/* style.css
   深蓝渐变 + 动态科技网格背景
   说明：背景由两个叠层组成：
   1) .bg-gradient - 渐变光晕（移动）
   2) .bg-grid - SVG 网格通过 repeating-linear-gradient + 动画实现
*/

/* reset */
* { box-sizing: border-box; margin: 0; padding: 0; }
html,body { height: 100%; }

/* page container */
body {
  font-family: Inter, "Helvetica Neue", Arial, sans-serif;
  color: #e6f0ff;
  background: #071428;
  overflow-x: hidden;
}

/* 背景层（伪元素） */
.page {
  position: relative;
  min-height: 100vh;
  isolation: isolate;
  z-index: 0;
  /* fallback background */
  background: linear-gradient(180deg, #041226 0%, #061f38 40%, #072845 100%);
}

/* 动态渐变光晕层 */
.page::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background: radial-gradient(600px 400px at 10% 20%, rgba(33,88,165,0.20), transparent 10%),
              radial-gradient(700px 500px at 85% 80%, rgba(120,43,220,0.16), transparent 10%);
  mix-blend-mode: screen;
  animation: drift 12s linear infinite;
  filter: blur(30px);
}

/* 网格与数据流动层 */
.page::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    /* diagonal grid (thin) */
    linear-gradient(transparent 49%, rgba(255,255,255,0.02) 50%, transparent 51%),
    linear-gradient(90deg, transparent 49%, rgba(255,255,255,0.02) 50%, transparent 51%),
    /* larger spaced grid for depth */
    linear-gradient(transparent 49%, rgba(255,255,255,0.01) 50%, transparent 51%),
    linear-gradient(90deg, transparent 49%, rgba(255,255,255,0.01) 50%, transparent 51%),
    /* subtle noise stripes to emulate data lines */
    repeating-linear-gradient(0deg, rgba(255,255,255,0.02) 0 1px, transparent 1px 30px);
  background-size:
    18px 18px,
    18px 18px,
    72px 72px,
    72px 72px,
    100% 6px;
  background-position:
    0 0,
    9px 9px,
    0 0,
    36px 36px,
    0 0;
  mix-blend-mode: overlay;
  opacity: 0.95;
  animation: gridShift 20s linear infinite;
  transform-origin: center;
  filter: drop-shadow(0 10px 30px rgba(0,0,0,0.6));
}

/* small animated nodes / glints using radial-gradients overlay */
.page .glints {
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(circle at 20% 10%, rgba(255,255,255,0.06) 0 1%, transparent 20%),
    radial-gradient(circle at 70% 80%, rgba(255,255,255,0.05) 0 1%, transparent 15%),
    radial-gradient(circle at 45% 40%, rgba(255,255,255,0.04) 0 1%, transparent 12%);
  animation: glintMove 18s linear infinite;
}

/* keyframes */
@keyframes drift {
  0% { transform: translate3d(-5%, -2%, 0) scale(1); }
  50% { transform: translate3d(5%, 2%, 0) scale(1.05); }
  100% { transform: translate3d(-5%, -2%, 0) scale(1); }
}

@keyframes gridShift {
  0% { background-position: 0 0, 9px 9px, 0 0, 36px 36px, 0 0; transform: rotate(0deg) scale(1); }
  50% { background-position: -80px -40px, -71px -31px, 20px -40px, -12px 40px, 0 -30px; transform: rotate(.25deg) scale(1.01); }
  100% { background-position: 0 0, 9px 9px, 0 0, 36px 36px, 0 0; transform: rotate(0deg) scale(1); }
}

@keyframes glintMove {
  0% { transform: translate3d(-2%,0,0); opacity: .9; }
  50% { transform: translate3d(2%,1%,0); opacity: .6; }
  100% { transform: translate3d(-2%,0,0); opacity: .9; }
}

/* header */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 28px 40px;
  position: relative;
  z-index: 2;
}
.logo {
  font-weight: 700;
  letter-spacing: 1px;
  font-size: 20px;
  color: #dff0ff;
}
.nav a {
  margin-left: 18px;
  color: rgba(230,240,255,0.9);
  text-decoration: none;
  font-size: 14px;
}

/* hero */
.hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 60px 8%;
  min-height: 64vh;
  position: relative;
  z-index: 1;
}
.hero-inner {
  max-width: 720px;
}
.hero h1 {
  font-size: 48px;
  line-height: 1.05;
  margin-bottom: 16px;
  color: #e8f5ff;
  text-shadow: 0 4px 30px rgba(3,18,35,0.6);
}
.tagline {
  margin-bottom: 22px;
  color: rgba(230,240,255,0.85);
  font-size: 18px;
}

/* CTA */
.btn {
  display: inline-block;
  padding: 12px 20px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 600;
  margin-right: 12px;
  transition: transform .18s ease, box-shadow .18s ease;
}
.btn.primary {
  background: linear-gradient(90deg, #2e86ff, #6d4cff);
  color: white;
  box-shadow: 0 6px 24px rgba(67,100,255,0.18);
}
.btn.primary:hover { transform: translateY(-3px); box-shadow: 0 10px 40px rgba(67,100,255,0.22); }
.btn.ghost {
  background: transparent;
  border: 1px solid rgba(255,255,255,0.08);
  color: rgba(230,240,255,0.95);
}

/* features */
.features {
  padding: 56px 8%;
  z-index: 2;
  position: relative;
}
.features h2 { margin-bottom: 18px; font-size: 28px; color: #eaf6ff; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px,1fr)); gap: 18px; margin-top: 18px; }
.card {
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border-radius: 12px;
  padding: 18px;
  backdrop-filter: blur(6px);
  box-shadow: 0 6px 30px rgba(2,10,20,0.6);
}

/* footer */
.site-footer {
  padding: 28px 8%;
  text-align: center;
  color: rgba(230,240,255,0.6);
  z-index: 2;
  position: relative;
}

/* responsive */
@media (max-width: 720px) {
  .hero { flex-direction: column; padding: 40px 6%; min-height: 56vh; }
  .hero h1 { font-size: 32px; }
  .site-header { padding: 18px 20px; }
}