/* =========================================
   1. 全局变量与基础设置 (原 index.css 内容)
   ========================================= */
:root {
    --bg-color: #0a0c10;
    --panel-bg-color: rgba(26, 31, 41, 0.65);
    --modal-bg-color: rgba(26, 31, 41, 0.8);
    --border-color: rgba(139, 148, 158, 0.2);
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent-color: #38bdf8;
    --danger-color: #f85149;
    --highlight-bg: rgba(56, 189, 248, 0.1);
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    --border-radius: 6px;
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

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

html { 
    box-sizing: border-box;
    -webkit-text-size-adjust: 100%; 
}

body {
    color: var(--text-primary);
    font-family: var(--font-family);
    background-color: var(--bg-color);
    background-image: radial-gradient(circle at 15% 15%, rgba(0, 170, 255, 0.1) 0%, transparent 30%), radial-gradient(circle at 85% 80%, rgba(244, 114, 182, 0.08) 0%, transparent 35%);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden; 
}

body.modal-open { 
    overflow: hidden; 
}

/* =========================================
   2. 页面布局框架 (Header, Sidebar, Container)
   ========================================= */
.page-container {
    display: flex;
    flex-direction: column;
    flex-grow: 1;
    padding: 0.5rem;
    gap: 1rem;
}

.page-header {
    flex-shrink: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
    padding-left: 0.5rem;
    padding-right: 0.5rem;
}

.page-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
    white-space: nowrap;
}

.header-link, .header-title-link {
    color: var(--text-primary);
    text-decoration: none;
}

.portal-wrapper {
    display: flex;
    flex-grow: 1;
    gap: 1rem;
    min-height: 0;
}

.sidebar-panel, .main-content {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--panel-bg-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.sidebar-panel {
    flex: 0 0 280px;
    overflow-y: auto;
    padding: 0.5rem;
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    overflow-y: auto;
}

.content-panel {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* 侧边栏导航样式 */
.sidebar-nav ul { list-style: none; }

.sidebar-nav li a {
    display: flex;
    align-items: center;
    padding: 0.5rem 0.75rem;
    border-radius: var(--border-radius);
    color: var(--text-secondary);
    text-decoration: none;
    transition: background-color 0.2s, color 0.2s;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    position: relative;
}

.sidebar-nav li a:hover {
    background-color: var(--highlight-bg);
    color: var(--text-primary);
}

.sidebar-nav li a.active {
    background-color: var(--highlight-bg);
    color: var(--text-primary);
    font-weight: 500;
}

.sidebar-nav li a .folder-icon {
    width: 20px;
    height: 20px;
    margin-right: 0.75rem;
    flex-shrink: 0;
}

/* 侧边栏搜索框样式 (从 PHP 移入) */
.sidebar-search {
    padding: 0 0.5rem 1rem 0.5rem;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 0.5rem;
}
.sidebar-search form {
    display: flex;
    gap: 0.5rem;
}
.sidebar-search-input {
    width: 100%;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.4rem 0.6rem;
    border-radius: var(--border-radius);
    font-size: 0.875rem;
}
.sidebar-search-input:focus {
    outline: none;
    border-color: var(--accent-color);
    background-color: rgba(26, 31, 41, 0.5);
}
.sidebar-search-btn {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: var(--border-radius);
    cursor: pointer;
    padding: 0 0.6rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}
.sidebar-search-btn:hover {
    color: var(--accent-color);
    border-color: var(--accent-color);
    background-color: rgba(56, 189, 248, 0.1);
}

/* 右侧边栏样式 (从 PHP 移入) */
.right-sidebar { flex: 0 0 320px; overflow-y: auto; padding: 1rem; }
.todays-posts-list { list-style: none; padding: 0; }
.todays-posts-list li { margin-bottom: 1rem; }
.todays-posts-list a { color: var(--text-secondary); text-decoration: none; font-size: 0.875rem; display: block; }
.todays-posts-list a:hover { color: var(--accent-color); }
.todays-post-content { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; text-overflow: ellipsis; margin-bottom: 0.25rem; }
.todays-post-time { font-size: 0.75rem; opacity: 0.7; }


