/* common.css */
:root {
    --primary: #0088cc;
    --primary-dark: #006da3;
    --primary-light: #e6f7ff;
    --accent: #ff6b35;
    --text-dark: #1a1a1a;
    --text-light: #666;
    --bg-light: #f8f9fa;
    --white: #ffffff;
    --gray-100: #f5f7f9;
    --gray-200: #e9ebed;
    --success: #34c759;
    --warning: #ff9500;
    --danger: #ff3b30;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.07);
    --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.12);
    --transition: all 0.25s ease;
    --container-width: 1200px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
header {
    background-color: var(--white);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.05);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-img {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 20px;
}

.logo-text {
    font-weight: 800;
    font-size: 22px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    font-size: 16px;
    position: relative;
}

.nav-link:hover {
    color: var(--primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary);
    transition: var(--transition);
}

.nav-link:hover::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-dark);
}

/* Footer */
footer {
    background-color: var(--text-dark);
    color: var(--white);
    padding: 80px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
}

.footer-description {
    margin-bottom: 20px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: var(--transition);
}

.social-link:hover {
    background: var(--primary);
    transform: translateY(-3px);
}

.footer-heading {
    font-size: 1.2rem;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-heading::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 40px;
    height: 2px;
    background-color: var(--primary);
}

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

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--white);
    padding-left: 5px;
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--white);
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
        text-align: center;
        gap: 20px;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: block;
    }
}

@media (max-width: 576px) {
    .features-grid, .articles-grid {
        grid-template-columns: 1fr;
    }
}