/* ============================================================
   Witontech — 源赓科技 官网 v2
   产品工程工作室 · 深邃科技感 · 古铜金高光 · 中英双语
   ============================================================ */

:root {
  --bg:        #08090c;
  --bg-2:      #0b0d12;
  --bg-3:      #0f1218;
  --surface:   #12151c;
  --surface-2: #161a23;
  --line:      rgba(255,255,255,.07);
  --line-2:    rgba(255,255,255,.13);
  --text:      #ecedf0;
  --text-2:    #9ca3af;
  --text-3:    #626974;
  --gold:      #c9a35e;
  --gold-2:    #e6c98e;
  --gold-soft: rgba(201,163,94,.10);
  --maxw: 1200px;
  --radius: 16px;
  --ease: cubic-bezier(.22,.61,.36,1);
  --font-en: "Inter", system-ui, -apple-system, sans-serif;
  --font-zh: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  background: var(--bg); color: var(--text);
  font-family: var(--font-zh), var(--font-en);
  font-size: 16px; line-height: 1.7;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
html[data-lang="en"] body { font-family: var(--font-en), var(--font-zh); }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 32px; }

/* bilingual */
[data-zh][data-en]::before { content: attr(data-zh); }
html[data-lang="en"] [data-zh][data-en]::before { content: attr(data-en); }

/* scroll progress */
.scroll-progress {
  position: fixed; top: 0; left: 0; height: 2px; width: 0%;
  background: linear-gradient(90deg, var(--gold), var(--gold-2));
  z-index: 200; transition: width .1s linear;
}

/* ============ NAV ============ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  transition: background .4s var(--ease), border-color .4s, backdrop-filter .4s;
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: rgba(8,9,12,.72);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  border-bottom-color: var(--line);
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.brand { display: flex; align-items: center; }
.brand__logo { height: 26px; width: auto; opacity: .96; }
.nav__links { display: flex; gap: 34px; }
.nav__links a { font-size: 14.5px; color: var(--text-2); position: relative; padding: 6px 0; transition: color .25s var(--ease); }
.nav__links a::after { content:""; position:absolute; left:0; bottom:0; height:1.5px; width:0; background:var(--gold); transition:width .3s var(--ease); }
.nav__links a:hover { color: var(--text); }
.nav__links a:hover::after, .nav__links a.is-active::after { width: 100%; }
.nav__links a.is-active { color: var(--text); }
.nav__right { display: flex; align-items: center; gap: 14px; }
.lang-toggle {
  font-family: var(--font-en); background: transparent; border: 1px solid var(--line-2);
  color: var(--text-2); padding: 6px 13px; border-radius: 999px; cursor: pointer;
  font-size: 12.5px; letter-spacing: .04em; transition: all .25s var(--ease);
}
.lang-toggle:hover { border-color: var(--gold); color: var(--gold); }
.lang-toggle__sep { opacity: .4; margin: 0 2px; }
html[data-lang="zh"] .lang-toggle__zh { color: var(--gold); font-weight: 600; }
html[data-lang="en"] .lang-toggle__en { color: var(--gold); font-weight: 600; }
.nav__burger { display: none; background: none; border: 0; cursor: pointer; flex-direction: column; gap: 5px; padding: 6px; }
.nav__burger span { width: 22px; height: 2px; background: var(--text); transition: .3s var(--ease); display: block; }

