/**
 * buzz.li Landing Page Styles
 *
 * Design: Minimal, Professional, Modern
 * Style Reference: Apple, Stripe, Linear.app, Vercel
 *
 * Color Palette:
 *   Primary:   #111827
 *   Secondary: #4F46E5
 *   Background:#F8FAFC
 *   Card:      #FFFFFF
 *   Accent:    #2563EB
 *
 * Typography: Noto Sans TC
 */

/* ============================================================
   CSS Variables (Custom Properties)
   ============================================================ */
:root {
  /* Colors */
  --color-primary: #111827;
  --color-secondary: #4F46E5;
  --color-background: #F8FAFC;
  --color-card: #FFFFFF;
  --color-accent: #2563EB;

  /* Text Colors */
  --color-text-primary: #111827;
  --color-text-secondary: #6B7280;
  --color-text-muted: #9CA3AF;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;

  /* Typography */
  --font-family: 'Noto Sans TC', sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 3rem;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;

  /* Border Radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
}

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

html {
  /* Smooth scrolling for anchor links */
  scroll-behavior: smooth;
  /* Prevent font size inflation on mobile */
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-background);
  /* Ensure footer sticks to bottom */
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  /* Improve text rendering */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================================
   Main Container (Centered Content)
   ============================================================ */
.container {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-2xl) var(--spacing-md);
  max-width: 800px;
  margin: 0 auto;
}

/* ============================================================
   Logo
   ============================================================ */
.logo {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
  letter-spacing: -0.02em;
  /* Fade In Animation */
  animation: fadeIn 0.6s ease-out;
}

/* 404 Error Code Style */
.error-code {
  font-size: 5rem;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-sm);
}

/* ============================================================
   Subtitle
   ============================================================ */
.subtitle {
  font-size: var(--font-size-xl);
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
  /* Fade In Animation with slight delay */
  animation: fadeIn 0.6s ease-out 0.15s both;
}

/* ============================================================
   Description
   ============================================================ */
.description {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
  /* Fade In Animation with delay */
  animation: fadeIn 0.6s ease-out 0.3s both;
}

/* ============================================================
   Badge
   ============================================================ */
.badge {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-md);
  background-color: var(--color-card);
  border: 1px solid var(--color-text-muted);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  font-weight: 500;
  box-shadow: 0 1px 2px rgba(17, 24, 39, 0.05);
  /* Fade In Animation with delay */
  animation: fadeIn 0.6s ease-out 0.45s both;
}

/* Link Badge (for 404 page) */
.link-badge {
  text-decoration: none;
  transition: background-color var(--transition-fast),
              border-color var(--transition-fast),
              color var(--transition-fast);
}

.link-badge:hover,
.link-badge:focus-visible {
  background-color: var(--color-secondary);
  border-color: var(--color-secondary);
  color: #FFFFFF;
  outline: none;
}

.link-badge:focus-visible {
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.3);
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  text-align: center;
  padding: var(--spacing-lg) var(--spacing-md);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  border-top: 1px solid rgba(156, 163, 175, 0.2);
}

/* ============================================================
   Animations
   ============================================================ */

/**
 * Fade In Animation
 * Subtle entrance animation for content elements
 */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   Responsive Design
   ============================================================ */

/* Tablet (768px and below) */
@media (max-width: 768px) {
  .logo {
    font-size: var(--font-size-2xl);
  }

  .error-code {
    font-size: 4rem;
  }

  .subtitle {
    font-size: var(--font-size-lg);
  }

  .container {
    padding: var(--spacing-xl) var(--spacing-md);
  }
}

/* Mobile (480px and below) */
@media (max-width: 480px) {
  :root {
    --font-size-3xl: 2rem;
    --font-size-2xl: 1.5rem;
    --font-size-xl: 1.125rem;
  }

  .logo {
    font-size: 2rem;
  }

  .error-code {
    font-size: 3rem;
  }

  .subtitle {
    font-size: var(--font-size-lg);
  }

  .description {
    font-size: var(--font-size-sm);
  }

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

/* ============================================================
   Accessibility: Reduced Motion
   Respect user's motion preferences
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ============================================================
   Print Styles
   ============================================================ */
@media print {
  body {
    background-color: #FFFFFF;
  }

  .badge {
    border: 1px solid #000000;
    box-shadow: none;
  }
}