/* =========================================
   3. 论坛/帖子核心样式 (原 PHP 内联样式移入)
   ========================================= */
.page-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }

/* 发帖表单区域 */
.post-form-container { padding: 1.5rem; }

.post-input { 
    min-height: 100px; 
    width: 100%; 
    padding: 1rem; 
    background-color: var(--bg-color); 
    border: 1px solid var(--border-color); 
    border-radius: var(--border-radius); 
    color: var(--text-primary); 
    font-size: 16px; 
    font-family: var(--font-family); 
    resize: vertical; 
    line-height: 1.6;
    overflow-y: hidden;
}
.post-input:focus { outline: none; border-color: var(--accent-color); box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.3); }

.post-actions { display: flex; justify-content: space-between; align-items: center; margin-top: 1rem; }

/* 图片预览 */
.image-preview-container { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 0.5rem; }
.img-preview { position: relative; }
.img-preview img { width: 80px; height: 80px; object-fit: cover; border-radius: var(--border-radius); }
.remove-img-btn { position: absolute; top: -5px; right: -5px; background: rgba(0,0,0,0.7); color: white; border-radius: 50%; width: 20px; height: 20px; border: none; cursor: pointer; font-size: 12px; line-height: 20px; text-align: center; }

/* 帖子卡片 */
.post-card { 
    background-color: var(--panel-bg-color); 
    border: 1px solid var(--border-color); 
    border-radius: var(--border-radius); 
    margin-bottom: 1rem; 
    overflow-wrap: break-word;
}
.post-content-wrapper { padding: 1.5rem; }
.post-header { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem; color: var(--text-secondary); font-size: 0.875rem; margin-bottom: 0.75rem; }
.post-body { 
    color: var(--text-primary); 
    line-height: 1.6; 
    white-space: pre-wrap; 
    overflow-wrap: anywhere; 
    word-break: break-word;
}
.post-images { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 0.5rem; margin-top: 1rem; align-items: start; }
.post-images img { 
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: var(--border-radius); 
    cursor: pointer; 
}
.post-footer { padding: 0.75rem 1.5rem; border-top: 1px solid var(--border-color); }

/* 回复区域 */
.replies-container { padding: 0 1.5rem 1.5rem 2.5rem; position: relative; overflow: hidden; }
.reply-card { position: relative; padding: 1rem 0 0 1.5rem; margin-top: 1rem; }
.reply-card::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 2px; background-color: var(--border-color); }
.reply-card::after { content: ''; position: absolute; left: 0; top: 1.7rem; height: 2px; width: 1rem; background-color: var(--border-color); }

.reply-form-container { padding: 1rem 0 0 1.5rem; margin-top: 1rem; }
.reply-input { min-height: 60px; width: 100%; font-size: 16px; }
.reply-actions { display: flex; justify-content: flex-end; gap: 0.5rem; margin-top: 0.5rem; }

#loading-spinner { text-align: center; padding: 2rem; color: var(--text-secondary); display: none; }
.empty-message { text-align: center; padding: 3rem; color: var(--text-secondary); }

/* 通用按钮 */
.action-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    background-color: rgba(56, 189, 248, 0.05);
    transition: background-color 0.2s;
}
.action-btn:hover { background-color: rgba(56, 189, 248, 0.15); }
.action-btn.secondary { background-color: transparent; border-color: var(--border-color); }
.action-btn.secondary:hover { background-color: rgba(139, 148, 158, 0.1); }


