/* /headphones/ — Tessel One exploded view. Base rules = static fallback (reduced motion / no WebGL):
   a still render with the chapters as a list. `html.hp-on` turns on the sticky live-3D scroll story. */
@font-face { font-family: "Space Grotesk"; src: url(/assets/fonts/space-grotesk-variable.woff2) format("woff2"); font-weight: 300 700; font-display: swap; }
.hp-page {
  --pg-bg: #eceef0; --pg-ink: #111316; --f-display: "Space Grotesk", system-ui, sans-serif; --h-weight: 600;
  --accent: #ff5a1f; --bar-bg: #111316; --bar-fg: #eceef0; --tag: #ff7a45; --btn-bg: #ff5a1f; --btn-fg: #fff;
  --order-bg: #111316; --order-fg: #eceef0; --muted: #5b6069;
}
.hp-page .dm-bar__name { font: 600 1.15rem "Space Grotesk", sans-serif; letter-spacing: .32em; }
.hp-page .dm-eyebrow { color: var(--accent); }
.hp-page h1, .hp-page h2 { letter-spacing: -.04em; }

/* ---------- Static fallback ---------- */
.hp-stage { position: relative; padding: 3rem max(16px, (100vw - 1160px) / 2) 4rem; background: radial-gradient(120% 90% at 60% 35%, #fbfcfc, #d6dade 78%); }
.hp-stage canvas, .hp-lines, .hp-tags, .hp-colours, .hp-prog, .hp-scroll { display: none; }
.hp-still { display: block; width: 100%; height: auto; border-radius: 18px; margin: 0 0 2rem; }
.hp-ch { margin: 0 0 2.2rem; max-width: 36rem; }
.hp-ch h1 { font-size: clamp(2.6rem, 6vw, 4.8rem); margin: .7rem 0 .8rem; }
.hp-ch h2 { font-size: clamp(1.8rem, 3.4vw, 2.7rem); margin: .6rem 0 .7rem; line-height: 1.02; }
.hp-ch p { margin: 0; color: var(--muted); }
.hp-ch .dm-eyebrow { color: var(--accent); }
.hp-stat { display: inline-block; margin-top: 1rem !important; padding: .35rem .75rem; border-radius: 999px; background: #111316; color: #fff !important; font: 500 .82rem var(--f-body); }
.hp-ch--final .dm-btn { margin-top: 1.4rem; }

/* ---------- Live 3D scroll story ---------- */
.hp-on .hp-story { height: 900svh; }
.hp-on .hp-stage { position: sticky; top: 0; height: 100svh; padding: 0; overflow: hidden; }
.hp-on .hp-still { display: none; }
.hp-on .hp-stage canvas { display: block; position: absolute; inset: 0; width: 100%; height: 100%; }
.hp-on .hp-ch {
  position: absolute; z-index: 3; left: max(24px, (100vw - 1240px) / 2); top: 50%; width: min(25rem, 34vw); margin: 0;
  opacity: 0; translate: 0 calc(-50% + 24px); transition: opacity .5s, translate .6s cubic-bezier(.2, .8, .2, 1); pointer-events: none;
}
.hp-on .hp-ch.is-on { opacity: 1; translate: 0 -50%; pointer-events: auto; }
.hp-on .hp-ch:not(.hp-ch--intro):not(.hp-ch--final) { padding: 1.6rem 1.7rem; border-radius: 22px; background: rgba(255, 255, 255, .72);
  backdrop-filter: blur(16px) saturate(1.2); -webkit-backdrop-filter: blur(16px) saturate(1.2); box-shadow: 0 24px 60px -34px rgba(17, 19, 22, .45); }
.hp-on .hp-ch h1 { font-size: clamp(2.8rem, 5.4vw, 5.2rem); }
.hp-on .hp-ch--intro .hp-scroll { display: inline-flex; align-items: center; gap: .6rem; margin-top: 2rem; font: 500 .72rem var(--f-mono); letter-spacing: .18em; text-transform: uppercase; color: var(--muted); }
.hp-scroll::after { content: ""; width: 1px; height: 36px; background: linear-gradient(var(--accent), transparent); animation: hp-drip 1.8s ease-in-out infinite; }
@keyframes hp-drip { 0% { transform: scaleY(0); transform-origin: top; } 50% { transform: scaleY(1); transform-origin: top; } 51% { transform-origin: bottom; } 100% { transform: scaleY(0); transform-origin: bottom; } }

