:root {
  --bg: #05070d;
  --bg-soft: #0a0f1c;
  --panel: rgba(16, 23, 41, 0.6);
  --panel-solid: #0d1424;
  --border: rgba(120, 150, 200, 0.14);
  --text: #eef2fa;
  --text-muted: #8a99b8;
  --accent: #5f8cff;
  --accent-2: #7b61ff;
  --accent-3: #25d0c4;
  --grad: linear-gradient(120deg, #6ea8ff, #7b61ff 55%, #25d0c4);
  --glow: rgba(95, 140, 255, 0.35);
  --mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: 'Inter', 'PingFang SC', 'Noto Sans SC', 'Segoe UI', sans-serif;
  --display: 'Space Grotesk', var(--sans);
  --radius: 18px;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.5);
}

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

em {
  font-style: normal;
}

.container {
  width: min(1120px, 92%);
  margin-inline: auto;
  position: relative;
  z-index: 2;
}

.mono {
  color: var(--accent);
  font-family: var(--mono);
}

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

/* ---------- 动态背景 ---------- */

#bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.aurora {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

.aurora-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.5;
  animation: drift 24s ease-in-out infinite alternate;
}

.b1 {
  width: 46rem;
  height: 46rem;
  left: -14rem;
  top: -12rem;
  background: radial-gradient(circle at 30% 30%, rgba(95, 140, 255, 0.5), transparent 65%);
}

.b2 {
  width: 38rem;
  height: 38rem;
  right: -10rem;
  top: 22%;
  background: radial-gradient(circle at 60% 40%, rgba(123, 97, 255, 0.45), transparent 65%);
  animation-delay: -8s;
}

.b3 {
  width: 40rem;
  height: 40rem;
  left: 30%;
  bottom: -18rem;
  background: radial-gradient(circle at 50% 50%, rgba(37, 208, 196, 0.32), transparent 65%);
  animation-delay: -16s;
}

@keyframes drift {
  0% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(4rem, -3rem) scale(1.12);
  }
  100% {
    transform: translate(-3rem, 4rem) scale(0.94);
  }
}

.grain {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='120' height='120' filter='url(%23n)' opacity='0.6'/%3E%3C/svg%3E");
}

/* ---------- 鼠标光标 ---------- */

.cursor-dot {
  position: fixed;
  left: 0;
  top: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 14px var(--glow), 0 0 34px var(--glow);
  pointer-events: none;
  z-index: 9999;
  transition: transform 0.15s ease, background 0.2s ease;
}

.cursor-dot.hovering {
  transform: scale(2.4);
  background: #fff;
  mix-blend-mode: difference;
}

@media (pointer: coarse) {
  .cursor-dot {
    display: none;
  }
}

/* ---------- 顶部导航 ---------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease, backdrop-filter 0.3s ease;
}

.site-header.scrolled {
  background: rgba(5, 7, 13, 0.72);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.18rem;
  letter-spacing: -0.01em;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 11px;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 6px 20px var(--glow);
}

.brand-name em {
  color: var(--accent);
  font-weight: 600;
}

.nav-links {
  display: flex;
  gap: 34px;
}

.nav-link {
  position: relative;
  color: var(--text-muted);
  font-size: 0.94rem;
  padding: 6px 2px;
  transition: color 0.2s ease;
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--grad);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.28s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.nav-link:hover,
.nav-link.active {
  color: var(--text);
}

.nav-link:hover::after,
.nav-link.active::after {
  transform: scaleX(1);
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: 14px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.96rem;
  padding: 13px 26px;
  border-radius: 12px;
  border: 1px solid transparent;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease, background 0.25s ease;
}

.btn-sm {
  padding: 9px 18px;
  font-size: 0.88rem;
  border-radius: 10px;
}

.btn-block {
  width: 100%;
  justify-content: center;
}

.btn-primary {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #fff;
  box-shadow: 0 10px 30px var(--glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 40px var(--glow);
}

.btn-ghost {
  border-color: var(--border);
  color: var(--text);
  background: var(--panel);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 12px 34px rgba(95, 140, 255, 0.18);
}

.btn-arrow {
  transition: transform 0.25s ease;
}

.btn:hover .btn-arrow {
  transform: translateX(4px);
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 140px 0 80px;
}

.hero-inner {
  max-width: 840px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 7px 15px;
  background: var(--panel);
  backdrop-filter: blur(8px);
  margin-bottom: 30px;
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-3);
  box-shadow: 0 0 0 0 rgba(37, 208, 196, 0.5);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(37, 208, 196, 0.5);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(37, 208, 196, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(37, 208, 196, 0);
  }
}

