/* Modern Clean UI Styles */
:root {
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --primary-light: #60a5fa;
  --surface: #ffffff;
  --surface-alt: #f8fafc;
  --background: #f1f5f9;
  --text: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --accent: #8b5cf6;
  --success: #10b981;
  --error: #ef4444;
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 2rem;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --gradient: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--background);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Header */
.header {
  background: var(--surface);
  box-shadow: var(--shadow-sm);
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 100;
}

.nav {
  height: 5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo i {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  gap: 3rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 1rem;
  transition: all 0.3s ease;
}

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

/* Hero Section */
.hero {
  padding: 10rem 0 6rem;
  text-align: center;
  background: var(--surface);
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 4rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
}

/* Generator Section */
.generator {
  padding: 4rem;
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  margin: -4rem auto 6rem;
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.input-group {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
}

.keyword-input {
  flex: 1;
  padding: 1.25rem 1.5rem;
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 1.125rem;
  color: var(--text);
  background: var(--surface);
  transition: all 0.3s ease;
}

.keyword-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1.25rem 2rem;
  border: none;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1.125rem;
  cursor: pointer;
  transition: all 0.3s ease;
}

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

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

.btn-secondary {
  background: var(--surface-alt);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--surface);
  transform: translateY(-2px);
}

/* Hashtag Results */
.hashtag-results {
  background: var(--surface-alt);
  border-radius: var(--radius-md);
  padding: 2rem;
  margin-top: 2rem;
}

.hashtag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
}

.hashtag {
  background: var(--surface);
  color: var(--primary);
  padding: 0.75rem 1.5rem;
  border-radius: 9999px;
  font-size: 1rem;
  font-weight: 500;
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: all 0.3s ease;
}

.hashtag:hover {
  background: var(--gradient);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Library Section */
.library {
  padding: 6rem 0;
  background: var(--surface);
}

.library-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 4rem;
}

.library-header h2 {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.search-box {
  position: relative;
  width: 350px;
}

.search-box i {
  position: absolute;
  left: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
}

.search-box input {
  width: 100%;
  padding: 1rem 1.5rem 1rem 3.5rem;
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 1rem;
  transition: all 0.3s ease;
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
}

.category-card {
  background: var(--surface-alt);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: all 0.3s ease;
}

.category-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.category-card h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text);
}

.hashtag-items {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.hashtag-item {
  background: var(--surface);
  padding: 1rem 1.5rem;
  border-radius: var(--radius-md);
  color: var(--text);
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.hashtag-item:hover {
  background: var(--gradient);
  color: white;
  transform: translateX(5px);
}

/* Footer */
.footer {
  background: var(--surface);
  padding: 6rem 0 2rem;
  margin-top: 6rem;
  border-top: 1px solid var(--border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 4rem;
  margin-bottom: 4rem;
}

.footer-section h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text);
}

.footer-section p {
  color: var(--text-muted);
  margin-bottom: 2rem;
}

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

.footer-section ul li {
  margin-bottom: 1rem;
}

.footer-section ul a {
  color: var(--text-muted);
  text-decoration: none;
  transition: all 0.3s ease;
}

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

.social-links {
  display: flex;
  gap: 1.5rem;
}

.social-links a {
  color: var(--text-muted);
  font-size: 1.5rem;
  transition: all 0.3s ease;
}

.social-links a:hover {
  color: var(--primary);
  transform: translateY(-3px);
}

.copyright {
  text-align: center;
  color: var(--text-muted);
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--surface);
  padding: 1.25rem 1.75rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  transform: translateY(100%);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.toast.success {
  border-left: 4px solid var(--success);
}

.toast.error {
  border-left: 4px solid var(--error);
}

/* Mobile Menu Button */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 1.5rem;
  }

  .hero {
    padding: 8rem 0 4rem;
  }

  .hero h1 {
    font-size: 2.5rem;
  }

  .hero p {
    font-size: 1.125rem;
  }

  .generator {
    padding: 2rem;
    margin: -2rem 1rem 4rem;
  }

  .input-group {
    flex-direction: column;
  }

  .library-header {
    flex-direction: column;
    gap: 2rem;
    text-align: center;
  }

  .search-box {
    width: 100%;
  }

  .mobile-menu-btn {
    display: block;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--surface);
    padding: 1.5rem;
    flex-direction: column;
    gap: 1rem;
    box-shadow: var(--shadow-md);
  }

  .nav-links.show {
    display: flex;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
}

.hidden {
  display: none;
}