:root {
  /* Colors */
  --bg-color: #f8fafc;
  --text-color: #0f172a;
  --text-light: #475569;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --secondary: #e2e8f0;
  --secondary-hover: #cbd5e1;
  --accent: #f59e0b;
  
  /* Tool UI Dark Theme */
  --tool-bg: #1e1e1e;
  --tool-text: #d4d4d4;
  --tool-border: #333333;
  --tool-header: #252526;
  --tool-accent: #007acc;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;
  
  /* Typography */
  --font-sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* Radii */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 1rem;
  
  /* Shadows */
  --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);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

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

h1 { font-size: 2.5rem; margin-bottom: 1rem; }
h2 { font-size: 2rem; margin-bottom: 1rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.75rem; }

p {
  margin-bottom: 1rem;
  color: var(--text-light);
}

/* Layout */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Header */
.header {
  background-color: #ffffff;
  border-bottom: 1px solid var(--secondary);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 4rem;
}

.logo a {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-color);
}

.logo svg {
  width: 24px;
  height: 24px;
  fill: var(--accent);
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.nav-links a {
  color: var(--text-light);
  font-weight: 500;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  font-size: 0.95rem;
}

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

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

.btn-secondary {
  background-color: #ffffff;
  color: var(--text-color);
  border-color: var(--secondary);
}

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

/* Mobile Menu */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
}

.mobile-menu-btn svg {
  width: 24px;
  height: 24px;
  fill: var(--text-color);
}

/* Hero Section */
.hero {
  padding: var(--spacing-xl) 0;
  text-align: center;
  background: linear-gradient(to bottom, #ffffff, var(--bg-color));
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.25rem;
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

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

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

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  background-color: var(--secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-light);
}

.badge svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

/* Tool Interface */
.tool-workspace {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
  height: calc(100vh - 250px);
  min-height: 500px;
}

.tool-panel {
  display: flex;
  flex-direction: column;
  background-color: var(--tool-bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--tool-border);
}

.tool-header {
  background-color: var(--tool-header);
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--tool-border);
}

.tool-title {
  color: var(--tool-text);
  font-size: 0.875rem;
  font-weight: 600;
  font-family: var(--font-sans);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tool-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.tool-btn {
  background: none;
  border: 1px solid var(--tool-border);
  color: var(--tool-text);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  cursor: pointer;
  transition: background 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.tool-btn:hover {
  background-color: #333;
}

.tool-btn svg {
  width: 14px;
  height: 14px;
  fill: currentColor;
}

.tool-editor {
  flex: 1;
  position: relative;
  display: flex;
}

.editor-textarea {
  width: 100%;
  height: 100%;
  background: transparent;
  border: none;
  color: #d4d4d4;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.5;
  padding: var(--spacing-md);
  resize: none;
  outline: none;
  tab-size: 2;
}

.editor-textarea::placeholder {
  color: #6b7280;
}

/* Tool Controls Bar */
.tool-controls {
  background-color: #ffffff;
  padding: var(--spacing-md);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  border: 1px solid var(--secondary);
}

.control-group {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.control-label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-light);
}

.control-select {
  padding: 0.375rem 1.5rem 0.375rem 0.75rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--secondary);
  background-color: #ffffff;
  font-size: 0.875rem;
  outline: none;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23475569' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.5rem center;
  background-size: 1em;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background-color: var(--text-color);
  color: #ffffff;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  z-index: 1000;
  box-shadow: var(--shadow-lg);
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* Sections */
.section {
  padding: var(--spacing-xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.feature-card {
  background: #ffffff;
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--secondary);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background-color: #eff6ff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
  color: var(--primary);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
  fill: currentColor;
}

/* Steps */
.steps {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}
@media (min-width: 768px) {
  .steps {
    flex-direction: row;
  }
}
.step {
  flex: 1;
  text-align: center;
  padding: var(--spacing-lg);
}
.step-number {
  font-size: 3rem;
  font-weight: 800;
  color: var(--secondary);
  margin-bottom: var(--spacing-sm);
  line-height: 1;
}

/* Content & Blog */
.content-wrapper {
  max-width: 800px;
  margin: 0 auto;
}
.article-header {
  margin-bottom: var(--spacing-lg);
  text-align: center;
}
.article-meta {
  color: var(--text-light);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
}
.article-body h2 {
  margin-top: var(--spacing-xl);
}
.article-body h3 {
  margin-top: var(--spacing-lg);
}
.article-body ul, .article-body ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
  color: var(--text-light);
}
.article-body li {
  margin-bottom: var(--spacing-sm);
}
.code-block {
  background-color: var(--tool-bg);
  color: var(--tool-text);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}
.faq-item {
  background: #ffffff;
  border: 1px solid var(--secondary);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
}
.faq-item h3 {
  font-size: 1.125rem;
  margin-bottom: var(--spacing-sm);
}
.faq-item p {
  margin-bottom: 0;
}

/* Footer */
.footer {
  background-color: #ffffff;
  border-top: 1px solid var(--secondary);
  padding: var(--spacing-xl) 0 var(--spacing-md);
  margin-top: auto;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}
.footer-col h4 {
  margin-bottom: var(--spacing-md);
}
.footer-links {
  list-style: none;
}
.footer-links li {
  margin-bottom: var(--spacing-sm);
}
.footer-links a {
  color: var(--text-light);
}
.footer-links a:hover {
  color: var(--primary);
}
.footer-bottom {
  text-align: center;
  color: var(--text-light);
  font-size: 0.875rem;
  border-top: 1px solid var(--secondary);
  padding-top: var(--spacing-md);
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 4rem;
    left: 0;
    right: 0;
    background: #ffffff;
    flex-direction: column;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--secondary);
    box-shadow: var(--shadow-md);
  }
  .nav-links.active {
    display: flex;
  }
  .mobile-menu-btn {
    display: block;
  }
  .tool-workspace {
    grid-template-columns: 1fr;
    height: auto;
  }
  .tool-editor {
    min-height: 400px;
  }
}