/* ============================================
   TeleFos USA - Clean Minimal CSS
   ============================================ */

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

:root {
    --dark: #1a1f36;
    --blue: #3b82f6;
    --cyan: #06b6d4;
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --radius: 8px;
    --radius-lg: 12px;
}

html { font-size: 16px; }
body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif; line-height: 1.6; color: var(--gray-700); background: var(--white); min-height: 100vh; overflow-x: hidden; }
a { color: var(--blue); text-decoration: none; }
a:hover { color: #2563eb; }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }

h1, h2, h3, h4 { color: var(--dark); font-weight: 700; line-height: 1.3; margin-bottom: 1rem; }
h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
p { margin-bottom: 1rem; }

/* Container */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }

/* Header */
.header { background: var(--white); box-shadow: var(--shadow); position: sticky; top: 0; z-index: 100; }
.header .container { display: flex; justify-content: space-between; align-items: center; padding: 1rem 1.5rem; }
.logo { display: flex; align-items: center; gap: 0.75rem; font-size: 1.5rem; font-weight: 800; color: var(--dark); }
.logo-icon { width: 45px; height: 45px; background: linear-gradient(135deg, var(--blue), var(--cyan)); border-radius: var(--radius); display: flex; align-items: center; justify-content: center; color: var(--white); font-size: 1.5rem; }
.logo span { color: var(--blue); }
.nav { display: flex; gap: 2rem; }
.nav a { font-weight: 500; color: var(--gray-600); padding: 0.5rem 0; }
.nav a:hover, .nav a.active { color: var(--blue); }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 1.5rem; color: var(--dark); cursor: pointer; padding: 0.5rem; }

/* Mobile Nav */
.mobile-nav { position: fixed; top: 0; right: -100%; width: 280px; height: 100vh; background: var(--white); box-shadow: var(--shadow-lg); z-index: 200; padding: 2rem; transition: right 0.3s ease; }
.mobile-nav.active { right: 0; }
.mobile-nav-close { position: absolute; top: 1rem; right: 1rem; background: none; border: none; font-size: 1.5rem; color: var(--gray-500); cursor: pointer; }
.mobile-nav a { display: block; padding: 1rem 0; font-size: 1.125rem; font-weight: 500; color: var(--gray-700); border-bottom: 1px solid var(--gray-100); }
.mobile-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 199; opacity: 0; visibility: hidden; transition: all 0.3s; }
.mobile-overlay.active { opacity: 1; visibility: visible; }

/* Hero */
.hero { background: linear-gradient(135deg, var(--dark) 0%, #2d3555 100%); color: var(--white); padding: 4rem 0; text-align: center; }
.hero h1 { color: var(--white); font-size: 2.75rem; margin-bottom: 1rem; }
.hero p { color: rgba(255,255,255,0.9); font-size: 1.125rem; max-width: 700px; margin: 0 auto 2rem; }
.text-gradient { background: linear-gradient(135deg, var(--blue), var(--cyan)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero-badge { display: inline-block; background: rgba(59,130,246,0.2); padding: 0.5rem 1rem; border-radius: 50px; font-size: 0.875rem; margin-bottom: 1.5rem; color: var(--cyan); }
.hero-buttons { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.75rem 1.5rem; font-size: 1rem; font-weight: 600; border-radius: var(--radius); border: none; cursor: pointer; transition: all 0.3s; text-decoration: none; }
.btn-primary { background: var(--blue); color: var(--white); }
.btn-primary:hover { background: #2563eb; color: var(--white); transform: translateY(-2px); }
.btn-outline { background: transparent; border: 2px solid var(--white); color: var(--white); }
.btn-outline:hover { background: var(--white); color: var(--dark); }
.btn-lg { padding: 1rem 2rem; font-size: 1.125rem; }

/* Sections */
.section { padding: 4rem 0; }
.section-light { background: var(--gray-50); }
.section-dark { background: var(--dark); color: var(--white); }
.section-header { text-align: center; max-width: 700px; margin: 0 auto 3rem; }
.section-header h2 { margin-bottom: 0.5rem; }
.section-header p { color: var(--gray-600); font-size: 1.125rem; }

