* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: "SF Pro Display","Helvetica Neue","PingFang SC","Microsoft YaHei",sans-serif; background: #000; color: #fff; overflow-x: hidden; }
.app { position: relative; width: 100%; }
.scene { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 1; }
.scroll-spacer { position: relative; z-index: 0; pointer-events: none; }

.ui-layer { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 10; pointer-events: none; }

.preloader { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 100; display: flex; flex-direction: column; align-items: center; justify-content: center; background: #0a0a0a; transition: opacity 600ms cubic-bezier(0,0,0.58,1); }

.gear-svg { width: 100px; height: 100px; }

.progress-num { margin-top: 24px; }
.progress-num p { font-size: 14px; letter-spacing: 3px; color: rgba(255,255,255,0.8); font-weight: 300; }

.content-overlay { position: absolute; top: 0; left: 0; width: 100%; height: 100%; display: flex; align-items: center; justify-content: space-between; padding: 0 60px; opacity: 0; transition: opacity 1.5s ease; pointer-events: none; }
.content-overlay.visible { opacity: 1; }
.anim-block { position: absolute; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; transition: opacity 0.6s cubic-bezier(0.22,1,0.36,1), transform 0.6s cubic-bezier(0.22,1,0.36,1); }
.anim-block.anim-active { opacity: 1; transform: translateY(0); }
.anim-block.anim-exit { opacity: 0; transform: translateY(-30px); }
.anim-block.anim-hidden { opacity: 0; transform: translateY(20px); pointer-events: none; }
.text-block-animate { animation: textFadeIn 0.7s cubic-bezier(0.22,1,0.36,1) 0.2s both; }
@keyframes textFadeIn { from { opacity: 0; transform: translateY(24px); } to { opacity: 1; transform: translateY(0); } }



.content-left { text-align: left; max-width: 35%; }
.content-title { font-size: clamp(20px, 2.2vmin, 34px); font-weight: 600; color: rgba(255,255,255,0.95); letter-spacing: -0.5px; margin-bottom: 8px; line-height: 1.2; }
.content-subtitle { font-size: clamp(11px, 1vmin, 15px); font-weight: 400; letter-spacing: 3px; color: rgba(255,255,255,0.5); text-transform: uppercase; }
.content-right { text-align: right; max-width: 40%; }
.content-desc { font-size: clamp(12px, 1.1vmin, 16px); font-weight: 300; line-height: 1.8; letter-spacing: 0.5px; color: rgba(255,255,255,0.75); }

.title-box { display: inline-block; border: 1px solid rgba(255,255,255,0.12); border-radius: 12px; padding: 20px 28px; background: rgba(255,255,255,0.03); backdrop-filter: blur(12px); box-shadow: 0 0 30px rgba(255,255,255,0.03); opacity: 0; animation: titleBoxEnter 1s cubic-bezier(0.22,1,0.36,1) 0.15s forwards; }
.title-box .content-title { margin-bottom: 6px; }
.title-box .content-subtitle { margin-bottom: 0; }

.right-inner { transition: all 0.7s cubic-bezier(0.22,1,0.36,1); opacity: 0; transform: translateX(80px); }
.right-inner.right-active { opacity: 1; transform: translateX(0); }
.right-inner.right-exit { opacity: 0; transform: translateX(80px); }
.right-inner.right-hidden { opacity: 0; transform: translateX(120px); }

.module-img { max-width: 280px; max-height: 180px; border-radius: 8px; opacity: 0.7; margin-bottom: 8px; object-fit: cover; display: block; }
.module-img, .engine-img { opacity: 1; }

.statetable-container { position: absolute; left: 0; top: 50%; transform: translateY(-50%); pointer-events: auto; }
.statetable-content { position: relative; padding-left: 24px; }

.st-item { position: relative; padding: 8px 16px 8px 32px; cursor: pointer; transition: all 0.4s cubic-bezier(0.22,1,0.36,1); border-radius: 0 20px 20px 0; margin: 2px 0; }
.st-item:hover { background: rgba(255,255,255,0.04); }
.st-item.active { background: rgba(10,40,80,0.9); }
.item-line { display: none; }
.table-name { font-size: clamp(10px, 0.8vw, 13px); letter-spacing: 2px; color: rgba(255,255,255,0.7); white-space: nowrap; transition: color 0.3s ease; }
.st-item.active .table-name { color: #fff; }
.st-item:hover .table-name { color: rgba(255,255,255,0.9); }

.content-left.home-left { position: absolute; top: 8vh; left: 80px; max-width: 50%; }
.content-title.home-title { font-size: clamp(32px, 4vmin, 52px); font-weight: 700; letter-spacing: -1px; }
.content-subtitle.home-subtitle { font-size: clamp(13px, 1.4vmin, 18px); font-weight: 400; letter-spacing: 4px; color: rgba(255,255,255,0.85); }

