/* ===== 基础变量 ===== */
:root {
  --bg: #05060a;
  --bg-soft: #0a0d16;
  --panel: rgba(8, 11, 20, 0.72);
  --neon-cyan: #00eaff;
  --neon-purple: #a855f7;
  --neon-pink: #ff2d78;
  --text: #e8edf5;
  --muted: #8b95ab;
  --line: rgba(255, 255, 255, 0.08);
  --maxw: 1180px;
}

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

html { scroll-behavior: auto; }

body {
  font-family: "Noto Sans SC", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, .brand {
  font-family: "Orbitron", "Noto Sans SC", sans-serif;
  letter-spacing: 0.02em;
}

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

.container { width: min(100% - 48px, var(--maxw)); margin: 0 auto; }

/* ===== 背景 3D 画布 ===== */
#bg {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  display: block;
}

/* ===== 加载动画 ===== */
#loader {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: var(--bg);
  display: grid;
  place-items: center;
  transition: opacity 0.8s ease, visibility 0.8s ease;
}
#loader.hidden { opacity: 0; visibility: hidden; }
.loader-inner { text-align: center; }
.loader-logo {
  font-family: "Orbitron", sans-serif;
  font-weight: 900;
  font-size: 64px;
  background: linear-gradient(120deg, var(--neon-cyan), var(--neon-purple));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: 0.1em;
  animation: pulse 1.4s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { opacity: 0.55; } 50% { opacity: 1; } }
.loader-bar {
  width: 220px; height: 3px; margin: 22px auto 10px;
  background: rgba(255,255,255,0.1); border-radius: 99px; overflow: hidden;
}
#loader-fill {
  display: block; height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple));
  box-shadow: 0 0 12px var(--neon-cyan);
}
.loader-pct { font-family: "Orbitron"; color: var(--muted); font-size: 13px; }

/* ===== 自定义光标 ===== */
#cursor, #cursor-dot {
  position: fixed; top: 0; left: 0; z-index: 9998;
  border-radius: 50%; pointer-events: none;
  transform: translate(-50%, -50%);
  mix-blend-mode: difference;
}
#cursor {
  width: 34px; height: 34px;
  border: 1.5px solid #fff; transition: width 0.25s, height 0.25s, background 0.25s;
}
#cursor-dot { width: 6px; height: 6px; background: #fff; }
#cursor.hover { width: 54px; height: 54px; background: rgba(255,255,255,0.12); }

/* ===== 导航 ===== */
#nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px clamp(20px, 5vw, 56px);
  transition: background 0.4s, padding 0.4s, border-color 0.4s;
  border-bottom: 1px solid transparent;
}
#nav.scrolled {
  background: rgba(5, 6, 10, 0.78);
  backdrop-filter: blur(14px);
  padding-top: 14px; padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.brand {
  font-weight: 900; font-size: 22px; letter-spacing: 0.06em;
}
.brand span { color: var(--neon-cyan); margin: 0 2px; }
.nav-cta {
  font-size: 14px; padding: 10px 20px; border-radius: 99px;
  border: 1px solid rgba(0, 234, 255, 0.4); color: var(--neon-cyan);
  transition: 0.3s;
}
.nav-cta:hover { background: var(--neon-cyan); color: #04121a; box-shadow: 0 0 22px rgba(0,234,255,0.5); }

/* —— 导航特效：底部流动光线 + 品牌辉光 —— */
#nav::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--neon-cyan), var(--neon-purple), var(--neon-pink), transparent);
  background-size: 220% 100%;
  opacity: 0; transition: opacity 0.4s;
  animation: navLine 5s linear infinite;
}
#nav.scrolled::after { opacity: 0.85; }
@keyframes navLine { from { background-position: 220% 0; } to { background-position: -220% 0; } }

.brand span { animation: brandPulse 2.6s ease-in-out infinite; }
@keyframes brandPulse {
  0%, 100% { text-shadow: 0 0 8px rgba(0,234,255,0.35); }
  50% { text-shadow: 0 0 20px rgba(0,234,255,0.95); }
}

/* ===== 区块通用 ===== */
.section { position: relative; z-index: 2; }
#hero { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; }

/* ===== Hero ===== */
.hero-content {
  width: min(100% - 48px, var(--maxw));
  margin: 0 auto; padding: 0 24px;
}
.hero-tag {
  font-family: "Orbitron"; letter-spacing: 0.4em; font-size: 13px;
  color: var(--neon-cyan); margin-bottom: 22px;
}
.hero-title {
  font-size: clamp(44px, 9vw, 104px); font-weight: 900; line-height: 1.02;
  text-shadow: 0 0 40px rgba(0,0,0,0.6);
}
.grad {
  background: linear-gradient(120deg, var(--neon-cyan), var(--neon-purple) 60%, var(--neon-pink));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub {
  max-width: 560px; margin-top: 26px; color: rgba(232,237,245,0.86); font-size: 18px;
  line-height: 1.7;
  animation: subGlow 4.5s ease-in-out infinite;
}
@keyframes subGlow {
  0%, 100% { filter: drop-shadow(0 0 4px rgba(0,234,255,0.12)); }
  50% { filter: drop-shadow(0 0 14px rgba(168,85,247,0.22)); }
}
.hero-sub .hl {
  font-weight: 700;
  background: linear-gradient(100deg, var(--neon-cyan), var(--neon-purple), var(--neon-pink), var(--neon-cyan));
  background-size: 300% 100%;
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 10px rgba(0,234,255,0.45));
  animation: hlFlow 6s linear infinite;
}
@keyframes hlFlow { from { background-position: 0% 0; } to { background-position: 300% 0; } }
.hero-actions { margin-top: 38px; display: flex; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 30px; border-radius: 99px; font-size: 15px; font-weight: 500;
  cursor: pointer; border: 1px solid transparent; transition: 0.3s;
}
.btn-primary {
  background: linear-gradient(120deg, var(--neon-cyan), var(--neon-purple));
  color: #04121a; font-weight: 700;
  box-shadow: 0 10px 30px rgba(0, 234, 255, 0.28);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 16px 40px rgba(168,85,247,0.4); }
.btn-ghost { border-color: var(--line); color: var(--text); }
.btn-ghost:hover { border-color: var(--neon-cyan); color: var(--neon-cyan); }

/* ===== 页脚 ===== */
#footer { position: relative; z-index: 2; border-top: 1px solid var(--line); background: var(--bg-soft); }
.footer-inner { padding: 40px 0; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
#footer p { color: var(--muted); font-size: 14px; }
.beian { color: var(--muted); margin-left: 10px; transition: color 0.3s; }
.beian:hover { color: var(--neon-cyan); }

/* ===== 滚动揭示初始态 ===== */
[data-reveal] { opacity: 0; transform: translateY(34px); }
[data-reveal].in { opacity: 1; transform: none; transition: opacity 0.9s cubic-bezier(0.2,0.8,0.2,1), transform 0.9s cubic-bezier(0.2,0.8,0.2,1); }

/* ===== 响应式 ===== */
@container (max-width: 540px) { .container { padding: 90px 0; } }
@media (hover: none) { #cursor, #cursor-dot { display: none; } }

/* AI 行走操作提示 */
.car-hint {
  position: absolute; bottom: 34px; left: clamp(20px, 5vw, 56px);
  color: var(--neon-cyan); font-size: 13px; letter-spacing: 0.08em;
  padding: 8px 16px; border: 1px solid rgba(0,234,255,0.3); border-radius: 99px;
  background: rgba(0,234,255,0.06); backdrop-filter: blur(4px);
}
@media (max-width: 540px) { .car-hint { display: none; } }