@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;600;700;800&family=Noto+Sans+JP:wght@400;500;700;900&display=swap');

/* --- デザインシステム変数 --- */
.yh-lp {
  --yh-ink: #0f172a;
  --yh-muted: #475569;
  --yh-line: #e2e8f0;
  --yh-paper: #ffffff;
  --yh-bg: #f8fafc;
  --yh-bg-accent: #f0fdf4;
  --yh-primary-gradient: linear-gradient(135deg, #047857 0%, #10b981 100%);
  --yh-primary: #10b981;
  --yh-primary-dark: #065f46;
  --yh-amber: #f59e0b;
  --yh-amber-light: #fef3c7;
  --yh-coral: #ef4444;
  --yh-blue: #0ea5e9;
  --yh-blue-light: #e0f2fe;
  
  color: var(--yh-ink);
  background: var(--yh-bg);
  font-family: 'Plus Jakarta Sans', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: 0.02em;
}

.yh-lp,
.yh-lp * {
  box-sizing: border-box;
}

.yh-lp a {
  color: inherit;
  text-decoration: none;
}

/* --- スムーズスクロール用 --- */
html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  background-color: #f8fafc;
}

/* --- スクロールフェードインアニメーション --- */
.yh-fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.yh-fade-in.yh-visible {
  opacity: 1;
  transform: translateY(0);
}

/* 遅延用クラス（必要に応じてJSで付与するか静的に指定） */
.yh-steps article:nth-child(2).yh-fade-in,
.yh-feature-list li:nth-child(even).yh-fade-in {
  transition-delay: 0.15s;
}

.yh-steps article:nth-child(3).yh-fade-in {
  transition-delay: 0.3s;
}

/* --- レイアウトコンテナ --- */
.yh-container {
  width: min(1200px, calc(100% - 32px));
  margin: 0 auto;
}

.yh-narrow {
  max-width: 800px;
}

/* --- スティッキーヘッダー --- */
.yh-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.7);
  padding: 16px 0;
  transition: padding 0.3s cubic-bezier(0.16, 1, 0.3, 1), background-color 0.3s ease, box-shadow 0.3s ease;
}

/* スクロール時の縮小ヘッダースタイル */
.yh-header--scrolled {
  padding: 10px 0;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.05);
}

.yh-header__wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.yh-header__logo {
  display: flex;
  flex-direction: column;
}

.yh-header__logo-main {
  font-size: 20px;
  font-weight: 800;
  color: var(--yh-primary-dark);
  letter-spacing: 0.05em;
  transition: font-size 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.yh-header--scrolled .yh-header__logo-main {
  font-size: 17px;
}

.yh-header__logo-sub {
  font-size: 10px;
  font-weight: 700;
  color: var(--yh-muted);
  transition: opacity 0.3s ease;
}

.yh-header--scrolled .yh-header__logo-sub {
  opacity: 0.8;
}

.yh-header__cta .yh-button {
  min-height: auto;
  padding: 8px 20px;
  font-size: 13px;
  border-radius: 9999px;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.2);
}

/* --- ヒーローセクション --- */
.yh-hero {
  padding: clamp(64px, 10vw, 112px) 0 clamp(80px, 12vw, 128px);
  background: linear-gradient(180deg, #f0fdf4 0%, #f8fafc 100%);
  position: relative;
  overflow: hidden;
}

.yh-hero::before {
  content: '';
  position: absolute;
  top: -15%;
  left: -5%;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.12) 0%, transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}

.yh-hero__grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.yh-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: #ffffff;
  border: 1px solid #d1fae5;
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 700;
  color: var(--yh-primary-dark);
  margin-bottom: 24px;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.05);
}

.yh-badge__ping {
  position: relative;
  display: flex;
  height: 8px;
  width: 8px;
}

.yh-badge__ping-circle {
  animation: yh-ping 1.5s cubic-bezier(0, 0, 0.2, 1) infinite;
  position: absolute;
  display: inline-flex;
  height: 100%;
  width: 100%;
  border-radius: 50%;
  background-color: var(--yh-primary);
  opacity: 0.75;
}

.yh-badge__ping-dot {
  position: relative;
  display: inline-flex;
  border-radius: 50%;
  height: 8px;
  width: 8px;
  background-color: var(--yh-primary);
}

@keyframes yh-ping {
  75%, 100% {
    transform: scale(2.5);
    opacity: 0;
  }
}

.yh-kicker {
  font-size: clamp(14px, 2vw, 16px);
  font-weight: 800;
  color: var(--yh-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 10px 0;
}

