:root {
  --bg: #060b1a;
  --bg-soft: #0b1330;
  --text: #e9f0ff;
  --text-soft: #a7b8df;
  --accent: #68e1ff;
  --accent-2: #9a7bff;
  --card: rgba(13, 21, 47, 0.72);
  --border: rgba(115, 158, 255, 0.25);
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  position: relative;
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 500px at 50% 115%, rgba(141, 164, 255, 0.14), transparent 65%),
    radial-gradient(680px 240px at 62% 36%, rgba(255, 255, 255, 0.08), transparent 70%),
    radial-gradient(900px 520px at 10% -10%, rgba(104, 225, 255, 0.18), transparent 60%),
    radial-gradient(900px 600px at 95% 15%, rgba(154, 123, 255, 0.2), transparent 60%),
    linear-gradient(145deg, var(--bg) 0%, var(--bg-soft) 45%, #111838 100%);
  background-attachment: fixed;
  overflow-x: hidden;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

body::before {
  background-image:
    radial-gradient(3.2px 3.2px at 8% 18%, rgba(255, 255, 255, 1), transparent 64%),
    radial-gradient(3px 3px at 28% 48%, rgba(232, 245, 255, 0.98), transparent 64%),
    radial-gradient(3.1px 3.1px at 52% 22%, rgba(255, 255, 255, 0.98), transparent 64%),
    radial-gradient(2.9px 2.9px at 76% 34%, rgba(230, 244, 255, 0.96), transparent 64%),
    radial-gradient(3.2px 3.2px at 90% 70%, rgba(255, 255, 255, 0.98), transparent 64%),
    radial-gradient(1.8px 1.8px at 16% 64%, rgba(196, 232, 255, 0.9), transparent 62%),
    radial-gradient(2px 2px at 26% 32%, rgba(255, 255, 255, 0.9), transparent 64%),
    radial-gradient(1.4px 1.4px at 34% 78%, rgba(184, 221, 255, 0.78), transparent 62%),
    radial-gradient(2px 2px at 46% 14%, rgba(255, 255, 255, 0.9), transparent 64%),
    radial-gradient(1.7px 1.7px at 56% 52%, rgba(171, 211, 255, 0.86), transparent 63%),
    radial-gradient(2px 2px at 68% 24%, rgba(255, 255, 255, 0.9), transparent 64%),
    radial-gradient(1.5px 1.5px at 78% 74%, rgba(180, 219, 255, 0.84), transparent 62%),
    radial-gradient(2.1px 2.1px at 88% 42%, rgba(255, 255, 255, 0.92), transparent 64%),
    radial-gradient(1.6px 1.6px at 95% 86%, rgba(178, 216, 255, 0.82), transparent 62%);
  background-size: 300px 300px;
  opacity: 0.72;
  filter: drop-shadow(0 0 4px rgba(210, 237, 255, 0.55));
  animation: star-drift 90s linear infinite, star-cluster-a 20s steps(1, end) infinite;
}

body::after {
  background-image:
    radial-gradient(1.1px 1.1px at 4% 12%, rgba(255, 255, 255, 0.78), transparent 58%),
    radial-gradient(1px 1px at 12% 58%, rgba(180, 220, 255, 0.68), transparent 58%),
    radial-gradient(1.2px 1.2px at 24% 86%, rgba(255, 255, 255, 0.72), transparent 58%),
    radial-gradient(1px 1px at 36% 24%, rgba(171, 214, 255, 0.68), transparent 58%),
    radial-gradient(1.2px 1.2px at 48% 66%, rgba(255, 255, 255, 0.72), transparent 58%),
    radial-gradient(1px 1px at 60% 40%, rgba(160, 208, 255, 0.66), transparent 58%),
    radial-gradient(1.2px 1.2px at 72% 84%, rgba(255, 255, 255, 0.74), transparent 58%),
    radial-gradient(1px 1px at 82% 14%, rgba(171, 215, 255, 0.68), transparent 58%),
    radial-gradient(1.2px 1.2px at 92% 56%, rgba(255, 255, 255, 0.7), transparent 58%),
    radial-gradient(1px 1px at 98% 30%, rgba(158, 207, 255, 0.64), transparent 58%);
  background-size: 180px 180px;
  opacity: 0.42;
  animation: star-drift 130s linear infinite reverse, star-cluster-b 26s steps(1, end) infinite;
  animation-delay: 0s, -8s;
}