.hero-title {
  font-family: var(--display);
  font-size: clamp(2.7rem, 6.4vw, 4.6rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.03em;
  margin-bottom: 22px;
}

.hero-sub {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: clamp(0.98rem, 2.2vw, 1.2rem);
  color: var(--text);
  margin-bottom: 20px;
}

.caret {
  display: inline-block;
  width: 9px;
  height: 1.1em;
  background: var(--accent);
  animation: blink 0.85s steps(2, start) infinite;
}

@keyframes blink {
  to {
    visibility: hidden;
  }
}

.hero-desc {
  max-width: 620px;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-metrics {
  display: flex;
  gap: 48px;
  margin-top: 56px;
  flex-wrap: wrap;
}

.hero-metrics li {
  display: flex;
  flex-direction: column;
}

.metric-num {
  font-family: var(--display);
  font-size: 2.3rem;
  font-weight: 700;
  color: var(--text);
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.metric-label {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ---------- Sections ---------- */

.section {
  padding: 120px 0;
  position: relative;
}

.section-alt {
  background: linear-gradient(to bottom, transparent, rgba(13, 20, 36, 0.55) 18%, rgba(13, 20, 36, 0.55) 82%, transparent);
}

.section-head {
  margin-bottom: 56px;
  max-width: 680px;
}

.section-head.no-margin {
  margin-bottom: 0;
}

.section-tag {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--display);
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.02rem;
}

/* ---------- 特性卡片 ---------- */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.feature-card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px 30px;
  backdrop-filter: blur(10px);
  overflow: hidden;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
  will-change: transform;
}

.feature-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(420px circle at var(--mx, 50%) var(--my, 50%), rgba(95, 140, 255, 0.16), transparent 60%);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.feature-card:hover {
  border-color: rgba(95, 140, 255, 0.45);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(95, 140, 255, 0.18);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  font-size: 1.3rem;
  border-radius: 13px;
  background: linear-gradient(135deg, rgba(95, 140, 255, 0.2), rgba(123, 97, 255, 0.2));
  border: 1px solid rgba(95, 140, 255, 0.3);
  color: var(--accent);
  margin-bottom: 20px;
}

.feature-card h3 {
  font-family: var(--display);
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.94rem;
  margin-bottom: 18px;
}

.feature-points {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feature-points li {
  position: relative;
  padding-left: 18px;
  font-size: 0.86rem;
  color: var(--text-muted);
}

.feature-points li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* ---------- 遥操作 ---------- */

.split {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 60px;
  align-items: center;
}

.check-list {
  display: flex;
  flex-direction: column;
  gap: 13px;
  margin: 28px 0 32px;
}

.check-list li {
  position: relative;
  padding-left: 30px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.check-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 0;
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  border-radius: 6px;
  background: rgba(37, 208, 196, 0.14);
  border: 1px solid rgba(37, 208, 196, 0.4);
  color: var(--accent-3);
  font-size: 0.7rem;
}

.teleop-visual {
  position: relative;
}

.teleop-frame {
  background: var(--panel-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.teleop-top {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 13px 18px;
  border-bottom: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--text-muted);
}

.teleop-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #ff5c5c;
  box-shadow: 0 0 12px rgba(255, 92, 92, 0.8);
  animation: pulse-red 1.6s infinite;
}

@keyframes pulse-red {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.4;
  }
}

.teleop-title {
  flex: 1;
}

.teleop-lat {
  color: var(--accent-3);
  font-weight: 600;
}

.teleop-body {
  position: relative;
  padding: 26px;
  display: grid;
  place-items: center;
}

.arm-svg {
  width: 100%;
  max-width: 300px;
  height: auto;
}

.arm-group {
  transform-box: view-box;
  transform-origin: 60px 200px;
  animation: arm-sway 5s ease-in-out infinite alternate;
}

@keyframes arm-sway {
  0% {
    transform: rotate(-4deg);
  }
  100% {
    transform: rotate(5deg);
  }
}

.arm-link {
  stroke: var(--accent);
  stroke-width: 5;
  stroke-linecap: round;
  filter: drop-shadow(0 0 6px var(--glow));
}

.arm-joint {
  fill: var(--accent);
  filter: drop-shadow(0 0 4px var(--glow));
}

.arm-grip {
  fill: none;
  stroke: var(--accent-3);
  stroke-width: 2;
  filter: drop-shadow(0 0 5px rgba(37, 208, 196, 0.8));
}