.yh-hero h1 {
  font-size: clamp(32px, 4.5vw, 52px);
  font-weight: 900;
  line-height: 1.2;
  color: var(--yh-ink);
  margin: 0 0 18px 0;
}

.yh-hero h1 span {
  background: var(--yh-primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.yh-hero__title-sub {
  font-size: clamp(18px, 2.2vw, 24px);
  font-weight: 800;
  color: var(--yh-muted);
  margin: 0 0 24px 0;
  border-left: 5px solid var(--yh-primary);
  padding-left: 14px;
}

.yh-hero__lead {
  font-size: clamp(16px, 2vw, 20px);
  font-weight: 700;
  line-height: 1.6;
  color: var(--yh-ink);
  margin: 0 0 18px 0;
}

.yh-hero__text {
  font-size: clamp(14px, 1.8vw, 16px);
  color: var(--yh-muted);
  margin: 0 0 32px 0;
}

/* --- ボタン ＆ CTA --- */
.yh-cta {
  margin-top: 24px;
}

.yh-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 56px;
  padding: 14px 36px;
  border-radius: 14px;
  font-size: 16px;
  font-weight: 800;
  line-height: 1.4;
  text-align: center;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  cursor: pointer;
  border: none;
}

.yh-button--primary {
  background: var(--yh-primary-gradient);
  color: #ffffff !important;
  box-shadow: 0 10px 25px rgba(16, 185, 129, 0.25);
  position: relative;
  overflow: hidden;
}

.yh-button--primary::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.25),
    transparent
  );
  transition: all 0.6s ease;
}

.yh-button--primary:hover::after {
  left: 100%;
}

.yh-button--primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 32px rgba(16, 185, 129, 0.35);
}

.yh-button--primary:active {
  transform: translateY(-1px);
}

.yh-cta__note {
  margin: 12px 0 0;
  color: var(--yh-muted);
  font-size: 13px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 6px;
}

.yh-cta__note::before {
  content: '🛡️';
}

/* --- 3D本風モックアップ --- */
.yh-book-wrap {
  perspective: 1000px;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.yh-book {
  position: relative;
  width: 270px;
  height: 375px;
  transform: rotateY(-20deg) rotateX(10deg);
  transform-style: preserve-3d;
  box-shadow: -10px 10px 30px rgba(0, 0, 0, 0.15);
  border-radius: 4px 18px 18px 4px;
  /* JSでの操作時はこのtransitionを一時的に切り替えるが、通常時の追従と戻りのために設定 */
  transition: transform 0.15s ease-out, box-shadow 0.3s ease;
}

.yh-book__cover {
  position: absolute;
  width: 100%;
  height: 100%;
  background: var(--yh-primary-gradient);
  border-radius: 4px 18px 18px 4px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 28px;
  color: #ffffff;
  overflow: hidden;
  z-index: 2;
  border: 1px solid rgba(255, 255, 255, 0.12);
  backface-visibility: hidden;
}

.yh-book__cover::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 14px;
  height: 100%;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.2) 0%, transparent 100%);
  border-radius: 4px 0 0 4px;
}

.yh-book__badge {
  align-self: flex-start;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.05em;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.yh-book__title-wrap {
  margin-top: auto;
}

.yh-book__title-sub {
  font-size: 13px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 8px;
}

.yh-book__title {
  font-size: 26px;
  font-weight: 900;
  line-height: 1.3;
  margin: 0;
  text-shadow: 0 2px 4px rgba(0,0,0,0.15);
}

.yh-book__author {
  font-size: 12px;
  font-weight: 600;
  margin-top: 20px;
  color: rgba(255, 255, 255, 0.7);
}

.yh-book__page {
  position: absolute;
  top: 3px;
  right: -8px;
  width: 100%;
  height: 98%;
  background: #f8fafc;
  border-radius: 0 18px 18px 0;
  z-index: 1;
  box-shadow: 3px 3px 6px rgba(0,0,0,0.08);
  border: 1px solid var(--yh-line);
}

/* --- セクション共通 --- */
.yh-section {
  padding: clamp(64px, 10vw, 100px) 0;
  background: var(--yh-paper);
  border-bottom: 1px solid var(--yh-line);
  position: relative;
}

.yh-section--quiet {
  background: var(--yh-bg);
}

.yh-section--accent {
  background: var(--yh-bg-accent);
}

.yh-section__head {
  max-width: 800px;
  margin: 0 auto 48px;
  text-align: center;
}

