:root {
  --bg: #0a0f1f;
  --bg2: #111a33;
  --surface: rgba(255, 255, 255, 0.06);
  --surface-strong: rgba(255, 255, 255, 0.1);
  --border: rgba(255, 255, 255, 0.12);
  --text: #f5f7ff;
  --muted: #a9b3d1;
  --accent: #7c9cff;
  --accent2: #5eead4;
  --accent3: #ff8bd6;
  --shadow: 0 20px 50px rgba(0, 0, 0, 0.35);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --container: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family:
    "Inter",
    "Noto Sans JP",
    "Hiragino Sans",
    "Yu Gothic",
    sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(124, 156, 255, 0.18), transparent 30%),
    radial-gradient(circle at top right, rgba(255, 139, 214, 0.12), transparent 28%),
    radial-gradient(circle at bottom center, rgba(94, 234, 212, 0.08), transparent 26%),
    linear-gradient(180deg, #0a0f1f 0%, #0c1327 40%, #0a1020 100%);
  line-height: 1.75;
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    linear-gradient(rgba(255,255,255,0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.015) 1px, transparent 1px);
  background-size: 30px 30px;
  pointer-events: none;
  opacity: 0.35;
  z-index: 0;
}

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

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

.container {
  width: min(var(--container), calc(100% - 32px));
  margin-inline: auto;
  position: relative;
  z-index: 1;
}

.container.narrow {
  width: min(860px, calc(100% - 32px));
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: rgba(8, 12, 24, 0.65);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.site-header .container {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 20px 0 18px;
}

.site-header h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1;
  font-weight: 900;
  letter-spacing: 0.04em;
  display: flex;
  align-items: center;
  gap: 10px;
  text-shadow:
    0 0 18px rgba(124, 156, 255, 0.22),
    0 0 34px rgba(94, 234, 212, 0.08);
}

.site-subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.site-nav,
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.site-nav a,
.footer-nav a {
  padding: 10px 16px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid transparent;
  color: #eef2ff;
  font-size: 0.95rem;
  transition: 0.25s ease;
}

.site-nav a:hover,
.footer-nav a:hover {
  transform: translateY(-1px);
  background: rgba(124, 156, 255, 0.14);
  border-color: rgba(124, 156, 255, 0.28);
  box-shadow: 0 8px 24px rgba(124, 156, 255, 0.14);
}

main {
  position: relative;
  z-index: 1;
}

section {
  padding: 72px 0;
}

.hero {
  padding-top: 84px;
  padding-bottom: 54px;
}

.hero .container {
  position: relative;
}

.hero .container::before {
  content: "";
  position: absolute;
  inset: -24px -20px auto;
  height: 100%;
  background:
    linear-gradient(135deg, rgba(124, 156, 255, 0.14), rgba(255, 139, 214, 0.08) 55%, rgba(94, 234, 212, 0.1));
  filter: blur(60px);
  z-index: -1;
  opacity: 0.9;
}

.hero h2,
.features h2,
.games-section h2,
.about-site h2,
.policy-note h2 {
  margin: 0 0 18px;
  font-size: clamp(1.8rem, 3vw, 2.7rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.hero p,
.about-site p,
.policy-note p,
.section-lead {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 1.03rem;
}

.hero p:last-child,
.about-site p:last-child,
.policy-note p:last-child,
.section-lead:last-child {
  margin-bottom: 0;
}

.features {
  padding-top: 26px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 28px;
}

.feature-card {
  position: relative;
  padding: 24px;
  border-radius: var(--radius-lg);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.04));
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: linear-gradient(180deg, var(--accent), var(--accent2), var(--accent3));
  border-radius: 999px;
}

.feature-card h3 {
  margin: 0 0 10px;
  font-size: 1.1rem;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.75;
}

.games-section {
  padding-top: 56px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 26px;
}

.card {
  position: relative;
  display: block;
  min-height: 240px;
  padding: 26px 22px 22px;
  border-radius: var(--radius-xl);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.05));
  border: 1px solid rgba(255,255,255,0.1);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition:
    transform 0.28s ease,
    box-shadow 0.28s ease,
    border-color 0.28s ease,
    background 0.28s ease;
  isolation: isolate;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at top right, rgba(124, 156, 255, 0.16), transparent 34%),
    radial-gradient(circle at bottom left, rgba(94, 234, 212, 0.12), transparent 32%);
  z-index: -1;
}

