/*
==============================================
CSS Variables & Base Styles
==============================================
*/
:root {
  --primary: #2c3e50;      /* 信頼のミッドナイトブルー */
  --secondary: #34495e;    /* 安定のダークグレー */
  --accent: #27ae60;       /* 希望のフォレストグリーン */
  --text: #2c3e50;         /* 可読性重視のダーク */
  --text-light: #7f8c8d;   /* サブテキスト */
  --bg-light: #ecf0f1;     /* セクション背景 */
  --white: #ffffff;        /* ベース背景 */
  --font-family: 'Noto Sans JP', sans-serif;
}

body {
  margin: 0;
  font-family: var(--font-family);
  font-size: 18px; /* デスクトップの基本文字サイズ */
  line-height: 1.8; /* 行間を調整 */
  color: var(--text);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
}

section {
    padding: 4rem 0;
}

section:nth-child(even) {
    background-color: var(--bg-light);
}

.section__title {
  font-size: 2.5rem;
  text-align: center;
  margin: 0 0 3rem 0;
  color: var(--primary);
  position: relative;
}

.section__title::after {
  content: '';
  width: 60px;
  height: 4px;
  background: var(--accent);
  display: block;
  margin: 1rem auto 0 auto;
}

/*
==============================================
1. HERO SECTION
==============================================
*/
.hero {
  background-color: var(--primary);
  color: var(--white);
  padding: 4rem 0;
}

.hero__container {
  display: grid;
  grid-template-columns: 1fr;
  align-items: center;
  gap: 40px;
  max-width: 1100px;
}

.hero__title {
  font-size: 2.8rem;
  line-height: 1.4;
  margin: 0 0 20px 0;
}

.hero__subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
  margin: 0 0 20px 0;
}

.hero__book-cover {
  width: 100%;
  max-width: 350px;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.3);
  margin: 0 auto;
  display: block;
}

/*
==============================================
2. PAIN POINTS (Checklist)
==============================================
*/
.pain-points {
  padding: 4rem 0;
}

.checklist {
  list-style: none;
  padding: 0;
  max-width: 700px;
  margin: 0 auto 30px auto;
}

.checklist__item {
  background-color: var(--white);
  padding: 1rem 1.5rem;
  margin-bottom: 1rem;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.07);
  display: flex;
  align-items: center;
}

.checklist__icon {
    margin-right: 1rem;
    font-size: 1.5rem;
}

.checklist__text {
    flex: 1;
}

.pain-points__message {
  text-align: center;
  font-size: 1.1rem;
  line-height: 1.8;
  max-width: 700px;
  margin: 2rem auto 0 auto;
}

/*
==============================================
3. VALUE PROPOSITIONS
==============================================
*/
.value-props__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem; /* カード間の余白を広げる */
}

.value-prop {
  position: relative;
  background: var(--white);
  padding: 2.5rem 2rem 2rem 2rem;
  border-radius: 8px;
  text-align: center;
  box-shadow: 0 5px 20px rgba(0,0,0,0.08);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.value-prop.animate-in {
    opacity: 1;
    transform: translateY(0);
}

.value-prop__number {
  position: absolute;
  top: -20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 1.5rem;
  box-shadow: 0 4px 10px rgba(39, 174, 96, 0.3);
}

.value-prop__icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.value-prop__title {
  font-size: 1.5rem;
  color: var(--primary);
  margin: 0 0 1rem 0;
}

.value-prop__description {
  color: var(--text-light);
  line-height: 1.7;
}

/*
==============================================
4. SOCIAL PROOF (Testimonials)
==============================================
*/
.social-proof {
    background-color: var(--bg-light);
}

.testimonial {
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    border-left: 5px solid var(--accent);
    box-shadow: 0 4px 15px rgba(0,0,0,0.07);
}

.testimonial__text {
    font-style: italic;
    margin: 0 0 1rem 0;
    font-size: 1.1rem;
}

.testimonial__author {
    text-align: right;
    color: var(--text-light);
    font-weight: bold;
}

/*
==============================================
5. TABLE OF CONTENTS
==============================================
*/
.toc__content {
  max-width: 700px;
  margin: 0 auto;
}

.toc__chapter {
  margin: 0 0 1rem 0;
  padding: 1.5rem;
  border-left: 4px solid var(--secondary);
  background-color: var(--white);
}

.toc__chapter h3 {
  font-size: 1.2rem;
  margin: 0 0 5px 0;
}

.toc__chapter p {
  margin: 0;
  color: var(--text-light);
}

/*
==============================================
6. CALL TO ACTION
==============================================
*/
.cta {
  padding: 4rem 0;
  text-align: center;
  background-color: var(--secondary);
  color: var(--white);
}

.cta__title {
  font-size: 2.2rem;
  color: var(--white);
  margin: 0 0 1.5rem 0;
}

.cta__title::after {
    background: var(--white);
}

.cta__description {
  max-width: 700px;
  margin: 0 auto 2.5rem auto;
  opacity: 0.9;
  line-height: 1.8;
}

.cta__button {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 1rem 2.5rem;
  border: none;
  border-radius: 50px;
  font-size: 1.2rem;
  font-weight: bold;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(39, 174, 96, 0.3);
}

.cta__button:hover {
  background: #2ecc71;
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(39, 174, 96, 0.4);
}

/*
==============================================
7. FOOTER
==============================================
*/
.footer {
  padding: 3rem 0;
  text-align: center;
}

.footer__content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.footer__info p {
    margin: 0;
}

.footer__copyright {
    color: var(--text-light);
    font-size: 0.9rem;
}

.social-icon {
    width: 24px;
    height: 24px;
    color: var(--secondary);
    transition: color 0.3s;
}

.social-icon:hover {
    color: var(--primary);
}

/*
==============================================
8. BACK TO TOP
==============================================
*/
.back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background-color: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  font-size: 1.5rem;
  line-height: 48px;
  text-align: center;
  cursor: pointer;
  display: none;
  opacity: 0.8;
  transition: opacity 0.3s, transform 0.3s;
}

.back-to-top:hover {
  opacity: 1;
  transform: scale(1.1);
}

/*
==============================================
AdSense Container
==============================================
*/
.ad-container {
    padding: 3rem 0;
    text-align: center;
}

/*
==============================================
Responsive Design
==============================================
*/
@media (min-width: 769px) {
  .hero__container {
    grid-template-columns: 1.2fr 1fr;
  }

  .hero__text-content {
    text-align: center;
  }

  .value-props__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
  }

  .footer__content {
    flex-direction: row;
    justify-content: space-between;
  }
}

@media (max-width: 768px) {
    body {
        font-size: 16px;
    }

    .section__title {
        font-size: 2rem;
    }

    .hero {
        padding: 2.5rem 0;
    }

    .hero__title {
        font-size: 2.2rem;
    }

    .value-prop {
        margin-bottom: 2.5rem;
    }

    .cta__button {
        width: 100%;
        padding: 1.2rem;
    }
}