.content-left.chassis-left { position: absolute; top: 64%; left: 200px; transform: translateY(-50%); max-width: 45%; }
.content-title.chassis-title { font-size: clamp(32px, 4vmin, 52px); font-weight: 700; letter-spacing: -1px; }
.content-subtitle.chassis-subtitle { font-size: clamp(13px, 1.4vmin, 18px); font-weight: 400; letter-spacing: 4px; color: rgba(255,255,255,0.6); }

.content-left.airflow-left { position: absolute; top: 8vh; right: 60px; max-width: 50%; text-align: right; }
.content-title.airflow-title { font-size: clamp(32px, 4vmin, 52px); font-weight: 700; letter-spacing: -1px; }
.content-subtitle.airflow-subtitle { font-size: clamp(13px, 1.4vmin, 18px); font-weight: 400; letter-spacing: 4px; color: rgba(255,255,255,0.6); }
.airflow-top-right { position: absolute; inset: 0; width: 100%; height: 100%; text-align: right; }
.airflow-top-right .module-img { position: absolute; left: 80px; bottom: 10vh; margin: 0; }
.airflow-desc-text { position: absolute; right: 60px; bottom: 10vh; width: min(42vw, 580px); margin: 0; text-align: right; font-size: clamp(18px, 2.2vmin, 28px); font-weight: 300; line-height: 1.75; letter-spacing: 0.5px; color: rgba(255,255,255,0.85); white-space: normal; }

.engine-top-left { position: absolute; top: 8vh; left: 80px; max-width: 420px; text-align: left; }
.engine-desc-text { font-size: clamp(20px, 2.6vmin, 30px); font-weight: 300; line-height: 1.6; letter-spacing: 0.8px; color: rgba(255,255,255,0.85); white-space: nowrap; }

.content-left.engine-left { position: absolute; bottom: 20vh; left: 80px; max-width: 50%; }
.content-title.engine-title { font-size: clamp(32px, 4vmin, 52px); font-weight: 700; letter-spacing: -1px; }
.content-subtitle.engine-subtitle { font-size: clamp(13px, 1.4vmin, 18px); font-weight: 400; letter-spacing: 4px; color: rgba(255,255,255,0.6); }

.content-left.allinone-left { position: absolute; bottom: 20vh; left: 80px; max-width: 50%; }
.content-title.allinone-title { font-size: clamp(32px, 4vmin, 52px); font-weight: 700; letter-spacing: -1px; }
.content-subtitle.allinone-subtitle { font-size: clamp(13px, 1.4vmin, 18px); font-weight: 400; letter-spacing: 4px; color: rgba(255,255,255,0.6); }
.allinone-top-right { position: absolute; top: 8vh; right: 60px; max-width: 420px; text-align: right; display: flex; flex-direction: column; align-items: flex-end; }
.allinone-desc-text { font-size: clamp(17px, 2vmin, 25px); font-weight: 300; line-height: 1.9; letter-spacing: 0.8px; color: rgba(255,255,255,0.85); }

.home-bottom-right { position: absolute; bottom: 18vh; right: 60px; max-width: 460px; text-align: justify; text-justify: inter-ideograph; }
.home-intro-text { font-size: clamp(17px, 2vmin, 25px); font-weight: 300; line-height: 1.9; letter-spacing: 0.8px; color: rgba(255,255,255,0.85); margin-bottom: 10px; text-indent: 2em; }
.home-intro-text:last-child { margin-bottom: 0; }

.guide-lines-svg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; z-index: 8; pointer-events: none; overflow: visible; }
.guide-line { stroke-linecap: round; transition: stroke 0.6s ease, stroke-width 0.6s ease; }
.guide-line.active { stroke: rgba(10,40,80,0.82); stroke-width: 1.5px; }

