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

body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    color: #333;
    line-height: 1.6;
}

/* Header Styles */
header {
    background-color: #333;
    color: white;
    padding: 40px 0;
    text-align: center;
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header p {
    font-size: 1.2em;
    opacity: 0.8;
}

/* Navigation Styles */
nav {
    background-color: #444;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.nav-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 15px 20px;
    display: block;
    transition: background-color 0.3s;
}

.nav-link:hover,
.nav-link.active {
    background-color: #555;
}

/* Main Content Styles */
main {
    padding: 30px 0;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Search Section */
.search-section {
    margin-bottom: 30px;
}

#search-input {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

/* Categories Section */
.categories-section {
    margin-bottom: 40px;
}

.categories-section h2 {
    color: #333;
    margin-bottom: 20px;
    border-bottom: 2px solid #4CAF50;
    padding-bottom: 10px;
}

.categories {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.category-tag {
    background-color: #f0f0f0;
    padding: 8px 15px;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.category-tag:hover {
    background-color: #4CAF50;
    color: white;
}

/* Articles Section */
.articles-section {
    margin-bottom: 40px;
}

.articles-section h2 {
    color: #333;
    margin-bottom: 20px;
    border-bottom: 2px solid #4CAF50;
    padding-bottom: 10px;
}

.article-card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    padding: 20px;
    margin-bottom: 20px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
}

.article-card h3 {
    color: #333;
    margin-bottom: 10px;
    font-size: 1.3em;
}

.article-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    font-size: 14px;
    color: #666;
}

.article-category {
    background-color: #e8f5e8;
    color: #4CAF50;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
}

.article-content {
    margin-bottom: 15px;
    line-height: 1.6;
}

.article-solution {
    background-color: #f9f9f9;
    padding: 15px;
    border-radius: 6px;
    border-left: 4px solid #4CAF50;
    margin-top: 15px;
}

.article-solution h4 {
    margin-bottom: 10px;
    color: #4CAF50;
}

/* About Section */
.about-section {
    margin-bottom: 40px;
}

.about-section h2 {
    color: #333;
    margin-bottom: 20px;
    border-bottom: 2px solid #4CAF50;
    padding-bottom: 10px;
}

.about-content {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* Footer Styles */
footer {
    background-color: #333;
    color: white;
    padding: 20px 0;
    text-align: center;
}

.footer-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

/* No Articles Message */
.no-articles {
    text-align: center;
    color: #666;
    padding: 60px 0;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* Responsive Styles */
@media (max-width: 600px) {
    header h1 {
        font-size: 2em;
    }
    
    header p {
        font-size: 1em;
    }
    
    .nav-content {
        flex-direction: column;
    }
    
    .nav-link {
        text-align: center;
        padding: 10px;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .article-card {
        padding: 15px;
    }
    
    .categories {
        justify-content: center;
    }
}