/* ============ HERO ============ */
.hero { position: relative; min-height: 100vh; display: flex; flex-direction: column; justify-content: center; overflow: hidden; }
.hero__grid {
  position: absolute; inset: 0; z-index: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(ellipse 90% 80% at 30% 30%, #000 20%, transparent 75%);
  mask-image: radial-gradient(ellipse 90% 80% at 30% 30%, #000 20%, transparent 75%);
}
.hero__glow {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(900px 520px at 82% 16%, rgba(201,163,94,.13), transparent 60%),
    radial-gradient(760px 480px at 8% 92%, rgba(60,100,150,.10), transparent 60%);
}
.hero__inner { position: relative; z-index: 2; padding: 130px 32px 40px; max-width: 1000px; }
.hero__eyebrow { display: inline-flex; align-items: center; gap: 10px; font-family: var(--font-mono); font-size: 12.5px; letter-spacing: .14em; color: var(--gold); margin-bottom: 28px; }
.hero__eyebrow .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--gold); box-shadow: 0 0 0 4px var(--gold-soft); animation: pulse 2.6s var(--ease) infinite; }
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:.4} }
.hero__title { font-weight: 700; font-size: clamp(2.6rem, 6.2vw, 5rem); line-height: 1.06; letter-spacing: -.02em; margin-bottom: 30px; }
.hero__title .line { display: block; }
.hero__title .accent { background: linear-gradient(110deg, var(--gold) 0%, var(--gold-2) 48%, var(--gold) 100%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero__lead { font-size: clamp(1.02rem, 1.4vw, 1.22rem); color: var(--text-2); max-width: 700px; margin-bottom: 40px; }
.hero__cta { display: flex; gap: 16px; flex-wrap: wrap; }

.btn { display: inline-flex; align-items: center; gap: 10px; padding: 15px 28px; border-radius: 999px; font-size: 15px; font-weight: 500; transition: all .3s var(--ease); cursor: pointer; border: 1px solid transparent; }
.btn--primary { background: var(--gold); color: #15100a; font-weight: 600; }
.btn--primary:hover { background: var(--gold-2); transform: translateY(-2px); box-shadow: 0 14px 34px -12px rgba(201,163,94,.55); }
.btn--ghost { border-color: var(--line-2); color: var(--text); }
.btn--ghost:hover { border-color: var(--gold); color: var(--gold); transform: translateY(-2px); }
.btn__arr { transition: transform .3s var(--ease); font-style: normal; }
.btn:hover .btn__arr { transform: translateX(4px); }

/* hero marquee */
.hero__marquee { position: relative; z-index: 2; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 20px 0; overflow: hidden; margin-top: 60px; -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent); mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent); }
.marquee__track { display: flex; align-items: center; gap: 30px; white-space: nowrap; width: max-content; animation: marquee 34s linear infinite; }
.marquee__track span { font-family: var(--font-en); font-weight: 600; font-size: 1.25rem; letter-spacing: .06em; color: var(--text-2); opacity: .65; }
.marquee__track i { color: var(--gold); font-style: normal; opacity: .5; }
@keyframes marquee { to { transform: translateX(-50%); } }

/* ============ SECTION base ============ */
.section { padding: 120px 0; position: relative; }
.section--alt { background: linear-gradient(180deg, var(--bg-2), var(--bg)); border-block: 1px solid var(--line); }
.kicker { display: inline-block; font-family: var(--font-mono); font-size: 12px; letter-spacing: .18em; text-transform: uppercase; color: var(--gold); margin-bottom: 18px; }
.kicker::before { content: attr(data-zh); }
html[data-lang="en"] .kicker::before { content: attr(data-en); }
.section h2 { font-size: clamp(1.8rem, 3.6vw, 2.9rem); font-weight: 700; line-height: 1.16; letter-spacing: -.015em; }
.section__sub { color: var(--text-2); font-size: 1.06rem; margin-top: 18px; }
.section__head--center { text-align: center; max-width: 780px; margin: 0 auto 66px; }

/* ---------- About lead ---------- */
.lead-block { max-width: 900px; margin: 0 auto 70px; text-align: center; }
.lead-block__text { font-size: clamp(1.5rem, 3vw, 2.3rem); font-weight: 600; line-height: 1.32; letter-spacing: -.01em; margin-bottom: 26px; }
.lead-block__sub { color: var(--text-2); font-size: 1.08rem; max-width: 720px; margin: 0 auto; }

.stats { display: grid; grid-template-columns: repeat(4,1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.stat { background: var(--surface); padding: 38px 24px; text-align: center; display: flex; flex-direction: column; align-items: center; transition: background .3s; }
.stat:hover { background: var(--surface-2); }
.stat__num { font-family: var(--font-en); font-weight: 700; font-size: clamp(2.2rem,3.4vw,3rem); color: var(--gold-2); line-height: 1; display: inline; }
.stat__plus { font-family: var(--font-en); font-weight: 700; font-size: clamp(1.4rem,2vw,1.8rem); color: var(--gold); margin-bottom: 14px; }
.stat__label { font-size: 13.5px; color: var(--text-3); }

