/* ===== RESET & BASE ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-accent: #10b981;
  --color-text: #111827;
  --color-text-secondary: #6b7280;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-bg-dark: #1e293b;
  --color-border: #e5e7eb;
  --color-card: #ffffff;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.08);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 72px 0;
}

.section:nth-child(even):not(.strengths) {
  background: var(--color-bg-alt);
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: 40px;
  letter-spacing: -0.02em;
}

.section-sub {
  text-align: center;
  color: var(--color-text-secondary);
  margin-top: -28px;
  margin-bottom: 40px;
  font-size: 0.95rem;
}

/* ===== BUTTONS ===== */
.btn-primary {
  display: inline-block;
  background: var(--color-primary);
  color: #fff;
  text-decoration: none;
  padding: 14px 32px;
  border-radius: 9999px;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  transition: background 0.2s, transform 0.1s;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
}

.btn-large {
  font-size: 1.15rem;
  padding: 18px 48px;
}

/* ===== HERO ===== */
.hero {
  background: linear-gradient(135deg, #1e293b 0%, #2563eb 100%);
  color: #fff;
  text-align: center;
  padding: 100px 20px 80px;
}

.app-badge {
  display: inline-block;
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 9999px;
  padding: 4px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 20px;
}

.app-name {
  font-size: clamp(2.5rem, 8vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  margin-bottom: 16px;
}

.tagline {
  font-size: clamp(1.1rem, 3vw, 1.35rem);
  opacity: 0.9;
  margin-bottom: 36px;
  line-height: 1.6;
}

.hero .btn-primary {
  background: #fff;
  color: var(--color-primary);
  font-size: 1.05rem;
  padding: 16px 40px;
}

.hero .btn-primary:hover {
  background: #f0f9ff;
}

.hero-note {
  margin-top: 14px;
  font-size: 0.85rem;
  opacity: 0.7;
}

/* ===== FOR WHOM ===== */
.for-whom-list {
  list-style: none;
  display: grid;
  gap: 16px;
}

.for-whom-list li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

.for-whom-list .icon {
  font-size: 1.8rem;
  flex-shrink: 0;
  line-height: 1;
}

.for-whom-list strong {
  display: block;
  margin-bottom: 4px;
}

/* ===== FEATURES ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.feature-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* ===== STRENGTHS ===== */
.strengths {
  background: var(--color-bg-dark);
  color: #fff;
}

.strengths h2 {
  color: #fff;
}

.strength-list {
  display: grid;
  gap: 32px;
}

.strength {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.strength-num {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-primary);
  flex-shrink: 0;
  line-height: 1;
  min-width: 48px;
}

.strength-body h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #fff;
}

.strength-body p {
  font-size: 0.95rem;
  opacity: 0.8;
  line-height: 1.7;
}

/* ===== SCREENSHOTS ===== */
.screenshots-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 24px;
}

.screenshot-item {
  text-align: center;
}

.screenshot-frame {
  position: relative;
  background: #f1f5f9;
  border-radius: var(--radius);
  border: 2px solid var(--color-border);
  overflow: hidden;
  aspect-ratio: 9 / 19.5;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
  box-shadow: var(--shadow-sm);
}

.screenshot-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  display: block;
}

/* 画像がない場合のプレースホルダー */
.screenshot-frame.placeholder img {
  display: none;
}

.screenshot-placeholder-text {
  position: absolute;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  text-align: center;
  pointer-events: none;
}

.screenshot-frame:not(.placeholder) .screenshot-placeholder-text {
  display: none;
}

.screenshot-caption {
  font-size: 0.82rem;
  color: var(--color-text);
  font-weight: 600;
  line-height: 1.5;
}

.screenshot-caption small {
  display: block;
  color: var(--color-text-secondary);
  font-weight: 400;
}

/* ===== PRICING ===== */
.pricing .container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.price-card {
  background: var(--color-card);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius);
  padding: 48px 40px;
  text-align: center;
  box-shadow: var(--shadow);
  max-width: 480px;
  width: 100%;
}

.price-badge {
  display: inline-block;
  background: var(--color-accent);
  color: #fff;
  border-radius: 9999px;
  padding: 4px 16px;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.price-amount {
  font-size: 3.5rem;
  font-weight: 800;
  color: var(--color-primary);
  letter-spacing: -0.04em;
  margin-bottom: 6px;
}

.price-note {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-bottom: 28px;
}

.price-includes {
  list-style: none;
  text-align: left;
  margin-bottom: 32px;
  display: grid;
  gap: 8px;
}

.price-includes li {
  font-size: 0.92rem;
  color: var(--color-text);
}

.price-future {
  margin-top: 16px;
  font-size: 0.78rem;
  color: var(--color-text-secondary);
}

/* ===== NOTES ===== */
.notes-list {
  display: grid;
  gap: 8px;
  max-width: 700px;
  margin: 0 auto;
}

.note-item {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.note-item summary {
  padding: 16px 20px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.95rem;
}

.note-item summary::-webkit-details-marker { display: none; }

.note-item summary::after {
  content: "＋";
  font-size: 1.1rem;
  color: var(--color-primary);
  flex-shrink: 0;
  margin-left: 12px;
}

.note-item[open] summary::after {
  content: "－";
}

.note-item p {
  padding: 0 20px 16px;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  border-top: 1px solid var(--color-border);
  padding-top: 12px;
}

/* ===== BUY ===== */
.buy {
  background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
  text-align: center;
}

.buy-sub {
  color: var(--color-text-secondary);
  margin-bottom: 28px;
  font-size: 1rem;
  line-height: 1.7;
}

.buy-price {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: 24px;
  letter-spacing: -0.03em;
}

.buy-price span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--color-text-secondary);
}

.buy-note {
  margin-top: 20px;
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* ===== FOOTER ===== */
.footer {
  background: var(--color-bg-dark);
  color: rgba(255,255,255,0.6);
  text-align: center;
  padding: 48px 20px;
}

.footer-app {
  font-size: 1.3rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 4px;
}

.footer-copy {
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.footer-small {
  font-size: 0.78rem;
  line-height: 1.8;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 600px) {
  .section {
    padding: 56px 0;
  }

  .hero {
    padding: 72px 20px 60px;
  }

  .strength {
    flex-direction: column;
    gap: 8px;
  }

  .strength-num {
    font-size: 1.8rem;
  }

  .price-card {
    padding: 36px 24px;
  }

  .price-amount {
    font-size: 2.8rem;
  }

  .screenshots-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
}