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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #9b59b6;
    --science-blue: #2980b9;
    --science-green: #27ae60;
    --science-purple: #8e44ad;
    --science-red: #e74c3c;
    --light-bg: #f8f9fa;
    --dark-text: #2c3e50;
    --light-text: #7f8c8d;
    --card-shadow: 0 4px 12px rgba(0,0,0,0.1);
    --transition: all 0.3s ease;
}

body {
    font-family: 'Source Serif Pro', serif;
    line-height: 1.6;
    color: var(--dark-text);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
.site-header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo a {
    text-decoration: none;
    color: var(--primary-color);
}

.logo h1 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.8rem;
    margin-bottom: 0.2rem;
}

.logo .tagline {
    font-size: 0.9rem;
    color: var(--light-text);
    font-style: italic;
}

.logo i {
    color: var(--science-blue);
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--dark-text);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 0;
    position: relative;
}

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

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--secondary-color);
}

.btn-subscribe {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.7rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.btn-subscribe:hover {
    background: var(--science-blue);
    transform: translateY(-2px);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--primary-color);
    cursor: pointer;
}

/* Hero Section */
.hero {
    padding: 5rem 0;
    background: linear-gradient(rgba(44, 62, 80, 0.9), rgba(52, 152, 219, 0.8)), url('/assets/images/science-bg.jpg');
    background-size: cover;
    background-position: center;
    color: white;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h2 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 2.8rem;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.btn-primary {
    display: inline-block;
    background: white;
    color: var(--secondary-color);
    padding: 1rem 2rem;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    border: 2px solid white;
}

.btn-primary:hover {
    background: transparent;
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.science-icons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.science-icons i {
    font-size: 4rem;
    background: rgba(255,255,255,0.1);
    padding: 2rem;
    border-radius: 50%;
    transition: var(--transition);
    animation: float 3s ease-in-out infinite;
}

.science-icons i:nth-child(1) { 
    color: #9b59b6; 
    animation-delay: 0s;
}
.science-icons i:nth-child(2) { 
    color: #e74c3c; 
    animation-delay: 0.5s;
}
.science-icons i:nth-child(3) { 
    color: #27ae60; 
    animation-delay: 1s;
}
.science-icons i:nth-child(4) { 
    color: #3498db; 
    animation-delay: 1.5s;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

/* Main Content Layout */
main.container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    padding: 3rem 0;
}

/* Stories Section */
.section-title {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 2.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    grid-column: 1 / -1;
}

.section-title i {
    color: var(--secondary-color);
    margin-right: 10px;
}

.section-subtitle {
    display: block;
    font-size: 1rem;
    color: var(--light-text);
    font-weight: normal;
    margin-top: 0.5rem;
}

/* Filters */
.filters {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
}

.filter-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.6rem 1.2rem;
    border: 2px solid var(--light-text);
    background: white;
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--secondary-color);
    color: white;
    border-color: var(--secondary-color);
}

.sort-select {
    padding: 0.6rem 1rem;
    border: 2px solid var(--light-text);
    border-radius: 5px;
    background: white;
    font-family: inherit;
    cursor: pointer;
}

/* Stories Grid */
.stories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.story-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    cursor: pointer;
}

.story-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

.story-image {
    height: 200px;
    background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    position: relative;
    overflow: hidden;
}

.story-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.story-category {
    position: absolute;
    top: 15px;
    left: 15px;
    background: rgba(255,255,255,0.9);
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
}

.story-content {
    padding: 1.5rem;
}

.story-title {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.3rem;
    margin-bottom: 0.8rem;
    color: var(--primary-color);
}

.story-excerpt {
    color: var(--light-text);
    margin-bottom: 1.2rem;
    line-height: 1.5;
}

.story-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #eee;
}

.story-author {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--light-text);
    font-size: 0.9rem;
}

.story-author i {
    color: var(--secondary-color);
}

.story-stats {
    display: flex;
    gap: 1rem;
}

.like-btn {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    background: none;
    border: none;
    color: var(--light-text);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
}

.like-btn:hover {
    color: var(--science-red);
}

.like-btn.liked {
    color: var(--science-red);
}

.views {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    color: var(--light-text);
    font-size: 0.9rem;
}

/* Load More Button */
.load-more-container {
    text-align: center;
    margin: 3rem 0;
}

.btn-secondary {
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
}

.btn-secondary:hover {
    background: var(--science-purple);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

/* Sidebar */
.sidebar-widget {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: var(--card-shadow);
    margin-bottom: 2rem;
}

.sidebar-widget h3 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.3rem;
    margin-bottom: 1.2rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.popular-stories {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.popular-story {
    display: flex;
    gap: 1rem;
    padding: 0.8rem 0;
    border-bottom: 1px solid #eee;
    cursor: pointer;
}

.popular-story:last-child {
    border-bottom: none;
}

.popular-story:hover .popular-title {
    color: var(--secondary-color);
}

.popular-rank {
    font-weight: bold;
    color: var(--secondary-color);
    min-width: 25px;
}

.popular-content {
    flex: 1;
}

.popular-title {
    font-weight: 500;
    margin-bottom: 0.3rem;
    transition: var(--transition);
}

.popular-likes {
    font-size: 0.8rem;
    color: var(--light-text);
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.science-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.science-tag {
    background: var(--light-bg);
    padding: 0.5rem 1rem;
    border-radius: 15px;
    font-size: 0.9rem;
    color: var(--primary-color);
    transition: var(--transition);
    cursor: pointer;
}

.science-tag:hover {
    background: var(--secondary-color);
    color: white;
}

.newsletter-form {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.newsletter-form input {
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: inherit;
}

.btn-submit {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.8rem;
    border-radius: 5px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.btn-submit:hover {
    background: var(--science-blue);
}

/* Footer */
.site-footer {
    background: var(--primary-color);
    color: white;
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-column h4 {
    font-family: 'Space Grotesk', sans-serif;
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.footer-column ul li {
    margin-bottom: 0.8rem;
}

.footer-column a {
    color: #bdc3c7;
    text-decoration: none;
    transition: var(--transition);
}

.footer-column a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    color: white;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--secondary-color);
    transform: translateY(-3px);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    margin-top: 1rem;
}

.contact-form input,
.contact-form textarea {
    padding: 0.8rem;
    border: none;
    border-radius: 5px;
    font-family: inherit;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: #bdc3c7;
    font-size: 0.9rem;
}

.science-quote {
    font-style: italic;
    margin-top: 1rem;
    color: #95a5a6;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    z-index: 1001;
    overflow-y: auto;
}

.modal-content {
    background: white;
    width: 90%;
    max-width: 800px;
    margin: 2rem auto;
    border-radius: 15px;
    padding: 2rem;
    position: relative;
    animation: modalSlide 0.3s ease;
}

@keyframes modalSlide {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.close-modal {
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    font-size: 2rem;
    cursor: pointer;
    color: var(--light-text);
    transition: var(--transition);
}

.close-modal:hover {
    color: var(--dark-text);
}

/* Loading Spinner */
.loading-spinner {
    text-align: center;
    padding: 3rem;
    color: var(--light-text);
    grid-column: 1 / -1;
}

.loading-spinner i {
    font-size: 2rem;
    margin-bottom: 1rem;
    display: block;
}

/* Responsive Design */
@media (max-width: 992px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    main.container {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 2rem;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .stories-grid {
        grid-template-columns: 1fr;
    }
    
    .filters {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }
    
    .filter-group {
        justify-content: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}