.scroll-hint { position: fixed; bottom: 120px; left: 50%; transform: translateX(-50%); z-index: 15; display: flex; flex-direction: column; align-items: center; gap: 10px; opacity: 0; transition: opacity 1.5s ease; }
.scroll-hint.show { opacity: 0.4; }
.scroll-hint > span:not(.scroll-arrow) { font-size: 28px; letter-spacing: 6px; color: rgba(255,255,255,0.98); font-weight: 500; animation: scrollTextPulse 2.2s ease-in-out infinite; }
.scroll-hint .scroll-arrow { display: flex; flex-direction: column; align-items: center; gap: 1px; width: 30px; height: 32px; margin-top: 4px; animation: scrollArrowPulse 1.6s ease-in-out infinite; }
.scroll-hint .scroll-arrow::before, .scroll-hint .scroll-arrow::after { content: ""; display: block; width: 14px; height: 14px; border-right: 2px solid rgba(255,255,255,0.95); border-bottom: 2px solid rgba(255,255,255,0.95); transform: rotate(45deg); }
@keyframes scrollTextPulse { 0%,100% { opacity: 0.6; transform: translateY(0); letter-spacing: 5px; } 50% { opacity: 1; transform: translateY(-6px); letter-spacing: 10px; } }
@keyframes scrollArrowPulse { 0%,100% { opacity: 0.35; transform: translateY(0); } 50% { opacity: 1; transform: translateY(6px); } }
.scroll-line { width: 1px; height: 40px; background: linear-gradient(180deg, rgba(255,255,255,0.3), transparent); animation: scrollPulse 2.5s ease-in-out infinite; }

.chassis-right { position: absolute; right: 60px; top: 50%; transform: translateY(-50%); max-width: 460px; text-align: right; }
.chassis-desc-text { font-size: clamp(17px, 2vmin, 25px); font-weight: 300; line-height: 1.9; letter-spacing: 0.8px; color: rgba(255,255,255,0.85); }

.allinone-img-fixed { position: absolute; bottom: 10vh; right: 80px; width: 280px; height: auto; border-radius: 12px; opacity: 0.75; object-fit: cover; z-index: 12; }

/* ===== Scroll Progress Bar ===== */
.scroll-progress { position: fixed; top: 0; left: 0; height: 2px; background: linear-gradient(90deg, #f5af19, #f12711); z-index: 200; transition: width 0.1s linear; pointer-events: none; }
.scroll-progress-track { position: fixed; top: 0; left: 0; right: 0; height: 2px; background: rgba(255,255,255,0.05); z-index: 199; pointer-events: none; }

/* ===== Tech Grid Background ===== */
.tech-grid { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 0; pointer-events: none; opacity: 0; transition: opacity 0.8s ease; will-change: opacity; background-image: linear-gradient(rgba(255,255,255,0.24) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.24) 1px, transparent 1px); background-size: 60px 60px; }

/* ===== Floating Tech Tags ===== */
.tech-tags { position: fixed; right: 60px; top: 50%; transform: translateY(-50%); display: flex; flex-direction: column; gap: 12px; z-index: 10; pointer-events: none; opacity: 0.8; }
.tech-tag { font-size: 10px; letter-spacing: 2px; color: rgba(255,255,255,0.6); text-align: right; padding: 6px 12px; border-right: 1px solid rgba(255,255,255,0.1); line-height: 1.4; }
.tech-tag .label { display: block; font-size: 9px; letter-spacing: 1px; color: rgba(255,255,255,0.35); }
/* ===== Decorative Elements ===== */
.section-number { position: absolute; bottom: 6vh; right: 60px; font-size: clamp(72px, 10vmin, 140px); font-weight: 800; letter-spacing: -4px; color: rgba(255,255,255,0.25); line-height: 1; pointer-events: none; z-index: 5; user-select: none; }
.section-number .total { color: rgba(255,255,255,0.12); }

.deco-line-left { position: fixed; left: 28px; top: 10vh; bottom: 10vh; width: 1px; background: linear-gradient(180deg, transparent 0%, rgba(255,255,255,0.2) 15%, rgba(255,255,255,0.2) 85%, transparent 100%); z-index: 10; pointer-events: none; }
.deco-line-right { position: fixed; right: 28px; top: 10vh; bottom: 10vh; width: 1px; background: linear-gradient(180deg, transparent 0%, rgba(255,255,255,0.12) 15%, rgba(255,255,255,0.12) 85%, transparent 100%); z-index: 10; pointer-events: none; }

.bottom-info { position: fixed; bottom: 3vh; right: 60px; font-size: 11px; letter-spacing: 1.5px; color: rgba(255,255,255,0.15); z-index: 10; pointer-events: none; }
.bottom-info-left { position: fixed; bottom: 3vh; left: 60px; font-size: 11px; letter-spacing: 1.5px; color: rgba(255,255,255,0.1); z-index: 10; pointer-events: none; }

