/* ==========================================================================
   TRBEXA — Electric Performance Karts
   Direction: Dark-stage / single light source
   ========================================================================== */

/* ---------- tokens ---------- */
:root {
  /* surfaces */
  --bg:        #08080A;
  --bg-2:      #0C0C0F;
  --panel:     #111114;
  --panel-2:   #16161A;
  --paper:     #E9E5DC;
  --paper-2:   #DFDACF;
  --paper-ink: #14140F;

  /* ink */
  --ink:       #F4F2EE;
  --dim:       #B6B2AA;
  --mute:      #8C8880;
  --on-paper-dim: #55524A;

  /* brand */
  --red:       #E8111F;
  --red-hi:    #FF3945;
  --red-deep:  #8E0B14;
  --red-ink:   #FF4A56;   /* 小字号红字（深底）*/
  --red-paper: #B60D17;   /* 小字号红字（米色底）*/

  /* lines */
  --line:      rgba(244, 242, 238, .12);
  --line-soft: rgba(244, 242, 238, .07);
  --line-paper: rgba(20, 20, 15, .16);

  /* type */
  --f-display: 'Saira Condensed', 'Bahnschrift Condensed', 'Arial Narrow', 'Helvetica Neue', sans-serif;
  --f-body: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --f-mono: 'IBM Plex Mono', ui-monospace, 'SFMono-Regular', Consolas, monospace;

  /* rhythm */
  --gutter: clamp(22px, 5.6vw, 88px);
  --maxw: 1560px;
  --nav-h: 86px;

  --ease-out: cubic-bezier(.16, 1, .3, 1);
  --ease-io:  cubic-bezier(.65, .05, .36, 1);
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; overflow-x: clip; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--f-body);
  font-weight: 300;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
h1, h2, h3, h4, p, figure, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }
::selection { background: var(--red); color: #fff; }
:focus-visible { outline: 2px solid var(--red-hi); outline-offset: 3px; }

/* ---------- film grain ---------- */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: .032;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
}
@media (prefers-reduced-motion: reduce) { body::after { display: none; } }

[id] { scroll-margin-top: calc(var(--nav-h) + 28px); }

/* ---------- layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }

/* ---------- type primitives ---------- */
.display {
  font-family: var(--f-display);
  font-weight: 800;
  line-height: .86;
  letter-spacing: -.012em;
  text-transform: uppercase;
}
.display--skew { font-style: normal; }
.display--skew > span { display: inline-block; transform: skewX(-8deg); transform-origin: 0 80%; }
.hero__l1 i, .hero__l2 i {
  font-style: normal;
  display: inline-block;
  transform: skewX(-8deg);
  transform-origin: 0 100%;
}

.mono {
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .16em;
  text-transform: uppercase;
  line-height: 1.5;
}
.mono--tight { letter-spacing: .1em; }

.lede {
  font-size: clamp(16px, 1.25vw, 19px);
  line-height: 1.62;
  color: var(--dim);
  font-weight: 300;
  max-width: 46ch;
}
.lede strong { color: var(--ink); font-weight: 500; }

/* ---------- buttons ---------- */
.btn {
  --btn-bg: var(--red);
  --btn-ink: #fff;
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: .7em;
  padding: 16px 26px;
  background: var(--btn-bg);
  color: var(--btn-ink);
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .13em;
  text-transform: uppercase;
  border-radius: 1px;
  transition: transform .18s var(--ease-out), background .18s linear, box-shadow .3s ease;
  will-change: transform;
}
.btn:hover { background: var(--red-hi); box-shadow: 0 10px 40px -12px rgba(232, 17, 31, .9); }
.btn:active { transform: scale(.975); }
.btn .arw { transition: transform .25s var(--ease-out); }
.btn:hover .arw { transform: translateX(4px); }

.btn--ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn--ghost:hover { background: rgba(244, 242, 238, .06); border-color: rgba(244, 242, 238, .3); box-shadow: none; }
.btn--ghost:active { transform: scale(.985); }

.link-u {
  display: inline-flex;
  align-items: center;
  gap: .55em;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .13em;
  text-transform: uppercase;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--line);
  transition: border-color .2s linear, color .2s linear;
}
.link-u:hover { border-color: var(--red); color: #fff; }