.card::after {
  content: "";
  position: absolute;
  inset: auto -30% -45% auto;
  width: 180px;
  height: 180px;
  background: radial-gradient(circle, rgba(255,255,255,0.12), transparent 68%);
  opacity: 0.3;
  transform: rotate(18deg);
  pointer-events: none;
}

.card:hover {
  transform: translateY(-8px) scale(1.01);
  border-color: rgba(124, 156, 255, 0.35);
  box-shadow:
    0 24px 60px rgba(0, 0, 0, 0.42),
    0 0 0 1px rgba(124, 156, 255, 0.08);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.11), rgba(255,255,255,0.06));
}

.card .icon {
  width: 66px;
  height: 66px;
  border-radius: 20px;
  display: grid;
  place-items: center;
  font-size: 2rem;
  margin-bottom: 18px;
  background:
    linear-gradient(135deg, rgba(124, 156, 255, 0.24), rgba(94, 234, 212, 0.18));
  border: 1px solid rgba(255,255,255,0.12);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.08),
    0 10px 24px rgba(0, 0, 0, 0.18);
}

.card h3,
.card h2 {
  margin: 0 0 10px;
  font-size: 1.18rem;
  line-height: 1.35;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.75;
}

.about-site,
.policy-note {
  padding-top: 48px;
}

.about-site .container,
.policy-note .container {
  padding: 34px;
  border-radius: var(--radius-xl);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.04));
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.ad-section {
  padding-top: 46px;
  padding-bottom: 80px;
}

.ad-label {
  margin: 0 0 12px;
  color: #c7d2fe;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  opacity: 0.85;
}

.ad-wrap {
  padding: 18px;
  border-radius: 22px;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.04));
  border: 1px solid rgba(255,255,255,0.1);
  box-shadow: var(--shadow);
}

.ad-wrap ins {
  border-radius: 14px;
  overflow: hidden;
}

.site-footer {
  position: relative;
  z-index: 1;
  padding: 28px 0 42px;
  border-top: 1px solid rgba(255,255,255,0.08);
  background: rgba(7, 10, 20, 0.7);
  backdrop-filter: blur(10px);
}

.site-footer .container {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.site-footer p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

/* hover sparkle */
.card:hover .icon {
  transform: translateY(-2px) rotate(-2deg);
  transition: transform 0.28s ease;
}

/* focus */
a:focus-visible {
  outline: 2px solid var(--accent2);
  outline-offset: 3px;
  border-radius: 12px;
}

/* responsive */
@media (max-width: 1080px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 720px) {
  section {
    padding: 56px 0;
  }

  .hero {
    padding-top: 56px;
    padding-bottom: 32px;
  }

  .site-header .container {
    padding: 16px 0 14px;
  }

  .site-header h1 {
    font-size: 2rem;
  }

  .site-nav,
  .footer-nav {
    gap: 8px;
  }

  .site-nav a,
  .footer-nav a {
    padding: 9px 13px;
    font-size: 0.88rem;
  }

  .feature-grid,
  .grid {
    grid-template-columns: 1fr;
  }

  .card {
    min-height: auto;
    padding: 22px 18px 20px;
    border-radius: 22px;
  }

  .card .icon {
    width: 58px;
    height: 58px;
    font-size: 1.7rem;
    border-radius: 18px;
  }

  .about-site .container,
  .policy-note .container,
  .ad-wrap {
    padding: 20px;
  }

  .hero h2,
  .features h2,
  .games-section h2,
  .about-site h2,
  .policy-note h2 {
    font-size: 1.7rem;
  }

  .hero p,
  .about-site p,
  .policy-note p,
  .section-lead,
  .feature-card p,
  .card p {
    font-size: 0.96rem;
  }
}

@media (max-width: 420px) {
  .container,
  .container.narrow {
    width: min(100% - 20px, var(--container));
  }

  .site-header h1 {
    font-size: 1.8rem;
  }

  .card h3,
  .card h2 {
    font-size: 1.08rem;
  }
}

.site-header.is-scrolled {
  background: rgba(8, 12, 24, 0.88);
  border-bottom: 1px solid rgba(124, 156, 255, 0.16);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.22);
}

.card {
  transform-style: preserve-3d;
  will-change: transform;
}