:root {
  --bg: #080D1A;
  --surface: rgba(255, 255, 255, 0.035);
  --surface-hover: rgba(255, 255, 255, 0.06);
  --surface-card: #0D1527;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --text-desc: #CBD5E1;
  --accent: #F59E0B;
  --accent-hover: #D97706;
  --accent-light: #FDE68A;
  --accent-bg: rgba(245, 158, 11, 0.12);
  --accent-border: rgba(245, 158, 11, 0.28);
  --line-green: #06C755;
  --line-hover: #05B34C;
  --font-sans: "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  color-scheme: dark;
  background-color: var(--bg);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  color: var(--text-desc);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 上部の淡いシアターグロー */
.bg-glow {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: min(100%, 800px);
  height: 380px;
  background: radial-gradient(circle at 50% 0%, rgba(245, 158, 11, 0.08) 0%, rgba(13, 21, 39, 0) 70%);
  pointer-events: none;
  z-index: 0;
}

.layout {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1040px;
  margin-inline: auto;
  padding: 12px 14px 48px;
}

/* タイポグラフィ基本 */
h1, h2, h3, p, ol, ul {
  margin: 0;
  overflow-wrap: anywhere;
}

/* 2-1. ヘッダー（ファーストビューで動画を高く保つため極限までコンパクト） */
.header {
  text-align: center;
  padding: 4px 4px 10px;
}

.header__badge {
  display: inline-flex;
  margin-bottom: 6px;
}

.badge {
  display: inline-flex;
  align-items: center;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 3px 9px;
  border-radius: 999px;
}

.badge--subtle {
  background: var(--accent-bg);
  color: var(--accent-light);
  border: 1px solid var(--accent-border);
}

.badge--accent {
  background: var(--accent-bg);
  color: var(--accent-light);
  border: 1px solid var(--accent-border);
}

.header__title {
  color: var(--text-primary);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.header__subtitle {
  color: var(--text-secondary);
  font-size: 0.8125rem;
  line-height: 1.45;
  margin-bottom: 6px;
}

.header__author {
  color: var(--text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
}

/* 2-2. 動画プレイヤー */
.section--player {
  margin-top: 4px;
}

.player-wrapper {
  width: 100%;
  background: var(--surface-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  overflow: hidden;
  box-shadow: 0 16px 36px -10px rgba(0, 0, 0, 0.6);
}

.player {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background-color: #0b111e;
  overflow: hidden;
}

.player iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* 空状態（公開準備中）のシアター風UI */
.player__standby {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: radial-gradient(circle at 50% 50%, #111a2e 0%, #080d18 100%);
  color: var(--text-secondary);
  user-select: none;
}

.standby-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  filter: drop-shadow(0 0 12px rgba(245, 158, 11, 0.3));
}

.standby-text {
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--text-primary);
}

/* セクション共通 */
.section {
  margin-top: 36px;
}

.section-head {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.section-icon {
  color: var(--accent);
  flex-shrink: 0;
}

.section-title {
  color: var(--text-primary);
  font-size: 1.1875rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* 2-3. 特典エリア */
.benefits-grid {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.card__header {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}

.card__title {
  color: var(--text-primary);
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.4;
}

.card__desc {
  color: var(--text-desc);
  font-size: 0.875rem;
  line-height: 1.65;
}

.card__note {
  color: var(--text-muted);
  font-size: 0.75rem;
  line-height: 1.5;
}

.card__action {
  margin-top: 4px;
}

/* ステップフロー */
.steps-flow {
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
}

.steps-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.steps-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-primary);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 999px;
  background: var(--accent-bg);
  border: 1px solid var(--accent-border);
  color: var(--accent-light);
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content {
  flex: 1;
}

/* 注意カード */
.card-notice {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 10px 12px;
  background: rgba(245, 158, 11, 0.05);
  border: 1px solid rgba(245, 158, 11, 0.18);
  border-radius: var(--radius-sm);
}

.card-notice__icon {
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 1px;
}

.card-notice__text {
  font-size: 0.75rem;
  color: #E2E8F0;
  line-height: 1.55;
}

/* ボタン */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  min-height: 50px;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 700;
  text-decoration: none;
  text-align: center;
  line-height: 1.4;
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.1s ease, box-shadow 0.15s ease;
  border: 1px solid transparent;
}

.btn:active {
  transform: scale(0.985);
}

.btn__icon {
  flex-shrink: 0;
}

.btn--primary {
  background: var(--accent);
  color: #0F172A;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.25);
}

.btn--primary:hover {
  background: var(--accent-hover);
  color: #0F172A;
  box-shadow: 0 6px 18px rgba(245, 158, 11, 0.35);
}

.btn--line {
  background: var(--line-green);
  color: #FFFFFF;
  box-shadow: 0 4px 14px rgba(6, 199, 85, 0.25);
}

.btn--line:hover {
  background: var(--line-hover);
  box-shadow: 0 6px 18px rgba(6, 199, 85, 0.35);
}

/* 2-4. 第1回の重要ポイント */
.points-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.point-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.15s ease;
}

.point-item:hover {
  border-color: var(--border-strong);
}

.point-item[open] {
  border-color: rgba(245, 158, 11, 0.25);
  background: rgba(255, 255, 255, 0.045);
}

.point-item__summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  user-select: none;
}

.point-item__summary::-webkit-details-marker {
  display: none;
}

.point-item__num {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--accent);
  flex-shrink: 0;
  opacity: 0.9;
}

.point-item__title {
  flex: 1;
  color: var(--text-primary);
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.45;
}

.point-item__chevron {
  color: var(--text-muted);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s ease, color 0.15s ease;
}

.point-item[open] .point-item__chevron {
  transform: rotate(180deg);
  color: var(--accent);
}

.point-item__body {
  padding: 0 16px 16px 16px;
  color: var(--text-desc);
  font-size: 0.875rem;
  line-height: 1.65;
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  padding-top: 12px;
}

/* 2-5. フッター */
.footer {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.75rem;
  line-height: 1.8;
}

.footer__publisher {
  margin-bottom: 4px;
}

.footer__link {
  color: var(--text-secondary);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.15s ease;
}

.footer__link:hover {
  color: var(--text-primary);
}

/* アクセシビリティ・フォーカス */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* デスクトップ対応（幅768px〜、1280×800 最適化） */
@media (min-width: 768px) {
  .layout {
    padding: 24px 24px 64px;
  }

  .header {
    padding: 8px 12px 20px;
  }

  .header__title {
    font-size: 1.75rem;
    line-height: 1.35;
    margin-bottom: 8px;
  }

  .header__subtitle {
    font-size: 0.9375rem;
    margin-bottom: 8px;
  }

  .header__author {
    font-size: 0.8125rem;
  }

  .player-wrapper {
    max-width: 920px;
    margin-inline: auto;
    border-radius: var(--radius-lg);
  }

  .section {
    margin-top: 48px;
  }

  .section-title {
    font-size: 1.3125rem;
  }

  .benefits-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    align-items: stretch;
  }

  .card {
    padding: 24px 20px;
  }

  .card--notion {
    display: flex;
    flex-direction: column;
  }

  .card--notion .card__action {
    margin-top: auto;
  }

  .points-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
  }

  .point-item {
    display: flex;
    flex-direction: column;
  }

  .point-item__body {
    flex: 1;
  }
}

/* ユーザーのモーション軽減設定 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}