/* Reset & Base */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, sans-serif; color: #111827; background: #f8fafc; line-height: 1.6; }

/* Container */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* Header */
.header { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,0.95); backdrop-filter: blur(8px); border-bottom: 1px solid #e5e7eb; }
.header .container { display: flex; justify-content: space-between; align-items: center; height: 64px; }
.logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.logo-icon { width: 40px; height: 40px; background: #2563eb; border-radius: 8px; display: flex; align-items: center; justify-content: center; font-size: 22px; }
.logo-title { font-size: 18px; font-weight: 700; color: #111827; }
.logo-sub { font-size: 11px; color: #6b7280; }
.nav { display: flex; gap: 24px; }
.nav-link { text-decoration: none; color: #4b5563; font-weight: 500; font-size: 15px; padding: 8px 0; }
.nav-link:hover, .nav-link.active { color: #2563eb; }

/* Hero */
.hero { text-align: center; padding: 80px 0 60px; }
.hero h1 { font-size: 48px; font-weight: 800; color: #111827; margin-bottom: 20px; line-height: 1.2; }
.hero .highlight { color: #2563eb; display: block; }
.hero-subtitle { font-size: 20px; color: #4b5563; max-width: 700px; margin: 0 auto 40px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-sm { padding: 40px 0; }
.hero-sm h1 { font-size: 36px; }
.hero-sm p { font-size: 18px; max-width: 600px; margin: 0 auto; }

/* Buttons */
.btn { display: inline-block; padding: 14px 28px; border-radius: 8px; font-weight: 600; font-size: 16px; text-decoration: none; transition: background 0.2s; }
.btn-primary { background: #2563eb; color: white; }
.btn-primary:hover { background: #1d4ed8; }
.btn-secondary { background: #f3f4f6; color: #374151; }
.btn-secondary:hover { background: #e5e7eb; }

/* Sections */
.section { padding: 60px 0; }
.bg-light { background: #f8fafc; }
.section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 40px; flex-wrap: wrap; gap: 12px; }
.section-header h2 { font-size: 32px; font-weight: 700; }
.section-link { text-decoration: none; color: #2563eb; font-weight: 600; }
.section-link:hover { color: #1d4ed8; }

/* Cards */
.features-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 24px; }
.card { display: block; background: white; border-radius: 12px; padding: 24px; border: 1px solid #e5e7eb; text-decoration: none; transition: box-shadow 0.2s; }
.card:hover { box-shadow: 0 8px 24px rgba(0,0,0,0.08); }
.card-icon { font-size: 32px; margin-bottom: 12px; }
.card h3 { color: #111827; font-size: 20px; font-weight: 600; margin-bottom: 8px; }
.card p { color: #6b7280; font-size: 15px; margin-bottom: 12px; }
.card-tag { font-size: 13px; color: #6b7280; margin-bottom: 8px; }
.card-link { color: #2563eb; font-weight: 600; font-size: 14px; }
.card-guide:hover { border-color: #2563eb; }

/* Stats */
.stats-section { background: linear-gradient(135deg, #eff6ff, #dbeafe); border-radius: 16px; margin: 0 24px; padding: 60px 0; }
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; text-align: center; }
.stat-number { font-size: 48px; font-weight: 800; color: #2563eb; margin-bottom: 8px; }
.stat-label { font-size: 18px; font-weight: 600; color: #111827; margin-bottom: 4px; }
.stat-desc { font-size: 14px; color: #6b7280; }

/* Tools Listing */
.tool-category { margin-bottom: 48px; }
.tool-category h2 { font-size: 28px; font-weight: 700; margin-bottom: 20px; }
.tools-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }

