/* ===========================
   AIBlack.tech — Global Styles
   Apple-style clean & bright
   =========================== */

/* MARK: - Reset & Base */

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --color-bg: #ffffff;
  --color-text: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-accent: #0071e3;
  --color-accent-hover: #0077ed;
  --color-border: #d2d2d7;
  --color-surface: #f5f5f7;
  --font-system: -apple-system, BlinkMacSystemFont, 'SF Pro Display',
    'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --max-width: 980px;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
}

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

body {
  font-family: var(--font-system);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
}

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

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

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

/* MARK: - Typography */

h1 {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.3;
}

p {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
}

/* MARK: - Layout */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: var(--spacing-xl) 0;
}

.section--surface {
  background-color: var(--color-surface);
}

/* MARK: - Navigation */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--color-border);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.nav__brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.nav__links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.nav__links a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  transition: color 0.2s ease;
}

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

/* MARK: - Hero */

.hero {
  text-align: center;
  padding: var(--spacing-xl) 0;
}

.hero__tagline {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--spacing-sm);
}

.hero h1 {
  margin-bottom: var(--spacing-sm);
}

.hero p {
  font-size: 1.25rem;
  max-width: 600px;
  margin: 0 auto var(--spacing-md);
}

.hero__app-icon {
  width: 120px;
  height: 120px;
  border-radius: 26px;
  margin: 0 auto var(--spacing-md);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: #fff;
  box-shadow: 0 8px 30px rgba(102, 126, 234, 0.3);
}

/* MARK: - App Store Badge */

.badge {
  display: inline-block;
  transition: opacity 0.2s ease;
}

.badge:hover {
  opacity: 0.85;
}

.badge img {
  height: 48px;
  width: auto;
}

/* MARK: - Features */

.features {
  text-align: center;
  padding: var(--spacing-xl) 0;
}

.features h2 {
  margin-bottom: var(--spacing-lg);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.feature-card {
  padding: var(--spacing-md);
  border-radius: 16px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.06);
}

.feature-card__icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-sm);
}

.feature-card h3 {
  margin-bottom: var(--spacing-xs);
}

.feature-card p {
  font-size: 1rem;
}

/* MARK: - CTA */

.cta {
  text-align: center;
  padding: var(--spacing-xl) 0;
}

.cta h2 {
  margin-bottom: var(--spacing-sm);
}

.cta p {
  margin-bottom: var(--spacing-md);
}

/* MARK: - Footer */

.footer {
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-md) 0;
  text-align: center;
}

.footer p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.footer__links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
  list-style: none;
}

.footer__links a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

/* MARK: - Legal Pages (Privacy, About) */

.legal {
  padding: var(--spacing-xl) 0;
}

.legal h1 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-xs);
}

.legal__updated {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

.legal h2 {
  font-size: 1.5rem;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

.legal h3 {
  margin-top: var(--spacing-md);
  margin-bottom: var(--spacing-xs);
}

.legal p,
.legal li {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: var(--spacing-sm);
}

.legal ul {
  padding-left: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.legal a {
  word-break: break-word;
}

/* MARK: - About Page */

.about-card {
  background: var(--color-surface);
  border-radius: 16px;
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
}

.about-card h3 {
  margin-bottom: var(--spacing-sm);
}

.contact-list {
  list-style: none;
  padding: 0;
}

.contact-list li {
  padding: var(--spacing-xs) 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 1rem;
}

.contact-list li:last-child {
  border-bottom: none;
}

/* MARK: - Responsive */

@media (max-width: 768px) {
  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .hero p {
    font-size: 1.125rem;
  }

  .features__grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }

  .nav__links {
    gap: var(--spacing-sm);
  }

  .section {
    padding: var(--spacing-lg) 0;
  }

  .hero {
    padding: var(--spacing-lg) 0;
  }

  .about-card {
    padding: var(--spacing-md);
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.75rem;
  }

  .nav__inner {
    padding: 0 var(--spacing-sm);
  }

  .container {
    padding: 0 var(--spacing-sm);
  }
}