/* ============ FSDTEK 全自动驾驶系统 官网样式 ============ */
:root {
  --bg: #04070f;
  --bg-2: #070d1d;
  --panel: #0a1428;
  --panel-2: #0d1a33;
  --line: rgba(120, 160, 255, 0.14);
  --line-strong: rgba(120, 160, 255, 0.28);
  --cyan: #22d3ee;
  --blue: #3b82f6;
  --violet: #8b5cf6;
  --grad: linear-gradient(100deg, #22d3ee 0%, #3b82f6 55%, #8b5cf6 100%);
  --text: #e8eefc;
  --muted: #93a3c2;
  --faint: #5c6b8c;
  --radius: 16px;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
  --header-h: 72px;
  --container: 1160px;
  --font: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", -apple-system, "Segoe UI", sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
::selection { background: rgba(59, 130, 246, 0.45); color: #fff; }

a { color: inherit; text-decoration: none; }
button { font-family: inherit; }
img, svg, canvas { display: block; }

.container {
  width: min(var(--container), 92%);
  margin: 0 auto;
}

.grad { color: var(--cyan); }
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.eyebrow {
  font-size: 12px;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 14px;
  font-weight: 600;
}

.section {
  padding: 104px 0;
  position: relative;
}

.section-head {
  max-width: 720px;
  margin: 0 auto 56px;
  text-align: center;
}
.section-title {
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: 0.02em;
  margin-bottom: 16px;
}
.section-desc { color: var(--muted); font-size: 16px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.03em;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, color 0.25s ease;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn--primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 10px 30px rgba(59, 130, 246, 0.35);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(59, 130, 246, 0.5); }
.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line-strong);
}
.btn--ghost:hover { border-color: var(--cyan); color: var(--cyan); transform: translateY(-2px); }

/* 入场动画 */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

/* ============ 测试提示条 ============ */
.test-banner {
  position: relative;
  z-index: 120;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 9px 46px;
  font-size: 13px;
  background: linear-gradient(90deg, rgba(34, 211, 238, 0.16), rgba(139, 92, 246, 0.16));
  border-bottom: 1px solid var(--line);
  color: #c9d8f5;
}
.test-banner strong { color: var(--cyan); font-weight: 700; }
.test-banner__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 0 rgba(34, 211, 238, 0.5);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(34, 211, 238, 0.45); }
  70% { box-shadow: 0 0 0 10px rgba(34, 211, 238, 0); }
  100% { box-shadow: 0 0 0 0 rgba(34, 211, 238, 0); }
}
.test-banner__close {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--muted);
  font-size: 20px;
  line-height: 1;
  cursor: pointer;
  padding: 4px 8px;
}
.test-banner__close:hover { color: #fff; }
.test-banner.is-hidden { display: none; }

/* ============ 顶部导航 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(4, 7, 15, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.site-header.is-scrolled {
  background: rgba(4, 7, 15, 0.94);
  border-bottom-color: var(--line);
}
.header-inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand { display: flex; align-items: center; gap: 11px; }
.brand__icon { width: 38px; height: 38px; }
.brand__name {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.08em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.brand__sub {
  font-size: 12px;
  color: var(--muted);
  border-left: 1px solid var(--line-strong);
  padding-left: 11px;
  letter-spacing: 0.18em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}
.site-nav a {
  font-size: 14px;
  color: var(--muted);
  transition: color 0.25s ease;
  position: relative;
}
.site-nav a:hover { color: var(--text); }
.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 2px;
  background: var(--grad);
  border-radius: 2px;
  transition: width 0.3s ease;
}
.site-nav a:hover::after { width: 100%; }
.site-nav .nav-cta {
  padding: 9px 22px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--text);
  background: rgba(59, 130, 246, 0.08);
}
.site-nav .nav-cta::after { display: none; }
.site-nav .nav-cta:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  background: rgba(34, 211, 238, 0.1);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============ HERO ============ */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
  overflow: hidden;
  padding: 72px 0 96px;
}
.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 70% 55% at 72% 38%, rgba(59, 130, 246, 0.18), transparent 65%),
    radial-gradient(ellipse 45% 40% at 20% 82%, rgba(34, 211, 238, 0.12), transparent 60%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
}
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(120, 160, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120, 160, 255, 0.05) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse 75% 65% at 65% 40%, #000 0%, transparent 75%);
  mask-image: radial-gradient(ellipse 75% 65% at 65% 40%, #000 0%, transparent 75%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
}
.hero__title {
  font-size: clamp(34px, 5.4vw, 58px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: 0.01em;
  margin-bottom: 20px;
}
.hero__sub {
  color: var(--muted);
  font-size: 16px;
  max-width: 520px;
  margin-bottom: 32px;
}
.hero__actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 44px; }