/* Content glow */
.content-glow { position: fixed; width: 80vw; height: 80vw; border-radius: 50%; pointer-events: none; z-index: 1; opacity: 0.35; transition: opacity 0.8s ease; }
.content-glow.glow-home { top: -20vh; right: -20vw; background: radial-gradient(circle, rgba(245,175,25,0.5) 0%, transparent 70%); }
.content-glow.glow-allinone { top: -10vh; right: -10vw; background: radial-gradient(circle, rgba(0,150,255,0.45) 0%, transparent 70%); }
.content-glow.glow-engine { bottom: -10vh; left: -10vw; background: radial-gradient(circle, rgba(10,40,80,0.42) 0%, transparent 70%); }
.content-glow.glow-airflow { top: 10vh; left: 30vw; background: radial-gradient(circle, rgba(100,200,255,0.35) 0%, transparent 70%); }
.content-glow.glow-chassis { bottom: -5vh; right: -5vw; background: radial-gradient(circle, rgba(100,255,150,0.35) 0%, transparent 70%); }

/* Enhanced statetable line */
.backgroundLine { background: linear-gradient(180deg, transparent 0%, rgba(255,255,255,0.08) 15%, rgba(255,255,255,0.08) 85%, transparent 100%) !important; }


@keyframes titleBoxEnter { from { opacity: 0; transform: translateY(24px) scale(0.97); } to { opacity: 1; transform: translateY(0) scale(1); } }
@keyframes scrollPulse { 0%,100% { opacity: 0.2; transform: scaleY(0.6); } 50% { opacity: 0.8; transform: scaleY(1); } }

@media (max-width: 768px) {
  .statetable-content { padding-left: 12px; }
  .st-item { padding: 6px 8px 6px 20px; }
  .table-name { font-size: 10px; }
  .content-overlay { padding: 0 16px; }
  .content-left, .content-right { max-width: 50%; }
  .content-title { font-size: 18px; }
  .content-desc { font-size: 12px; }
  .chassis-right { position: absolute; right: 16px; top: 50%; transform: translateY(-50%); max-width: 45%; }
}
.gear-loader { width: 120px; height: 120px; display: flex; align-items: center; justify-content: center; margin-bottom: 16px; }
.gear-rotator { animation: gearSpin 2s linear infinite; transform-origin: 50% 50%; }
@keyframes gearSpin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }


.chassis-img { margin-left: auto; display: block; }
.home-top-right { position: absolute; top: 12vh; right: 60px; z-index: 15; }
.home-big-title { font-size: clamp(48px, 7vmin, 96px); font-weight: 800; letter-spacing: 4px; white-space: nowrap; background: linear-gradient(135deg, #f5af19 0%, #f12711 50%, #f5af19 100%); background-size: 200% auto; -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; animation: shimmer 8s ease-in-out infinite; text-shadow: none; filter: drop-shadow(0 0 30px rgba(241,39,17,0.4)); }
@keyframes shimmer { 0%,100% { background-position: 0% center; } 50% { background-position: 200% center; } }
.img-right { margin-left: auto; }
.engine-img { position: absolute; top: 8vh; left: 80px; width: 280px; height: auto; border-radius: 12px; opacity: 0.75; object-fit: cover; z-index: 12; }
.engine-text-block { position: absolute; bottom: 18vh; right: 60px; text-align: right; }


.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 60px;
  background: rgba(10,10,10,0.3);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background 0.4s ease, backdrop-filter 0.4s ease;
  pointer-events: auto;
}
.navbar.scrolled {
  background: rgba(10,10,10,0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.nav-logo {
  height: 30px;
  width: auto;
  filter: brightness(0) invert(1);
  object-fit: contain;
}


.lang-btns {
  display: flex;
  gap: 4px;
  margin-left: auto;
}
.lang-btn {
  background: none;
  border: 1px solid rgba(255,255,255,0.3);
  color: rgba(255,255,255,0.6);
  font-size: clamp(12px, 1vmin, 15px);
  padding: 4px 12px;
  border-radius: 4px;
  cursor: pointer;
  letter-spacing: 1px;
  transition: all 0.3s;
  font-family: inherit;
}
.lang-btn:hover {
  border-color: rgba(255,255,255,0.7);
  color: #fff;
  background: rgba(255,255,255,0.1);
}
.lang-btn.active {
  border-color: rgba(10,40,80,0.8);
  color: #fff;
  background: rgba(10,40,80,0.2);
}

.nav-brand {
  font-size: clamp(16px, 1.4vmin, 22px);
  font-weight: 700;
  letter-spacing: 2px;
  color: rgba(255,255,255,0.9);
}
.nav-links {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: clamp(16px, 2vw, 40px);
}
.nav-links a {
  font-size: clamp(16px, 1.5vmin, 22px);
  font-weight: 400;
  letter-spacing: 1px;
  color: rgba(255,255,255,0.65);
  text-decoration: none;
  transition: color 0.3s ease;
  cursor: pointer;
}
.nav-links a:hover {
  color: rgba(255,255,255,0.95);
}


