/* ===================================
   TaskAgents.ai Design System
   =================================== */

/* CSS Variables */
:root {
  /* Colors */
  --color-primary: #2563eb;
  --color-primary-dark: #1e40af;
  --color-primary-light: #60a5fa;
  --color-accent: #8b5cf6;
  --color-text-primary: #1f2937;
  --color-text-secondary: #6b7280;
  --color-text-light: #9ca3af;
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f9fafb;
  --color-bg-tertiary: #f3f4f6;
  --color-border: #e5e7eb;
  --color-border-light: #f3f4f6;
  --color-success: #10b981;
  --color-error: #ef4444;
  --color-warning: #f59e0b;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;

  /* 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), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 200ms ease-in-out;
  --transition-slow: 300ms ease-in-out;

  /* Container */
  --container-max: 1280px;
  --container-narrow: 768px;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-4);
  color: var(--color-text-primary);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

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

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

ul, ol {
  margin-left: var(--space-6);
  margin-bottom: var(--space-4);
}

li {
  margin-bottom: var(--space-2);
  color: var(--color-text-secondary);
}

strong {
  font-weight: 600;
  color: var(--color-text-primary);
}

/* Container */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container-narrow {
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border-light);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) 0;
}

.logo {
  display: flex;
  align-items: center;
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text-primary);
  gap: var(--space-3);
}

.logo img {
  height: 32px;
  width: auto;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
  margin: 0;
}

.nav-menu a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--color-primary);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
}

.mobile-menu-toggle svg {
  width: 24px;
  height: 24px;
  stroke: var(--color-text-primary);
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: block;
  }

  .nav-menu {
    position: fixed;
    top: 65px;
    left: 0;
    right: 0;
    background-color: var(--color-bg-primary);
    flex-direction: column;
    gap: 0;
    padding: var(--space-4);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-base), opacity var(--transition-base);
  }

  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-menu li {
    width: 100%;
    margin: 0;
  }

  .nav-menu a {
    display: block;
    padding: var(--space-3) 0;
  }
}

/* Footer */
.site-footer {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: var(--space-24);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-section h4 {
  font-size: var(--text-lg);
  margin-bottom: var(--space-4);
}

.footer-section ul {
  list-style: none;
  margin: 0;
}

.footer-section ul li {
  margin-bottom: var(--space-3);
}

.footer-section a {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

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

.footer-bottom {
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-bottom p {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-text-light);
}

.social-links {
  display: flex;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-lg);
  background-color: var(--color-bg-tertiary);
  transition: background-color var(--transition-fast);
}

.social-links a:hover {
  background-color: var(--color-primary);
}

.social-links svg {
  width: 20px;
  height: 20px;
  fill: var(--color-text-secondary);
  transition: fill var(--transition-fast);
}

.social-links a:hover svg {
  fill: white;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-base);
  font-weight: 500;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  font-family: inherit;
}

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

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  color: white;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

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

.btn-large {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-lg);
}

.btn-small {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
}

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

/* Cards */
.card {
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: all var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}

.card-header {
  margin-bottom: var(--space-6);
}

.card-title {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-3);
}

.card-subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

/* Grid Layouts */
.grid {
  display: grid;
  gap: var(--space-8);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* Sections */
.section {
  padding: var(--space-20) 0;
}

.section-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto var(--space-16);
}

.section-title {
  font-size: var(--text-4xl);
  margin-bottom: var(--space-4);
}

.section-subtitle {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

.section-gray {
  background-color: var(--color-bg-secondary);
}

/* Hero */
.hero {
  padding: var(--space-24) 0;
  text-align: center;
}

.hero-title {
  font-size: var(--text-6xl);
  margin-bottom: var(--space-6);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: var(--text-2xl);
  color: var(--color-text-secondary);
  max-width: 800px;
  margin: 0 auto var(--space-8);
}

.hero-cta {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* Forms */
.form-group {
  margin-bottom: var(--space-6);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  margin-bottom: var(--space-2);
  color: var(--color-text-primary);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  font-family: inherit;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-error {
  font-size: var(--text-sm);
  color: var(--color-error);
  margin-top: var(--space-2);
}

.form-input.error,
.form-textarea.error,
.form-select.error {
  border-color: var(--color-error);
}

.form-helper {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-top: var(--space-2);
}

/* Alert Messages */
.alert {
  padding: var(--space-4) var(--space-6);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-6);
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
}

.alert-success {
  background-color: rgba(16, 185, 129, 0.1);
  border: 1px solid var(--color-success);
  color: #065f46;
}

.alert-error {
  background-color: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--color-error);
  color: #991b1b;
}

.alert-warning {
  background-color: rgba(245, 158, 11, 0.1);
  border: 1px solid var(--color-warning);
  color: #92400e;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-primary {
  background-color: rgba(37, 99, 235, 0.1);
  color: var(--color-primary);
}

.badge-accent {
  background-color: rgba(139, 92, 246, 0.1);
  color: var(--color-accent);
}

/* Icon Containers */
.icon-container {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
  margin-bottom: var(--space-4);
}

.icon-container svg {
  width: 24px;
  height: 24px;
  stroke: var(--color-primary);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-0 { margin-top: 0; }
.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }
.mt-16 { margin-top: var(--space-16); }

.mb-0 { margin-bottom: 0; }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }
.mb-16 { margin-bottom: var(--space-16); }

.hidden { display: none; }

/* Responsive */
@media (max-width: 768px) {
  :root {
    --text-5xl: 2.5rem;
    --text-4xl: 2rem;
    --text-3xl: 1.5rem;
  }

  .hero {
    padding: var(--space-16) 0;
  }

  .hero-title {
    font-size: var(--text-4xl);
  }

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

  .section {
    padding: var(--space-12) 0;
  }

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

/* Loading State */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

/* Smooth Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

/* Process Timeline */
.timeline {
  position: relative;
  padding-left: var(--space-8);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--color-primary) 0%, var(--color-accent) 100%);
}

.timeline-item {
  position: relative;
  margin-bottom: var(--space-12);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -42px;
  top: 0;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 3px solid var(--color-bg-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.timeline-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: white;
  font-weight: 700;
  font-size: var(--text-sm);
  margin-bottom: var(--space-3);
}