.hero__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}
.stat__num {
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.2;
}
.stat__unit { font-size: 14px; color: var(--muted); margin-left: 2px; font-weight: 600; }
.stat p { font-size: 12.5px; color: var(--faint); margin-top: 4px; }

.hero__visual {
  position: relative;
  aspect-ratio: 4 / 3.4;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(10, 20, 40, 0.65), rgba(4, 7, 15, 0.9));
  box-shadow: var(--shadow);
  overflow: hidden;
}
.hero__visual canvas { width: 100%; height: 100%; }
.hero__visual-caption {
  position: absolute;
  left: 16px;
  bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: #a9bce0;
  background: rgba(4, 7, 15, 0.72);
  border: 1px solid var(--line);
  padding: 6px 12px;
  border-radius: 999px;
  backdrop-filter: blur(8px);
}
.pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 0 rgba(34, 211, 238, 0.5);
  animation: pulse 2s infinite;
}

.hero__scroll {
  position: absolute;
  left: 50%;
  bottom: 22px;
  transform: translateX(-50%);
  z-index: 2;
  width: 24px;
  height: 38px;
  border: 1.5px solid var(--line-strong);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 7px;
}
.hero__scroll span {
  width: 3px;
  height: 8px;
  border-radius: 3px;
  background: var(--cyan);
  animation: scrollHint 1.8s ease-in-out infinite;
}
@keyframes scrollHint {
  0% { transform: translateY(0); opacity: 1; }
  70% { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ============ 核心系统 ============ */
.system { background: var(--bg); }
.system-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 44px;
  align-items: center;
  margin-bottom: 56px;
}
.system-core {
  text-align: center;
  padding: 44px 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  position: relative;
  overflow: hidden;
}
.system-core::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 30%, rgba(34, 211, 238, 0.12), transparent 60%);
  pointer-events: none;
}
.system-core__ring {
  position: relative;
  width: 170px;
  height: 170px;
  margin: 0 auto 26px;
  border-radius: 50%;
  border: 1px dashed rgba(34, 211, 238, 0.4);
  animation: spin 22s linear infinite;
}
.system-core__ring::before,
.system-core__ring::after {
  content: "";
  position: absolute;
  inset: 18px;
  border-radius: 50%;
  border: 1px solid rgba(139, 92, 246, 0.35);
}
.system-core__ring::after { inset: 38px; border-color: rgba(34, 211, 238, 0.55); }
.system-core__hub {
  position: absolute;
  inset: 58px;
  border-radius: 50%;
  background: var(--grad);
  box-shadow: 0 0 34px rgba(59, 130, 246, 0.65);
  animation: spin 22s linear infinite reverse;
}
@keyframes spin { to { transform: rotate(360deg); } }
.system-core h3 {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: 0.04em;
  line-height: 1.4;
  margin-bottom: 6px;
}
.system-core > p { font-size: 12.5px; color: var(--faint); letter-spacing: 0.08em; margin-bottom: 18px; }
.system-core__tags { list-style: none; display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.system-core__tags li {
  font-size: 12.5px;
  color: #bfd3f5;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(59, 130, 246, 0.1);
}

.system-specs { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.spec {
  display: flex;
  gap: 14px;
  padding: 22px 20px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(13, 26, 51, 0.55);
  transition: border-color 0.3s ease, transform 0.3s ease, background 0.3s ease;
}
.spec:hover {
  border-color: var(--line-strong);
  transform: translateY(-3px);
  background: rgba(13, 26, 51, 0.9);
}
.spec__icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  font-size: 18px;
  color: var(--cyan);
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid rgba(34, 211, 238, 0.22);
}
.spec h4 { font-size: 15.5px; margin-bottom: 4px; letter-spacing: 0.02em; }
.spec p { font-size: 13px; color: var(--muted); line-height: 1.65; }

.pipeline {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 18px;
  align-items: stretch;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(13, 26, 51, 0.45), rgba(7, 13, 29, 0.6));
}
.pipeline__step { text-align: center; }
.pipeline__num {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  font-size: 13px;
  font-weight: 700;
  color: var(--cyan);
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid rgba(34, 211, 238, 0.3);
  margin-bottom: 12px;
}
.pipeline__step h4 { font-size: 16px; margin-bottom: 6px; }
.pipeline__step p { font-size: 13px; color: var(--muted); max-width: 260px; margin: 0 auto; }
.pipeline__arrow {
  align-self: center;
  color: var(--faint);
  font-size: 20px;
}