/* leader line from the focused part to the card */
.hp-on .hp-lines { display: block; position: absolute; inset: 0; width: 100%; height: 100%; z-index: 2; pointer-events: none; opacity: 0; transition: opacity .35s; }
.hp-lines.on { opacity: 1; }
.hp-lines line { stroke: var(--accent); stroke-width: 1.5; stroke-dasharray: 4 5; }
.hp-lines circle { fill: #fff; stroke: var(--accent); stroke-width: 3; }

/* labels on every part in the overview */
.hp-on .hp-tags { display: block; position: absolute; inset: 0; z-index: 2; pointer-events: none; opacity: 0; transition: opacity .4s; }
.hp-tags.on { opacity: 1; }
.hp-tag { position: absolute; left: 0; top: 0; translate: -50% -140%; white-space: nowrap; padding: .28rem .6rem; border-radius: 999px;
  background: rgba(17, 19, 22, .86); color: #fff; font: 500 .72rem var(--f-body); box-shadow: 0 6px 18px -8px rgba(0, 0, 0, .5); }
.hp-tag::after { content: ""; position: absolute; left: 50%; top: 100%; width: 1px; height: 12px; background: rgba(17, 19, 22, .6); }
.hp-tag--b { translate: -50% 60%; }
.hp-tag--b::after { top: auto; bottom: 100%; }

/* colour picker + progress */
.hp-on .hp-colours { display: flex; align-items: center; gap: 1rem; position: absolute; z-index: 4; left: max(24px, (100vw - 1240px) / 2); top: calc(52px + 1.4rem); font-size: .88rem; color: var(--muted); }   /* at the top: visible as soon as the page opens (John) */
.hp-colours b { color: var(--pg-ink); font-weight: 600; }
.hp-colours div { display: flex; gap: .55rem; }
.hp-colours button { width: 30px; height: 30px; border-radius: 50%; border: 0; padding: 0; cursor: pointer; background: var(--c);
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .15), 0 0 0 3px transparent; transition: box-shadow .25s, transform .2s; }
.hp-colours button:hover { transform: scale(1.08); }
.hp-colours button[aria-checked="true"] { box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .15), 0 0 0 3px #eceef0, 0 0 0 4.5px var(--pg-ink); }
.hp-on .hp-prog { display: block; position: absolute; z-index: 4; left: 0; right: 0; bottom: 0; height: 3px; background: rgba(17, 19, 22, .08); }
.hp-prog i { display: block; height: 100%; background: var(--accent); transform: scaleX(0); transform-origin: left; }

/* ---------- Specs ---------- */
.hp-specs { background: var(--pg-bg); }
.hp-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; margin: 0; }
.hp-grid > div { padding: 1.6rem; border-radius: 20px; background: #fff; box-shadow: 0 18px 40px -30px rgba(17, 19, 22, .45); }
.hp-grid dt { font: 500 .72rem var(--f-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
.hp-grid dd { margin: .5rem 0 .3rem; font: 600 clamp(2rem, 3.4vw, 2.8rem)/1 "Space Grotesk", sans-serif; letter-spacing: -.04em; }
.hp-grid p { margin: 0; color: var(--muted); font-size: .95rem; }
.hp-order { padding-top: 0; }

@media (max-width: 800px) {
  .hp-grid { grid-template-columns: minmax(0, 1fr); }
  .hp-on .hp-ch { left: 12px; right: 12px; top: auto; bottom: 86px; width: auto; translate: 0 24px; padding: 1.1rem 1.2rem; border-radius: 18px;
    background: rgba(255, 255, 255, .86); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); box-shadow: 0 16px 40px -24px rgba(17, 19, 22, .5); }
  .hp-on .hp-ch.is-on { translate: 0 0; }
  .hp-on .hp-ch--intro, .hp-on .hp-ch--final { background: none; box-shadow: none; backdrop-filter: none; -webkit-backdrop-filter: none; top: 128px; bottom: auto; }
  .hp-on .hp-ch h1 { font-size: 2.6rem; }
  .hp-on .hp-ch h2 { font-size: 1.45rem; margin: .4rem 0 .45rem; }
  .hp-on .hp-ch p { font-size: .93rem; }
  .hp-stat { margin-top: .7rem !important; }
  .hp-on .hp-colours { left: auto; right: 12px; top: 84px; }
  .hp-colours > span { display: none; }                      /* just the dots on phones */
  .hp-colours button { width: 26px; height: 26px; }
  .hp-tag { font-size: .62rem; padding: .2rem .45rem; }
  .hp-tag--minor { display: none; }
}

/* Own fonts (not the studio's Hanken Grotesk / IBM Plex Mono): body text and labels */
.hp-page { --f-body: "Space Grotesk", system-ui, sans-serif; --f-mono: "Space Grotesk", system-ui, sans-serif; }