:root {
  --bg: linear-gradient(135deg,#eef2ff 0%,#f7f9ff 50%,#ffffff 100%);
  --bg-accent: radial-gradient(circle at 25% -10%,rgba(99,102,241,0.18),transparent 60%),
                radial-gradient(circle at 80% 0,rgba(79,70,229,0.12),transparent 65%);
  --text: #0f172a;
  --muted: #64748b;
  --primary: #2563eb;
  --card: rgba(255,255,255,0.92);
  --border: rgba(148,163,184,0.28);
  --shadow: 0 32px 60px -36px rgba(15,23,42,0.48);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: "Noto Sans SC", system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: var(--bg-accent);
  pointer-events: none;
  z-index: -1;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

header.site-head {
  padding: 28px clamp(24px, 4vw, 48px);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  background: rgba(15,23,42,0.86);
  color: #e2e8f0;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: 0 14px 32px -24px rgba(15,23,42,0.85);
}
header .brand {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
header .brand .logo {
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 800;
  letter-spacing: 0.08em;
}
header .brand .tagline {
  margin: 0;
  font-size: 14px;
  opacity: 0.8;
}
header nav {
  display: flex;
  align-items: center;
  gap: 14px;
}
header nav a {
  color: #e2e8f0;
  font-size: 15px;
  padding: 8px 14px;
  border: 1px solid rgba(148,163,184,0.28);
  border-radius: 999px;
  transition: background 0.2s ease, color 0.2s ease;
}
header nav a:hover {
  background: rgba(37,99,235,0.2);
  color: #fff;
}

main {
  width: min(960px, 92vw);
  margin: clamp(32px, 6vw, 64px) auto;
  display: flex;
  flex-direction: column;
  gap: clamp(24px, 4vw, 48px);
}

.hero-card {
  background: var(--card);
  border: 1px solid rgba(255,255,255,0.6);
  border-radius: 28px;
  padding: clamp(28px, 4vw, 48px);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}
.hero-card h1 {
  margin: 0 0 12px;
  font-size: clamp(28px, 5vw, 38px);
}
.hero-card p {
  margin: 0;
  font-size: 16px;
  color: var(--muted);
  line-height: 1.7;
}

.section-card {
  background: rgba(255,255,255,0.85);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: clamp(24px, 3vw, 36px);
  display: flex;
  flex-direction: column;
  gap: 16px;
  box-shadow: 0 20px 48px -32px rgba(15,23,42,0.35);
}
.section-card h2 {
  margin: 0;
  font-size: clamp(22px, 3.2vw, 28px);
  color: var(--primary);
}
.section-card p,
.section-card li {
  margin: 0;
  font-size: 15px;
  color: var(--muted);
  line-height: 1.75;
}
.section-card ul,
.section-card ol {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 8px;
}

aside.notice {
  border-left: 4px solid var(--primary);
  padding: 18px 22px;
  border-radius: 18px;
  background: rgba(37,99,235,0.08);
  color: var(--muted);
  font-size: 14px;
}

footer.site-foot {
  margin-top: auto;
  padding: 28px clamp(24px, 4vw, 48px);
  background: rgba(15,23,42,0.92);
  color: #e2e8f0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
footer .links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}
footer .links a {
  color: #cbd5f5;
  font-size: 14px;
}
footer .links a:hover { color: #fff; }
footer small { color: rgba(226,232,240,0.75); }

@media (max-width: 640px) {
  header.site-head {
    flex-direction: column;
    align-items: flex-start;
  }
  header nav {
    flex-wrap: wrap;
    justify-content: flex-start;
  }
}