@media (max-width: 768px) {
  .navbar { padding: 12px 16px; }
  .nav-links { gap: 12px; }
  .nav-links a { font-size: 11px; }
  .nav-brand { font-size: 14px; }
  .airflow-top-right .module-img { left: 16px; bottom: 12vh; }
  .airflow-desc-text { right: 16px; bottom: 12vh; width: 52vw; font-size: 15px; line-height: 1.65; }
}

/* Match main-site controls while preserving the existing navbar background. */
.nav-links { gap: clamp(8px, 1.55vw, 24px); }
.nav-links a {
  font-size: clamp(14px, 1.05vw, 16px);
  font-weight: 500;
  padding: 6px clamp(3px, 0.5vw, 8px);
  border-radius: 6px;
  color: rgba(255,255,255,0.95);
}
.nav-links a:hover { color: #fff; background: rgba(255,255,255,0.15); }
.lang-btns { gap: clamp(6px, 0.85vw, 14px); }
.lang-btn {
  border: 0;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  background: transparent;
  color: rgba(255,255,255,0.5);
  padding: 6px 0;
}
.lang-btn:hover { border-color: rgba(255,255,255,0.5); color: #fff; background: transparent; }
.lang-btn.active { border-color: #fff; color: #fff; background: transparent; }

/* Main-site header parity */
.navbar, .navbar.scrolled { height: 70px; padding: 0; background: #0b0b0b; color: #fff; box-shadow: 0 2px 12px rgba(0,0,0,0.3); backdrop-filter: none; -webkit-backdrop-filter: none; }
.navbar-inner { max-width: 1400px; width: 100%; height: 100%; margin: 0 auto; display: flex; align-items: center; gap: clamp(12px, 1.6vw, 28px); padding: 0 clamp(18px, 2.4vw, 40px); }
.nav-logo-link { display: flex; align-items: center; flex-shrink: 0; }
.nav-logo { height: 36px; filter: brightness(0) invert(1); }
.nav-links { position: static; transform: none; flex: 1; min-width: 0; justify-content: center; gap: clamp(8px, 1.55vw, 24px); }
.nav-links a, .nav-links a:hover { color: rgba(255,255,255,0.95); background: transparent; font-size: clamp(14px, 1.05vw, 16px); font-weight: 500; padding: 6px clamp(3px, 0.5vw, 8px); }
.nav-links a:hover { background: rgba(255,255,255,0.15); }
.header-right { display: flex; align-items: center; gap: clamp(6px, 0.85vw, 14px); flex-shrink: 0; }
.header-right .lang-btn { border: 0; border-bottom: 2px solid transparent; border-radius: 0; padding: 4px 8px; background: transparent; color: rgba(255,255,255,0.5); font-size: 15px; font-weight: 500; }
.header-right .lang-btn.active { border-color: #fff; color: #fff; background: transparent; }
.header-right .lang-btn:hover { color: #fff; border-color: rgba(255,255,255,0.8); background: transparent; }
.social-icon { width: 34px; height: 34px; border: 1px solid rgba(255,255,255,0.5); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; transition: all 0.3s; }
.social-icon:hover { background: rgba(255,255,255,0.15); color: #fff; }
.quote-btn { display: flex; align-items: center; gap: 6px; margin-left: 4px; padding: 8px clamp(10px, 1.2vw, 18px); border: 1px solid rgba(255,255,255,0.7); border-radius: 4px; color: #fff; font-size: 15px; text-decoration: none; white-space: nowrap; }
.quote-btn:hover { background: rgba(255,255,255,0.15); }