/* ---------- nav ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background .35s linear, backdrop-filter .35s linear, border-color .35s linear;
  border-bottom: 1px solid transparent;
}
.nav.is-stuck {
  background: rgba(8, 8, 10, .78);
  backdrop-filter: blur(16px) saturate(140%);
  border-bottom-color: var(--line-soft);
}
.nav__inner {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: clamp(20px, 3vw, 56px);
}
.nav__logo { display: block; width: clamp(118px, 9.8vw, 146px); flex: none; }
.nav__logo img { width: 100%; height: auto; }

.nav__links { display: flex; align-items: center; gap: clamp(16px, 2.1vw, 34px); margin-left: auto; }
.nav__link {
  position: relative;
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--dim);
  padding: 6px 0;
  transition: color .2s linear;
  display: inline-flex;
  align-items: baseline;
  gap: .5em;
  white-space: nowrap;
}
.nav__link::after {
  content: '';
  position: absolute;
  left: 0; right: 100%; bottom: 0;
  height: 1px;
  background: var(--red);
  transition: right .3s var(--ease-out);
}
.nav__link:hover, .nav__link[aria-current] { color: var(--ink); }
.nav__link:hover::after, .nav__link[aria-current]::after { right: 0; }
.nav__link[aria-current] { color: var(--ink); }
.nav__soon {
  font-size: 9px;
  letter-spacing: .12em;
  color: #FF5A66;
  border: 1px solid rgba(232, 17, 31, .55);
  padding: 1px 4px 0;
  line-height: 1.5;
  translate: 0 -4px;
}
.nav__cta { margin-left: clamp(6px, 1.2vw, 20px); padding: 12px 18px; white-space: nowrap; }

.nav__burger { display: none; width: 44px; height: 44px; margin-left: auto; position: relative; }
.nav__burger span {
  position: absolute; left: 11px; width: 22px; height: 1.5px; background: var(--ink);
  transition: transform .3s var(--ease-out), opacity .2s linear;
}
.nav__burger span:nth-child(1) { top: 18px; }
.nav__burger span:nth-child(2) { top: 25px; }
.nav.is-open .nav__burger span:nth-child(1) { transform: translateY(3.5px) rotate(45deg); }
.nav.is-open .nav__burger span:nth-child(2) { transform: translateY(-3.5px) rotate(-45deg); }

/* ---------- hero ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  overflow: clip;
  background: radial-gradient(120% 90% at 50% 4%, #16161A 0%, #0A0A0C 52%, #060607 100%);
}
.hero__stage {
  position: relative;
  flex: 1;
  min-height: clamp(560px, 78svh, 900px);
  isolation: isolate;
  overflow: clip;
}
/* 主光：从左上斜落的一束红光 */
.hero__beam {
  position: absolute;
  z-index: 0;
  left: -18%;
  top: 2%;
  width: 150%;
  height: 260px;
  background: linear-gradient(to bottom,
    transparent 0%,
    rgba(232, 17, 31, .34) 34%,
    rgba(255, 74, 84, .5) 52%,
    rgba(232, 17, 31, .1) 74%,
    transparent 100%);
  transform: rotate(15deg);
  transform-origin: 0 0;
  filter: blur(38px);
  mix-blend-mode: screen;
  pointer-events: none;
}
.hero__glow {
  position: absolute;
  left: 50%; top: 54%;
  width: min(1120px, 88vw);
  aspect-ratio: 1.6;
  translate: -50% -50%;
  z-index: 0;
  background: radial-gradient(ellipse at 50% 50%, rgba(232, 17, 31, .16), rgba(232, 17, 31, .05) 42%, transparent 68%);
  pointer-events: none;
}
.hero__type {
  position: relative;
  z-index: 1;
  padding-top: clamp(124px, 16.4vh, 188px);
  padding-inline: var(--gutter);
}
.hero__l1 {
  font-size: clamp(34px, 4.6vw, 74px);
  display: block;
}
.hero__l2 {
  font-size: clamp(56px, 11vw, 162px);
  display: block;
  margin-top: -.02em;
  color: var(--ink);
}
.hero__l2 em {
  font-style: normal;
  color: transparent;
  -webkit-text-stroke: 2.4px rgba(244, 242, 238, .62);
}