/* ============ 应用场景 ============ */
.scenarios {
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
}
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.card {
  padding: 30px 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(10, 20, 40, 0.55);
  transition: transform 0.3s ease, border-color 0.3s ease, background 0.3s ease;
  position: relative;
  overflow: hidden;
}
.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--grad);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}
.card:hover {
  transform: translateY(-5px);
  border-color: var(--line-strong);
  background: rgba(13, 26, 51, 0.85);
}
.card:hover::before { transform: scaleX(1); }
.card svg {
  width: 46px;
  height: 46px;
  color: var(--cyan);
  margin-bottom: 18px;
  stroke-width: 1.7;
}
.card h3 { font-size: 18px; margin-bottom: 8px; letter-spacing: 0.03em; }
.card p { font-size: 13.5px; color: var(--muted); margin-bottom: 16px; }
.card__tag {
  display: inline-block;
  font-size: 12px;
  color: #a9d9ef;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.2);
}

/* ============ 技术优势 ============ */
.advantage { background: var(--bg); }
.advantage-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.advantage-item {
  display: flex;
  gap: 16px;
  padding: 26px 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(13, 26, 51, 0.45);
  transition: border-color 0.3s ease, transform 0.3s ease;
}
.advantage-item:hover { border-color: var(--line-strong); transform: translateY(-3px); }
.advantage-item__icon {
  flex-shrink: 0;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  font-size: 19px;
  color: var(--cyan);
  background: rgba(34, 211, 238, 0.09);
  border: 1px solid rgba(34, 211, 238, 0.22);
  border-radius: 10px;
}
.advantage-item h3 { font-size: 16.5px; margin-bottom: 6px; letter-spacing: 0.02em; }
.advantage-item p { font-size: 13px; color: var(--muted); line-height: 1.7; }

/* ============ 安全体系 ============ */
.safety {
  background: linear-gradient(180deg, var(--bg-2) 0%, var(--bg) 100%);
}
.safety-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.safety-card {
  position: relative;
  padding: 30px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(10, 20, 40, 0.6);
  overflow: hidden;
  transition: border-color 0.3s ease, transform 0.3s ease;
}
.safety-card:hover { border-color: rgba(34, 211, 238, 0.4); transform: translateY(-4px); }
.safety-card__badge {
  position: absolute;
  top: 14px;
  right: 18px;
  font-size: 34px;
  font-weight: 800;
  color: rgba(120, 160, 255, 0.1);
  line-height: 1;
}
.safety-card h3 {
  font-size: 17px;
  margin-bottom: 10px;
  padding-top: 4px;
  position: relative;
}
.safety-card h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: -10px;
  width: 26px;
  height: 3px;
  border-radius: 3px;
  background: var(--grad);
}
.safety-card p { font-size: 13.5px; color: var(--muted); }

/* ============ 研发历程 ============ */
.roadmap { background: var(--bg); }
.timeline {
  position: relative;
  max-width: 860px;
  margin: 0 auto;
  padding-left: 34px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, rgba(34, 211, 238, 0.6), rgba(139, 92, 246, 0.4));
  border-radius: 2px;
}
.timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 92px 1fr;
  gap: 24px;
  padding-bottom: 30px;
}
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, 0.15);
}
.timeline__year {
  font-size: 18px;
  font-weight: 800;
  color: var(--cyan);
  letter-spacing: 0.04em;
  padding-top: 4px;
}
.timeline__card {
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(13, 26, 51, 0.5);
  transition: border-color 0.3s ease, transform 0.3s ease;
}
.timeline__card:hover { border-color: var(--line-strong); transform: translateX(4px); }
.timeline__card h4 { font-size: 16px; margin-bottom: 6px; }
.timeline__card p { font-size: 13.5px; color: var(--muted); }
.roadmap__note {
  margin-top: 34px;
  text-align: center;
  font-size: 12.5px;
  color: var(--faint);
}

/* ============ 关于我们 ============ */
.about {
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
}
.about-head { margin-bottom: 44px; }
.values {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.value {
  text-align: center;
  padding: 28px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(10, 20, 40, 0.5);
  transition: transform 0.3s ease, border-color 0.3s ease;
}
.value:hover { transform: translateY(-4px); border-color: var(--line-strong); }
.value span {
  display: block;
  font-size: 13px;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.2em;
  margin-bottom: 12px;
}
.value h4 { font-size: 16px; margin-bottom: 8px; }
.value p { font-size: 13px; color: var(--muted); }

