/* ================================================
   UNLOCK — Brain Capital Landing Page
   Monochrome Design (matches app design system)
   ================================================ */

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --black: #000000;
  --gray-900: #111111;
  --gray-800: #222222;
  --gray-700: #333333;
  --gray-600: #555555;
  --gray-500: #777777;
  --gray-400: #999999;
  --gray-300: #BBBBBB;
  --gray-200: #DDDDDD;
  --gray-150: #E8E8E8;
  --gray-100: #F0F0F0;
  --gray-50: #F7F7F7;
  --white: #FFFFFF;

  --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.1);
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  color: var(--gray-800);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; }
a { text-decoration: none; color: inherit; }
strong { font-weight: 700; }

/* ---------- Container ---------- */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- HERO ---------- */
.hero {
  background: var(--gray-900);
  color: var(--white);
  padding: 80px 0 72px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 3px;
  color: var(--gray-400);
  border: 1px solid var(--gray-600);
  padding: 6px 20px;
  border-radius: 100px;
  margin-bottom: 40px;
  text-transform: uppercase;
}

.hero-title {
  font-size: 32px;
  font-weight: 800;
  line-height: 1.5;
  margin-bottom: 28px;
  letter-spacing: -0.02em;
}

.hero-em {
  position: relative;
  display: inline;
}

.hero-em::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 2px;
  height: 3px;
  background: var(--white);
  opacity: 0.4;
}

.hero-lead {
  font-size: 16px;
  line-height: 1.9;
  color: var(--gray-300);
  margin-bottom: 44px;
}

.hero-lead strong {
  color: var(--white);
}

/* ---------- CTA Button ---------- */
.btn-cta {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  background: var(--white);
  color: var(--gray-900);
  padding: 18px 48px;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 700;
  transition: var(--transition);
  box-shadow: 0 4px 24px rgba(255,255,255,0.15);
}

.btn-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 32px rgba(255,255,255,0.25);
}

.btn-cta-sub {
  font-size: 12px;
  font-weight: 400;
  color: var(--gray-500);
  margin-top: 4px;
}

.btn-cta-large {
  padding: 22px 56px;
  font-size: 18px;
}

/* ---------- Sections ---------- */
.section {
  padding: 80px 0;
}

.section-dark {
  background: var(--gray-50);
}

.section-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 3px;
  color: var(--gray-400);
  text-transform: uppercase;
  margin-bottom: 16px;
  text-align: center;
}

.section-title {
  font-size: 26px;
  font-weight: 800;
  color: var(--gray-900);
  text-align: center;
  line-height: 1.5;
  margin-bottom: 48px;
  letter-spacing: -0.01em;
}

.section-footnote {
  text-align: center;
  font-size: 14px;
  color: var(--gray-600);
  margin-top: 40px;
  line-height: 1.8;
}

/* ---------- Problem Grid ---------- */
.problem-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.problem-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  text-align: center;
}

.problem-icon {
  font-size: 32px;
  display: block;
  margin-bottom: 16px;
}

.problem-text {
  font-size: 14px;
  color: var(--gray-700);
  line-height: 1.8;
}

/* ---------- Pillar Grid (3 columns) ---------- */
.pillar-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.pillar-card {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
}

.pillar-number {
  font-size: 13px;
  font-weight: 700;
  color: var(--gray-400);
  font-family: var(--font-mono);
  margin-bottom: 16px;
}

.pillar-name {
  font-size: 20px;
  font-weight: 800;
  color: var(--gray-900);
  margin-bottom: 4px;
}

.pillar-sub {
  font-size: 13px;
  color: var(--gray-500);
  margin-bottom: 16px;
}

.pillar-desc {
  font-size: 14px;
  color: var(--gray-600);
  line-height: 1.8;
  margin-bottom: 20px;
}

.pillar-categories {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.pillar-categories span {
  font-size: 11px;
  font-weight: 500;
  color: var(--gray-600);
  background: var(--white);
  border: 1px solid var(--gray-200);
  padding: 3px 10px;
  border-radius: 100px;
}

/* ---------- Benefit List ---------- */
.benefit-list {
  max-width: 640px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.benefit-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px 0;
  border-bottom: 1px solid var(--gray-200);
}

.benefit-item:last-child {
  border-bottom: none;
}

.benefit-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gray-900);
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
}

.benefit-body {
  flex: 1;
}

.benefit-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 6px;
}

.benefit-desc {
  font-size: 14px;
  color: var(--gray-600);
  line-height: 1.7;
}

/* ---------- Step Grid ---------- */
.step-grid {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.step-card {
  flex: 1;
  max-width: 220px;
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 32px 20px;
  text-align: center;
}

.step-num {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--gray-400);
  margin-bottom: 12px;
}

.step-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 12px;
}

.step-desc {
  font-size: 13px;
  color: var(--gray-600);
  line-height: 1.7;
}

.step-arrow {
  font-size: 24px;
  color: var(--gray-300);
  flex-shrink: 0;
}

/* ---------- Science Grid ---------- */
.science-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.science-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  text-align: center;
}

.science-stat {
  font-size: 48px;
  font-weight: 900;
  color: var(--gray-900);
  font-family: var(--font-mono);
  letter-spacing: -2px;
  margin-bottom: 16px;
  line-height: 1;
}

.science-desc {
  font-size: 13px;
  color: var(--gray-600);
  line-height: 1.8;
}

/* ---------- Final CTA ---------- */
.section-cta {
  background: var(--gray-900);
  color: var(--white);
  padding: 80px 0;
  text-align: center;
}

.cta-title {
  font-size: 28px;
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.cta-lead {
  font-size: 16px;
  color: var(--gray-300);
  line-height: 1.9;
  margin-bottom: 40px;
}

.cta-note {
  margin-top: 20px;
  font-size: 12px;
  color: var(--gray-500);
}

/* ---------- Footer ---------- */
.lp-footer {
  padding: 40px 0;
  text-align: center;
  border-top: 1px solid var(--gray-150);
}

.footer-brand {
  font-size: 13px;
  font-weight: 500;
  color: var(--gray-600);
  margin-bottom: 8px;
}

.footer-copy {
  font-size: 11px;
  color: var(--gray-400);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
  .hero {
    padding: 60px 0 56px;
  }

  .hero-title {
    font-size: 26px;
  }

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 22px;
    margin-bottom: 36px;
  }

  .problem-grid {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .pillar-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .step-grid {
    flex-direction: column;
    gap: 12px;
  }

  .step-arrow {
    transform: rotate(90deg);
    font-size: 20px;
  }

  .step-card {
    max-width: 100%;
    width: 100%;
  }

  .science-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .section-cta {
    padding: 60px 0;
  }

  .cta-title {
    font-size: 24px;
  }

  .btn-cta-large {
    padding: 18px 40px;
    font-size: 16px;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 48px 0 44px;
  }

  .hero-badge {
    font-size: 10px;
    letter-spacing: 2px;
    margin-bottom: 28px;
  }

  .hero-title {
    font-size: 22px;
  }

  .hero-lead {
    font-size: 14px;
    margin-bottom: 36px;
  }

  .btn-cta {
    padding: 16px 36px;
    font-size: 15px;
    width: 100%;
    max-width: 320px;
  }

  .section-title {
    font-size: 20px;
  }

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

  .problem-card {
    padding: 20px 16px;
  }

  .benefit-item {
    gap: 16px;
    padding: 20px 0;
  }

  .science-stat {
    font-size: 40px;
  }
}