/* Scientific American Website Styles */

/* ===== Base Styles ===== */
:root {
    /* Color Palette */
    --primary: #003366;      /* Dark Blue */
    --secondary: #ff6600;    /* Orange */
    --accent: #00a86b;       /* Green */
    --text: #333333;         /* Dark Gray */
    --text-light: #777777;   /* Light Gray */
    --background: #ffffff;   /* White */
    --background-alt: #f4f7fa; /* Light Blue Gray */
    --border: #e0e0e0;       /* Light Border */
    
    /* Typography */
    --font-heading: 'Montserrat', sans-serif;
    --font-body: 'Open Sans', sans-serif;
    
    /* Spacing */
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
}

/* Font Import */
@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500;600;700&family=Open+Sans:wght@400;600&display=swap');

/* Reset & Basic Styles */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--text);
    line-height: 1.6;
    background-color: var(--background);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

img, svg {
    max-width: 100%;
    height: auto;
}

ul {
    list-style: none;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-family: var(--font-heading);
    font-weight: 600;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background-color: var(--secondary);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary);
    color: white;
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background-color: var(--primary);
    color: white;
}

/* Section Styles */
.section-heading {
    text-align: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
    padding-bottom: var(--spacing-md);
}

.section-heading::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--secondary);
}

.section-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-lg);
    color: var(--text-light);
    font-size: 1.1rem;
}

/* ===== Header ===== */
header {
    background-color: var(--background);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: var(--spacing-md) 0;
}

.logo a {
    display: flex;
    align-items: center;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary);
    text-decoration: none;
}

.logo span {
    font-weight: 400;
    margin-right: 5px;
}

.logo-icon {
    margin-right: var(--spacing-sm);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.main-nav {
    display: flex;
    gap: var(--spacing-lg);
}

.main-nav li a {
    color: var(--text);
    font-weight: 500;
    position: relative;
}

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

.main-nav li a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--secondary);
    transition: width 0.3s ease;
}

.main-nav li a:hover::after {
    width: 100%;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--primary);
    margin: 5px 0;
    border-radius: 3px;
    transition: all 0.3s ease;
}

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, #001f3f 100%);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    color: white;
    margin-bottom: var(--spacing-md);
    font-size: 3rem;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

/* ===== Featured Articles ===== */
.featured-section {
    padding: var(--spacing-xl) 0;
    background-color: var(--background);
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.article-card {
    background-color: white;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 3px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.article-img {
    height: 180px;
    overflow: hidden;
}

.article-content {
    padding: var(--spacing-lg);
}

.article-content h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
}

.read-more {
    display: inline-block;
    color: var(--secondary);
    font-weight: 600;
    margin-top: var(--spacing-sm);
    position: relative;
}

.read-more::after {
    content: '→';
    margin-left: 5px;
    transition: transform 0.3s ease;
}

.read-more:hover::after {
    transform: translateX(5px);
}

/* ===== News Section ===== */
.news-section {
    padding: var(--spacing-xl) 0;
    background-color: var(--background-alt);
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.news-item {
    background-color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
}

.news-item h3 {
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
    font-size: 1.3rem;
}

.news-item a {
    font-weight: 600;
    color: var(--secondary);
}

.news-item a:hover {
    text-decoration: underline;
}

/* ===== Footer ===== */
.footer {
    background-color: var(--primary);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand {
    flex: 1;
    min-width: 250px;
}

.footer-brand a {
    display: flex;
    align-items: center;
    color: white;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

.footer-brand span {
    font-weight: 400;
    margin-right: 5px;
}

.footer-logo {
    margin-right: var(--spacing-sm);
}

.footer-brand p {
    opacity: 0.8;
    max-width: 300px;
}

.footer-links {
    flex: 2;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    gap: var(--spacing-lg);
}

.footer-column h3 {
    color: white;
    margin-bottom: var(--spacing-md);
    font-size: 1.2rem;
    position: relative;
    padding-bottom: var(--spacing-sm);
}

.footer-column h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background-color: var(--secondary);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-column ul li a {
    color: rgba(255, 255, 255, 0.8);
    transition: all 0.3s ease;
}

.footer-column ul li a:hover {
    color: var(--secondary);
    padding-left: 5px;
}

.copyright {
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
}

.copyright p {
    margin-bottom: 0;
    opacity: 0.7;
}

.legal-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.legal-links a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.legal-links a:hover {
    color: var(--secondary);
}

/* ===== Media Queries ===== */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.7rem;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .main-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: white;
        box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
        flex-direction: column;
        gap: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }
    
    .main-nav.active {
        display: flex;
        max-height: 300px;
    }
    
    .main-nav li {
        width: 100%;
    }
    
    .main-nav li a {
        display: block;
        padding: 15px;
        border-bottom: 1px solid var(--border);
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .copyright {
        flex-direction: column;
        text-align: center;
    }
    
    .legal-links {
        justify-content: center;
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
}

@media (max-width: 576px) {
    .news-grid,
    .article-grid {
        grid-template-columns: 1fr;
    }
    
    .hero {
        padding: var(--spacing-lg) 0;
    }
    
    .hero h1 {
        font-size: 1.8rem;
    }
}