/* Modern CSS Variables for Consistent Design */
:root {
  --primary-color: #4f46e5;
  --secondary-color: #7c3aed;
  --accent-color: #0891b2;
  --success-color: #059669;
  --error-color: #dc2626;
  --warning-color: #d97706;
  
  --text-primary: #1f2937;
  --text-secondary: #374151;
  --text-muted: #6b7280;
  --text-light: #ffffff;
  --text-on-gradient: #ffffff;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-dark: #1f2937;
  --bg-card: #ffffff;
  
  --border-color: #e5e7eb;
  --border-focus: var(--primary-color);
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 0.15s ease-out;
}

/* Dark mode variables */
@media (prefers-color-scheme: dark) {
  :root {
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    --text-on-gradient: #ffffff;
    
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-card: #1f2937;
    
    --border-color: #374151;
  }
}

/* Global Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-primary);
  line-height: 1.6;
  color: var(--text-primary);
  background: linear-gradient(135deg, #f0f4ff 0%, #f8f0ff 50%, #f0f9ff 100%);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Prevent scrolling when mobile menu is open */
body.menu-open {
  overflow: hidden;
  position: fixed;
  width: 100%;
  height: 100%;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.gradient-text {
  background: linear-gradient(135deg, #4338ca 0%, #7c3aed 50%, #0891b2 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  background-size: 200% auto;
  animation: gradientShift 3s ease-in-out infinite;
}

@keyframes gradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: var(--transition);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.nav-brand a {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, #4338ca 0%, #7c3aed 50%, #0891b2 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-decoration: none;
  transition: var(--transition-fast);
}

.nav-brand a:hover {
  transform: scale(1.02);
}

.nav-brand a i {
  color: #4338ca;
  -webkit-text-fill-color: #4338ca !important;
  background: none !important;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: #374151;
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition-fast);
  position: relative;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -0.5rem;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: width 0.3s ease;
}

.nav-link:hover::after {
  width: 100%;
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 0.25rem;
  padding: 1rem;
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
  background: rgba(255, 255, 255, 0.1);
  border: none;
  position: relative;
  z-index: 1002;
  min-width: 48px;
  min-height: 48px;
  justify-content: center;
  align-items: center;
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  touch-action: manipulation;
}

.hamburger:hover {
  background: rgba(79, 70, 229, 0.2);
  transform: scale(1.05);
}

.hamburger:active {
  background: rgba(79, 70, 229, 0.3);
  transform: scale(0.95);
}

.hamburger span {
  width: 1.75rem;
  height: 2px;
  background: #374151;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: 2px;
  transform-origin: center;
  display: block;
  position: relative;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(0.35rem, 0.35rem);
  background: var(--primary-color);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
  transform: translateX(20px);
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(0.35rem, -0.35rem);
  background: var(--primary-color);
}

/* Main Content */
.main-content {
  margin-top: 5rem;
}

/* Hero Section */
.hero-section {
  padding: 4rem 0;
  text-align: center;
}

.hero-content {
  margin-bottom: 3rem;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  margin-bottom: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.hero-title-accent {
  color: #1f2937;
  font-weight: 700;
  text-shadow: none;
}

.hero-description {
  font-size: 1.125rem;
  color: #4b5563;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
  font-weight: 500;
}

/* Generator Card */
.generator-card {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  margin: 0 auto;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.card-header {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--text-light);
  padding: 1.5rem;
  text-align: center;
}

.card-header h3 {
  font-size: 1.25rem;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.card-body {
  padding: 2rem;
}

.input-group {
  margin-bottom: 2rem;
}

.input-group label {
  display: block;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.input-group input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-family: var(--font-mono);
  transition: var(--transition-fast);
  background: var(--bg-secondary);
  color: #ffffff;
}

.input-group input:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-group input.error {
  border-color: var(--error-color);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.error-message {
  display: none;
  color: var(--error-color);
  font-size: 0.875rem;
  margin-top: 0.5rem;
  padding: 0.5rem;
  background: rgba(239, 68, 68, 0.1);
  border-radius: var(--radius-sm);
  align-items: center;
  gap: 0.5rem;
}

.error-message.show {
  display: flex;
}

.generate-btn {
  width: 100%;
  padding: 1rem 2rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--text-light);
  border: none;
  border-radius: var(--radius-md);
  font-size: 1.125rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
}

.generate-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.generate-btn:hover::before {
  left: 100%;
}

.generate-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.generate-btn:active {
  transform: translateY(0);
}

.result-container {
  text-align: center;
  padding: 1.5rem;
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  opacity: 0;
  transform: translateY(20px);
  transition: var(--transition);
}

.result-container.show {
  opacity: 1;
  transform: translateY(0);
}

.result-label {
  font-size: 0.875rem;
  color: #6b7280;
  font-weight: 500;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.result-number {
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary-color);
  font-family: var(--font-mono);
  margin-bottom: 1rem;
  text-shadow: none;
  animation: numberAppear 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

@keyframes numberAppear {
  0% {
    transform: scale(0.5);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

