/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Header Styles */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo h1 {
    color: #4a5568;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.2rem;
}

.tagline {
    font-size: 0.9rem;
    color: #718096;
    font-weight: 400;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #4a5568;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #667eea;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: #4a5568;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #ffffff, #f7fafc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 3rem;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 2rem;
}

.stat {
    text-align: center;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: transform 0.3s ease;
}

.stat:hover {
    transform: translateY(-5px);
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* Main Content */
.main-content {
    background: #f7fafc;
    padding: 4rem 0;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 2rem;
}

.blog-article {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    margin-bottom: 3rem;
}

.article-header {
    padding: 3rem 3rem 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.article-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.article-meta {
    display: flex;
    justify-content: center;
    gap: 2rem;
    opacity: 0.9;
    font-size: 0.9rem;
}

.article-content {
    padding: 3rem;
    line-height: 1.8;
}

.lead-paragraph {
    font-size: 1.2rem;
    color: #4a5568;
    margin-bottom: 2rem;
    font-weight: 400;
    line-height: 1.7;
}

.article-content p {
    margin-bottom: 1.5rem;
    color: #2d3748;
}

.article-content h2 {
    font-size: 1.8rem;
    color: #2d3748;
    margin: 2.5rem 0 1rem;
    font-weight: 600;
    position: relative;
    padding-left: 1rem;
}

.article-content h2::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 2px;
}

.article-content h3 {
    font-size: 1.4rem;
    color: #4a5568;
    margin: 2rem 0 1rem;
    font-weight: 600;
}

.inline-link {
    color: #667eea;
    text-decoration: none;
    font-weight: 600;
    position: relative;
    transition: all 0.3s ease;
}

.inline-link:hover {
    color: #764ba2;
}

.inline-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.inline-link:hover::after {
    transform: scaleX(1);
}

.calculation-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.calc-item {
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    padding: 2rem;
    border-radius: 15px;
    border: 2px solid #e2e8f0;
    transition: all 0.3s ease;
}

.calc-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    border-color: #667eea;
}

.calc-item h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

/* Footer */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #f7fafc;
}

.footer-section p {
    color: #a0aec0;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #a0aec0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #667eea;
}

.footer-bottom {
    border-top: 1px solid #4a5568;
    padding-top: 1rem;
    text-align: center;
    color: #a0aec0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
        align-items: center;
    }
    
    .stat {
        width: 200px;
    }
    
    .article-header,
    .article-content {
        padding: 2rem 1.5rem;
    }
    
    .article-title {
        font-size: 2rem;
    }
    
    .article-meta {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .calculation-breakdown {
        grid-template-columns: 1fr;
    }
    
    .nav-container {
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .article-header,
    .article-content {
        padding: 1.5rem 1rem;
    }
    
    .article-title {
        font-size: 1.8rem;
    }
    
    .container {
        padding: 0 1rem;
    }
}

/* Animation Classes */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Scroll Animations */
.scroll-reveal {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.6s ease;
}

.scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* Focus Styles for Accessibility */
.nav-link:focus,
.inline-link:focus {
    outline: 2px solid #667eea;
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .header,
    .footer {
        display: none;
    }
    
    .hero {
        background: none;
        color: black;
    }
    
    .article-header {
        background: none;
        color: black;
    }
}