/* ============ 联系合作 ============ */
.contact { background: var(--bg); }
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 44px;
  align-items: start;
}
.contact-info { display: grid; gap: 14px; }
.contact-item {
  display: flex;
  gap: 14px;
  align-items: center;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(13, 26, 51, 0.45);
  transition: border-color 0.3s ease, transform 0.3s ease;
}
a.contact-item:hover { border-color: rgba(34, 211, 238, 0.4); transform: translateX(4px); }
.contact-item__icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  font-size: 16px;
  color: var(--cyan);
  background: rgba(34, 211, 238, 0.09);
  border: 1px solid rgba(34, 211, 238, 0.22);
  border-radius: 10px;
}
.contact-item h4 { font-size: 14px; color: var(--muted); font-weight: 500; margin-bottom: 2px; }
.contact-item p { font-size: 15px; font-weight: 600; }

.contact-form {
  display: grid;
  gap: 16px;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(13, 26, 51, 0.65), rgba(10, 20, 40, 0.5));
}
.form-row { display: grid; gap: 7px; }
.form-row label { font-size: 13px; color: var(--muted); font-weight: 600; letter-spacing: 0.03em; }
.form-row input,
.form-row select,
.form-row textarea {
  width: 100%;
  font-family: inherit;
  font-size: 14px;
  color: var(--text);
  background: rgba(4, 7, 15, 0.7);
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  padding: 12px 14px;
  outline: none;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}
.form-row input::placeholder,
.form-row textarea::placeholder { color: var(--faint); }
.form-row input:focus,
.form-row select:focus,
.form-row textarea:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.14);
}
.form-row select {
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--muted) 50%),
    linear-gradient(135deg, var(--muted) 50%, transparent 50%);
  background-position: calc(100% - 20px) 50%, calc(100% - 14px) 50%;
  background-size: 6px 6px, 6px 6px;
  background-repeat: no-repeat;
}
.form-row textarea { resize: vertical; min-height: 100px; }
.form-submit { width: 100%; margin-top: 4px; }
.form-note { font-size: 12px; color: var(--faint); text-align: center; }

/* ============ 页脚 ============ */
.site-footer {
  border-top: 1px solid var(--line);
  background: var(--bg-2);
  padding: 46px 0 34px;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}
.footer-brand { display: flex; align-items: center; gap: 13px; }
.footer-brand svg { width: 40px; height: 40px; }
.footer-brand__name {
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.08em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.footer-brand__slogan { font-size: 12.5px; color: var(--faint); margin-top: 2px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-links a { font-size: 13.5px; color: var(--muted); transition: color 0.25s ease; }
.footer-links a:hover { color: var(--cyan); }
.footer-meta { width: 100%; text-align: center; font-size: 12.5px; color: var(--faint); }
.footer-beian a { color: var(--muted); transition: color 0.25s ease; }
.footer-beian a:hover { color: var(--cyan); }

/* ============ Toast ============ */
.toast {
  position: fixed;
  left: 50%;
  bottom: 34px;
  transform: translate(-50%, 24px);
  z-index: 200;
  max-width: 90vw;
  padding: 13px 26px;
  border-radius: 12px;
  background: rgba(13, 26, 51, 0.96);
  border: 1px solid rgba(34, 211, 238, 0.4);
  color: var(--text);
  font-size: 14px;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
  .advantage-list { grid-template-columns: repeat(2, 1fr); }
  .safety-grid { grid-template-columns: repeat(2, 1fr); }
  .values { grid-template-columns: repeat(2, 1fr); }
  .hero-inner { grid-template-columns: 1fr; gap: 44px; }
  .hero__visual { max-width: 620px; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 76px 0; }
  .system-grid { grid-template-columns: 1fr; }
  .system-specs { grid-template-columns: 1fr; }
  .pipeline { grid-template-columns: 1fr; }
  .pipeline__arrow { transform: rotate(90deg); justify-self: center; }
  .cards { grid-template-columns: 1fr; }
  .advantage-list { grid-template-columns: 1fr; }
  .safety-grid { grid-template-columns: 1fr; }
  .values { grid-template-columns: 1fr; }
  .hero__stats { grid-template-columns: repeat(2, 1fr); }
  .timeline__item { grid-template-columns: 1fr; gap: 10px; }
  .timeline__year { padding-top: 0; }
  .test-banner { font-size: 12px; padding: 8px 40px; }
  .contact-form { padding: 24px 20px; }
  .footer-inner { justify-content: center; text-align: center; }
  .footer-links { justify-content: center; }
  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(4, 7, 15, 0.98);
    border-bottom: 1px solid var(--line);
    padding: 12px 24px 20px;
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
  }
  .site-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .site-nav a { padding: 13px 0; width: 100%; font-size: 15px; border-bottom: 1px solid rgba(120, 160, 255, 0.07); }
  .site-nav a::after { display: none; }
  .site-nav .nav-cta { border: none; background: none; text-align: left; }
  .nav-toggle { display: flex; }
}

@media (max-width: 420px) {
  .brand__sub { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}