:root {
    --primary: #1a5276;
    --secondary: #2e86ab;
    --accent: #e67e22;
    --light: #f8f9fa;
    --dark: #2c3e50;
    --text: #333;
    --text-light: #666;
    --border: #ddd;
    --success: #27ae60;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; line-height: 1.6; color: var(--text); background: #fff; }
a { color: var(--secondary); text-decoration: none; }
a:hover { color: var(--primary); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; }
.site-header { background: var(--primary); color: white; padding: 1rem 0; position: sticky; top: 0; z-index: 100; box-shadow: var(--shadow); }
.header-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
.logo { font-size: 1.5rem; font-weight: bold; color: white; display: flex; align-items: center; gap: 0.5rem; }
.logo:hover { color: white; }
.main-nav { display: flex; gap: 1.5rem; flex-wrap: wrap; }
.main-nav a { color: rgba(255,255,255,0.9); font-weight: 500; transition: color 0.2s; }
.main-nav a:hover, .main-nav a.active { color: white; }
.nav-dropdown { position: relative; }
.nav-dropdown-content { display: none; position: absolute; top: 100%; left: 0; background: white; min-width: 200px; box-shadow: var(--shadow); border-radius: 8px; z-index: 1000; }
.nav-dropdown:hover .nav-dropdown-content { display: block; }
.nav-dropdown-content a { display: block; padding: 0.75rem 1rem; color: var(--text); }
.nav-dropdown-content a:hover { background: var(--light); color: var(--primary); }
.hero { background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%); color: white; padding: 4rem 0; text-align: center; }
.hero h1 { font-size: 2.5rem; margin-bottom: 1rem; }
.hero p { font-size: 1.2rem; opacity: 0.9; max-width: 600px; margin: 0 auto 2rem; }
.btn-primary { background: var(--accent); color: white; padding: 0.75rem 1.5rem; border: none; border-radius: 8px; font-size: 1rem; cursor: pointer; transition: transform 0.2s, box-shadow 0.2s; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 4px 15px rgba(230,126,34,0.4); color: white; }
.btn-secondary { background: var(--secondary); color: white; padding: 0.75rem 1.5rem; border: none; border-radius: 8px; cursor: pointer; }
.breadcrumb { padding: 1rem 0; color: var(--text-light); font-size: 0.875rem; }
.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--primary); }
.tool-card { display: block; padding: 1.5rem; background: var(--light); border-radius: 12px; transition: transform 0.2s, box-shadow 0.2s; text-decoration: none; color: inherit; }
.tool-card:hover { transform: translateY(-4px); box-shadow: 0 8px 25px rgba(0,0,0,0.15); }
.tool-icon { font-size: 2.5rem; margin-bottom: 0.5rem; }
.tool-card h3 { color: var(--primary); margin-bottom: 0.5rem; }
.tool-card p { color: var(--text-light); font-size: 0.875rem; }
.tool-detail { background: white; border-radius: 12px; padding: 2rem; box-shadow: var(--shadow); margin: 2rem 0; }
.tool-header { display: flex; gap: 1.5rem; margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 2px solid var(--light); }
.tool-info h1 { color: var(--primary); }
.tool-category { background: var(--light); padding: 0.25rem 0.75rem; border-radius: 20px; font-size: 0.875rem; color: var(--text-light); }
.form-group { margin-bottom: 1rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 500; color: var(--text); }
.form-group input, .form-group select { width: 100%; padding: 0.75rem; border: 1px solid var(--border); border-radius: 8px; font-size: 1rem; }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--secondary); box-shadow: 0 0 0 3px rgba(46,134,171,0.1); }
.article-page { max-width: 800px; margin: 0 auto; padding: 2rem 0; }
.article-header { margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 2px solid var(--light); }
.article-category { background: var(--secondary); color: white; padding: 0.25rem 0.75rem; border-radius: 20px; font-size: 0.875rem; }
.article-header h1 { font-size: 2rem; margin: 1rem 0; color: var(--primary); }
.article-meta { color: var(--text-light); font-size: 0.875rem; }
.article-body { line-height: 1.8; }
.article-body h2 { color: var(--primary); margin: 2rem 0 1rem; font-size: 1.5rem; border-left: 4px solid var(--accent); padding-left: 1rem; }
.article-body h3 { color: var(--secondary); margin: 1.5rem 0 0.75rem; font-size: 1.25rem; }
.article-body p { margin-bottom: 1rem; }
.article-body ul, .article-body ol { margin: 1rem 0 1rem 1.5rem; }
.article-body li { margin-bottom: 0.5rem; }
.article-image-placeholder { background: linear-gradient(135deg, var(--light) 0%, #e8e8e8 100%); border-radius: 12px; padding: 3rem; text-align: center; font-size: 3rem; margin: 2rem 0; border: 2px dashed var(--border); }
.callout { background: var(--light); border-left: 4px solid var(--secondary); padding: 1.5rem; border-radius: 0 8px 8px 0; margin: 1.5rem 0; }
.callout h4 { color: var(--primary); margin-bottom: 0.5rem; }
.related-articles { margin-top: 3rem; padding-top: 2rem; border-top: 2px solid var(--light); }
.related-articles h3 { color: var(--primary); margin-bottom: 1rem; }
.related-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 1rem; }
.related-item a { display: block; padding: 1rem; background: var(--light); border-radius: 8px; transition: background 0.2s; }
.related-item a:hover { background: var(--secondary); color: white; }
.internal-link { color: var(--secondary); font-weight: 500; border-bottom: 1px dashed var(--secondary); }
.internal-link:hover { color: var(--primary); border-color: var(--primary); }
.site-footer { background: var(--dark); color: white; padding: 3rem 0 1rem; margin-top: 4rem; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 2rem; margin-bottom: 2rem; }
.footer-col h4 { margin-bottom: 1rem; color: var(--accent); }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 0.5rem; }
.footer-col a { color: rgba(255,255,255,0.7); }
.footer-col a:hover { color: white; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 1rem; text-align: center; color: rgba(255,255,255,0.5); font-size: 0.875rem; }
.page-content { padding: 3rem 0; max-width: 800px; margin: 0 auto; }
.page-content h1 { color: var(--primary); margin-bottom: 1.5rem; }
.page-content h2 { color: var(--secondary); margin: 1.5rem 0 1rem; }
.page-content p { margin-bottom: 1rem; line-height: 1.8; }
.page-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.5rem; margin: 2rem 0; }
.contact-form { background: var(--light); padding: 2rem; border-radius: 12px; margin: 2rem 0; }
.contact-form input, .contact-form textarea { width: 100%; padding: 0.75rem; border: 1px solid var(--border); border-radius: 8px; margin-bottom: 1rem; font-size: 1rem; }
.contact-form textarea { min-height: 150px; resize: vertical; }
@media (max-width: 768px) {
    .header-inner { flex-direction: column; text-align: center; }
    .main-nav { justify-content: center; }
    .hero h1 { font-size: 1.75rem; }
    .tool-header { flex-direction: column; }
    .footer-grid { grid-template-columns: 1fr; text-align: center; }
}