:root {
  --bg: #050b10;
  --surface: rgba(11, 21, 32, 0.72);
  --line: rgba(125, 211, 252, 0.14);
  --text: #eef7fb;
  --muted: #8faabb;
  --accent: #2dd4bf;
  --accent-2: #67e8f9;
  --danger: #f87171;
  --nav-h: 72px;
  --font-display: "Orbitron", "DIN Alternate", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Manrope", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
video { display: block; }
a { color: inherit; text-decoration: none; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }

/* —— Full-site background (image / video) —— */
.site-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  z-index: 0;
  overflow: hidden;
  background: #000;
  pointer-events: none;
}
.site-bg-media {
  position: absolute;
  top: 50%;
  left: 50%;
  width: auto;
  height: auto;
  min-width: 100%;
  min-height: 100%;
  max-width: none !important;
  transform: translate(-50%, -50%);
  object-fit: cover;
  object-position: center center;
}
.site-bg video.site-bg-media {
  /* 强制按视口覆盖，避免黑边/不满屏 */
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  min-width: 100vw;
  min-height: 100vh;
  min-height: 100dvh;
}
.site-bg-mask {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(5,11,16,0.28) 0%, rgba(5,11,16,0.12) 32%, rgba(5,11,16,0.45) 72%, rgba(5,11,16,0.78) 100%);
}
.site-shell {
  position: relative;
  z-index: 2;
}

.panel-surface {
  background: var(--surface);
  border: 1px solid var(--line);
  backdrop-filter: blur(10px);
  padding: 24px;
}

/* —— Transparent top nav —— */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--nav-h);
  transition: background .35s ease, backdrop-filter .35s ease, border-color .35s ease;
  border-bottom: 1px solid transparent;
  background: transparent;
}
.site-header.is-scrolled {
  background: rgba(5, 11, 16, 0.72);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}
.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.18em;
  font-size: 15px;
  color: rgba(255,255,255,0.92);
  text-transform: uppercase;
}
.brand span { color: var(--accent); }
.nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  display: block;
  padding: 10px 14px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: rgba(255,255,255,0.78);
  transition: color .25s ease;
  background: transparent;
  border: 0;
}
.nav-links a:hover,
.nav-links a.is-active { color: #fff; }
.nav-toggle {
  display: none;
  width: 42px; height: 42px;
  border: 1px solid rgba(255,255,255,0.2);
  background: transparent;
  color: #fff;
  cursor: pointer;
}

/* —— Hero —— */
.hero {
  position: relative;
  min-height: 100vh;
  display: grid;
  align-items: end;
}
.hero-content {
  position: relative;
  z-index: 2;
  padding: calc(var(--nav-h) + 40px) 0 14vh;
  animation: rise 1s ease both;
}
.hero-kicker {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.35em;
  color: var(--accent);
  margin: 0 0 18px;
  text-transform: uppercase;
}
.hero-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(42px, 8vw, 88px);
  line-height: 1.05;
  letter-spacing: 0.08em;
  font-weight: 700;
  max-width: 12ch;
  text-shadow: 0 8px 40px rgba(0,0,0,0.35);
}
.hero-sub {
  margin: 22px 0 0;
  max-width: 36ch;
  color: rgba(238,247,251,0.78);
  font-size: clamp(15px, 2vw, 18px);
}
.hero-cta {
  margin-top: 34px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.site-btn-wrap {
  position: relative;
  display: inline-flex;
}
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 24px;
  border: 1px solid transparent;
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.18em;
  cursor: pointer;
  transition: transform .2s ease, background .2s ease, color .2s ease, border-color .2s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #04201c; }
.btn-ghost {
  background: rgba(5,11,16,0.35);
  border-color: rgba(255,255,255,0.28);
  color: #fff;
}
.btn-ghost:hover { border-color: #fff; }

/* Hover QR popup */
.btn-qr-pop {
  position: absolute;
  left: 50%;
  bottom: calc(100% + 14px);
  transform: translateX(-50%) translateY(6px);
  width: 148px;
  padding: 10px;
  background: rgba(5,11,16,0.94);
  border: 1px solid var(--line);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity .2s ease, transform .2s ease, visibility .2s ease;
  z-index: 30;
  box-shadow: 0 12px 40px rgba(0,0,0,0.35);
}
.btn-qr-pop img {
  width: 100%;
  height: auto;
  background: #fff;
}
.btn-qr-pop::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 100%;
  transform: translateX(-50%);
  border: 8px solid transparent;
  border-top-color: rgba(5,11,16,0.94);
}
.site-btn.has-qr:hover .btn-qr-pop,
.site-btn.has-qr:focus-visible .btn-qr-pop {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* —— Sections —— */
.section {
  padding: 100px 0;
  position: relative;
}
.section-head {
  margin-bottom: 48px;
  max-width: 640px;
}
.section-kicker {
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--accent);
  margin: 0 0 12px;
  text-transform: uppercase;
}
.section-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 40px);
  letter-spacing: 0.08em;
  text-shadow: 0 6px 24px rgba(0,0,0,0.35);
}
.section-desc {
  margin: 16px 0 0;
  color: var(--muted);
  white-space: pre-line;
}

.contact-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}
.contact-block.is-solo {
  grid-template-columns: 1fr;
}
.contact-text {
  white-space: pre-line;
  color: rgba(238,247,251,0.86);
  font-size: 16px;
}
.contact-qr-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 20px;
}
.contact-qr-item {
  margin: 0;
  text-align: center;
}
.contact-qr-item img {
  width: 100%;
  max-width: 168px;
  aspect-ratio: 1;
  object-fit: contain;
  background: #fff;
  border: 1px solid var(--line);
  padding: 10px;
  margin: 0 auto;
}
.contact-qr-item figcaption {
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: rgba(238,247,251,0.82);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 40px;
  color: var(--muted);
  font-size: 13px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  align-items: flex-end;
}
.footer-meta { display: grid; gap: 6px; }
.footer-beian {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}
.footer-beian a:hover { color: var(--accent-2); }

.article-hero {
  padding: calc(var(--nav-h) + 60px) 0 40px;
  border-bottom: 1px solid var(--line);
}
.article-body {
  padding: 48px 0 80px;
  max-width: 760px;
  color: rgba(238,247,251,0.88);
}
.article-body img { margin: 24px 0; border: 1px solid var(--line); }

.empty {
  color: var(--muted);
  border-style: dashed;
  text-align: center;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 960px) {
  .contact-block { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .nav-links {
    position: fixed;
    inset: var(--nav-h) 0 auto;
    display: none;
    flex-direction: column;
    background: rgba(5,11,16,0.94);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
    padding: 12px 20px 20px;
  }
  .nav-links.open { display: flex; }
  .btn-qr-pop { width: 132px; }
  .contact-qr-grid { grid-template-columns: repeat(2, 1fr); }
}