/* Product switcher floats on the page, separately from the header. */
.navbar, .navbar.scrolled { background: #fff; color: #333; box-shadow: 0 2px 12px rgba(0,0,0,0.08); }
.nav-logo { filter: none; }
.nav-links a, .nav-links a:hover { color: #333; }
.nav-links a:hover { background: rgba(0,0,0,0.08); }
.header-right .lang-btn { color: #999; }
.header-right .lang-btn.active { border-color: #0a2850; color: #0a2850; }
.header-right .lang-btn:hover { color: #0a2850; border-color: #0a2850; }
.social-icon { border-color: #ddd; color: #333; }
.social-icon:hover { background: rgba(0,0,0,0.05); color: #333; }
.quote-btn { border-color: #ddd; color: #0a2850; }
.quote-btn:hover { background: rgba(0,0,0,0.05); }
.navbar, .navbar.scrolled { background: transparent; color: #fff; box-shadow: none; }
.nav-logo { filter: brightness(0) invert(1); }
.nav-links a, .nav-links a:hover { color: rgba(255,255,255,0.95); }
.nav-links a:hover { background: rgba(255,255,255,0.15); }
.header-right .lang-btn { color: rgba(255,255,255,0.5); }
.header-right .lang-btn.active { border-color: #fff; color: #fff; }
.header-right .lang-btn:hover { color: #fff; border-color: rgba(255,255,255,0.8); }
.social-icon { border-color: rgba(255,255,255,0.5); color: #fff; }
.social-icon:hover { background: rgba(255,255,255,0.15); color: #fff; }
.quote-btn { border-color: rgba(255,255,255,0.7); color: #fff; }
.quote-btn:hover { background: rgba(255,255,255,0.15); }
.product-switcher {
  position: fixed; top: 94px; left: 42px; z-index: 60; margin-left: 0;
  opacity: 1; transform: translateY(0);
  transition: opacity 0.28s ease, transform 0.28s ease;
}
.product-switcher.is-hidden { opacity: 0; transform: translateY(-12px); pointer-events: none; }
.product-switcher-toggle {
  display: flex; align-items: center; gap: 11px; min-height: 48px;
  padding: 0 20px; border: 1px solid rgba(255,255,255,0.34); border-radius: 7px;
  background: rgba(10,10,10,0.76); color: #fff; font: inherit; font-size: 16px;
  letter-spacing: 0.8px; cursor: pointer; box-shadow: 0 8px 22px rgba(0,0,0,0.2);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); transition: all 0.25s ease;
}
.product-switcher-toggle:hover, .product-switcher-toggle[aria-expanded="true"] { background: rgba(10,10,10,0.92); border-color: rgba(255,255,255,0.7); }
.product-switcher-arrow { font-size: 18px; line-height: 1; transition: transform 0.25s ease; }
.product-switcher-arrow.open { transform: rotate(180deg); }
.product-switcher-menu {
  position: absolute; top: calc(100% + 8px); left: 0; width: 244px; padding: 6px; border: 1px solid rgba(255,255,255,0.2); border-radius: 8px;
  background: rgba(10,10,10,0.94); box-shadow: 0 12px 30px rgba(0,0,0,0.3);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
}
.product-switcher-menu a { display: block; padding: 11px 13px; border-radius: 5px; color: rgba(255,255,255,0.76); font-size: 14px; line-height: 1.35; text-decoration: none; transition: all 0.2s ease; }
.product-switcher-menu a:hover { color: #fff; background: rgba(255,255,255,0.12); }
.product-switcher-menu a.active { color: #fff; background: rgba(10,40,80,0.56); }
@media (max-width: 768px) {
  .navbar, .navbar.scrolled { height: 64px; }
  .navbar-inner { padding: 0 16px; gap: 10px; }
  .nav-logo { height: 28px; }
  .nav-links { gap: 8px; }
  .nav-links a { font-size: 11px; padding: 4px 2px; }
  .header-right .social-icon, .header-right .quote-btn { display: none; }
  .header-right { gap: 4px; }
  .header-right .lang-btn { font-size: 12px; padding: 4px; }
  .product-switcher { top: 78px; left: 16px; }
  .product-switcher-toggle { min-height: 38px; padding: 0 12px; font-size: 12px; }
  .product-switcher-menu { width: 208px; }
  .product-switcher-menu a { font-size: 12px; }
}


/* ===== Unified Shenchai brand shell ===== */
:root {
  --brand-navy: #0a2850;
  --brand-navy-deep: #061a33;
  --brand-red: #e63946;
  --brand-surface: #f5f7fa;
  --brand-ink: #172033;
  --brand-white: #fff;
  --font-brand: Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

body,
button,
input,
textarea,
select {
  font-family: var(--font-brand);
}

body,
.preloader {
  background-color: var(--brand-navy-deep);
}

.st-item.active { background: var(--brand-navy); }
.guide-line.active { stroke: var(--brand-navy); }
.scroll-progress { background: var(--brand-navy); }
.product-switcher-menu a.active { background: rgba(10, 40, 80, 0.56); }

.home-big-title {
  color: var(--brand-white);
  background: none;
  -webkit-text-fill-color: currentColor;
  animation: none;
  filter: none;
  letter-spacing: 0.02em;
}

.content-glow.glow-home,
.content-glow.glow-allinone,
.content-glow.glow-engine,
.content-glow.glow-airflow,
.content-glow.glow-chassis {
  background: radial-gradient(circle, rgba(10, 40, 80, 0.38) 0%, transparent 70%);
}

.navbar,
.navbar.scrolled {
  height: 70px;
  padding: 0;
  color: var(--brand-white);
  background: rgba(6, 26, 51, 0.94);
  box-shadow: 0 4px 8px rgba(6, 26, 51, 0.16);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.navbar-inner {
  width: 100%;
  max-width: 1400px;
  height: 100%;
  margin: 0 auto;
  padding: 0 clamp(18px, 2.4vw, 40px);
  gap: clamp(12px, 1.6vw, 28px);
}