/* ---------- About (grid-2 + prose) ---------- */
.grid-2 { display: grid; grid-template-columns: .85fr 1.15fr; gap: 56px; align-items: start; }
.prose p { color: var(--text-2); margin-bottom: 20px; }
.prose p:last-child { margin-bottom: 0; }

/* ---------- Approach (split sticky) ---------- */
.grid-split { display: grid; grid-template-columns: .9fr 1.1fr; gap: 64px; align-items: start; }
.grid-split__sticky { position: sticky; top: 120px; }
.grid-split__sticky h2 { margin-top: 6px; }
.approach-list { display: flex; flex-direction: column; gap: 2px; }
.approach { padding: 34px 0; border-top: 1px solid var(--line); position: relative; }
.approach:last-child { border-bottom: 1px solid var(--line); }
.approach__no { font-family: var(--font-mono); font-size: 13px; color: var(--gold); letter-spacing: .1em; }
.approach h3 { font-size: 1.35rem; font-weight: 600; margin: 12px 0 12px; }
.approach p { color: var(--text-2); }

/* ---------- Cards ---------- */
.cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.card { background: var(--surface); padding: 40px 34px; transition: background .35s var(--ease); position: relative; }
.card:hover { background: var(--surface-2); }
.card__idx { font-family: var(--font-mono); font-size: 12.5px; color: var(--gold); letter-spacing: .12em; }
.card h3 { font-size: 1.22rem; margin: 16px 0 12px; font-weight: 600; }
.card p { color: var(--text-2); font-size: .97rem; }

/* ---------- Showcase ---------- */
.showcase { display: grid; grid-template-columns: 1.5fr 1fr; gap: 18px; margin-bottom: 80px; }
.showcase figure { position: relative; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); background: var(--surface); }
.showcase img { width: 100%; height: 100%; object-fit: cover; transition: transform .7s var(--ease); }
.showcase figure:hover img { transform: scale(1.05); }
.showcase figcaption { position: absolute; left: 0; right: 0; bottom: 0; padding: 22px 20px 18px; display: flex; flex-direction: column; gap: 7px; font-size: 13.5px; color: var(--text); background: linear-gradient(transparent, rgba(6,7,10,.94)); }
.showcase__tag { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--gold-2); }
.showcase__main { min-height: 380px; }
.showcase__side { display: grid; grid-template-rows: 1fr 1fr; gap: 18px; }
.showcase__side figure { min-height: 181px; }

/* ---------- ONNO highlight ---------- */
.highlight {
  display: grid; grid-template-columns: 1.6fr 1fr; gap: 40px; align-items: center;
  padding: 48px; border-radius: var(--radius); margin-bottom: 80px;
  background:
    radial-gradient(600px 300px at 90% 10%, rgba(201,163,94,.10), transparent 60%),
    var(--surface);
  border: 1px solid var(--line-2);
}
.highlight__badge { display: inline-block; font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .1em; color: var(--gold-2); padding: 6px 14px; border: 1px solid var(--gold-soft); border-radius: 999px; background: var(--gold-soft); margin-bottom: 20px; }
.highlight__body h3 { font-size: clamp(1.4rem,2.6vw,2rem); font-weight: 700; margin-bottom: 16px; letter-spacing: -.01em; }
.highlight__body p { color: var(--text-2); }
.highlight__meta { display: flex; flex-direction: column; gap: 18px; border-left: 1px solid var(--line); padding-left: 32px; }
.highlight__meta > div { display: flex; flex-direction: column; gap: 4px; }
.highlight__k { font-family: var(--font-mono); font-size: 11px; letter-spacing: .1em; text-transform: uppercase; color: var(--text-3); }
.highlight__k::before { content: attr(data-zh); }
html[data-lang="en"] .highlight__k::before { content: attr(data-en); }
.highlight__v { font-size: 1rem; color: var(--text); font-weight: 500; }

