/* ==========================================================================
   Skeleton Crew - Main Stylesheet
   ========================================================================== */

/* CSS Custom Properties (Theme Variables) */
:root {
  /* Light theme - default */
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-secondary: #7c3aed;
  --color-success: #059669;
  --color-warning: #d97706;
  --color-danger: #dc2626;
  --color-info: #0ea5e9;
  
  /* Background colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-surface: #ffffff;
  --bg-overlay: rgba(0, 0, 0, 0.5);
  
  /* Text colors */
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --text-on-primary: #ffffff;
  --text-on-dark: #f1f5f9;
  
  /* Border colors */
  --border-color: #e2e8f0;
  --border-color-light: #f1f5f9;
  --border-color-dark: #cbd5e1;
  
  /* Spacing */
  --spacing-xs: 0.25rem;   /* 4px */
  --spacing-sm: 0.5rem;    /* 8px */
  --spacing-md: 1rem;      /* 16px */
  --spacing-lg: 1.5rem;    /* 24px */
  --spacing-xl: 2rem;      /* 32px */
  --spacing-2xl: 3rem;     /* 48px */
  --spacing-3xl: 4rem;     /* 64px */
  
  /* Typography */
  --font-family-base: 'Inter', system-ui, -apple-system, sans-serif;
  --font-family-mono: 'Roboto Mono', monospace;
  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-base: 1rem;     /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;    /* 24px */
  --font-size-3xl: 1.875rem;  /* 30px */
  --font-size-4xl: 2.25rem;   /* 36px */
  --font-size-5xl: 3rem;      /* 48px */
  
  /* Font weights */
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* Line heights */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  
  /* Border radius */
  --radius-sm: 0.25rem;   /* 4px */
  --radius-md: 0.375rem;  /* 6px */
  --radius-lg: 0.5rem;    /* 8px */
  --radius-xl: 0.75rem;   /* 12px */
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms;
  --transition-normal: 250ms;
  --transition-slow: 350ms;
  --transition-timing: cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Layout */
  --container-max-width: 1200px;
  --header-height: 64px;
  --footer-height: auto;
}

/* Dark theme variables */
.theme-dark {
  /* Background colors */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-surface: #334155;
  
  /* Text colors */
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-on-primary: #0f172a;
  --text-on-dark: #f1f5f9;
  
  /* Border colors */
  --border-color: #475569;
  --border-color-light: #334155;
  --border-color-dark: #64748b;
  
  /* Shadows - darker for dark theme */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5);
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal) var(--transition-timing),
              color var(--transition-normal) var(--transition-timing);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: var(--font-size-4xl);
}

h2 {
  font-size: var(--font-size-3xl);
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast) var(--transition-timing);
}

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

/* Utility Classes */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.text-center {
  text-align: center;
}

.text-muted {
  color: var(--text-muted);
}

/* Header Styles */
.app-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  height: var(--header-height);
  transition: background-color var(--transition-normal) var(--transition-timing),
              border-color var(--transition-normal) var(--transition-timing);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.logo .logo-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.logo .logo-link:hover {
  color: var(--color-primary);
}

/* Navigation */
.main-nav {
  display: none;
}

@media (min-width: 768px) {
  .main-nav {
    display: block;
  }
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-fast) var(--transition-timing);
}

.nav-link:hover {
  color: var(--color-primary);
  background-color: var(--bg-secondary);
}

.nav-link.active {
  color: var(--color-primary);
  background-color: var(--bg-secondary);
}

.nav-link i {
  font-size: var(--font-size-sm);
}

/* User Actions */
.user-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast) var(--transition-timing);
}

.theme-toggle:hover {
  background-color: var(--border-color-light);
  color: var(--text-primary);
}

.signin-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  background-color: var(--color-primary);
  color: var(--text-on-primary);
  border: none;
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: background-color var(--transition-fast) var(--transition-timing);
}

.signin-btn:hover {
  background-color: var(--color-primary-hover);
}

.mobile-menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast) var(--transition-timing);
}

@media (min-width: 768px) {
  .mobile-menu-toggle {
    display: none;
  }
}

.mobile-menu-toggle:hover {
  background-color: var(--border-color-light);
  color: var(--text-primary);
}

/* Mobile Navigation */
.mobile-nav {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-md);
  transform: translateY(-100%);
  opacity: 0;
  visibility: hidden;
  transition: transform var(--transition-normal) var(--transition-timing),
              opacity var(--transition-normal) var(--transition-timing),
              visibility var(--transition-normal) var(--transition-timing);
  z-index: 999;
}