.arm-target {
  fill: none;
  stroke: #fff;
  stroke-width: 2;
  stroke-dasharray: 4 4;
  opacity: 0.7;
  animation: target-rot 6s linear infinite;
  transform-box: fill-box;
  transform-origin: center;
}

@keyframes target-rot {
  to {
    transform: rotate(360deg);
  }
}

.teleop-overlay {
  position: absolute;
  left: 50%;
  bottom: 18px;
  transform: translateX(-50%);
  text-align: center;
  font-family: var(--mono);
}

.teleop-val {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--accent-3);
  text-shadow: 0 0 20px rgba(37, 208, 196, 0.5);
  display: block;
}

.teleop-axis {
  font-size: 0.72rem;
  color: var(--text-muted);
}

.demo-video {
  margin-top: 22px;
  background: var(--panel-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.demo-video-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 0.74rem;
}

.demo-video-label {
  color: var(--accent);
}

.demo-video-meta {
  color: var(--text-muted);
}

.demo-video video {
  display: block;
  width: 100%;
  max-height: 340px;
  object-fit: cover;
  background: #000;
}

/* ---------- API ---------- */

.api-wrap {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 40px;
  align-items: center;
}

.terminal {
  background: var(--panel-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.terminal-head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 18px;
  border-bottom: 1px solid var(--border);
}

.terminal-dots {
  display: flex;
  gap: 6px;
}

.terminal-dots i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #ff5f57;
}

.terminal-dots i:nth-child(2) {
  background: #febc2e;
}

.terminal-dots i:nth-child(3) {
  background: #28c840;
}

.terminal-name {
  font-family: var(--mono);
  font-size: 0.76rem;
  color: var(--text-muted);
}

.terminal-body {
  padding: 22px 24px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.8;
}

.tok-c {
  color: #5b6b89;
}

.tok-k {
  color: #7b9cff;
}

.tok-s {
  color: #7ee0b8;
}

.tok-n {
  color: #f0a05c;
}

.tok-b {
  color: #f07c9a;
}

.api-side {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.api-stat {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: border-color 0.25s ease, transform 0.25s ease;
}

.api-stat:hover {
  border-color: rgba(95, 140, 255, 0.4);
  transform: translateY(-3px);
}

.api-stat-num {
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.15rem;
}

.api-stat-label {
  color: var(--text-muted);
  font-size: 0.82rem;
}

/* ---------- 案例 ---------- */

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 26px;
}

.showcase-card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  backdrop-filter: blur(10px);
  overflow: hidden;
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.showcase-card::after {
  content: '';
  position: absolute;
  right: -20px;
  top: -20px;
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(95, 140, 255, 0.2), transparent 70%);
  transition: transform 0.3s ease;
}

.showcase-card:hover {
  transform: translateY(-5px);
  border-color: rgba(95, 140, 255, 0.4);
}

.showcase-card h3 {
  font-family: var(--display);
  font-size: 1.12rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.showcase-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
}

/* ---------- CTA ---------- */

.cta-panel {
  text-align: center;
  padding: 72px 40px;
  border-radius: 24px;
  background: linear-gradient(160deg, rgba(95, 140, 255, 0.14), rgba(123, 97, 255, 0.1) 60%, rgba(37, 208, 196, 0.1));
  border: 1px solid rgba(95, 140, 255, 0.25);
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.cta-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(600px circle at var(--mx, 50%) var(--my, 30%), rgba(95, 140, 255, 0.14), transparent 60%);
  pointer-events: none;
}

.cta-title {
  font-family: var(--display);
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  position: relative;
}

.cta-desc {
  color: var(--text-muted);
  max-width: 480px;
  margin: 0 auto 30px;
  position: relative;
}

.cta-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.footer-brand {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.05rem;
}

.footer-brand em {
  color: var(--accent);
}

.footer-copy {
  color: var(--text-muted);
  font-size: 0.84rem;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.84rem;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--accent);
}

/* ---------- Reveal ---------- */

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.2, 0.7, 0.2, 1), transform 0.7s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Responsive ---------- */

@media (max-width: 960px) {
  .feature-grid,
  .showcase-grid {
    grid-template-columns: 1fr;
  }

  .split,
  .api-wrap {
    grid-template-columns: 1fr;
  }

  .hero-metrics {
    gap: 28px;
  }
}

@media (max-width: 720px) {
  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(5, 7, 13, 0.96);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
  }

  .nav-links.open {
    max-height: 340px;
  }

  .nav-link {
    padding: 16px 8vw;
    border-bottom: 1px solid var(--border);
  }

  .nav-toggle {
    display: flex;
  }

  .section {
    padding: 84px 0;
  }
}