/* ---------- Timeline ---------- */
.timeline { list-style: none; max-width: 840px; margin: 0 auto 80px; position: relative; padding-left: 28px; }
.timeline::before { content:""; position:absolute; left:5px; top:6px; bottom:6px; width:1px; background:linear-gradient(var(--gold), transparent); opacity:.45; }
.timeline__item { position: relative; padding: 0 0 34px 30px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before { content:""; position:absolute; left:-29px; top:8px; width:10px; height:10px; border-radius:50%; background:var(--bg); border:2px solid var(--gold); }
.timeline__year { display:block; font-family:var(--font-mono); font-weight:500; color:var(--gold-2); font-size:.95rem; letter-spacing:.04em; margin-bottom:6px; }
.timeline__item p { color: var(--text-2); }

/* ---------- Logos / Certs ---------- */
/* ---------- Brand logo wall ---------- */
.brandwall {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding-bottom: 56px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 56px;
}
.brandwall__item {
  flex: 1;
  min-width: 0;
  height: 80px;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 10px;
  transition: transform .35s var(--ease);
}
.brandwall__item:hover {
  transform: translateY(-4px);
}
.brandwall__item img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  opacity: 0.85;
  transition: opacity .25s ease;
}
.brandwall__item img:hover {
  opacity: 1;
}
.brand-hbuster img {
  transform: scale(2.4) translateX(-8px);
}
.brand-volvo img {
  transform: translateX(10px); /* 正值向右移动，负值向左移动；也可以如 scale(1.1) 加大缩放 */
}
.brandwall__item--invert img {
  filter: none;
}
.certs { display: grid; grid-template-columns: repeat(3,1fr); gap: 22px; }
.cert { background: #fff; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); aspect-ratio: 3/4; display: grid; place-items: center; padding: 10px; transition: transform .35s var(--ease), box-shadow .35s; }
.cert:hover { transform: translateY(-4px); box-shadow: 0 22px 44px -20px rgba(0,0,0,.7); }
.cert img { width: 100%; height: 100%; object-fit: contain; }
.certs__note { text-align: center; color: var(--text-3); font-size: 13px; margin-top: 22px; }

/* ---------- Future ---------- */
.section--future { position: relative; background: var(--bg-2); overflow: hidden; }
.future__grid { position: absolute; inset: 0; z-index: 0; background-image: linear-gradient(rgba(255,255,255,.02) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.02) 1px, transparent 1px); background-size: 64px 64px; -webkit-mask-image: radial-gradient(ellipse 80% 90% at 70% 0%, #000, transparent 70%); mask-image: radial-gradient(ellipse 80% 90% at 70% 0%, #000, transparent 70%); }
.section--future .container { position: relative; z-index: 1; }
.future-cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 22px; }
.future-card { background: linear-gradient(180deg, var(--surface), var(--bg-3)); border: 1px solid var(--line); border-radius: var(--radius); padding: 38px 32px; transition: transform .35s var(--ease), border-color .35s; }
.future-card:hover { transform: translateY(-6px); border-color: var(--gold-soft); }
.future-card__ic { width: 52px; height: 52px; border-radius: 13px; display: grid; place-items: center; background: var(--gold-soft); color: var(--gold-2); font-size: 24px; margin-bottom: 24px; }
.future-card h3 { font-size: 1.22rem; font-weight: 600; margin-bottom: 12px; }
.future-card p { color: var(--text-2); font-size: .97rem; }
.future__cta { text-align: center; margin-top: 64px; display: flex; flex-direction: column; align-items: center; gap: 22px; }
.future__cta p { color: var(--text); font-size: 1.15rem; max-width: 560px; }

