* {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
  --bg: #0d1117;
  --surface: #111c2d;
  --text: #f9fafb;
  --muted: #cbd5f5;
  --primary: #5dd2a8;
  --primary-dark: #3fbf92;
  --accent: #7aa7ff;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 22px 50px rgba(15, 23, 42, 0.35);
  --radius-lg: 24px;
  --radius-md: 16px;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  background:
    radial-gradient(1200px 600px at 85% -10%, #20305a 0%, transparent 70%),
    radial-gradient(900px 500px at 10% 10%, #183244 0%, transparent 65%),
    var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

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

.no-break {
  white-space: nowrap;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  width: min(1120px, 92vw);
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(12, 17, 26, 0.85);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: grid;
  place-items: center;
  color: #0b1220;
  font-weight: 800;
}

.nav {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 15px;
  color: var(--muted);
}

.nav a:hover,
.nav a[aria-current="page"] {
  color: var(--text);
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 999px;
  font: inherit;
  font-size: 14px;
  cursor: pointer;
}

.hero {
  padding: 90px 0 60px;
}

.hero-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 36px;
  align-items: center;
}

.hero h1 {
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.25;
  margin: 18px 0;
  letter-spacing: 0;
}

.hero p {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.9;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(125, 211, 252, 0.12);
  color: #cfe6ff;
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
}

.cta-group {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.button.primary {
  background: var(--primary);
  color: #0b1220;
}

.button.primary:hover {
  background: var(--primary-dark);
}

.button.ghost {
  border-color: var(--border);
  color: var(--text);
}

.section {
  padding: 60px 0;
}

.section-title {
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.4;
  margin: 0 0 10px;
  letter-spacing: 0;
}

.section-subtitle {
  color: var(--muted);
  max-width: 700px;
  line-height: 1.9;
  margin: 0 0 32px;
}

.grid {
  display: grid;
  gap: 20px;
}

.grid.three {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.grid.two {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.card {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: 22px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.card h3 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 18px;
  line-height: 1.5;
}

.card p {
  color: var(--muted);
  line-height: 1.9;
  margin: 0;
}

.highlight {
  background: linear-gradient(135deg, rgba(93, 210, 168, 0.2), rgba(122, 167, 255, 0.15));
  border-radius: var(--radius-lg);
  padding: 32px;
  border: 1px solid rgba(125, 211, 252, 0.15);
}

.note {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.9;
}

.footer {
  margin-top: 60px;
  padding: 40px 0;
  border-top: 1px solid var(--border);
  background: #0b0f16;
}

.footer-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.footer-title {
  font-weight: 700;
  margin-bottom: 8px;
}

.footer a {
  color: var(--muted);
}

.footer a:hover {
  color: var(--text);
}

.page-header {
  padding: 60px 0 30px;
}

.page-header h1 {
  margin: 0 0 12px;
  font-size: clamp(30px, 4vw, 46px);
  line-height: 1.35;
  letter-spacing: 0;
}

.content {
  color: var(--muted);
  line-height: 1.95;
  font-size: 16px;
}

.content h2 {
  color: var(--text);
  margin-top: 32px;
  margin-bottom: 12px;
  font-size: 22px;
  line-height: 1.5;
}

.content a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (max-width: 860px) {
  .topbar-inner {
    padding: 14px 0;
  }

  .nav {
    position: absolute;
    top: 68px;
    inset-inline: 0;
    background: #0b101a;
    flex-direction: column;
    align-items: stretch;
    padding: 20px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
    display: none;
  }

  .nav[data-open="true"] {
    display: flex;
  }

  .nav a {
    padding: 8px 0;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .hero {
    padding-top: 56px;
  }

  .highlight {
    padding: 24px;
  }
}

@media (max-width: 520px) {
  .brand {
    gap: 8px;
    font-size: 14px;
  }

  .brand-mark {
    width: 36px;
    height: 36px;
  }

  .hero h1 {
    font-size: 34px;
  }

  .hero p {
    font-size: 16px;
  }

  .button {
    width: 100%;
  }
}