.nav-logo { height: 36px; filter: brightness(0) invert(1); }
.nav-links { gap: clamp(8px, 1.55vw, 24px); }
.nav-links a,
.nav-links a:hover {
  padding: 6px clamp(3px, 0.5vw, 8px);
  color: rgba(255, 255, 255, 0.94);
  background: transparent;
  border-radius: 4px;
  font-size: clamp(14px, 1.05vw, 16px);
  font-weight: 500;
}
.nav-links a:hover { color: var(--brand-white); background: rgba(255, 255, 255, 0.12); }

.header-right .lang-btn {
  padding: 5px 3px 7px;
  color: rgba(255, 255, 255, 0.58);
  border: 0;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  background: transparent;
  font-size: 14px;
  font-weight: 500;
  line-height: 1;
}
.header-right .lang-btn:hover,
.header-right .lang-btn.active {
  color: var(--brand-white);
  border-color: var(--brand-red);
  background: transparent;
}

.social-icon {
  color: var(--brand-white);
  border-color: rgba(255, 255, 255, 0.42);
}
.social-icon:hover {
  color: var(--brand-white);
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.72);
}

.quote-btn {
  min-height: 36px;
  color: var(--brand-white);
  background: var(--brand-red);
  border: 1px solid var(--brand-red);
  border-radius: 4px;
  font-weight: 600;
}
.quote-btn:hover {
  color: var(--brand-white);
  background: #c92f3b;
  border-color: #c92f3b;
}

.product-switcher-toggle,
.product-switcher-menu {
  background: rgba(6, 26, 51, 0.96);
}

@media (max-width: 768px) {
  .navbar,
  .navbar.scrolled { height: 64px; }
  .navbar-inner { padding: 0 16px; gap: 10px; }
  .nav-logo { height: 28px; }
}


/* ===== Product inquiry finale ===== */
.inquiry-footer {
  position: fixed;
  inset: 0;
  z-index: 40;
  display: flex;
  flex-direction: column;
  color: var(--brand-white);
  background: #061a33;
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  transform: translate3d(0, 104%, 0);
  pointer-events: none;
  transition: transform 1s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.5s ease, visibility 0s linear 1s;
  will-change: transform;
}

.inquiry-footer::before {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: url("/inquiry-factory.png") center 56% / cover no-repeat;
  content: "";
  opacity: 1;
  transform: translate3d(0, 7%, 0) scale(1.08);
  transition: transform 1.35s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: transform;
}

.inquiry-footer::after {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(90deg, rgba(3, 22, 44, 0.82) 0%, rgba(5, 31, 60, 0.64) 55%, rgba(5, 31, 60, 0.45) 100%),
    linear-gradient(180deg, rgba(2, 17, 35, 0.44), rgba(4, 24, 48, 0.64));
  content: "";
  backdrop-filter: blur(1.5px);
}

.inquiry-footer.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translate3d(0, 0, 0);
  pointer-events: auto;
  transition-delay: 0s;
}

.inquiry-footer.is-visible::before {
  transform: translate3d(0, 0, 0) scale(1.025);
}

.inquiry-footer-inner {
  position: relative;
  z-index: 2;
  width: min(1040px, calc(100% - 80px));
  margin: auto;
  padding: clamp(40px, 5vw, 70px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 24px;
  background: linear-gradient(135deg, rgba(6, 34, 66, 0.76), rgba(6, 34, 66, 0.5));
  box-shadow: 0 36px 100px rgba(0, 0, 0, 0.34);
  backdrop-filter: blur(16px) saturate(118%);
  opacity: 0;
  transform: translate3d(0, 90px, 0);
  transition: transform 0.9s cubic-bezier(0.16, 1, 0.3, 1) 0.16s, opacity 0.6s ease 0.16s;
}

.inquiry-footer.is-visible .inquiry-footer-inner {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.inquiry-brand,
.inquiry-footer h2,
.inquiry-copy,
.inquiry-actions {
  opacity: 0;
  transform: translate3d(0, 30px, 0);
  transition: transform 0.72s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.52s ease;
}

.inquiry-footer.is-visible .inquiry-brand,
.inquiry-footer.is-visible h2,
.inquiry-footer.is-visible .inquiry-copy,
.inquiry-footer.is-visible .inquiry-actions {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.inquiry-footer.is-visible .inquiry-brand { transition-delay: 0.3s; }
.inquiry-footer.is-visible h2 { transition-delay: 0.38s; }
.inquiry-footer.is-visible .inquiry-copy { transition-delay: 0.46s; }
.inquiry-footer.is-visible .inquiry-actions { transition-delay: 0.54s; }