.hero__kart {
  position: absolute;
  z-index: 2;
  right: 3.2vw;
  bottom: 4.5%;
  width: min(880px, 57vw);
  will-change: transform;
  transform-origin: 50% 90%;
}
.hero__kart img { width: 100%; height: auto; filter: drop-shadow(0 40px 60px rgba(0, 0, 0, .85)); position: relative; z-index: 2; }
/* 舞台地面：机身倒影 */
.hero__kart::after {
  content: '';
  position: absolute;
  z-index: 1;
  left: 0; right: 0; top: 99.2%;
  height: 34%;
  background: url("../img/d1-hero.webp") top center / 100% no-repeat;
  transform: scaleY(-1);
  opacity: .26;
  filter: blur(1px) saturate(.6) brightness(1.1);
  -webkit-mask-image: linear-gradient(to top, transparent 0%, rgba(0,0,0,.55) 46%, #000 96%);
  mask-image: linear-gradient(to top, transparent 0%, rgba(0,0,0,.55) 46%, #000 96%);
  pointer-events: none;
}
.hero__floor {
  position: absolute;
  inset: auto 0 0 0;
  height: 34%;
  z-index: 1;
  background: linear-gradient(to top, #050506 8%, rgba(8, 8, 10, .55) 46%, transparent 100%);
  pointer-events: none;
}

.hero__foot {
  position: absolute;
  z-index: 4;
  left: var(--gutter);
  bottom: clamp(96px, 13vh, 150px);
  display: flex;
  flex-direction: column;
  gap: clamp(20px, 2.9vh, 30px);
  max-width: min(372px, 34vw);
}
.hero__label { max-width: min(340px, 31vw); }
.hero__label .mono { color: var(--red-ink); }
.hero__label h2 {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(26px, 2.2vw, 34px);
  line-height: 1;
  letter-spacing: .01em;
  text-transform: uppercase;
  margin: 10px 0 12px;
  color: var(--ink);
}
.hero__label p { font-size: 14.5px; line-height: 1.55; color: var(--dim); font-weight: 300; }

.hero__actions {
  display: flex;
  align-items: center;
  gap: 26px;
}
.hero__actions .btn { min-width: 208px; justify-content: space-between; }

.hero__hud {
  position: relative;
  z-index: 4;
  border-top: 1px solid var(--line-soft);
  background: rgba(6, 6, 7, .55);
  backdrop-filter: blur(6px);
}
.hero__hud-inner {
  display: grid;
  grid-template-columns: repeat(5, 1fr) auto;
  align-items: center;
  gap: clamp(12px, 2vw, 40px);
  padding-block: 15px;
  padding-inline: var(--gutter);
  max-width: var(--maxw);
  margin-inline: auto;
}
.hud-item { display: flex; align-items: baseline; gap: 8px; }
.hud-item b {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(17px, 1.5vw, 22px);
  letter-spacing: .01em;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.hud-item span { font-family: var(--f-mono); font-size: 10px; letter-spacing: .13em; color: var(--mute); text-transform: uppercase; }
.hud-item--flag b { color: var(--red); }

.hero__scroll {
  position: absolute;
  z-index: 4;
  left: 50%;
  bottom: calc(100% - 100svh + 74px);
  display: none;
}

/* ---------- section shell ---------- */
.sec { position: relative; padding-block: clamp(88px, 12vw, 172px); }
.sec--paper { background: var(--paper); color: var(--paper-ink); }
.sec--paper .lede { color: var(--on-paper-dim); }
.sec--paper .mono { color: var(--mute); }

.sec-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: clamp(14px, 3vw, 64px); margin-bottom: clamp(38px, 5vw, 76px); }
.sec-head h2 {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(34px, 5.1vw, 86px);
  line-height: .9;
  letter-spacing: -.01em;
  text-transform: uppercase;
  max-width: 16ch;
}
.sec-head .mono { color: var(--red-ink); }