.mobile-nav.active {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.mobile-nav-links {
  list-style: none;
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-fast) var(--transition-timing);
}

.mobile-nav-link:hover {
  color: var(--color-primary);
  background-color: var(--bg-secondary);
}

.mobile-nav-link.active {
  color: var(--color-primary);
  background-color: var(--bg-secondary);
}

/* Main Content */
.main-content {
  flex: 1;
  padding: var(--spacing-xl) 0;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: var(--spacing-3xl) 0;
  margin-bottom: var(--spacing-3xl);
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-md);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto var(--spacing-xl);
}

.hero-actions {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-xl);
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--transition-fast) var(--transition-timing);
  border: 2px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--text-on-primary);
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: var(--text-on-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-2xl);
  font-size: var(--font-size-lg);
}

/* Features Section */
.features {
  margin-bottom: var(--spacing-3xl);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: var(--font-size-lg);
  max-width: 600px;
  margin: 0 auto;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
}

@media (min-width: 768px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.feature-card {
  background-color: var(--bg-surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  border: 1px solid var(--border-color);
  transition: transform var(--transition-normal) var(--transition-timing),
              box-shadow var(--transition-normal) var(--transition-timing),
              border-color var(--transition-normal) var(--transition-timing);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-lg);
  color: white;
  font-size: var(--font-size-lg);
}

.feature-card h4 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-sm);
}

.feature-card p {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

/* CTA Section */
.cta {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-xl);
  padding: var(--spacing-3xl) var(--spacing-xl);
  margin: var(--spacing-3xl) 0;
  text-align: center;
}

.cta-content {
  max-width: 600px;
  margin: 0 auto;
}

.cta h3 {
  color: white;
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-md);
}

.cta p {
  color: rgba(255, 255, 255, 0.9);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-xl);
}

.cta-actions {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.cta .btn-primary {
  background-color: white;
  color: var(--color-primary);
}

.cta .btn-primary:hover {
  background-color: rgba(255, 255, 255, 0.9);
}

.cta .btn-outline {
  background-color: transparent;
  color: white;
  border-color: white;
}

.cta .btn-outline:hover {
  background-color: white;
  color: var(--color-primary);
}

/* Footer Styles */
.app-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-2xl) 0;
  margin-top: auto;
  transition: background-color var(--transition-normal) var(--transition-timing),
              border-color var(--transition-normal) var(--transition-timing);
}

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

.footer-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

@media (min-width: 768px) {
  .footer-content {
    grid-template-columns: 2fr 3fr;
  }
}

.footer-brand .footer-logo {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-sm);
}

.footer-brand .footer-tagline {
  color: var(--text-secondary);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-xl);
}

@media (min-width: 768px) {
  .footer-links {
    grid-template-columns: repeat(3, 1fr);
  }
}

.footer-column h4 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.footer-column ul {
  list-style: none;
}

.footer-column li {
  margin-bottom: var(--spacing-sm);
}

.footer-column a {
  color: var(--text-secondary);
  transition: color var(--transition-fast) var(--transition-timing);
}

.footer-column a:hover {
  color: var(--color-primary);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-md);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
  }
}

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

.footer-nav {
  display: flex;
  gap: var(--spacing-md);
}

.footer-nav-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  transition: all var(--transition-fast) var(--transition-timing);
}

.footer-nav-link:hover {
  background-color: var(--color-primary);
  color: var(--text-on-primary);
  transform: translateY(-2px);
}

/* Responsive Adjustments */
@media (max-width: 767px) {
  :root {
    --font-size-4xl: 1.875rem;
    --font-size-5xl: 2.25rem;
    --spacing-3xl: 3rem;
  }
  
  .hero {
    padding: var(--spacing-2xl) 0;
  }
  
  .hero-actions,
  .cta-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-actions .btn,
  .cta-actions .btn {
    width: 100%;
    max-width: 300px;
  }
}

/* Focus Styles for Accessibility */
button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Print Styles */
@media print {
  .app-header,
  .app-footer,
  .theme-toggle,
  .signin-btn,
  .mobile-menu-toggle,
  .hero-actions,
  .cta-actions {
    display: none !important;
  }
  
  body {
    color: #000;
    background: #fff;
  }
  
  a {
    color: #000;
    text-decoration: underline;
  }
}