/* ============================================
   Brain2 Landing Page
   ============================================ */

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

:root {
  --bg-primary: #07070d;
  --bg-surface: #111119;
  --bg-card: #16161f;
  --bg-card-hover: #1c1c28;
  --border: #222233;
  --text-primary: #eeeef0;
  --text-secondary: #9999aa;
  --text-muted: #666677;
  --accent: #7c6cf0;
  --accent-light: #9d8ff7;
  --accent-glow: rgba(124, 108, 240, 0.15);
  --cyan: #22d3ee;
  --green: #34d399;
  --pink: #f472b6;
  --orange: #fb923c;
  --radius: 12px;
  --radius-sm: 8px;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Fira Code", monospace;
  --max-width: 1080px;
  --section-gap: 120px;
}

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

body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
}

a {
  color: var(--accent-light);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--cyan);
}

img {
  max-width: 100%;
  display: block;
}

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: var(--section-gap) 0;
}

/* --- Typography --- */
.section-label {
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 3px;
  color: var(--accent);
  margin-bottom: 16px;
}

.section-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.8;
}

/* --- Header / Nav --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(7, 7, 13, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--text-primary);
}

.logo-icon {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--accent), var(--cyan));
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 800;
  color: #fff;
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav a {
  font-size: 14px;
  color: var(--text-secondary);
  transition: color 0.2s;
}

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

.lang-switch {
  font-size: 13px;
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.lang-switch:hover {
  border-color: var(--accent);
  color: var(--text-primary);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 0 24px var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent-light);
  color: #fff;
  box-shadow: 0 0 40px var(--accent-glow);
  transform: translateY(-1px);
}

.btn-secondary {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--text-muted);
  color: var(--text-primary);
}

/* --- Hero --- */
.hero {
  padding-top: 160px;
  padding-bottom: var(--section-gap);
  text-align: center;
}

.hero-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}

.hero-title .accent {
  background: linear-gradient(135deg, var(--accent-light), var(--cyan));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 40px;
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 24px;
  font-size: 13px;
  color: var(--text-muted);
}

.hero-badge .dot {
  width: 6px;
  height: 6px;
  background: var(--green);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* --- Pain section --- */
.pain-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 48px;
}

.pain-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: all 0.2s;
}

.pain-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--text-muted);
}

.pain-number {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 12px;
}

.pain-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
}

.pain-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Solution section --- */
.solution-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 48px;
}

.solution-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.solution-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
}

.solution-card:nth-child(1)::before {
  background: linear-gradient(90deg, var(--accent), transparent);
}

.solution-card:nth-child(2)::before {
  background: linear-gradient(90deg, var(--cyan), transparent);
}

.solution-card:nth-child(3)::before {
  background: linear-gradient(90deg, var(--pink), transparent);
}

.solution-icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.solution-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.solution-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* --- Features section --- */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 48px;
}

.feature-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all 0.2s;
}

.feature-item:hover {
  border-color: var(--text-muted);
}

.feature-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 2px;
  padding: 4px 10px;
  border-radius: 4px;
  display: inline-block;
  margin-bottom: 16px;
}

.feature-tag.capture { background: rgba(124, 108, 240, 0.15); color: var(--accent-light); }
.feature-tag.ai { background: rgba(34, 211, 238, 0.15); color: var(--cyan); }
.feature-tag.report { background: rgba(244, 114, 182, 0.15); color: var(--pink); }
.feature-tag.search { background: rgba(251, 146, 60, 0.15); color: var(--orange); }

.feature-item h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-item p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Privacy section --- */
.privacy-section {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.privacy-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 40px;
}

.privacy-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px 20px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.privacy-check {
  color: var(--green);
  font-size: 18px;
  flex-shrink: 0;
  margin-top: 1px;
}

.privacy-item p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.privacy-item strong {
  color: var(--text-primary);
}

/* --- Use Cases section --- */
.usecase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 48px;
}

.usecase-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
}

.usecase-emoji {
  font-size: 28px;
  margin-bottom: 16px;
}

.usecase-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 12px;
}

.usecase-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Pricing section --- */
.pricing-section {
  text-align: center;
}

.pricing-cards {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-top: 48px;
  flex-wrap: wrap;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 36px;
  width: 320px;
  text-align: left;
  transition: all 0.2s;
}

.pricing-card.featured {
  border-color: var(--accent);
  box-shadow: 0 0 40px var(--accent-glow);
  position: relative;
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: 20px;
  white-space: nowrap;
}

.pricing-plan {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.pricing-price {
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 4px;
}

.pricing-price span {
  font-size: 16px;
  font-weight: 400;
  color: var(--text-secondary);
}

.pricing-note {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
}

.pricing-features li {
  font-size: 14px;
  color: var(--text-secondary);
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-features li:last-child {
  border-bottom: none;
}

.pricing-features li::before {
  content: "✓";
  color: var(--green);
  font-weight: 700;
}

/* --- FAQ section --- */
.faq-list {
  max-width: 720px;
  margin: 48px auto 0;
}

.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
}

.faq-item:first-child {
  border-top: 1px solid var(--border);
}

.faq-question {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
  cursor: default;
}

.faq-answer {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* --- CTA section --- */
.cta-section {
  text-align: center;
  padding: 100px 0;
}

.cta-title {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.cta-subtitle {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 13px;
  color: var(--text-muted);
}

.footer-links a:hover {
  color: var(--text-secondary);
}

.footer-copy {
  font-size: 13px;
  color: var(--text-muted);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --section-gap: 80px;
  }

  .nav {
    display: none;
  }

  .header-inner {
    height: 52px;
  }

  .hero {
    padding-top: 120px;
  }

  .hero-subtitle {
    font-size: 16px;
  }

  .pain-grid,
  .solution-grid,
  .usecase-grid {
    grid-template-columns: 1fr;
  }

  .feature-block {
    grid-template-columns: 1fr;
  }

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

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

  .pricing-card {
    width: 100%;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }
}