/* ---------- manifesto ---------- */
.manifesto { padding-block: clamp(120px, 16vw, 240px); position: relative; }
.manifesto__inner { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
.manifesto p[data-manifesto] {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(30px, 4.9vw, 82px);
  line-height: 1.0;
  letter-spacing: -.008em;
  text-transform: uppercase;
  max-width: 22ch;
}
.manifesto p .w { display: inline-block; color: rgba(244, 242, 238, .16); transition: color .5s linear; }
.manifesto p .w.on { color: var(--ink); }
.manifesto p .w--red.on { color: var(--red); }
.manifesto__foot {
  margin-top: clamp(40px, 5vw, 72px);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: clamp(20px, 3vw, 56px);
  border-top: 1px solid var(--line-soft);
  padding-top: 28px;
}
.manifesto__foot p { font-family: var(--f-body); font-size: 15.5px; line-height: 1.65; color: var(--dim); text-transform: none; font-weight: 300; max-width: 38ch; }
.manifesto__foot .mono { color: var(--mute); display: block; margin-bottom: 8px; }

/* ---------- engineering plate ---------- */
.plate { position: relative; }
.plate__top { display: grid; grid-template-columns: 1.1fr .9fr clamp(140px, 17vw, 236px); gap: clamp(24px, 4vw, 64px); align-items: start; margin-bottom: clamp(40px, 5vw, 72px); }
.plate__top h2 {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(38px, 6vw, 96px);
  line-height: .88;
  letter-spacing: -.012em;
  text-transform: uppercase;
}
.plate__top .lede { color: var(--on-paper-dim); max-width: 38ch; padding-top: .55em; }
.plate__macro {
  position: relative;
  width: 100%;
  margin-top: -.2em;
  aspect-ratio: 1;
  border-radius: 50%;
  overflow: hidden;
  background-image: url("../img/d1-hero.webp");
  background-size: 460%;
  background-position: 27.8% 41%;
  background-repeat: no-repeat;
  mix-blend-mode: multiply;
  opacity: .92;
  pointer-events: none;
}

.speccols { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(24px, 3.4vw, 64px); border-top: 2px solid var(--paper-ink); padding-top: 0; }
.specgroup { padding-top: 18px; }
.specgroup__tab {
  display: inline-block;
  background: var(--red);
  color: #fff;
  font-family: var(--f-mono);
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  padding: 5px 9px 4px;
  margin-bottom: 18px;
}
.specgroup dl { margin: 0; }
.specgroup .row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 9px 0;
  border-bottom: 1px solid var(--line-paper);
}
.specgroup .row:first-of-type { border-top: 1px solid var(--line-paper); }
.specgroup dt { font-size: 13.5px; font-weight: 400; color: var(--on-paper-dim); }
.specgroup dd {
  margin: 0;
  font-family: var(--f-mono);
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: .01em;
  color: var(--paper-ink);
  text-align: right;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
.specgroup dd .u { color: var(--on-paper-dim); font-weight: 400; }
.plate__note {
  margin-top: clamp(28px, 3vw, 44px);
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 13px;
  line-height: 1.55;
  color: var(--on-paper-dim);
  max-width: 78ch;
}
.plate__note b { color: var(--red-paper); font-family: var(--f-mono); font-size: 11px; letter-spacing: .12em; font-weight: 500; flex: none; padding-top: 2px; }

/* ---------- key figures ---------- */
.figures {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  border-top: 2px solid var(--paper-ink);
}
.figure {
  padding: 20px 16px 22px 0;
  border-right: 1px solid var(--line-paper);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.figure:last-child { border-right: 0; }
.figure b {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(30px, 3.4vw, 52px);
  line-height: .92;
  letter-spacing: -.01em;
  color: var(--paper-ink);
  font-variant-numeric: tabular-nums;
}
.figure span {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--red-paper);
}
.figure i {
  font-style: normal;
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.4;
  color: var(--on-paper-dim);
}
.plate__row {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-top: clamp(28px, 3vw, 42px);
}
.plate__row .plate__note { margin-top: 0; }

