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

/* Variables */
:root {
    --primary-color: #2a2a72;
    --secondary-color: #009ffd;
    --text-color: #333;
    --background-color: #f5f5f5;
    --container-width: 800px;
}

/* Base */
body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.nav-container {
    background: white;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.nav-menu {
    display: flex;
    gap: 2rem;
    padding: 1rem 0;
    list-style: none;
}

.nav-menu a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: var(--secondary-color);
}

/* Header */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 4rem 0;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.author-info {
    display: flex;
    gap: 1rem;
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Content */
.lead {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 2rem;
}

h2 {
    color: var(--primary-color);
    margin: 2rem 0 1rem;
    font-size: 1.8rem;
}

p {
    margin-bottom: 1.5rem;
}

a {
    color: var(--secondary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.highlight-box {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 2rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.highlight-box h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.highlight-box ul {
    list-style-position: inside;
    margin-left: 1rem;
}

.highlight-box li {
    margin-bottom: 0.5rem;
}

.quote-box {
    border-left: 4px solid var(--secondary-color);
    padding-left: 1.5rem;
    margin: 2rem 0;
}

blockquote {
    font-style: italic;
    color: #555;
}

cite {
    display: block;
    margin-top: 0.5rem;
    font-size: 0.9rem;
    color: #666;
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.feature {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

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

.feature h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.feature p {
    margin-bottom: 0;
    color: #666;
}

/* Reading Time */
.reading-time {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    margin-left: auto;
}

/* Progress Bar */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 4px;
    background: var(--secondary-color);
    width: 0;
    transition: width 0.2s ease;
    z-index: 1000;
}

/* Footer */
footer {
    background: #333;
    color: white;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .author-info {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
}