.yh-section__label {
  display: inline-block;
  font-size: 12px;
  font-weight: 800;
  color: var(--yh-primary);
  background: var(--yh-bg-accent);
  padding: 4px 14px;
  border-radius: 8px;
  margin-bottom: 16px;
  letter-spacing: 0.1em;
}

.yh-section h2 {
  font-size: clamp(24px, 3.5vw, 36px);
  font-weight: 800;
  line-height: 1.35;
  color: var(--yh-ink);
  margin: 0 0 16px 0;
}

.yh-section__head p {
  font-size: 16px;
  color: var(--yh-muted);
  margin: 0;
}

/* --- チェックリスト (問題提起) --- */
.yh-checklist {
  display: grid;
  gap: 12px;
  margin: 32px 0;
  padding: 0;
  list-style: none;
}

.yh-checklist li {
  position: relative;
  padding: 18px 24px 18px 54px;
  border: 1px solid var(--yh-line);
  border-radius: 14px;
  background: #ffffff;
  color: var(--yh-ink);
  font-weight: 700;
  font-size: 15px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.02);
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.yh-checklist li:hover {
  border-color: #fca5a5;
  background: #fff5f5;
  transform: translateX(4px);
}

.yh-checklist li::before {
  content: "⚠️";
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 16px;
}

.yh-callout {
  margin: 36px 0;
  padding: 24px 36px;
  border-left: 6px solid var(--yh-primary);
  border-radius: 0 18px 18px 0;
  background: var(--yh-bg-accent);
  font-size: clamp(16px, 2.2vw, 20px);
  font-weight: 800;
  color: var(--yh-primary-dark) !important;
  box-shadow: 0 10px 25px rgba(16, 185, 129, 0.05);
}

/* --- プロミス・ステップ --- */
.yh-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.yh-card {
  padding: 36px;
  border: 1px solid var(--yh-line);
  border-radius: 20px;
  background: var(--yh-paper);
  box-shadow: 0 8px 30px rgba(0,0,0,0.03);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
}

.yh-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(16, 185, 129, 0.08);
  border-color: rgba(16, 185, 129, 0.3);
}

.yh-card__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--yh-primary-gradient);
  color: #ffffff;
  font-weight: 800;
  font-size: 16px;
  margin-bottom: 24px;
}

.yh-card h3 {
  margin: 0 0 12px 0;
  color: var(--yh-ink);
  font-size: 20px;
  font-weight: 800;
}

.yh-card p {
  margin: 0;
  color: var(--yh-muted);
  font-size: 14.5px;
  line-height: 1.65;
}

/* --- ベネフィット 2カラム --- */
.yh-two-col {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 48px;
  align-items: start;
}

.yh-feature-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.yh-feature-list li {
  position: relative;
  padding: 16px 20px 16px 48px;
  border-radius: 12px;
  background: #ffffff;
  color: var(--yh-ink);
  font-weight: 700;
  font-size: 14px;
  border: 1px solid var(--yh-line);
  box-shadow: 0 4px 12px rgba(0,0,0,0.02);
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.yh-feature-list li:hover {
  border-color: rgba(16, 185, 129, 0.3);
  box-shadow: 0 8px 20px rgba(16, 185, 129, 0.05);
  transform: translateY(-2px);
}

.yh-feature-list li::before {
  content: "✅";
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 15px;
}

.yh-recommend {
  min-width: 0;
}

.yh-recommend .yh-checklist li::before {
  content: "👤";
}

.yh-recommend .yh-checklist li:hover {
  border-color: rgba(16, 185, 129, 0.3);
  background: #ffffff;
  transform: translateX(4px);
}

.yh-note-box,
.yh-template-line {
  margin: 24px 0 0;
  padding: 20px;
  border-radius: 14px;
  border: 1px solid #bae6fd;
  background: #f0f9ff;
  color: var(--yh-ink) !important;
  font-weight: 700;
  font-size: 14px;
}

/* --- 目次アコーディオン --- */
.yh-chapters {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 800px;
  margin: 0 auto;
}

.yh-chapters details {
  background: #ffffff;
  border: 1px solid var(--yh-line);
  border-radius: 16px;
  overflow: hidden;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.yh-chapters details[open] {
  border-color: rgba(16, 185, 129, 0.4);
  box-shadow: 0 10px 30px rgba(16, 185, 129, 0.06);
}

.yh-chapters summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 800;
  list-style: none;
  user-select: none;
  font-size: 16px;
  outline: none;
}

.yh-chapters summary::-webkit-details-marker {
  display: none;
}

.yh-chapters__summary-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.yh-chapters__summary-num {
  font-size: 11px;
  font-weight: 800;
  color: var(--yh-primary);
  background: var(--yh-bg-accent);
  padding: 4px 10px;
  border-radius: 6px;
}

