:root {
  --primary: #0f172a;
  --secondary: #334155;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --bg: #f8fafc;
  --surface: #ffffff;
  --border: #e2e8f0;
  --text: #0f172a;
  --text-light: #475569;
  --danger: #ef4444;
  --success: #22c55e;
  --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;
  --radius: 8px;
  --radius-sm: 4px;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { overflow-x: hidden; }
body { font-family: var(--font-sans); background-color: var(--bg); color: var(--text); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-hover); }
img, svg { max-width: 100%; height: auto; }

/* Layout */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 1rem; }
.main-content { min-height: calc(100vh - 200px); padding: 3rem 0; }
.grid { display: grid; gap: 2rem; }
.grid-2 { grid-template-columns: 1fr; }
.grid-3 { grid-template-columns: 1fr; }
@media (min-width: 768px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
}

/* Header */
.header { background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.header-container { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { display: flex; align-items: center; gap: 0.5rem; font-weight: 700; font-size: 1.25rem; color: var(--primary); }
.logo svg { width: 24px; height: 24px; color: var(--accent); }
.nav-links { display: none; align-items: center; gap: 1.5rem; }
@media (min-width: 768px) { .nav-links { display: flex; } }
.nav-link { color: var(--text-light); font-weight: 500; }
.nav-link:hover, .nav-link.active { color: var(--accent); }
.menu-btn { display: block; background: none; border: none; cursor: pointer; padding: 0.5rem; color: var(--primary); }
@media (min-width: 768px) { .menu-btn { display: none; } }
.mobile-menu { display: none; background: var(--surface); border-bottom: 1px solid var(--border); padding: 1rem; flex-direction: column; gap: 1rem; }
.mobile-menu.active { display: flex; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.75rem 1.5rem; font-weight: 600; border-radius: var(--radius); cursor: pointer; transition: all 0.2s; font-family: var(--font-sans); border: none; font-size: 1rem; }
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-secondary { background: var(--surface); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { background: var(--bg); border-color: var(--text-light); }
.btn-outline { background: transparent; border: 1px solid var(--accent); color: var(--accent); }
.btn-outline:hover { background: var(--accent); color: white; }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.875rem; }

/* Hero */
.hero { text-align: center; padding: 5rem 1rem; background: var(--surface); border-bottom: 1px solid var(--border); }
.hero h1 { font-size: 2.5rem; font-weight: 800; margin-bottom: 1rem; letter-spacing: -0.025em; }
.hero p { font-size: 1.125rem; color: var(--text-light); max-width: 600px; margin: 0 auto 2rem; }
.hero-btns { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
@media (min-width: 768px) { .hero h1 { font-size: 3.5rem; } }

/* Tool Workspace */
.workspace { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.5rem; margin-bottom: 3rem; box-shadow: var(--shadow-sm); }
.workspace-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.workspace-title { font-size: 1.125rem; font-weight: 700; }
.panel-grid { display: grid; gap: 2rem; }
@media (min-width: 1024px) { .panel-grid { grid-template-columns: 1fr 1fr; } }
.panel { display: flex; flex-direction: column; gap: 0.5rem; }
.textarea { width: 100%; min-height: 250px; padding: 1rem; font-family: var(--font-mono); font-size: 0.875rem; border: 1px solid var(--border); border-radius: var(--radius); resize: vertical; background: var(--bg); color: var(--text); line-height: 1.5; outline: none; transition: border-color 0.2s; }
.textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1); }
.textarea[readonly] { background: #f1f5f9; cursor: text; }
.panel-controls { display: flex; justify-content: space-between; align-items: center; margin-top: 0.5rem; flex-wrap: wrap; gap: 1rem; }
.controls-left, .controls-right { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.status-text { font-size: 0.875rem; color: var(--text-light); }

/* Toast */
.toast { position: fixed; bottom: 2rem; right: 2rem; background: var(--primary); color: white; padding: 1rem 1.5rem; border-radius: var(--radius); box-shadow: var(--shadow); opacity: 0; transform: translateY(100%); transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); z-index: 1000; display: flex; align-items: center; gap: 0.5rem; }
.toast.show { opacity: 1; transform: translateY(0); }
.toast svg { color: var(--success); }

