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

/* Base Styles */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

/* Container */
.container {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 1rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Grid Utilities */
.col-1 { grid-column: span 1; }
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: #222;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #666;
}

/* Header */
.site-header {
    background-color: #fff;
    border-bottom: 1px solid #eee;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.main-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    grid-column: 1 / -1;
}

.nav-brand .brand-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: #222;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 0.5rem 0;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #666;
}

.dropdown-arrow {
    margin-left: 0.5rem;
    font-size: 0.8rem;
    transition: transform 0.3s ease;
}

/* Dropdown Menu */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    border: 1px solid #eee;
    border-radius: 4px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    min-width: 200px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    z-index: 1001;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown:hover .dropdown-arrow {
    transform: rotate(180deg);
}

.dropdown-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #333;
    border-bottom: 1px solid #f5f5f5;
    transition: background-color 0.3s ease;
}

.dropdown-link:hover,
.dropdown-link.active {
    background-color: #f8f9fa;
    color: #333;
}

.dropdown-link:last-child {
    border-bottom: none;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.hamburger-line {
    width: 25px;
    height: 3px;
    background-color: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 2rem 0;
}

/* Homepage Styles */
.hero {
    background-color: #f8f9fa;
    padding: 4rem 0;
    text-align: center;
}

.hero-content {
    grid-column: 1 / -1;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #222;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: #666;
    margin-bottom: 2rem;
}

.hero-description {
    font-size: 1.1rem;
    line-height: 1.7;
}

/* Section Styles */
.research-preview,
.insights-preview {
    padding: 4rem 0;
}

.section-title {
    grid-column: 1 / -1;
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2.5rem;
}

.research-grid,
.insights-grid {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.research-item,
.insight-item {
    background-color: #f8f9fa;
    padding: 2rem;
    border-radius: 8px;
    transition: transform 0.3s ease;
}

.research-item:hover,
.insight-item:hover {
    transform: translateY(-2px);
}

.research-item h3,
.insight-item h3 {
    margin-bottom: 1rem;
}

.research-item h3 a,
.insight-item h3 a {
    color: #222;
}

/* Article Styles */
.single-article,
.list-content {
    grid-column: 1 / -1;
    max-width: 800px;
    margin: 0 auto;
}

/* General list page styles */
.list-description {
    grid-column: 1 / -1;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
    line-height: 1.7;
    text-align: center;
}

.list-description h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
}

.list-description h2 {
    font-size: 1.8rem;
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    color: #333;
    text-align: left;
}

.list-description h3 {
    font-size: 1.4rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: #444;
    text-align: left;
}

.list-description p {
    margin-bottom: 1.5rem;
    color: #555;
    text-align: center;
}

.list-description ul, 
.list-description ol {
    text-align: left;
    max-width: 800px;
    margin: 1.5rem auto;
}

/* About page specific styles */
.about-page .list-description h2,
.about-page .list-description h3 {
    text-align: left;
}

.about-page .list-description p {
    text-align: left;
}

.article-header,
.list-header {
    grid-column: 1 / -1;
    margin-bottom: 2rem;
    text-align: center;
    width: 100%;
}

.article-title,
.list-title {
    margin-bottom: 1rem;
}

.article-date,
.list-item-date {
    color: #666;
    font-size: 0.9rem;
}

.article-content {
    line-height: 1.8;
    margin-bottom: 2rem;
}

.article-content img {
    max-width: 100%;
    height: auto;
    margin: 2rem 0;
}

.list-item {
    margin-bottom: 4rem;
    padding: 2.5rem;
    background-color: #fafafa;
    border-radius: 8px;
    border: 1px solid #f0f0f0;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.list-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-color: #e0e0e0;
}

.list-item:last-child {
    margin-bottom: 2rem;
}

.list-item-title {
    margin-bottom: 1rem;
    font-size: 1.5rem;
    line-height: 1.3;
}

.list-item-title a {
    color: #222;
    text-decoration: none;
    transition: color 0.3s ease;
}

.list-item-title a:hover {
    color: #666;
}

.list-item-date {
    display: block;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: #888;
    font-weight: 500;
}

.list-item-summary {
    margin-top: 1rem;
    color: #666;
    line-height: 1.6;
    font-size: 1rem;
}

/* Tags */
.article-tags {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid #eee;
}

.tags-label {
    font-weight: 600;
    margin-right: 1rem;
}

.tag {
    display: inline-block;
    background-color: #f8f9fa;
    padding: 0.25rem 0.75rem;
    margin: 0.25rem 0.25rem 0.25rem 0;
    border-radius: 4px;
    font-size: 0.9rem;
    color: #666;
}

/* Footer */
.site-footer {
    background-color: #222;
    color: #fff;
    padding: 3rem 0 1rem;
}

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

.footer-title {
    color: #fff;
    margin-bottom: 1rem;
}

.footer-subtitle {
    color: #ccc;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.footer-description {
    color: #ccc;
    line-height: 1.6;
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    color: #ccc;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: #fff;
}

.footer-bottom {
    grid-column: 1 / -1;
    padding-top: 2rem;
    border-top: 1px solid #444;
    text-align: center;
}

.copyright {
    color: #999;
    margin: 0;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .container {
        padding: 0 1.5rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
        gap: 0.75rem;
    }
    
    /* Mobile Navigation */
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: #fff;
        border-top: 1px solid #eee;
        flex-direction: column;
        padding: 1rem;
        gap: 0;
    }
    
    .nav-item {
        width: 100%;
        border-bottom: 1px solid #f5f5f5;
    }
    
    .nav-item:last-child {
        border-bottom: none;
    }
    
    .nav-link {
        padding: 1rem 0;
        width: 100%;
    }
    
    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: none;
        background-color: #f8f9fa;
        margin-top: 0.5rem;
    }
    
    .dropdown-link {
        padding: 0.5rem 1rem;
    }
    
    /* Hero Section */
    .hero {
        padding: 2rem 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    /* Sections */
    .research-preview,
    .insights-preview {
        padding: 2rem 0;
    }
    
    .section-title {
        font-size: 2rem;
        margin-bottom: 2rem;
    }
    
    .research-grid,
    .insights-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .research-item,
    .insight-item {
        padding: 1.5rem;
    }
    
    /* Footer */
    .footer-content {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.25rem; }
}