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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

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

/* Navbar */
.navbar {
    background-color: #673de6;
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

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

.nav-links {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.nav-links a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-links a:hover {
    background-color: rgba(255,255,255,0.1);
}

/* Headings */
h1, h2, h3 {
    margin: 1.5rem 0 1rem;
    color: #333;
}

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

/* Categories */
.categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.category-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
}

.category-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.category-card h3 a {
    color: #673de6;
    text-decoration: none;
}

.category-card h3 a:hover {
    text-decoration: underline;
}

.category-stats {
    margin-top: 0.5rem;
    color: #666;
    font-size: 0.9rem;
}

/* Topics List */
.topics-list {
    margin: 2rem 0;
}

.topic-item {
    background: white;
    padding: 1.5rem;
    margin-bottom: 1rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: box-shadow 0.2s;
}

.topic-item:hover {
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.topic-item h3, .topic-item h4 {
    margin: 0 0 0.5rem;
}

.topic-item a {
    color: #673de6;
    text-decoration: none;
}

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

.topic-meta {
    display: flex;
    gap: 1rem;
    color: #666;
    font-size: 0.9rem;
}

.topic-meta span::after {
    content: "•";
    margin-left: 1rem;
}

.topic-meta span:last-child::after {
    content: "";
}

/* Forms */
.auth-form {
    max-width: 400px;
    margin: 3rem auto;
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #673de6;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    text-decoration: none;
    cursor: pointer;
    transition: background-color 0.3s;
    margin: 0.5rem 0;
}

.btn-primary {
    background-color: #673de6;
    color: white;
}

.btn-primary:hover {
    background-color: #5a32c7;
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
}

/* Alerts */
.alert {
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 4px;
}

.alert-error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background-color: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

/* Posts */
.posts {
    margin: 2rem 0;
}

.post {
    background: white;
    margin-bottom: 1rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 1.5rem;
}

.post-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid #eee;
}

.post-date {
    color: #666;
    font-size: 0.9rem;
}

.badge {
    background-color: #673de6;
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
}

.post-content {
    line-height: 1.8;
}

/* Reply Form */
.reply-form {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-top: 2rem;
}

.reply-form h3 {
    margin-top: 0;
}

/* Breadcrumb */
.breadcrumb {
    padding: 1rem 0;
    color: #666;
}

.breadcrumb a {
    color: #673de6;
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

/* Topic Form */
.topic-form {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin: 2rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    .categories {
        grid-template-columns: 1fr;
    }
    
    .topic-meta {
        flex-wrap: wrap;
        gap: 0.5rem;
    }
    
    .topic-meta span::after {
        display: none;
    }
    
    .nav-links {
        flex-direction: column;
        gap: 0.5rem;
    }
}