/* ---------- lineup selector ---------- */
.lineup { position: relative; padding-bottom: clamp(64px, 8vw, 120px); }
.lineup__grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(32px, 5vw, 90px); align-items: center; }
.lineup__stage {
  position: relative;
  aspect-ratio: 4 / 3.1;
  display: grid;
  place-items: center;
  isolation: isolate;
}
.lineup__stage::before {
  content: '';
  position: absolute;
  inset: 12% 4%;
  background: radial-gradient(ellipse at 50% 58%, rgba(232, 17, 31, .2), transparent 66%);
  z-index: -1;
}
.lineup__stage img { width: 100%; height: auto; filter: drop-shadow(0 30px 50px rgba(0, 0, 0, .85)); transition: opacity .4s linear; }
.lineup__badge {
  position: absolute;
  left: 0; top: 4%;
  font-family: var(--f-mono);
  font-size: 10.5px;
  letter-spacing: .15em;
  text-transform: uppercase;
  color: var(--mute);
  writing-mode: vertical-rl;
}
.lineup__badge b { color: var(--red); font-weight: 500; }

.lineup__models { display: flex; flex-direction: column; }
.model {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 16px;
  padding: 20px 0 18px;
  border-top: 1px solid var(--line-soft);
  text-align: left;
  transition: padding-left .35s var(--ease-out), color .3s linear;
  width: 100%;
}
.model:last-child { border-bottom: 1px solid var(--line-soft); }
.model__name {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(26px, 2.5vw, 38px);
  line-height: 1;
  letter-spacing: .01em;
  text-transform: uppercase;
  color: var(--mute);
  transition: color .3s linear;
}
.model__meta { font-family: var(--f-mono); font-size: 10.5px; letter-spacing: .13em; text-transform: uppercase; color: var(--mute); text-align: right; }
.model:hover .model__name { color: var(--ink); }
.model[aria-selected="true"] { padding-left: 22px; }
.model[aria-selected="true"] .model__name { color: var(--ink); }
.model[aria-selected="true"] .model__meta { color: var(--red-ink); }
.model::before {
  content: '';
  position: absolute;
  left: 0; top: 50%;
  width: 12px; height: 2px;
  background: var(--red);
  transform: translateY(-50%) scaleX(0);
  transform-origin: 0 50%;
  transition: transform .3s var(--ease-out);
}
.model[aria-selected="true"]::before { transform: translateY(-50%) scaleX(1); }
.model__status { font-family: var(--f-mono); font-size: 9.5px; letter-spacing: .12em; padding: 2px 5px 1px; border: 1px solid var(--line); color: var(--mute); }
.model__status--live { color: var(--red-ink); border-color: rgba(232, 17, 31, .5); }

.lineup__panel { margin-top: clamp(28px, 3vw, 44px); border-top: 1px solid var(--line-soft); padding-top: 26px; }
.lineup__speed { display: flex; align-items: baseline; gap: 10px; }
.lineup__speed b {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(56px, 6.6vw, 104px);
  line-height: .82;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}
.lineup__speed span { font-family: var(--f-mono); font-size: 11px; letter-spacing: .14em; color: var(--mute); text-transform: uppercase; }
.lineup__desc { margin-top: 16px; font-size: 15px; line-height: 1.6; color: var(--dim); max-width: 42ch; }
.lineup__foot { margin-top: 22px; display: flex; flex-wrap: wrap; gap: 20px 32px; align-items: center; }
.lineup__foot .mono { color: var(--mute); }