/* Typography & Content */
.content { max-width: 800px; margin: 0 auto; }
.content h1 { font-size: 2.25rem; font-weight: 800; margin-bottom: 1.5rem; letter-spacing: -0.025em; }
.content h2 { font-size: 1.875rem; font-weight: 700; margin: 2.5rem 0 1rem; letter-spacing: -0.025em; }
.content h3 { font-size: 1.5rem; font-weight: 600; margin: 2rem 0 1rem; }
.content p { margin-bottom: 1.5rem; font-size: 1.125rem; color: var(--text-light); }
.content ul, .content ol { margin: 0 0 1.5rem 1.5rem; font-size: 1.125rem; color: var(--text-light); }
.content li { margin-bottom: 0.5rem; }
.content table { width: 100%; border-collapse: collapse; margin-bottom: 2rem; }
.content th, .content td { padding: 1rem; text-align: left; border: 1px solid var(--border); }
.content th { background: var(--bg); font-weight: 600; }
.content pre { background: var(--primary); color: #f8fafc; padding: 1.5rem; border-radius: var(--radius); overflow-x: auto; margin-bottom: 1.5rem; font-family: var(--font-mono); font-size: 0.875rem; line-height: 1.5; }
.content code { font-family: var(--font-mono); background: var(--bg); color: var(--accent); padding: 0.2em 0.4em; border-radius: 4px; font-size: 0.875em; }
.content pre code { background: none; color: inherit; padding: 0; border-radius: 0; }
.content img { border-radius: var(--radius); box-shadow: var(--shadow-sm); margin-bottom: 1.5rem; }

/* Blog Cards */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.5rem; transition: transform 0.2s, box-shadow 0.2s; display: flex; flex-direction: column; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--accent); }
.card-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 0.5rem; }
.card-title a { color: var(--primary); }
.card-title a:hover { color: var(--accent); }
.card-excerpt { color: var(--text-light); font-size: 1rem; margin-bottom: 1.5rem; flex-grow: 1; }
.card-meta { display: flex; justify-content: space-between; font-size: 0.875rem; color: var(--text-light); }

/* Features Section */
.features { padding: 4rem 0; }
.feature-icon { width: 48px; height: 48px; background: rgba(37, 99, 235, 0.1); color: var(--accent); border-radius: 12px; display: flex; align-items: center; justify-content: center; margin-bottom: 1.5rem; }
.feature-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 0.5rem; }
.feature-desc { color: var(--text-light); }

/* FAQ */
.faq-item { border-bottom: 1px solid var(--border); padding: 1.5rem 0; }
.faq-q { font-size: 1.125rem; font-weight: 600; margin-bottom: 0.5rem; }
.faq-a { color: var(--text-light); margin-bottom: 0; }

/* Breadcrumb */
.breadcrumb { margin-bottom: 2rem; display: flex; gap: 0.5rem; color: var(--text-light); font-size: 0.875rem; }
.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb span { color: var(--border); }

/* Footer */
.footer { background: var(--surface); border-top: 1px solid var(--border); padding: 4rem 0 2rem; margin-top: auto; }
.footer-grid { display: grid; gap: 2rem; margin-bottom: 3rem; }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; } }
.footer-brand p { color: var(--text-light); margin-top: 1rem; max-width: 300px; font-size: 0.875rem; }
.footer-heading { font-weight: 700; margin-bottom: 1rem; font-size: 1rem; }
.footer-links { list-style: none; margin: 0; }
.footer-links li { margin-bottom: 0.5rem; }
.footer-links a { color: var(--text-light); font-size: 0.875rem; }
.footer-links a:hover { color: var(--accent); }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 2rem; display: flex; flex-direction: column; gap: 1rem; align-items: center; justify-content: space-between; font-size: 0.875rem; color: var(--text-light); }
@media (min-width: 768px) { .footer-bottom { flex-direction: row; } }

/* Forms */
.form-group { margin-bottom: 1.5rem; }
.form-label { display: block; font-weight: 500; margin-bottom: 0.5rem; }
.form-input { width: 100%; padding: 0.75rem 1rem; border: 1px solid var(--border); border-radius: var(--radius); font-family: var(--font-sans); font-size: 1rem; background: var(--surface); transition: border-color 0.2s; }
.form-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1); }