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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8fafc;
    color: #334155;
    line-height: 1.6;
}

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

/* Header Styles */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.nav-brand h1 {
    font-size: 1.8rem;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: background-color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    background-color: rgba(255, 255, 255, 0.2);
}

.auth-buttons {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.username {
    font-weight: 600;
}

/* Button Styles */
.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: #3b82f6;
    color: white;
}

.btn-primary:hover {
    background-color: #2563eb;
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid white;
    color: white;
}

.btn-outline:hover {
    background-color: white;
    color: #667eea;
}

.btn-secondary {
    background-color: #6b7280;
    color: white;
}

.btn-secondary:hover {
    background-color: #4b5563;
}

/* Main Content */
.main-content {
    padding: 2rem 0;
    min-height: calc(100vh - 80px);
}

.page {
    display: none;
}

.page.active {
    display: block;
}

/* Welcome Section */
.welcome-section {
    text-align: center;
    margin-bottom: 2rem;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.welcome-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.welcome-section p {
    font-size: 1.1rem;
    color: #6b7280;
}

/* Forum Stats */
.forum-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-card i {
    font-size: 2rem;
    color: #3b82f6;
}

.stat-info h3 {
    font-size: 1.8rem;
    font-weight: 700;
    color: #1f2937;
}

.stat-info p {
    color: #6b7280;
    font-size: 0.9rem;
}

/* Forum Actions */
.forum-actions {
    margin-bottom: 2rem;
    text-align: center;
}

/* Topics Container */
.topics-container {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.topics-container h3 {
    margin-bottom: 1.5rem;
    color: #1f2937;
    font-size: 1.5rem;
}

.topics-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.topic-item {
    padding: 1.5rem;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #f9fafb;
}

.topic-item:hover {
    border-color: #3b82f6;
    background: white;
    transform: translateY(-1px);
}

.topic-header-info {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 0.5rem;
}

.topic-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #1f2937;
    margin: 0;
}

.topic-category {
    background: #3b82f6;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.topic-meta {
    display: flex;
    gap: 1rem;
    color: #6b7280;
    font-size: 0.9rem;
}

.topic-description {
    color: #6b7280;
    margin-top: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

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

.category-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    text-align: center;
    transition: transform 0.3s ease;
}

.category-card:hover {
    transform: translateY(-4px);
}

.category-card i {
    font-size: 3rem;
    color: #3b82f6;
    margin-bottom: 1rem;
}

.category-card h3 {
    margin-bottom: 1rem;
    color: #1f2937;
}

.category-card p {
    color: #6b7280;
    margin-bottom: 1rem;
}

.topic-count {
    background: #f3f4f6;
    color: #6b7280;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

/* Members List */
.members-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.member-card {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    text-align: center;
}

.member-avatar {
    width: 60px;
    height: 60px;
    background: #3b82f6;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 1rem;
}

.member-name {
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.member-info {
    color: #6b7280;
    font-size: 0.9rem;
}

/* Topic View Page */
.topic-header {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 2rem;
}

.topic-header h2 {
    margin: 1rem 0;
    color: #1f2937;
}

.topic-content {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 2rem;
}

.replies-section {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 2rem;
}

.replies-section h3 {
    margin-bottom: 1.5rem;
    color: #1f2937;
}

.reply-item {
    padding: 1.5rem;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.reply-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.reply-author {
    font-weight: 600;
    color: #1f2937;
}

.reply-date {
    color: #6b7280;
    font-size: 0.9rem;
}

.reply-content {
    color: #374151;
    line-height: 1.7;
}

.reply-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.reply-form h4 {
    margin-bottom: 1rem;
    color: #1f2937;
}

/* Form Styles */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #374151;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e5e7eb;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #3b82f6;
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    padding: 0;
    border-radius: 12px;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
    animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.95);
    }

    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 2px solid #f1f5f9;
}

.modal-header h3 {
    color: #1f2937;
    margin: 0;
}

.close-modal {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #6b7280;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: background-color 0.3s ease;
}

.close-modal:hover {
    background-color: #f1f5f9;
}

.modal form {
    padding: 2rem;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.auth-required {
    opacity: 0.6;
    pointer-events: none;
}

.empty-state {
    text-align: center;
    padding: 3rem;
    color: #6b7280;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: #d1d5db;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-menu {
        width: 100%;
        justify-content: space-between;
    }

    .welcome-section h2 {
        font-size: 2rem;
    }

    .forum-stats {
        grid-template-columns: 1fr;
    }

    .categories-grid {
        grid-template-columns: 1fr;
    }

    .members-list {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }

    .topic-header-info {
        flex-direction: column;
        gap: 1rem;
    }

    .topic-meta {
        flex-direction: column;
        gap: 0.5rem;
    }

    .modal-content {
        width: 95%;
        margin: 20px;
    }

    .modal form {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .main-content {
        padding: 1rem 0;
    }

    .welcome-section,
    .topics-container,
    .topic-header,
    .topic-content,
    .replies-section,
    .reply-form {
        padding: 1.5rem;
    }

    .stat-card {
        padding: 1rem;
    }

    .category-card {
        padding: 1.5rem;
    }
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}