:root {
  --bg: #0b1020;
  --surface: #121a33;
  --surface-2: #1b2750;
  --text: #e8ecff;
  --muted: #b3bddf;
  --accent: #6ea8fe;
  --accent-2: #8f7bff;
  --border: #2b3a6e;
  --ok: #35d49a;
  --radius: 16px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Inter', 'Noto Sans JP', 'Hiragino Sans', 'Yu Gothic', sans-serif;
  background: radial-gradient(circle at 20% 0%, #18274f 0%, var(--bg) 45%);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.7;
}

.topbar {
  max-width: 1080px;
  margin: 0 auto;
  padding: 24px 20px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.topbar h1 {
  font-size: 1.1rem;
}

.lang-switcher {
  display: flex;
  gap: 8px;
}

.lang-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 999px;
  padding: 6px 14px;
  cursor: pointer;
}

.lang-btn.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-color: transparent;
  color: #050811;
  font-weight: 700;
}

.deck-wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 12px 20px 32px;
}

.deck-head {
  margin-bottom: 22px;
}

.kicker {
  color: var(--ok);
  font-size: 0.9rem;
  font-weight: 700;
}

.deck-head h2 {
  font-size: clamp(1.4rem, 2.8vw, 2.2rem);
  margin-top: 6px;
}

.deck-note {
  color: var(--muted);
  margin-top: 8px;
}

.slide-shell {
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.03), rgba(255, 255, 255, 0));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  min-height: 390px;
  padding: 28px;
}

.slide {
  display: none;
}

.slide.active {
  display: block;
  animation: fade 0.25s ease;
}

.badge {
  display: inline-block;
  font-size: 0.78rem;
  color: #070d1e;
  background: linear-gradient(135deg, #a2ccff, #baa9ff);
  border-radius: 999px;
  padding: 5px 10px;
  font-weight: 700;
  margin-bottom: 10px;
}

.slide h3 {
  font-size: clamp(1.2rem, 2vw, 1.6rem);
  margin-bottom: 12px;
}

.slide ul,
.slide ol {
  margin-left: 20px;
  color: var(--muted);
}

.slide li + li {
  margin-top: 10px;
}

.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.compare-grid h4 {
  margin-bottom: 8px;
}

.deck-controls {
  margin-top: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.nav-btn {
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
  border-radius: 10px;
  padding: 10px 16px;
  cursor: pointer;
}

.dots {
  display: flex;
  gap: 8px;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: none;
  background: #55608d;
  cursor: pointer;
}

.dot.active {
  background: #d6ddff;
}

footer {
  text-align: center;
  color: var(--muted);
  padding: 14px 20px 26px;
  font-size: 0.88rem;
}

@keyframes fade {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

[data-i18n] {
  transition: opacity 0.15s ease;
}

.lang-transitioning [data-i18n] {
  opacity: 0;
}

@media (max-width: 760px) {
  .topbar {
    flex-direction: column;
    align-items: flex-start;
  }

  .slide-shell {
    min-height: 430px;
    padding: 20px;
  }

  .compare-grid {
    grid-template-columns: 1fr;
  }
}