.yh-chapters__summary-arrow {
  width: 18px;
  height: 18px;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  color: var(--yh-muted);
}

.yh-chapters details[open] .yh-chapters__summary-arrow {
  transform: rotate(180deg);
  color: var(--yh-primary);
}

/* JSのぬるっとスライド用CSS */
.yh-chapters__content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  background: #fafafb;
  border-top: 1px solid transparent;
}

.yh-chapters details[open] .yh-chapters__content {
  border-top-color: #f1f5f9;
}

.yh-chapters__content-inner {
  padding: 20px 24px;
  font-size: 14.5px;
  color: var(--yh-muted);
  line-height: 1.75;
}

/* --- Q&Aセクション --- */
.yh-qa-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 800px;
  margin: 0 auto;
}

.yh-qa-item {
  background: #ffffff;
  border: 1px solid var(--yh-line);
  border-radius: 16px;
  padding: 24px;
}

.yh-qa-item__q {
  font-size: 16px;
  font-weight: 800;
  color: var(--yh-ink);
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin-bottom: 12px;
}

.yh-qa-item__q::before {
  content: 'Q';
  color: var(--yh-primary);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 900;
  font-size: 18px;
}

.yh-qa-item__a {
  font-size: 14.5px;
  color: var(--yh-muted);
  display: flex;
  gap: 12px;
  align-items: flex-start;
  line-height: 1.75;
}

.yh-qa-item__a::before {
  content: 'A';
  color: var(--yh-amber);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 900;
  font-size: 18px;
}

/* --- ゆはなメッセージセクション --- */
.yh-author {
  background: #1e293b;
  color: #ffffff;
  border-bottom: none;
}

.yh-author .yh-section__label {
  background: rgba(255, 255, 255, 0.1);
  color: #a7f3d0;
}

.yh-author h2 {
  color: #ffffff;
}

.yh-author__box {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 48px;
  align-items: center;
}

.yh-author__text {
  color: #cbd5e1 !important;
  font-size: 16px;
  line-height: 1.8;
}

.yh-author__text p {
  margin-bottom: 20px;
}

.yh-author__text p:last-child {
  margin-bottom: 0;
}

/* --- ファイナルセクション --- */
.yh-final {
  padding: clamp(64px, 10vw, 112px) 0;
  background: linear-gradient(180deg, #f8fafc 0%, #f0fdf4 100%);
  text-align: center;
}

.yh-final__box {
  max-width: 800px;
  margin: 0 auto;
}

.yh-final h2 {
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 16px;
}

.yh-final p {
  color: var(--yh-muted);
  margin-bottom: 32px;
}

.yh-cta--center {
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* --- フッター --- */
.yh-footer {
  background: #0f172a;
  color: #64748b;
  font-size: 12px;
  text-align: center;
  padding: 36px 0;
  border-top: 1px solid #1e293b;
}

/* --- メディアクエリ（レスポンシブ） --- */
@media (max-width: 1024px) {
  .yh-hero__grid,
  .yh-two-col,
  .yh-author__box {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .yh-book-wrap {
    order: -1; /* モバイルではモックアップを上部に配置 */
    padding: 10px 0;
  }
  
  .yh-book {
    /* モバイルでは自動で正面を向かせる */
    transform: rotateY(0deg) rotateX(0deg) !important;
  }
}

@media (max-width: 768px) {
  .yh-header__logo-sub {
    display: none; /* スマホではヘッダーのサブテキストを非表示にしてスリム化 */
  }
  
  .yh-steps {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .yh-feature-list {
    grid-template-columns: 1fr;
  }
  
  .yh-card {
    padding: 24px;
  }
  
  .yh-feature-list li,
  .yh-checklist li {
    font-size: 14.5px;
    padding: 14px 16px 14px 44px;
  }
  
  .yh-callout {
    padding: 20px 24px;
  }
}

@media (max-width: 480px) {
  .yh-header__logo-main {
    font-size: 16px;
  }
  
  .yh-header__cta .yh-button {
    padding: 6px 16px;
    font-size: 12px;
  }
  
  .yh-button {
    width: 100%; /* スマホではCTAボタンを全幅に */
    min-height: 58px; /* タップしやすさの向上 */
  }
  
  .yh-chapters summary {
    padding: 16px;
    font-size: 14px;
  }
  
  .yh-chapters__content-inner {
    padding: 16px;
    font-size: 13.5px;
  }
}