.copy-btn {
  background: var(--accent-color);
  color: var(--text-light);
  border: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  cursor: pointer;
  transition: var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.copy-btn:hover {
  background: #0891b2;
  transform: translateY(-1px);
}

.copy-btn.copied {
  background: var(--success-color);
}

/* About Section */
.about-section {
  padding: 5rem 0;
  background: var(--bg-primary);
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 3rem;
  color: var(--text-primary);
}

.about-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.about-card {
  background: linear-gradient(135deg, #1f2937, #374151);
  padding: 2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.about-icon {
  width: 4rem;
  height: 4rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: var(--text-light);
  font-size: 1.5rem;
}

.about-card h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: #ffffff;
}

.about-card p {
  color: #ffffff;
  line-height: 1.6;
}

.about-text {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  background: linear-gradient(135deg, #1f2937, #374151);
  padding: 2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.about-text p {
  font-size: 1.125rem;
  line-height: 1.7;
  color: #ffffff;
}

/* Footer */
.foot {
  background: var(--bg-dark);
  color: var(--text-light);
  padding: 2rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.credit {
  margin: 0;
  font-size: 1rem;
}

.chinmay-link {
  background: linear-gradient(90deg, #a855f7, #ec4899, #fbbf24);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  background-size: 200% auto;
  transition: background-position 0.5s ease;
  text-decoration: none;
  font-weight: 600;
}

.chinmay-link:hover,
.chinmay-link:focus {
  background-position: right center;
  -webkit-text-fill-color: transparent !important;
  text-decoration: none !important;
}

.copyright {
  color: rgba(255, 255, 255, 0.8);
  opacity: 0.9;
  font-size: 0.95em;
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 100%;
    left: 0;
    width: 100vw;
    height: calc(100vh - 5rem);
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding: 3rem 2rem;
    gap: 2rem;
    box-shadow: var(--shadow-xl);
    border-top: 1px solid var(--border-color);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1001;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav-menu .nav-link {
    padding: 1.25rem 2rem;
    border-radius: var(--radius-lg);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-align: center;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 2px solid transparent;
    font-size: 1.2rem;
    font-weight: 600;
    color: #374151;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    min-width: 200px;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
  }
  
  .nav-menu .nav-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(79, 70, 229, 0.1), transparent);
    transition: left 0.5s ease;
  }
  
  .nav-menu .nav-link:hover::before,
  .nav-menu .nav-link:active::before {
    left: 100%;
  }
  
  .nav-menu .nav-link:hover,
  .nav-menu .nav-link:active {
    background: rgba(79, 70, 229, 0.15);
    border-color: var(--primary-color);
    transform: translateY(-3px) scale(1.02);
    color: var(--primary-color);
    box-shadow: var(--shadow-md);
  }
  
  .hamburger {
    display: flex !important;
  }
  
  /* Improved mobile layout */
  .nav-container {
    padding: 1rem 1.5rem;
  }
  
  .hero-title {
    font-size: 2.2rem;
  }
  
  .generator-card {
    margin: 0 1rem;
    box-shadow: var(--shadow-lg);
  }
  
  .card-body {
    padding: 1.5rem;
  }
  
  .about-content {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .foot {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
    padding: 2rem 1rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }
  
  .nav-container {
    padding: 0.75rem 1rem;
  }
  
  .hamburger {
    min-width: 44px;
    min-height: 44px;
    padding: 0.75rem;
  }
  
  .hero-section {
    padding: 2rem 0;
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-description {
    font-size: 1rem;
    padding: 0 1rem;
  }
  
  .generator-card {
    margin: 0 0.5rem;
    border-radius: var(--radius-lg);
  }
  
  .card-body {
    padding: 1.25rem;
  }
  
  .input-group input {
    font-size: 1rem;
    padding: 0.875rem 1rem;
  }
  
  .generate-btn {
    padding: 1rem 1.5rem;
    font-size: 1rem;
  }
  
  .result-number {
    font-size: 2.25rem;
  }
  
  .about-card {
    padding: 1.5rem;
  }
  
  .about-text {
    padding: 1.5rem;
  }
  
  .nav-menu .nav-link {
    min-width: 180px;
    font-size: 1.1rem;
    padding: 1rem 1.5rem;
  }
}

/* Extra small devices */
@media (max-width: 320px) {
  .hero-title {
    font-size: 1.75rem;
  }
  
  .hero-description {
    font-size: 0.95rem;
  }
  
  .generator-card {
    margin: 0 0.25rem;
  }
  
  .card-body {
    padding: 1rem;
  }
  
  .result-number {
    font-size: 2rem;
  }
  
  .nav-menu .nav-link {
    min-width: 160px;
    font-size: 1rem;
  }
}

/* Loading and Animation States */
.loading {
  pointer-events: none;
  opacity: 0.7;
}

.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1rem;
  height: 1rem;
  margin: -0.5rem;
  border: 2px solid transparent;
  border-top: 2px solid var(--text-light);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}