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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    color: #333;
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

body.dark-mode {
    background: #1a1a2e;
    color: #e0e0e0;
}

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

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

.dark-mode header {
    background: rgba(26, 26, 46, 0.95);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #4a90d9;
    text-decoration: none;
}

.logo i {
    margin-right: 8px;
}

.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #333;
}

.dark-mode .hamburger {
    color: #e0e0e0;
}

.nav-menu {
    list-style: none;
    display: flex;
    gap: 20px;
}

.nav-menu li a {
    text-decoration: none;
    color: #555;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu li a:hover {
    color: #4a90d9;
}

.dark-mode .nav-menu li a {
    color: #ccc;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.theme-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: #555;
}

.dark-mode .theme-btn {
    color: #e0e0e0;
}

.btn-login {
    background: #4a90d9;
    color: #fff;
    padding: 8px 20px;
    border-radius: 25px;
    text-decoration: none;
    transition: background 0.3s;
}

.btn-login:hover {
    background: #357abd;
}

/* Hero */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 80px 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.search-bar {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
}

.search-bar input {
    padding: 12px 20px;
    border: none;
    border-radius: 25px;
    width: 400px;
    max-width: 80%;
    font-size: 1rem;
}

.search-bar button {
    background: #fff;
    color: #4a90d9;
    border: none;
    padding: 12px 25px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s;
}

.search-bar button:hover {
    background: #f0f0f0;
}

.filter-group {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.filter-group select {
    padding: 10px 15px;
    border: none;
    border-radius: 20px;
    background: rgba(255,255,255,0.9);
    font-size: 0.9rem;
}

/* Articles */
.articles {
    padding: 60px 0;
}

.articles h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 2rem;
    color: #333;
}

.dark-mode .articles h2 {
    color: #e0e0e0;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background: #fff;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

.dark-mode .card {
    background: #2d2d44;
}

.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.card-body {
    padding: 20px;
}

.category {
    background: #4a90d9;
    color: #fff;
    padding: 3px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    display: inline-block;
    margin-bottom: 10px;
}

.card-body h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: #333;
}

.dark-mode .card-body h3 {
    color: #e0e0e0;
}

.card-body p {
    color: #777;
    margin-bottom: 15px;
}

.dark-mode .card-body p {
    color: #aaa;
}

.card-meta {
    display: flex;
    gap: 15px;
    font-size: 0.9rem;
    color: #999;
    margin-bottom: 15px;
}

.btn-read {
    display: inline-block;
    background: #4a90d9;
    color: #fff;
    padding: 8px 20px;
    border-radius: 25px;
    text-decoration: none;
    transition: background 0.3s;
}

.btn-read:hover {
    background: #357abd;
}

/* Popular */
.popular {
    background: #f9f9f9;
    padding: 60px 0;
}

.dark-mode .popular {
    background: #222;
}

.popular h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 2rem;
}

.popular-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.popular-card {
    background: #fff;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    position: relative;
}

.dark-mode .popular-card {
    background: #2d2d44;
}

.hot-badge {
    background: #ff6b6b;
    color: #fff;
    padding: 3px 10px;
    border-radius: 15px;
    font-size: 0.8rem;
    position: absolute;
    top: -10px;
    left: 20px;
}

.popular-card h3 {
    margin-bottom: 10px;
    color: #333;
}

.dark-mode .popular-card h3 {
    color: #e0e0e0;
}

.popular-card p {
    color: #777;
    margin-bottom: 15px;
}

.popular-card a {
    color: #4a90d9;
    text-decoration: none;
    font-weight: bold;
}

/* Stats */
.stats {
    padding: 60px 0;
    text-align: center;
}

.stats h2 {
    margin-bottom: 40px;
    font-size: 2rem;
}

.stats-grid {
    display: flex;
    justify-content: center;
    gap: 50px;
    margin-bottom: 40px;
}

.stat-item i {
    font-size: 2.5rem;
    color: #4a90d9;
    margin-bottom: 10px;
}

.stat-item span {
    display: block;
    font-size: 2rem;
    font-weight: bold;
    color: #333;
}

.dark-mode .stat-item span {
    color: #e0e0e0;
}

.stat-item p {
    color: #999;
}

.heatmap {
    max-width: 600px;
    margin: 0 auto;
    height: 200px;
    background: #e0e0e0;
    border-radius: 15px;
    overflow: hidden;
}

.dark-mode .heatmap {
    background: #333;
}

#heatmap-canvas {
    width: 100%;
    height: 100%;
}

/* Footer */
footer {
    background: #2c3e50;
    color: #fff;
    padding: 40px 0;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.footer-links a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s;
}

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

.social-share {
    margin-bottom: 20px;
}

.social-share a {
    color: #ccc;
    font-size: 1.5rem;
    margin: 0 10px;
    transition: color 0.3s;
}

.social-share a:hover {
    color: #4a90d9;
}

/* Responsive */
@media (max-width: 768px) {
    .hamburger {
        display: block;
    }
    .nav-menu {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.95);
        padding: 20px;
        box-shadow: 0 5px 10px rgba(0,0,0,0.1);
    }
    .dark-mode .nav-menu {
        background: rgba(26,26,46,0.95);
    }
    .nav-menu.active {
        display: flex;
    }
    .hero h1 {
        font-size: 1.8rem;
    }
    .search-bar input {
        width: 200px;
    }
    .card-grid {
        grid-template-columns: 1fr;
    }
    .stats-grid {
        flex-direction: column;
        gap: 20px;
    }
}

/* Dark mode specific */
.dark-mode .hero {
    background: linear-gradient(135deg, #1a1a2e, #16213e);
}

.dark-mode .btn-login {
    background: #4a90d9;
}

/* Login page */
.admin-login {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.login-container {
    background: #fff;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
    text-align: center;
    max-width: 400px;
    width: 100%;
}

.login-container h2 {
    margin-bottom: 30px;
    color: #333;
}

.login-container input {
    width: 100%;
    padding: 12px;
    margin-bottom: 15px;
    border: 1px solid #ddd;
    border-radius: 25px;
    outline: none;
}

.login-container button {
    width: 100%;
    padding: 12px;
    background: #4a90d9;
    color: #fff;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

.login-container button:hover {
    background: #357abd;
}

.back-link {
    display: block;
    margin-top: 15px;
    color: #4a90d9;
    text-decoration: none;
}

.error {
    color: #ff6b6b;
    margin-bottom: 15px;
}

.success {
    color: #27ae60;
    margin-bottom: 15px;
}

/* Admin panel */
.admin-panel {
    background: #f5f7fa;
}

.admin-nav {
    background: #2c3e50;
    padding: 15px 0;
}

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

.admin-nav .logo {
    color: #fff;
}

.admin-nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

.admin-nav ul li a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s;
}

.admin-nav ul li a:hover {
    color: #fff;
}

.admin-panel main {
    padding: 40px 0;
}

.admin-panel section {
    background: #fff;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.admin-panel h2 {
    margin-bottom: 20px;
    color: #333;
}

.admin-panel textarea, .admin-panel input {
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid #ddd;
    border-radius: 10px;
}

.admin-panel button {
    background: #4a90d9;
    color: #fff;
    padding: 10px 25px;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: background 0.3s;
}

.admin-panel button:hover {
    background: #357abd;
}

.ai-result {
    background: #f9f9f9;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
}

.ai-result pre {
    white-space: pre-wrap;
    word-wrap: break-word;
}