/* ============================================
   OddLens — YC-style Landing Page
   Clean, formal, enterprise-ready
   ============================================ */

:root {
  /* Colors — Minimal, professional palette */
  --color-bg: #FFFFFF;
  --color-bg-subtle: #FAFAFA;
  --color-text: #111111;
  --color-text-secondary: #666666;
  --color-text-muted: #999999;
  --color-border: #EAEAEA;
  --color-accent: #FF5733;
  --color-accent-bg: #FFF4F1;
  --color-success: #0D9445;
  --color-error: #E5231A;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 
               'Helvetica Neue', Arial, sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 5rem;

  /* Layout */
  --max-width: 1080px;
  --content-width: 640px;
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.5;
}

/* Accessibility */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-sm) var(--space-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

/* Main */
.main {
  min-height: calc(100vh - 120px);
}

/* Hero */
.hero {
  padding: var(--space-2xl) var(--space-md);
  border-bottom: 1px solid var(--color-border);
}

.hero-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  text-align: center;
}

/* Hero Typography */
.hero-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-md);
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: 1.6;
  max-width: 520px;
  margin: 0 auto var(--space-xl);
}

/* Form */
.form {
  max-width: 420px;
  margin: 0 auto var(--space-md);
}

.form-row {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

input[type="email"] {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: inherit;
  font-size: var(--font-size-base);
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  transition: border-color 150ms ease, box-shadow 150ms ease;
}

input[type="email"]::placeholder {
  color: var(--color-text-muted);
}

input[type="email"]:focus {
  outline: none;
  border-color: var(--color-text);
  box-shadow: 0 0 0 1px var(--color-text);
}

.btn {
  width: 100%;
  padding: 0.75rem 1.25rem;
  font-family: inherit;
  font-size: var(--font-size-base);
  font-weight: 500;
  color: white;
  background: var(--color-text);
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: opacity 150ms ease;
}

.btn:hover {
  opacity: 0.85;
}

.btn:focus-visible {
  outline: 2px solid var(--color-text);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.form-message {
  min-height: 1.25rem;
  margin-top: var(--space-xs);
  font-size: var(--font-size-sm);
  text-align: center;
}

.form-message.success { color: var(--color-success); }
.form-message.error { color: var(--color-error); }

.hero-note {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* Features */
.features {
  padding: var(--space-2xl) var(--space-md);
  background: var(--color-bg-subtle);
  border-bottom: 1px solid var(--color-border);
}

.features-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

.feature {
  text-align: center;
}

.feature-title {
  font-size: var(--font-size-base);
  font-weight: 600;
  margin-bottom: var(--space-xs);
  letter-spacing: -0.01em;
}

.feature-text {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
  max-width: 280px;
  margin: 0 auto;
}

/* About */
.about {
  padding: var(--space-2xl) var(--space-md);
  border-bottom: 1px solid var(--color-border);
}

.about-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  text-align: center;
}

.about-text {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* Footer */
.footer {
  padding: var(--space-md);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
}

.footer-left {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.footer-logo {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
}

.footer-copyright {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.footer-right {
  display: flex;
  gap: var(--space-md);
}

.footer-link {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 150ms ease;
}

.footer-link:hover {
  color: var(--color-text);
}

/* Responsive */
@media (min-width: 640px) {
  .form-row {
    flex-direction: row;
  }

  input[type="email"] {
    flex: 1;
  }

  .btn {
    width: auto;
  }

  .features-inner {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
  }

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

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
  }
}