/* ---------- R series entry ---------- */
.rseries {
  position: relative;
  overflow: clip;
  border-block: 1px solid var(--line-soft);
  background:
    linear-gradient(180deg, #0A0A0C 0%, #0E0E11 100%);
}
.rseries__inner { position: relative; z-index: 1; padding-block: clamp(88px, 11vw, 150px); max-width: 820px; }
.rseries__code {
  position: absolute;
  z-index: 0;
  right: -1vw;
  top: 50%;
  translate: 0 -50%;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(88px, 16.4vw, 250px);
  line-height: .78;
  letter-spacing: -.025em;
  text-transform: uppercase;
  color: transparent;
  -webkit-text-stroke: 1.3px rgba(244, 242, 238, .17);
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
}
.rseries h2 {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(36px, 5vw, 76px);
  line-height: .9;
  letter-spacing: -.01em;
  text-transform: uppercase;
  margin-bottom: 18px;
  max-width: 14ch;
}
.rseries p { font-size: 16.5px; line-height: 1.65; color: var(--dim); max-width: 47ch; margin-bottom: 30px; }
.rseries__actions { display: flex; flex-wrap: wrap; gap: 12px; }
.rseries__hazard {
  position: absolute;
  inset: auto 0 0 0;
  height: 6px;
  background: repeating-linear-gradient(-45deg, var(--red) 0 14px, transparent 14px 28px);
  opacity: .55;
}

/* ---------- systems ---------- */
.systems__grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: var(--line-soft); border-block: 1px solid var(--line-soft); }
.system {
  position: relative;
  background: var(--bg);
  padding: clamp(28px, 3.4vw, 52px);
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-height: 320px;
  transition: background .3s linear;
}
.system:hover { background: var(--bg-2); }
.system__idx {
  position: absolute;
  top: clamp(20px, 2.4vw, 30px); right: clamp(20px, 2.4vw, 30px);
  font-family: var(--f-mono); font-size: 10px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--mute);
}
.system h3 {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(24px, 2.2vw, 34px);
  line-height: 1;
  text-transform: uppercase;
  letter-spacing: .01em;
}
.system p { font-size: 15px; line-height: 1.62; color: var(--dim); max-width: 40ch; }
.system__list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; }
.system__list li { font-family: var(--f-mono); font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase; color: var(--mute); border: 1px solid var(--line-soft); padding: 5px 8px 4px; }
.system .link-u { align-self: flex-start; margin-top: 4px; }

/* ---------- quote ---------- */
.quote { position: relative; isolation: isolate; }
.quote__glow {
  position: absolute;
  right: -10%; top: -20%;
  width: 70vw; aspect-ratio: 1;
  background: radial-gradient(circle at 50% 50%, rgba(232, 17, 31, .14), transparent 62%);
  z-index: -1;
  pointer-events: none;
}
.quote__grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: clamp(40px, 6vw, 110px); align-items: start; }
.quote h2 {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(38px, 5.6vw, 88px);
  line-height: .88;
  text-transform: uppercase;
  letter-spacing: -.012em;
}
.quote__contact { margin-top: 32px; display: flex; flex-direction: column; gap: 14px; }
.quote__contact a { display: inline-flex; flex-direction: column; gap: 2px; }
.quote__contact .mono { color: var(--mute); }
.quote__contact b { font-family: var(--f-mono); font-size: 15px; font-weight: 400; letter-spacing: .01em; color: var(--ink); }
.quote__contact a:hover b { color: var(--red-hi); }

.form { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 20px; }
.field { display: flex; flex-direction: column; gap: 7px; }
.field--full { grid-column: 1 / -1; }
.field label { font-family: var(--f-mono); font-size: 11px; letter-spacing: .13em; text-transform: uppercase; color: var(--dim); }
.field label .req { color: var(--red); }
.field input, .field select, .field textarea {
  width: 100%;
  background: rgba(244, 242, 238, .03);
  border: 1px solid var(--line);
  border-radius: 1px;
  color: var(--ink);
  font-family: var(--f-body);
  font-size: 15px;
  font-weight: 300;
  padding: 13px 14px;
  transition: border-color .18s linear, background .18s linear;
  appearance: none;
}
.field textarea { min-height: 104px; resize: vertical; line-height: 1.55; }
.field select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%23B6B2AA' stroke-width='1.4'/%3E%3C/svg%3E");
  background-position: calc(100% - 14px) 50%;
  background-size: 12px 8px;
  background-repeat: no-repeat;
  padding-right: 36px;
}
.field input:hover, .field select:hover, .field textarea:hover { border-color: rgba(244, 242, 238, .26); }
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--red); background: rgba(232, 17, 31, .04); }
.field input::placeholder, .field textarea::placeholder { color: #75726B; }
.field.is-invalid input, .field.is-invalid select, .field.is-invalid textarea { border-color: var(--red); }
.field__err { font-family: var(--f-mono); font-size: 10.5px; letter-spacing: .06em; color: var(--red-hi); min-height: 0; opacity: 0; transition: opacity .18s linear; }
.field.is-invalid .field__err { opacity: 1; }
.form__foot { grid-column: 1 / -1; display: flex; flex-wrap: wrap; align-items: center; gap: 18px; margin-top: 4px; }
.form__note { font-size: 12.5px; color: var(--mute); max-width: 34ch; line-height: 1.5; }
.form__ok {
  grid-column: 1 / -1;
  border: 1px solid rgba(232, 17, 31, .4);
  background: rgba(232, 17, 31, .07);
  padding: 16px 18px;
  font-size: 14px;
  color: var(--ink);
  display: none;
}
.form__ok.is-on { display: block; }

