/* ──────────────────────────────────────────────────────────
   ElitePC — Scroll-driven teardown hero  (image sequence)
   ────────────────────────────────────────────────────────── */

:root {
  --td-bg:        #0C0E0F;
  --td-ink:       #F4F6F6;
  --td-ink-soft:  rgba(244,246,246,.62);
  --td-ink-faint: rgba(244,246,246,.34);
  --td-line:      rgba(244,246,246,.12);
  --td-scroll:    7;
}

/* ── tall scroll track + pinned stage ── */
.teardown {
  position: relative;
  height: calc(var(--td-scroll) * 100dvh);
  background: var(--td-bg);
}
.td-stage {
  position: sticky; top: 0;
  height: 100dvh; width: 100%;
  overflow: hidden;
  background: var(--td-bg);
  color: var(--td-ink);
}

/* ── image sequence stack ── */
.td-frames {
  position: absolute; inset: 0;
  z-index: 1;
}
.td-frame {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  object-fit: cover; object-position: center;
  opacity: 0;
  will-change: opacity, transform;
  transform-origin: center;
  pointer-events: none;
  -webkit-user-drag: none;
  user-select: none;
}

/* left-side gradient keeps caption text legible over bright photos */
.td-frames::after {
  content: "";
  position: absolute; inset: 0; z-index: 2; pointer-events: none;
  background:
    linear-gradient(to right,  rgba(0,0,0,.72) 0%, rgba(0,0,0,.38) 44%, rgba(0,0,0,.08) 100%),
    linear-gradient(to top,    rgba(0,0,0,.55) 0%, transparent 34%),
    linear-gradient(to bottom, rgba(0,0,0,.40) 0%, transparent 22%);
}

/* faint engineering grid */
.td-gridlines {
  position: absolute; inset: 0; pointer-events: none; opacity: .22; z-index: 3;
  background-image:
    linear-gradient(var(--td-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--td-line) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(70% 60% at 50% 45%, #000 30%, transparent 78%);
          mask-image: radial-gradient(70% 60% at 50% 45%, #000 30%, transparent 78%);
}

.td-vignette {
  position: absolute; inset: 0; pointer-events: none; z-index: 4;
  box-shadow: inset 0 0 180px 40px rgba(0,0,0,.45);
}

/* bottom fade into the light page */
.td-fade-out {
  position: absolute; left: 0; right: 0; bottom: 0; height: 24vh;
  pointer-events: none; z-index: 4;
  background: linear-gradient(to bottom, transparent, var(--bg));
  opacity: 0; transition: opacity .2s linear;
}

/* ── HUD : step counter + name + progress bar ── */
.td-hud {
  position: absolute; left: var(--gutter); bottom: clamp(28px,5vh,52px); z-index: 6;
  display: flex; align-items: center; gap: 18px;
  font-family: var(--mono);
}
.td-step { display: flex; align-items: baseline; gap: 5px; letter-spacing: .06em; }
.td-step b { font-size: 14px; color: var(--td-ink); font-weight: 500; }
.td-step span { font-size: 11px; color: var(--td-ink-faint); }
.td-stepname {
  font-size: 11px; letter-spacing: .22em; text-transform: uppercase;
  color: var(--td-ink-soft); padding-left: 18px; border-left: 1px solid var(--td-line);
  min-width: 160px;
}
.td-bar { position: relative; flex: 1; max-width: 240px; height: 2px; background: var(--td-line); }
.td-bar span { position: absolute; left: 0; top: 0; height: 2px; width: 0; background: var(--teal-bright); }

/* ── beat dots — mobile progress indicator ── */
.td-dots {
  display: none;
  align-items: center;
  gap: 7px;
  padding-left: 16px;
  border-left: 1px solid var(--td-line);
  flex-shrink: 0;
}
.td-dots span {
  display: block;
  width: 7px; height: 7px; border-radius: 999px;
  background: rgba(244,246,246,.22);
  transition: background .15s ease;
  flex: 0 0 auto;
  will-change: width;
}
.td-dots span.is-past  { background: rgba(21,191,203,.45); }
.td-dots span.is-active { background: var(--teal-bright); height: 7px; border-radius: 999px; }

/* ── scroll hint ── */
.td-hint {
  position: absolute; left: 50%; bottom: clamp(28px,5vh,52px); transform: translateX(-50%); z-index: 6;
  display: flex; flex-direction: column; align-items: center; gap: 9px;
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .22em; text-transform: uppercase;
  color: var(--td-ink-faint); transition: opacity .4s var(--ease);
}
.td-hint .mouse {
  width: 20px; height: 30px; border: 1px solid var(--td-ink-faint); border-radius: 11px; position: relative;
}
.td-hint .mouse::after {
  content: ""; position: absolute; left: 50%; top: 6px; width: 2px; height: 5px; border-radius: 2px;
  background: var(--td-ink-soft); transform: translateX(-50%);
  animation: tdwheel 1.6s var(--ease) infinite;
}
@keyframes tdwheel {
  0%   { opacity: 0; transform: translate(-50%,0); }
  30%  { opacity: 1; }
  70%  { opacity: 1; }
  100% { opacity: 0; transform: translate(-50%,9px); }
}
@media (prefers-reduced-motion: reduce) { .td-hint .mouse::after { animation: none; } }