/* Tool Page */
.tool-page { max-width: 800px; margin: 0 auto; }
.breadcrumb { font-size: 14px; color: #6b7280; margin-bottom: 24px; }
.breadcrumb a { color: #2563eb; text-decoration: none; }
.breadcrumb span { color: #111827; font-weight: 500; }
.tool-container { background: white; border-radius: 12px; padding: 32px; border: 1px solid #e5e7eb; margin: 32px 0; }
.tool-input { width: 100%; padding: 12px 16px; border: 1px solid #d1d5db; border-radius: 8px; font-size: 16px; margin-bottom: 16px; }
.tool-input:focus { outline: none; border-color: #2563eb; box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
.tool-label { display: block; font-size: 14px; font-weight: 500; color: #374151; margin-bottom: 8px; }
.tool-btn { padding: 12px 24px; border-radius: 8px; font-weight: 600; border: none; cursor: pointer; font-size: 15px; }
.tool-btn-primary { background: #2563eb; color: white; }
.tool-btn-primary:hover { background: #1d4ed8; }
.tool-result { background: #f0f9ff; border-radius: 12px; padding: 24px; margin-top: 24px; }
.tool-result h3 { font-size: 20px; margin-bottom: 16px; }
.result-row { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; border-bottom: 1px solid #e0f2fe; }
.result-row:last-child { border-bottom: none; }
.result-label { color: #475569; }
.result-value { font-size: 24px; font-weight: 700; color: #111827; }
.result-total { font-size: 32px; font-weight: 800; color: #111827; }

/* Guide Page */
.guide-content h2 { font-size: 28px; margin: 40px 0 16px; }
.guide-content h3 { font-size: 22px; margin: 24px 0 12px; }
.guide-content p { margin-bottom: 16px; color: #374151; }
.guide-content ul { margin: 0 0 24px 24px; }
.guide-content li { margin-bottom: 8px; color: #374151; }
.guide-tip { background: #fef3c7; border-left: 4px solid #f59e0b; padding: 16px; border-radius: 8px; margin: 24px 0; }

/* Sidebar */
.sidebar-section { background: white; border-radius: 12px; padding: 24px; border: 1px solid #e5e7eb; margin-bottom: 24px; }
.sidebar-section h3 { font-size: 20px; margin-bottom: 16px; }
.sidebar-nav a { display: block; padding: 12px 0; border-bottom: 1px solid #f3f4f6; color: #2563eb; text-decoration: none; }
.sidebar-nav a:last-child { border-bottom: none; }
.sidebar-nav a:hover { color: #1d4ed8; }
.cta-box { background: linear-gradient(135deg, #2563eb, #3b82f6); border-radius: 12px; padding: 24px; color: white; }
.cta-box h3 { font-size: 20px; margin-bottom: 12px; }
.cta-box p { margin-bottom: 16px; opacity: 0.9; }
.cta-box .btn { background: white; color: #2563eb; display: inline-block; }

/* Footer */
.footer { background: #111827; color: #d1d5db; padding: 48px 0 24px; margin-top: 60px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 32px; }
.footer-brand .logo-title { color: white; }
.footer-title { color: white; font-size: 18px; font-weight: 700; }
.footer-sub { color: #9ca3af; font-size: 11px; }
.footer-brand p { margin-top: 16px; color: #9ca3af; font-size: 14px; }
.footer-links h4 { color: white; font-size: 16px; margin-bottom: 16px; }
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 8px; }
.footer-links a { color: #9ca3af; text-decoration: none; font-size: 14px; }
.footer-links a:hover { color: white; }
.footer-bottom { border-top: 1px solid #374151; padding-top: 24px; text-align: center; }
.footer-bottom p { font-size: 14px; color: #6b7280; }
.disclaimer { margin-top: 8px; font-size: 12px; }

/* SEO Content */
.seo-content { max-width: 800px; margin: 0 auto; }
.seo-content h2 { font-size: 32px; margin: 48px 0 16px; }
.seo-content h3 { font-size: 24px; margin: 32px 0 12px; }
.seo-content p { margin-bottom: 16px; color: #374151; font-size: 16px; }
.seo-content ul { margin: 0 0 24px 32px; }
.seo-content li { margin-bottom: 8px; color: #374151; }
.seo-content li strong { color: #111827; }

/* Responsive */
@media (max-width: 768px) {
    .hero h1 { font-size: 32px; }
    .hero-subtitle { font-size: 16px; }
    .stats-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .section-header { flex-direction: column; align-items: flex-start; }
    .tools-grid { grid-template-columns: 1fr; }
}

@media (max-width: 500px) {
    .nav { gap: 12px; }
    .nav-link { font-size: 14px; }
    .footer-grid { grid-template-columns: 1fr; }
}