/* =========================================
   4. 探索页面样式 (原 PHP 内联样式移入)
   ========================================= */
.explore-page-container {
    padding: 2rem;
    width: 100%;
}
.explore-header {
    text-align: center;
    margin-bottom: 2rem;
}
.explore-title {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}
.explore-search-form {
    max-width: 600px;
    margin: 0 auto;
    position: relative;
    display: flex; /* 确保flex布局 */
    gap: 10px;
}
.explore-search-input {
    width: 100%;
    padding: 1rem 3rem 1rem 1.5rem;
    font-size: 1.1rem;
    background-color: var(--panel-bg-color);
    border: 2px solid var(--border-color);
    border-radius: 50px;
    color: var(--text-primary);
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}
.explore-search-input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.2);
}
.explore-search-btn {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
}
.explore-search-btn:hover {
    color: var(--accent-color);
    background-color: rgba(255,255,255,0.05);
}
.explore-results-header {
    margin: 2rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}
.explore-empty-state {
    text-align: center;
    padding: 4rem 1rem;
    color: var(--text-secondary);
}
.explore-empty-icon {
    width: 64px;
    height: 64px;
    margin-bottom: 1rem;
    opacity: 0.5;
}


/* =========================================
   5. 模态框与弹窗 (Modal & Lightbox)
   ========================================= */
/* 通用遮罩 */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(5px);
    z-index: 10001;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}
.modal-overlay.visible { opacity: 1; visibility: visible; }

/* 图片灯箱 */
.lightbox { 
    position: fixed; top: 0; left: 0; width: 100%; height: 100%; 
    background: rgba(0,0,0,0.8); backdrop-filter: blur(5px); z-index: 10000; 
    display: none; justify-content: center; align-items: center;
    padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}
.lightbox.visible { display: flex; }
.lightbox img { 
    display: block; 
    max-width: 90vw; 
    max-height: 90vh; 
    width: auto; height: auto; border-radius: var(--border-radius); 
}
.lightbox-close { position: absolute; top: 2rem; right: 2rem; width: 40px; height: 40px; background: rgba(0,0,0,0.5); color: white; border: none; border-radius: 50%; font-size: 24px; cursor: pointer; }

/* 密码/通用对话框 */
.modal-dialog, .password-modal-dialog {
    background: var(--modal-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    width: 90%;
    max-width: 400px;
    box-shadow: var(--shadow);
    transform: scale(0.95);
    transition: transform 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}
.modal-overlay.visible .modal-dialog, 
.modal-overlay.visible .password-modal-dialog { transform: scale(1); }

.modal-dialog h3, .password-modal-dialog h3 { margin-bottom: 1.5rem; font-size: 1.25rem; }
.modal-actions { display: flex; justify-content: flex-end; gap: 0.75rem; margin-top: 1.5rem; }

.modal-input {
    width: 100%;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.75rem 1rem;
    border-radius: var(--border-radius);
    font-size: 16px;
}
.modal-input:focus { outline: none; border-color: var(--accent-color); box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.3); }

.error-message {
    color: var(--danger-color);
    font-size: 0.875rem;
    min-height: 1.2em;
    margin-top: 0.5rem;
    visibility: hidden;
}
.error-message.visible { visibility: visible; }


/* =========================================
   6. 响应式适配 (Media Queries)
   ========================================= */
@media (max-width: 1024px) { 
    .right-sidebar { display: none; } 
}

@media (max-width: 768px) {
    .sidebar-panel { display: none; }
    .portal-wrapper { display: block; }
    .page-container { padding: 0.5rem; }
    .page-header { flex-wrap: wrap; gap: 0.5rem; }
    .explore-page-container { padding: 1rem; }
    
    .action-btn span { display: none; }
    .action-btn { padding: 0.5rem; flex-grow: 1; justify-content: center; }
}

@media (max-width: 480px) {
    .post-form-container, 
    .post-content-wrapper { padding: 1rem; }
    .post-footer { padding-left: 1rem; padding-right: 1rem; }
    .replies-container { padding-left: 1.5rem; padding-right: 1rem; }
    .reply-card { padding-left: 1rem; }
}