/* ---------- Contact ---------- */
.section--contact { background: radial-gradient(800px 420px at 50% 0%, rgba(201,163,94,.08), transparent 60%), var(--bg); }
.contact__inner { text-align: center; max-width: 900px; margin: 0 auto; }
.contact__mail { display: inline-block; font-family: var(--font-en); font-size: clamp(1.5rem,3.6vw,2.6rem); font-weight: 600; color: var(--gold-2); margin: 38px 0 48px; letter-spacing: -.01em; transition: color .25s, transform .25s; }
.contact__mail:hover { color: var(--gold); transform: translateY(-2px); }
.contact__cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; text-align: left; }
.contact__cards--two { grid-template-columns: repeat(2, minmax(0, 1fr)); max-width: 760px; margin: 0 auto; }
.contact__cards--two .contact__value { white-space: nowrap; }
.contact__card { display: flex; flex-direction: column; gap: 8px; padding: 26px 24px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
.contact__label { font-family: var(--font-mono); font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--gold); }
.contact__label::before { content: attr(data-zh); }
html[data-lang="en"] .contact__label::before { content: attr(data-en); }
.contact__value { font-size: .98rem; color: var(--text); font-family: var(--font-en); word-break: break-word; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--line); padding: 52px 0; background: var(--bg); }
.footer__inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 26px; }
.footer__brand { display: flex; flex-direction: column; gap: 12px; }
.footer__logo { height: 24px; width: auto; opacity: .92; }
.footer__brand > span:last-child { font-size: 13px; color: var(--text-3); }
.footer__meta { display: flex; flex-wrap: wrap; gap: 10px 24px; font-size: 13px; color: var(--text-3); align-items: center; }
.footer__meta a { transition: color .25s; }
.footer__meta a:hover { color: var(--gold); }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity .85s var(--ease), transform .85s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }

/* ============ RESPONSIVE ============ */
@media (max-width: 960px) {
  .grid-split { grid-template-columns: 1fr; gap: 36px; }
  .grid-split__sticky { position: static; }
  .grid-2 { grid-template-columns: 1fr; gap: 28px; }
  .contact__cards--two { grid-template-columns: 1fr; max-width: 520px; }
  .contact__cards--two .contact__value { white-space: normal; }
  .cards { grid-template-columns: repeat(2,1fr); }
  .future-cards { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2,1fr); }
  .showcase { grid-template-columns: 1fr; }
  .highlight { grid-template-columns: 1fr; gap: 28px; padding: 36px; }
  .highlight__meta { border-left: 0; border-top: 1px solid var(--line); padding-left: 0; padding-top: 24px; flex-direction: row; flex-wrap: wrap; gap: 24px 40px; }
  .contact__cards { grid-template-columns: 1fr; }
  /* brandwall → 4 columns on tablet */
  .brandwall {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
  }
  .brandwall__item { height: 60px; flex: none; }
}
@media (max-width: 680px) {
  .nav__links { position: fixed; inset: 76px 0 auto 0; flex-direction: column; gap: 0; background: rgba(8,9,12,.98); backdrop-filter: blur(16px); padding: 8px 32px 20px; border-bottom: 1px solid var(--line); transform: translateY(-130%); transition: transform .4s var(--ease); pointer-events: none; }
  .nav__links.is-open { transform: none; pointer-events: auto; }
  .nav__links a { padding: 16px 0; border-bottom: 1px solid var(--line); font-size: 16px; }
  .nav__burger { display: flex; }
  .nav__burger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav__burger.is-open span:nth-child(2) { opacity: 0; }
  .nav__burger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .section { padding: 84px 0; }
  .cards { grid-template-columns: 1fr; }
  /* brandwall → 3 columns on mobile */
  .brandwall {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    padding-bottom: 36px;
    margin-bottom: 36px;
  }
  .brandwall__item { height: 52px; }
  .brand-hbuster img { transform: scale(1.6) translateX(-4px); }
  .brand-volvo img { transform: translateX(4px); }
  .certs { grid-template-columns: 1fr; }
  .cert { aspect-ratio: 4/3; }
  .showcase__side { grid-template-columns: 1fr 1fr; grid-template-rows: none; }
  .footer__inner { flex-direction: column; align-items: flex-start; }
  /* heading word-break: prevent Chinese character splitting */
  .hero__title { word-break: keep-all; line-height: 1.12; }
  .section h2 { word-break: keep-all; line-height: 1.2; }
  h3 { word-break: keep-all; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .marquee__track { animation: none; }
  .hero__eyebrow .dot { animation: none; }
}