/* ==========================================================================
   NovaCDN 样式
   设计基调：深色底、纯白标题、冷灰层级，唯一点缀色 #38bdf8
   ========================================================================== */

:root {
  --bg:     #05070d;
  --panel:  #0b101a;
  --line:   rgba(255, 255, 255, .09);
  --txt:    #f2f5f9;
  --sub:    #9aa4b2;
  --dim:    #6b7482;
  --accent: #38bdf8;
  --accent-dim: rgba(56, 189, 248, .14);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--txt);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
::selection { background: rgba(56, 189, 248, .25); }
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #1c2536; border-radius: 6px; }

a { color: inherit; text-decoration: none; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block; padding: 13px 30px; border-radius: 10px;
  font-size: 15px; font-weight: 600; cursor: pointer;
  transition: transform .2s ease, background .2s ease, border-color .2s ease;
}
.btn:active { transform: scale(.97); }
.btn-primary { background: var(--txt); color: #0a0e17; }
.btn-primary:hover { background: #fff; transform: translateY(-1px); }
.btn-ghost { border: 1px solid var(--line); color: var(--txt); }
.btn-ghost:hover { border-color: rgba(56, 189, 248, .5); }

/* ---------- 面板 ---------- */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  transition: border-color .3s ease;
}
.panel:hover { border-color: rgba(56, 189, 248, .35); }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  transition: background .3s ease, border-color .3s ease;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(5, 7, 13, .82);
  backdrop-filter: blur(10px);
  border-bottom-color: var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.nav-links { display: flex; gap: 34px; font-size: 14px; color: var(--sub); }
.nav-links a:hover { color: var(--txt); }
.logo { font-size: 18px; font-weight: 800; letter-spacing: -.02em; }
.logo b { color: var(--accent); font-weight: 800; }
.nav-btn { padding: 8px 18px; border-radius: 8px; font-size: 14px; background: var(--txt); color: #0a0e17; font-weight: 600; }
@media (max-width: 720px) { .nav-links { display: none; } }

/* ---------- Hero ---------- */
.hero { position: relative; min-height: 100vh; display: flex; align-items: center; overflow: hidden; }
.shield-canvas { position: absolute; right: -6%; top: 0; width: 62%; height: 100%; touch-action: pan-y; }
.shield-canvas canvas { display: block; }
/* 电影感暗角：把视线收进场景中心，避免边缘发灰 */
.hero-vignette {
  position: absolute; inset: 0; pointer-events: none; z-index: 1;
  background: radial-gradient(ellipse 90% 75% at 62% 46%, transparent 52%, rgba(3, 5, 10, .6) 100%);
}
@media (max-width: 900px) {
  .hero { display: block; min-height: auto; }
  .hero-copy { text-align: center; padding: 110px 0 0; max-width: none; }
  .hero-sub { margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-hint { margin-top: 14px; }
  /* 移动端：3D 场景独占一块全亮度显示，不再当半透明背景 */
  .shield-canvas {
    position: relative; right: auto; top: auto; transform: none;
    width: 100%; height: 54vh; opacity: 1;
  }
  .hero-vignette {
    background: radial-gradient(ellipse 100% 90% at 50% 50%, transparent 55%, rgba(3, 5, 10, .5) 100%);
  }
}
.hero-copy { position: relative; z-index: 2; padding: 120px 0 80px; max-width: 560px; }
.eyebrow {
  display: inline-block; font-size: 12px; letter-spacing: .25em;
  color: var(--accent); margin-bottom: 22px;
}
h1 { font-size: clamp(40px, 6vw, 66px); font-weight: 800; line-height: 1.15; letter-spacing: -.025em; color: var(--txt); }
.hero-sub { margin-top: 22px; font-size: 17px; color: var(--sub); max-width: 460px; font-weight: 300; }
.hero-cta { margin-top: 38px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero-hint { margin-top: 46px; font-size: 12px; color: var(--dim); letter-spacing: .18em; }

/* ---------- 跑马灯 ---------- */
.marquee-sec { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 26px 0; overflow: hidden; }
.marquee { display: flex; width: max-content; animation: marquee 30s linear infinite; }
.marquee span { margin: 0 44px; font-size: 15px; font-weight: 700; letter-spacing: .22em; color: var(--dim); white-space: nowrap; }
@keyframes marquee { to { transform: translateX(-50%); } }