/* ---------- footer ---------- */
.foot { border-top: 1px solid var(--line-soft); padding-top: clamp(44px, 5vw, 72px); overflow: clip; }
.foot__top { display: grid; grid-template-columns: 1.5fr .85fr .85fr .9fr; gap: clamp(28px, 4vw, 64px); align-items: start; }
.foot__brand img { width: clamp(150px, 13vw, 190px); margin-bottom: 18px; }
.foot__brand p { font-size: 13.5px; color: var(--mute); max-width: 30ch; line-height: 1.55; }
.foot__col h4 { font-family: var(--f-mono); font-size: 10.5px; letter-spacing: .15em; text-transform: uppercase; color: var(--mute); margin-bottom: 14px; font-weight: 400; }
.foot__col li { margin-bottom: 9px; }
.foot__col a { font-size: 14px; color: var(--dim); transition: color .18s linear; }
.foot__col a:hover { color: var(--ink); }
.foot__wordmark {
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(72px, 18vw, 286px);
  line-height: .82;
  letter-spacing: -.03em;
  text-transform: uppercase;
  color: transparent;
  -webkit-text-stroke: 1px rgba(244, 242, 238, .17);
  margin-top: clamp(44px, 5.6vw, 78px);
  margin-bottom: .04em;
  user-select: none;
  white-space: nowrap;
}
.foot__legal {
  display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: center;
  border-top: 1px solid var(--line-soft);
  padding-block: 22px 30px;
  font-family: var(--f-mono);
  font-size: 10.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--mute);
}
.foot__legal span:last-child { margin-left: auto; }

/* ---------- page hero (inner pages) ---------- */
.phero {
  position: relative;
  padding-top: calc(var(--nav-h) + clamp(50px, 7vw, 96px));
  padding-bottom: clamp(36px, 5vw, 66px);
  overflow: clip;
  isolation: isolate;
}
.phero::after {
  content: '';
  position: absolute;
  z-index: -1;
  right: -14%;
  top: -30%;
  width: 58vw;
  aspect-ratio: 1;
  background: radial-gradient(circle, rgba(232, 17, 31, .16), rgba(232, 17, 31, .03) 46%, transparent 66%);
  pointer-events: none;
}
.phero__crumb { display: flex; gap: 10px; align-items: center; color: var(--mute); margin-bottom: 22px; }
.phero__crumb a:hover { color: var(--ink); }
.phero h1 {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(44px, 8.4vw, 140px);
  line-height: .86;
  letter-spacing: -.015em;
  text-transform: uppercase;
}
.phero .lede { margin-top: 22px; }

/* ---------- reveal base ---------- */
[data-reveal] { opacity: 0; will-change: transform, opacity; }

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
  .manifesto p .w { color: var(--ink) !important; }
  .manifesto p .w--red { color: var(--red) !important; }
}

/* ==========================================================================
   responsive
   ========================================================================== */
@media (max-width: 1180px) {
  .plate__top { grid-template-columns: 1fr; }
  .plate__macro { display: none; }
  .foot__top { grid-template-columns: 1fr 1fr; row-gap: 36px; }
}

