; max-width: 17ch; }
.hero-engine h1 em { font-style: normal; color: var(--phos); }
.hero-engine .lede { margin-top: 22px; font-size: clamp(15px, 1.2vw, 18px); color: rgba(243,239,230,0.78); max-width: 44ch; line-height: 1.55; }
.hero-engine .actions { position: absolute; left: max(24px, calc((100% - var(--w)) / 2)); bottom: clamp(30px, 6vh, 64px); display: flex; gap: 10px; flex-wrap: wrap; pointer-events: auto; }
.hero-engine .btn.amber { background: var(--phos); border-color: var(--phos); color: var(--phos-ink); }
.hero-engine .btn.amber:hover { background: var(--phos-hi); }
.hero-engine .btn.dark { background: rgba(255,255,255,0.08); border-color: rgba(255,255,255,0.18); color: #fff; }
.hero-engine .btn.dark:hover { background: rgba(255,255,255,0.15); }
.hero-engine .side { position: absolute; right: max(24px, calc((100% - var(--w)) / 2)); bottom: clamp(30px, 6vh, 64px); display: flex; align-items: center; gap: 18px; pointer-events: auto; }
.hero-engine .hint { font-family: var(--mono); font-size: 11px; letter-spacing: .14em; text-transform: uppercase; color: rgba(var(--phos-rgb),0.85); display: flex; align-items: center; gap: 10px; }
.hero-engine .hint b { display: inline-block; width: 34px; height: 1px; background: currentColor; }
/* sound: a clear speaker button that says what it does */
.snd { display: inline-flex; align-items: center; gap: 10px; border: 1px solid rgba(var(--phos-rgb),.55); background: rgba(var(--phos-rgb),.1); color: var(--phos); border-radius: 999px; padding: 10px 16px 10px 12px; font: 600 13px/1 var(--body); cursor: pointer; transition: background .2s, color .2s, box-shadow .2s; }
.snd svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.snd svg path:first-child { fill: currentColor; stroke: none; }
.snd .i-on { display: none; }
.snd.on { background: var(--phos); color: var(--phos-ink); box-shadow: 0 0 24px rgba(var(--phos-rgb),.45); }
.snd.on .i-on { display: block; } .snd.on .i-off { display: none; }
.snd:hover { background: rgba(var(--phos-rgb),.2); } .snd.on:hover { background: var(--phos-hi); }
.snd.nudge { animation: nudge 1.4s ease-in-out 3; }
@keyframes nudge { 0%, 100% { box-shadow: 0 0 0 0 rgba(var(--phos-rgb),.6); } 50% { box-shadow: 0 0 0 12px rgba(var(--phos-rgb),0); } }
.scroll-cue { position: absolute; left: 50%; bottom: 18px; width: 22px; height: 36px; margin-left: -11px; border: 1.5px solid rgba(243,239,230,.35); border-radius: 12px; pointer-events: auto; }
.scroll-cue span { position: absolute; left: 50%; top: 7px; width: 3px; height: 7px; margin-left: -1.5px; border-radius: 2px; background: rgba(243,239,230,.7); animation: cue 1.8s ease-in-out infinite; }
@keyframes cue { 0% { transform: translateY(0); opacity: 1; } 70% { transform: translateY(10px); opacity: 0; } 100% { opacity: 0; } }
@media (prefers-reduced-motion: reduce) { .scroll-cue span, .snd.nudge { animation: none; } }
@media (max-width: 860px) {
  .hero-engine { height: auto; min-height: 0; display: flex; flex-direction: column; padding-top: 72px; }
  .hero-engine .ui { position: static; display: contents; }
  .hero-engine .copy { position: static; transform: none; padding: 36px 24px 18px; order: 1; }
  .hero-engine .stage { position: relative; height: 56svh; min-height: 340px; order: 2; }
  .hero-engine .actions { position: static; padding: 18px 24px 8px; order: 3; }
  .hero-engine .side { position: static; padding: 8px 24px 28px; order: 4; justify-content: space-between; }
  .hero-engine .hint span::after { content: " (tap it)"; letter-spacing: 0; text-transform: none; }
  .scroll-cue { display: none; }
}