/* ── captions — cross-fade per beat ── */
.td-captions {
  position: absolute; left: var(--gutter); top: 0; bottom: 0; z-index: 5;
  width: min(40ch, 38vw);
  display: flex; flex-direction: column; justify-content: center;
  pointer-events: none;
}
.cap {
  position: absolute; left: var(--gutter); right: auto;
  max-width: min(40ch, 38vw);
  opacity: 0; transform: translateY(16px);
  will-change: opacity, transform;
}
.cap .cap-kicker {
  font-family: var(--mono); font-size: 11px; letter-spacing: .24em; text-transform: uppercase;
  color: var(--teal-bright); display: flex; align-items: center; gap: 11px; margin-bottom: 18px;
}
.cap .cap-kicker .tick { width: 24px; height: 1px; background: rgba(120,210,220,.5); }
.cap h2, .cap h1 {
  font-family: var(--serif); font-weight: 400; line-height: 1.02; letter-spacing: -.01em;
  color: var(--td-ink); text-wrap: balance;
}
.cap h1 { font-size: clamp(40px, 5.6vw, 82px); }
.cap h2 { font-size: clamp(30px, 3.8vw, 54px); }
.cap em { color: var(--teal-bright); font-style: italic; }
.cap p {
  color: var(--td-ink-soft); font-size: clamp(15px, 1.5vw, 18px); line-height: 1.6;
  margin-top: 20px; max-width: 38ch; text-wrap: pretty;
}
.cap .cap-spec { display: flex; gap: 26px; margin-top: 26px; flex-wrap: wrap; }
.cap .cap-spec .sp .k {
  font-family: var(--serif); font-size: clamp(20px, 2vw, 27px); line-height: 1; white-space: nowrap;
}
.cap .cap-spec .sp .l {
  font-family: var(--mono); font-size: 10px; letter-spacing: .16em; text-transform: uppercase;
  color: var(--td-ink-faint); margin-top: 8px;
}
.cap .cap-cta { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; pointer-events: auto; }

.teardown.no-caps .td-captions { display: none; }

/* ── header theme while over the dark stage ── */
.site-header.on-dark { background: transparent !important; box-shadow: none !important; }
.site-header.on-dark .nav a { color: rgba(244,246,246,.72); }
.site-header.on-dark .nav a:hover { color: #fff; }
.site-header.on-dark .nav a::after { background: var(--teal-bright); }
.site-header.on-dark .brand-sub { color: rgba(244,246,246,.5); border-left-color: var(--td-line); }
.site-header.on-dark .brand img { filter: brightness(0) invert(1); }
.site-header.on-dark .header-cta.btn-primary { background: #fff; color: #0c0e0f; }
.site-header.on-dark .header-cta.btn-primary:hover { background: var(--teal-bright); color: #06262a; }
.site-header.on-dark .nav-toggle span,
.site-header.on-dark .nav-toggle span::before,
.site-header.on-dark .nav-toggle span::after { background: #fff; }

.scroll-rail { transition: opacity .4s var(--ease); }
.scroll-rail.td-hide { opacity: 0; }

/* ── responsive ── */
@media (max-width: 1100px) {
  .td-captions {
    top: auto; bottom: auto; left: 0; right: 0; width: 100%;
    height: auto; padding: clamp(96px,15vh,140px) var(--gutter) 0; justify-content: flex-start;
  }
  .cap { left: var(--gutter); right: var(--gutter); max-width: none; }
  .cap h1 { font-size: clamp(38px, 9vw, 60px); }
  .cap h2 { font-size: clamp(26px, 6.5vw, 40px); }
  .cap p { max-width: 46ch; }
  .td-hud { left: var(--gutter); right: var(--gutter); }
  .td-bar { max-width: 120px; }
  .td-dots { display: flex; }
}
@media (max-width: 680px) {
  :root { --td-scroll: 5; }
  .td-stepname { min-width: 0; }
  .td-hint { display: none; }
  .td-bar { display: none; }
  .cap .cap-spec { gap: 18px; }
  /* lift HUD clear of the fixed m-cta bar (50px button + 14px bottom = ~76px) */
  .td-hud { bottom: 84px; }
}

@media (prefers-reduced-motion: reduce) {
  .teardown { height: 100vh; }
  .td-hint { display: none; }
}