@media (max-width: 1120px) {
  .nav__links { display: none; }
  .nav__burger { display: block; }
  .nav__cta { display: none; }
  .nav.is-open .nav__links {
    display: flex;
    position: fixed;
    inset: var(--nav-h) 0 auto 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: rgba(8, 8, 10, .97);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--line-soft);
    padding: 12px var(--gutter) 26px;
  }
  .nav.is-open .nav__link { font-size: 13px; padding: 14px 0; width: 100%; border-bottom: 1px solid var(--line-soft); }
  .nav.is-open .nav__cta { display: inline-flex; position: fixed; left: var(--gutter); right: var(--gutter); bottom: 24px; justify-content: center; }

  .speccols { grid-template-columns: 1fr; gap: 34px; }
  .figures { grid-template-columns: repeat(3, 1fr); }
  .figure:nth-child(3n) { border-right: 0; }
  .figure:nth-child(-n+3) { border-bottom: 1px solid var(--line-paper); }
  .lineup__grid { grid-template-columns: 1fr; }
  .lineup__stage { order: -1; margin-bottom: 8px; }
  .rseries__inner { grid-template-columns: 1fr; align-items: start; }
  .systems__grid { grid-template-columns: 1fr; }
  .quote__grid { grid-template-columns: 1fr; }
  .foot__top { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  :root { --nav-h: 64px; }
  body { font-size: 16px; }
  .hero__stage { min-height: 0; display: flex; flex-direction: column; }
  .hero__type { padding-top: calc(var(--nav-h) + 26px); }
  .hero__l1 { font-size: clamp(30px, 8.4vw, 46px); }
  .hero__l2 { font-size: clamp(40px, 10.4vw, 70px); }
  .hero__kart { position: relative; right: auto; bottom: auto; width: 100%; margin-left: 0; margin-top: 10px; padding-inline: 8px; }
  .hero__kart::after { display: none; }
  .hero__beam { top: 18%; height: 180px; }
  .hero__glow { top: 56%; width: 130vw; }
  .hero__foot { position: relative; left: auto; bottom: auto; max-width: none; padding-inline: var(--gutter); margin-top: auto; padding-top: 22px; gap: 20px; }
  .hero__label { max-width: none; }
  .hero__label h2 { font-size: 26px; margin: 6px 0 8px; }
  .hero__label p:last-child { font-size: 13.5px; }
  .hero__actions { flex-direction: column; align-items: stretch; gap: 14px; }
  .hero__actions .btn { justify-content: center; width: 100%; }
  .hero__actions .link-u { justify-content: center; align-self: center; }
  .hero__hud-inner { grid-template-columns: repeat(2, 1fr); gap: 12px 10px; padding-block: 14px; }
  .hud-item { flex-direction: column; gap: 1px; align-items: flex-start; }
  .hud-item span { font-size: 8.5px; letter-spacing: .1em; }
  .hud-item:nth-child(4), .hud-item:nth-child(5) { display: none; }
  .lineup__stage { aspect-ratio: 1 / .86; }
  .form { grid-template-columns: 1fr; }
  .sec-head { gap: 10px; }
  /* 宣言：标题与三条说明各归各位，压紧纵向节奏（原来 .manifesto p 误伤了下方三条正文） */
  .manifesto { padding-block: clamp(52px, 12vw, 88px); }
  .manifesto p[data-manifesto] { font-size: clamp(23px, 7vw, 34px); line-height: 1.04; max-width: 24ch; text-wrap: balance; }
  .manifesto__foot { margin-top: 26px; padding-top: 18px; gap: 15px; }
  .manifesto__foot p { font-size: 14px; line-height: 1.58; max-width: none; }
  .manifesto__foot .mono { font-size: 10px; margin-bottom: 5px; }
  .plate__top { gap: 18px; }
  .speccols { gap: 30px; }
  .rseries__code { display: none; }
  .figures { grid-template-columns: repeat(2, 1fr); }
  .figure:nth-child(3n) { border-right: 1px solid var(--line-paper); }
  .figure:nth-child(2n) { border-right: 0; }
  .figure:nth-child(-n+4) { border-bottom: 1px solid var(--line-paper); }
  .figure b { font-size: 34px; }
  .foot__legal span:last-child { margin-left: 0; }
}