/* Stats */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }
.stat-item { text-align: center; padding: 2rem 1rem; background: var(--white); border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.stat-number { font-size: 3rem; font-weight: 800; color: var(--blue); margin-bottom: 0.5rem; }
.stat-label { color: var(--gray-500); font-size: 0.95rem; }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.5rem; }
.card { background: var(--white); border-radius: var(--radius-lg); padding: 1.5rem; box-shadow: var(--shadow); transition: all 0.3s; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card-icon { width: 60px; height: 60px; background: linear-gradient(135deg, var(--blue), var(--cyan)); border-radius: var(--radius); display: flex; align-items: center; justify-content: center; margin-bottom: 1rem; }
.card-icon i { font-size: 1.5rem; color: var(--white); }
.card h3 { font-size: 1.25rem; margin-bottom: 0.75rem; }
.card p { color: var(--gray-600); font-size: 0.95rem; margin-bottom: 1rem; }
.card-link { font-weight: 600; display: inline-flex; align-items: center; gap: 0.5rem; }
.card-link i { transition: transform 0.3s; }
.card-link:hover i { transform: translateX(4px); }

/* Blog Cards */
.blog-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); gap: 1.5rem; }
.blog-card { background: var(--white); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); transition: all 0.3s; }
.blog-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.blog-card-image { height: 200px; overflow: hidden; }
.blog-card-image img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.3s; }
.blog-card:hover .blog-card-image img { transform: scale(1.05); }
.blog-card-body { padding: 1.5rem; }
.blog-card-meta { display: flex; gap: 1rem; font-size: 0.875rem; color: var(--gray-500); margin-bottom: 0.75rem; }
.blog-card h3 { font-size: 1.25rem; margin-bottom: 0.5rem; }
.blog-card h3 a { color: var(--dark); }
.blog-card h3 a:hover { color: var(--blue); }
.blog-card p { color: var(--gray-600); font-size: 0.95rem; }

/* Features */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; }
.feature-item { display: flex; gap: 1rem; padding: 1.5rem; background: var(--gray-50); border-radius: var(--radius-lg); }
.feature-item i { color: var(--blue); font-size: 1.5rem; margin-top: 0.25rem; }
.feature-item h4 { margin-bottom: 0.25rem; font-size: 1.125rem; }
.feature-item p { margin-bottom: 0; font-size: 0.9rem; color: var(--gray-600); }

/* Footer */
.footer { background: var(--dark); color: var(--gray-400); padding: 4rem 0 2rem; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 3rem; margin-bottom: 3rem; }
.footer-brand p { margin-bottom: 1rem; }
.footer h4 { color: var(--white); font-size: 1rem; margin-bottom: 1.25rem; }
.footer-links li { margin-bottom: 0.75rem; }
.footer-links a { color: var(--gray-400); font-size: 0.95rem; }
.footer-links a:hover { color: var(--white); }
.footer-bottom { padding-top: 2rem; border-top: 1px solid var(--gray-700); display: flex; justify-content: space-between; align-items: center; }
.footer-bottom p { font-size: 0.875rem; margin-bottom: 0; }
.social-links { display: flex; gap: 1rem; }
.social-links a { color: var(--gray-400); font-size: 1.25rem; }
.social-links a:hover { color: var(--white); }

/* Page Header */
.page-header { background: linear-gradient(135deg, var(--dark) 0%, #2d3555 100%); color: var(--white); padding: 3rem 0; text-align: center; }
.page-header h1 { color: var(--white); font-size: 2.5rem; margin-bottom: 0.5rem; }
.page-header p { color: rgba(255,255,255,0.9); font-size: 1.125rem; }

/* Tools Page */
.tool-container { max-width: 900px; margin: 0 auto; }
.tool-header { text-align: center; margin-bottom: 2rem; }
.tool-header h1 { font-size: 2.25rem; }
.tool-box { background: var(--white); border-radius: var(--radius-lg); padding: 2rem; box-shadow: var(--shadow); margin-bottom: 2rem; }
.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; font-weight: 600; margin-bottom: 0.5rem; color: var(--dark); }
.form-control { width: 100%; padding: 0.75rem 1rem; font-size: 1rem; border: 1px solid var(--gray-300); border-radius: var(--radius); transition: all 0.3s; }
.form-control:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(59,130,246,0.1); }
textarea.form-control { min-height: 150px; resize: vertical; }
.tool-btn { background: var(--blue); color: var(--white); border: none; padding: 0.875rem 1.5rem; border-radius: var(--radius); font-size: 1rem; font-weight: 600; cursor: pointer; transition: all 0.3s; }
.tool-btn:hover { background: #2563eb; transform: translateY(-2px); }
.tool-result { background: var(--gray-50); border-radius: var(--radius); padding: 1.5rem; margin-top: 1.5rem; }