.inquiry-brand {
  margin: 0 0 24px;
  color: var(--brand-red);
  font-size: 15px;
  font-weight: 700;
}

.inquiry-footer h2 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(42px, 6vw, 80px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.06;
  text-wrap: balance;
}

.inquiry-copy {
  max-width: 680px;
  margin: 28px 0 0;
  color: rgba(255, 255, 255, 0.76);
  font-size: clamp(16px, 1.45vw, 19px);
  line-height: 1.75;
  text-wrap: pretty;
}

.inquiry-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 42px;
}

.inquiry-primary,
.inquiry-secondary {
  min-height: 46px;
  padding: 0 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.25s ease, border-color 0.25s ease, color 0.25s ease;
}

.inquiry-primary {
  color: var(--brand-white);
  background: var(--brand-red);
  border: 1px solid var(--brand-red);
}
.inquiry-primary:hover { background: #c92f3b; border-color: #c92f3b; }

.inquiry-secondary {
  color: var(--brand-white);
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.52);
}
.inquiry-secondary:hover { background: rgba(255, 255, 255, 0.1); border-color: rgba(255, 255, 255, 0.82); }

.inquiry-site-footer {
  position: relative;
  z-index: 2;
  min-height: 68px;
  padding: 18px clamp(24px, 4vw, 60px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  color: rgba(255, 255, 255, 0.58);
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  font-size: 12px;
  background: rgba(3, 21, 42, 0.48);
  backdrop-filter: blur(14px);
  opacity: 0;
  transform: translate3d(0, 32px, 0);
  transition: transform 0.72s cubic-bezier(0.16, 1, 0.3, 1) 0.58s, opacity 0.5s ease 0.58s;
}
.inquiry-footer.is-visible .inquiry-site-footer { opacity: 1; transform: translate3d(0, 0, 0); }
.inquiry-site-footer a { color: var(--brand-white); text-decoration: none; }

@media (max-width: 768px) {
  .inquiry-footer::before { background-position: 52% center; }
  .inquiry-footer-inner { width: calc(100% - 32px); padding: 34px 22px; border-radius: 18px; }
  .inquiry-footer h2 { font-size: clamp(34px, 10vw, 48px); }
  .inquiry-copy { margin-top: 20px; font-size: 15px; }
  .inquiry-actions { margin-top: 30px; }
  .inquiry-primary,
  .inquiry-secondary { width: 100%; }
  .inquiry-site-footer { padding: 16px 20px; flex-direction: column; align-items: flex-start; gap: 7px; }
}

@media (prefers-reduced-motion: reduce) {
  .inquiry-footer,
  .inquiry-footer::before,
  .inquiry-footer-inner,
  .inquiry-brand,
  .inquiry-footer h2,
  .inquiry-copy,
  .inquiry-actions,
  .inquiry-site-footer {
    transition: opacity 0.2s ease;
    transform: none;
  }
}

/* ===== Scroll-mapped cool-blue screen halo ===== */
.scene > canvas { position: relative; z-index: 1; }
.scroll-light-atmosphere {
  position: absolute;
  inset: 0;
  z-index: 2;
  overflow: hidden;
  pointer-events: none;
  mix-blend-mode: screen;
  isolation: isolate;
  will-change: opacity;
  transition: opacity .9s cubic-bezier(.22,.72,.18,1);
}
.screen-light-halo {
  position: absolute;
  inset: -2px;
  display: block;
  background:
    radial-gradient(ellipse 78vw 72vh at var(--light-x) var(--light-y), rgba(184,224,255,.19) 0%, rgba(126,193,247,.085) 29%, rgba(70,153,224,.032) 51%, rgba(49,126,202,.009) 67%, transparent 82%),
    radial-gradient(ellipse 52vw 48vh at calc(var(--light-x) - 5%) calc(var(--light-y) + 4%), rgba(218,240,255,.07) 0%, rgba(132,196,246,.022) 46%, transparent 74%);
  filter: blur(7px);
  will-change: background, opacity;
}
.content-glow.glow-home,
.content-glow.glow-allinone,
.content-glow.glow-engine,
.content-glow.glow-airflow,
.content-glow.glow-chassis { background: transparent; }
@media (max-width: 768px) {
  .screen-light-halo {
    background:
      radial-gradient(ellipse 110vw 76vh at var(--light-x) var(--light-y), rgba(184,224,255,.18) 0%, rgba(111,184,242,.07) 31%, rgba(65,146,216,.022) 54%, transparent 82%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .scroll-light-atmosphere { transition: none; }
}