.grid-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background: none;
  -webkit-mask-image: none;
  mask-image: none;
  opacity: 0;
}

.shell {
  position: relative;
  z-index: 2;
  width: min(960px, calc(100vw - 40px));
  margin: 48px auto;
  padding: 28px;
  border-radius: 24px;
  background: var(--card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.top {
  margin-bottom: 28px;
}

.kicker {
  margin: 0 0 8px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12px;
  font-weight: 600;
}

h1 {
  margin: 0;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.15;
}

.top h1 {
  position: relative;
  padding-bottom: 16px;
  margin-bottom: 12px;
}

.top h1::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: min(320px, 72vw);
  height: 2px;
  border-radius: 999px;
  background:
    linear-gradient(
      90deg,
      rgba(120, 206, 255, 0.2) 0%,
      rgba(130, 216, 255, 0.9) 20%,
      rgba(255, 255, 255, 0.95) 50%,
      rgba(130, 216, 255, 0.9) 80%,
      rgba(120, 206, 255, 0.2) 100%
    );
  background-size: 220% 100%;
  box-shadow: 0 0 10px rgba(150, 223, 255, 0.5);
  animation: title-line-scroll 4.2s linear infinite;
}

.subtitle {
  margin-top: 10px;
  color: var(--text-soft);
  font-size: 14px;
}

.content {
  line-height: 1.85;
  color: #d9e5ff;
}

.content h2,
.content h3 {
  margin-top: 28px;
  margin-bottom: 10px;
  line-height: 1.35;
}

/* Hide duplicated first markdown title under page H1 */
.content > h2:first-child {
  display: none;
}

.content h2 {
  font-size: clamp(20px, 2.5vw, 28px);
  color: #f1f6ff;
}

.content h3 {
  font-size: clamp(16px, 2vw, 21px);
  color: #d8e6ff;
}

.content p {
  margin: 10px 0;
}

.content ul {
  margin: 10px 0 10px 20px;
  padding: 0;
}

.content li {
  margin: 8px 0;
}

.content strong {
  color: #ffffff;
}

.content code {
  font-family: "Cascadia Mono", Consolas, monospace;
  padding: 2px 7px;
  border-radius: 6px;
  background: rgba(104, 225, 255, 0.1);
  color: #d5f7ff;
}

.footer {
  margin-top: 30px;
  padding-top: 18px;
  border-top: 1px solid rgba(115, 158, 255, 0.22);
  color: var(--text-soft);
  font-size: 13px;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

@keyframes star-drift {
  from {
    transform: translateY(0);
  }
  to {
    transform: translateY(-120px);
  }
}

@keyframes star-cluster-a {
  0%, 12%, 28%, 46%, 62%, 78%, 92%, 100% {
    opacity: 0.62;
    filter: brightness(0.96) drop-shadow(0 0 3px rgba(210, 237, 255, 0.42));
  }
  20%, 55%, 86% {
    opacity: 0.92;
    filter: brightness(1.35) drop-shadow(0 0 8px rgba(227, 245, 255, 0.9));
  }
  36%, 70% {
    opacity: 0.75;
    filter: brightness(1.08) drop-shadow(0 0 5px rgba(212, 238, 255, 0.62));
  }
}

@keyframes star-cluster-b {
  0%, 18%, 36%, 52%, 68%, 84%, 100% {
    opacity: 0.34;
    filter: brightness(0.9);
  }
  26%, 60%, 90% {
    opacity: 0.58;
    filter: brightness(1.2);
  }
  44%, 76% {
    opacity: 0.46;
    filter: brightness(1.02);
  }
}

@keyframes title-line-scroll {
  from {
    background-position: 0% 0;
  }
  to {
    background-position: 220% 0;
  }
}

@media (max-width: 700px) {
  .shell {
    width: calc(100vw - 20px);
    margin: 20px auto;
    padding: 20px;
    border-radius: 16px;
  }
}