/* Article */
.article-content { max-width: 800px; margin: 0 auto; }
.article-content img { border-radius: var(--radius-lg); margin: 2rem 0; }
.article-content h2 { font-size: 1.75rem; margin-top: 2.5rem; margin-bottom: 1rem; border-bottom: 2px solid var(--gray-100); padding-bottom: 0.5rem; }
.article-content h3 { font-size: 1.375rem; margin-top: 2rem; margin-bottom: 0.75rem; }
.article-meta { display: flex; gap: 1.5rem; color: var(--gray-500); font-size: 0.875rem; margin-bottom: 2rem; }
.article-meta span { display: flex; align-items: center; gap: 0.25rem; }
.author-box { display: flex; gap: 1.5rem; padding: 2rem; background: var(--gray-50); border-radius: var(--radius-lg); margin-top: 3rem; }
.author-avatar { width: 80px; height: 80px; border-radius: 50%; object-fit: cover; }
.author-info h4 { margin-bottom: 0.25rem; }
.author-info p { margin-bottom: 0; font-size: 0.9rem; color: var(--gray-600); }
.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; margin-top: 3rem; }
.social-share { display: flex; gap: 0.75rem; margin-top: 1.5rem; }
.social-share a { width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; background: var(--gray-100); color: var(--gray-600); transition: all 0.3s; }
.social-share a:hover { background: var(--blue); color: var(--white); }

/* Contact Form */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; }
.contact-info h3 { margin-bottom: 1rem; }
.contact-info p { margin-bottom: 1.5rem; }
.contact-item { display: flex; align-items: center; gap: 1rem; margin-bottom: 1rem; }
.contact-item i { color: var(--blue); font-size: 1.25rem; width: 24px; }

/* Privacy/Terms */
.legal-content { max-width: 800px; margin: 0 auto; padding: 2rem 0; }
.legal-content h2 { font-size: 1.5rem; margin-top: 2rem; margin-bottom: 1rem; border-bottom: 1px solid var(--gray-200); padding-bottom: 0.5rem; }

/* ============================================
   RESPONSIVE - TABLET (1024px)
   ============================================ */
@media (max-width: 1024px) {
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .contact-grid { grid-template-columns: 1fr; }
}

/* ============================================
   RESPONSIVE - MOBILE (768px)
   ============================================ */
@media (max-width: 768px) {
    .nav { display: none; }
    .mobile-menu-btn { display: block; }
    
    .hero { padding: 3rem 0; }
    .hero h1 { font-size: 2rem; }
    .hero p { font-size: 1rem; }
    .hero-buttons { flex-direction: column; align-items: center; }
    .hero-buttons .btn { width: 100%; max-width: 280px; }
    
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .stat-number { font-size: 2.5rem; }
    
    .section { padding: 2.5rem 0; }
    .section-header h2 { font-size: 1.5rem; }
    .section-header p { font-size: 1rem; }
    
    .card-grid { grid-template-columns: 1fr; }
    .blog-grid { grid-template-columns: 1fr; }
    .feature-grid { grid-template-columns: 1fr; }
    
    .footer-grid { grid-template-columns: 1fr; gap: 2rem; text-align: center; }
    .footer-bottom { flex-direction: column; gap: 1rem; text-align: center; }
    
    .page-header { padding: 2rem 0; }
    .page-header h1 { font-size: 1.75rem; }
    
    .tool-container { padding: 0 1rem; }
    .tool-box { padding: 1.5rem; }
    
    .related-grid { grid-template-columns: 1fr; }
    .author-box { flex-direction: column; text-align: center; }
    .author-avatar { margin: 0 auto; }
    
    .blog-card-image { height: 180px; }
}

/* ============================================
   RESPONSIVE - SMALL MOBILE (480px)
   ============================================ */
@media (max-width: 480px) {
    .container { padding: 0 1rem; }
    .hero h1 { font-size: 1.625rem; }
    .stats-grid { grid-template-columns: 1fr 1fr; gap: 1rem; }
    .stat-item { padding: 1.25rem 0.75rem; }
    .stat-number { font-size: 2rem; }
    .btn-lg { padding: 0.875rem 1.25rem; font-size: 1rem; }
    .blog-card-image { height: 160px; }
    .section-header h2 { font-size: 1.375rem; }
}