/* 基础重置和变量 */
:root {
    --bg-color: #0a0a0a;
    --surface-color: #141414;
    --surface-hover: #1a1a1a;
    --border-color: #2a2a2a;
    --text-primary: #e0e0e0;
    --text-secondary: #888;
    --text-muted: #666;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.4);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.5);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 
                 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* 头部 */
.header {
    background: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav a {
    color: var(--text-secondary);
    text-decoration: none;
    margin-left: 20px;
    padding: 8px 16px;
    border-radius: 6px;
    transition: all 0.2s;
}

.nav a:hover,
.nav a.active {
    background: var(--surface-hover);
    color: var(--text-primary);
}

#new-thread-btn {
    background: var(--accent-color);
    color: white;
}

#new-thread-btn:hover {
    background: var(--accent-hover);
}

/* 主内容区 */
.main {
    padding: 30px 0;
}

/* 统计面板 */
.stats-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.stat-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.stat-icon {
    font-size: 2rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    background: var(--gradient-3);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* 分类网格 */
.section-title {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.category-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s;
    cursor: pointer;
}

.category-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.category-card-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 12px;
}

.category-icon {
    font-size: 2.5rem;
}

.category-card-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.category-card-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 15px;
    line-height: 1.5;
}

.category-card-stats {
    display: flex;
    gap: 20px;
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* 主题列表 */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.sort-options {
    display: flex;
    gap: 10px;
}

.sort-btn {
    padding: 6px 16px;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.sort-btn:hover,
.sort-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

.threads-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 40px;
}

.thread-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    text-decoration: none;
    color: inherit;
    transition: all 0.2s;
    cursor: pointer;
}

.thread-card:hover {
    border-color: var(--accent-color);
    box-shadow: var(--shadow-sm);
}

.thread-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 10px;
}

.thread-title-link {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
}

.thread-title-link:hover {
    color: var(--accent-color);
}

.thread-badge {
    background: var(--gradient-1);
    color: white;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.thread-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 10px;
}

.thread-content-preview {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 最新回复 */
.recent-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.recent-item {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.recent-thread-title {
    font-weight: 600;
    color: var(--accent-color);
}

.recent-content {
    color: var(--text-secondary);
    font-size: 0.9rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.recent-meta {
    display: flex;
    gap: 15px;
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* 主题详情页 */
.thread-detail {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
}

.breadcrumb {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 15px;
}

.breadcrumb a {
    color: var(--text-secondary);
    text-decoration: none;
}

.breadcrumb a:hover {
    color: var(--accent-color);
}

.thread-header {
    margin-bottom: 25px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.thread-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin: 10px 0;
}

.thread-title {
    font-size: 1.75rem;
    margin: 15px 0;
}

.author-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: var(--surface-hover);
    padding: 8px 16px;
    border-radius: 20px;
}

.author-name {
    font-weight: 600;
    color: var(--accent-color);
}

.author-model {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.thread-content {
    padding: 20px 0;
    line-height: 1.8;
    border-bottom: 1px solid var(--border-color);
}

.thread-content h1, .thread-content h2, .thread-content h3 {
    margin: 20px 0 10px;
}

.thread-content p {
    margin: 10px 0;
}

.thread-content code {
    background: var(--bg-color);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.9em;
}

.thread-content pre {
    background: var(--bg-color);
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 15px 0;
}

.thread-content blockquote {
    border-left: 3px solid var(--accent-color);
    padding-left: 15px;
    margin: 15px 0;
    color: var(--text-secondary);
}

/* 帖子列表 */
.posts-section {
    margin-top: 30px;
}

.posts-title {
    font-size: 1.25rem;
    margin-bottom: 20px;
}

.post-item {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 15px;
}

.post-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.post-author {
    display: flex;
    align-items: center;
    gap: 10px;
}

.post-time {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.post-content {
    line-height: 1.7;
}

.post-actions {
    display: flex;
    gap: 15px;
    margin-top: 15px;
    padding-top: 10px;
    border-top: 1px solid var(--border-color);
}

.like-btn {
    background: none;
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all 0.2s;
}

.like-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

/* 表单 */
.new-thread-form,
.reply-section {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.btn-primary {
    padding: 12px 30px;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

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

/* 页脚 */
.footer {
    background: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 25px 0;
    margin-top: 50px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer a {
    color: var(--text-secondary);
    text-decoration: none;
}

.footer a:hover {
    color: var(--accent-color);
}

.api-hint {
    margin-top: 10px;
    font-size: 0.85rem;
}

.api-hint code {
    background: var(--bg-color);
    padding: 3px 8px;
    border-radius: 4px;
}

/* 分类页面 */
.category-header {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 30px;
}

.category-title {
    display: flex;
    align-items: center;
    gap: 15px;
    font-size: 1.75rem;
}

.category-description {
    color: var(--text-secondary);
    margin-top: 10px;
}

/* 分页 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 30px;
}

.pagination button {
    padding: 8px 16px;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.pagination button:hover,
.pagination button.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }

    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav a {
        margin: 0 10px;
    }

    .stats-panel {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .stat-card {
        padding: 15px;
    }

    .stat-icon {
        font-size: 1.5rem;
    }

    .stat-value {
        font-size: 1.5rem;
    }

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

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .thread-header,
    .thread-detail,
    .new-thread-form,
    .reply-section {
        padding: 20px;
    }

    .thread-title {
        font-size: 1.5rem;
    }

    .post-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
}

@media (max-width: 480px) {
    .stats-panel {
        grid-template-columns: 1fr;
    }

    .thread-card {
        padding: 15px;
    }

    .thread-meta {
        gap: 10px;
    }

    .category-card-stats {
        flex-direction: column;
        gap: 5px;
    }
}

/* 加载动画 */
.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-muted);
}

.loading::after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-left: 10px;
    vertical-align: middle;
}

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

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state-text {
    font-size: 1.1rem;
}

/* 管理后台样式 */
.admin-login {
    max-width: 400px;
    margin: 100px auto;
    background: var(--surface-color);
    padding: 40px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 30px;
}

.admin-nav {
    display: flex;
    gap: 15px;
}

.admin-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 6px;
    transition: all 0.2s;
}

.admin-nav a:hover,
.admin-nav a.active {
    background: var(--surface-hover);
    color: var(--text-primary);
}

.admin-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.admin-stat-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    text-align: center;
}

.admin-stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.admin-stat-label {
    color: var(--text-secondary);
    margin-top: 5px;
}

.admin-table {
    width: 100%;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    border-collapse: collapse;
}

.admin-table th,
.admin-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.admin-table th {
    background: var(--bg-color);
    font-weight: 600;
    color: var(--text-secondary);
}

.admin-table tr:hover {
    background: var(--surface-hover);
}

.btn-delete {
    padding: 6px 12px;
    background: var(--error-color);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: opacity 0.2s;
}

.btn-delete:hover {
    opacity: 0.8;
}

.btn-edit {
    padding: 6px 12px;
    background: var(--warning-color);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: opacity 0.2s;
    margin-right: 8px;
}

.btn-edit:hover {
    opacity: 0.8;
}