/* ---------- 区块通用 ---------- */
section { position: relative; }
.sec-pad { padding: 110px 0; }
.metrics-sec { padding-bottom: 70px; }
.cta-sec { padding-bottom: 0; }
.sec-head { text-align: center; margin-bottom: 64px; }
.sec-tag { font-size: 12px; letter-spacing: .3em; color: var(--accent); margin-bottom: 14px; }
h2 { font-size: clamp(30px, 4vw, 46px); font-weight: 800; letter-spacing: -.02em; color: var(--txt); }
.sec-desc { margin-top: 16px; color: var(--sub); font-size: 16px; font-weight: 300; }

/* ---------- 指标 ---------- */
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
@media (max-width: 900px) { .metrics { grid-template-columns: repeat(2, 1fr); } }
.metric { text-align: center; padding: 36px 16px; }
.metric .num { font-size: 42px; font-weight: 800; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.metric .num small { font-size: 20px; font-weight: 600; color: var(--sub); margin-left: 3px; }
.metric .label { margin-top: 8px; font-size: 14px; color: var(--sub); }

/* ---------- 特性卡片：3D 倾斜 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 980px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .grid-3 { grid-template-columns: 1fr; } }
.grid-3 > .reveal { perspective: 1000px; }
.tilt-card {
  transform-style: preserve-3d; will-change: transform;
  transition: transform .3s ease;
}
.feat { padding: 30px 26px; height: 100%; }
.feat-icon {
  width: 44px; height: 44px; border-radius: 10px; margin-bottom: 20px;
  display: flex; align-items: center; justify-content: center;
  background: var(--accent-dim); border: 1px solid rgba(56, 189, 248, .25);
  font-size: 20px;
}
.feat h3 { font-size: 17px; font-weight: 700; color: var(--txt); margin-bottom: 10px; }
.feat p { font-size: 13.5px; color: var(--sub); font-weight: 300; }
.feat .more { display: inline-block; margin-top: 18px; font-size: 12.5px; color: var(--accent); }

/* ---------- 进视口上浮淡入（同排错峰由 data-delay 控制） ---------- */
.reveal { opacity: 0; transform: translateY(36px); transition: opacity .8s cubic-bezier(.16,1,.3,1), transform .8s cubic-bezier(.16,1,.3,1); }
.reveal.on { opacity: 1; transform: none; }

/* ---------- 全球网络 ---------- */
.net-panel { position: relative; padding: 26px; overflow: hidden; }
.net-bg {
  position: absolute; inset: 0; pointer-events: none; opacity: .5;
  background-image:
    linear-gradient(rgba(120,150,200,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120,150,200,.06) 1px, transparent 1px);
  background-size: 48px 48px;
}
.net-svg { width: 100%; height: auto; display: block; position: relative; }
.net-flow { stroke-dasharray: 3 25; animation: netFlow 2.2s linear infinite; }
@keyframes netFlow { to { stroke-dashoffset: -28; } }
.net-legend {
  position: relative; margin-top: 14px; display: flex; justify-content: center; gap: 36px; flex-wrap: wrap;
  font-size: 12px; color: var(--dim); letter-spacing: .08em;
}

/* ---------- 页脚 ---------- */
footer { border-top: 1px solid var(--line); margin-top: 110px; padding: 56px 0 40px; }
.cta-box { text-align: center; padding: 40px 0 0; }
.cta-box p { margin-top: 14px; color: var(--sub); font-weight: 300; }
.foot-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
@media (max-width: 720px) { .foot-grid { grid-template-columns: 1fr 1fr; } }
.foot-grid h4 { font-size: 13px; letter-spacing: .15em; color: var(--txt); margin-bottom: 16px; font-weight: 700; }
.foot-grid li { list-style: none; margin-bottom: 10px; }
.foot-grid li a { font-size: 13.5px; color: var(--sub); }
.foot-grid li a:hover { color: var(--txt); }
.foot-desc { font-size: 13.5px; color: var(--dim); margin-top: 12px; font-weight: 300; }
.foot-bottom { margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; font-size: 12px; color: var(--dim); }