/* ==================== CSS Variables & Theme ==================== */
:root {
    /* Day Theme (Default) */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #eeeeee;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-tertiary: #999999;
    --border-color: #e0e0e0;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
    --accent-color: #2c2c2c;
    --accent-hover: #1a1a1a;
    --success-color: #4caf50;
    --error-color: #f44336;
    --overlay: rgba(0, 0, 0, 0.5);
}

[data-theme="dark"] {
    /* Night Theme */
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --bg-tertiary: #2a2a2a;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-tertiary: #808080;
    --border-color: #333333;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --accent-color: #e0e0e0;
    --accent-hover: #ffffff;
    --overlay: rgba(0, 0, 0, 0.8);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* ==================== Theme Toggle Button (Old styles removed) ==================== */

/* ==================== Sidebar ==================== */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 240px;
    height: 100vh;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    padding: 24px 0;
    z-index: 100;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.sidebar.collapsed {
    width: 80px;
}

.sidebar-header {
    padding: 0 24px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
    overflow: hidden;
}

.sidebar.collapsed .sidebar-header {
    padding: 0 16px 24px;
    justify-content: center;
}

.sidebar-title {
    font-size: 20px;
    font-weight: 600;
    white-space: nowrap;
    opacity: 1;
    transition: opacity 0.2s ease;
}

.sidebar.collapsed .sidebar-title {
    opacity: 0;
    display: none;
}

.sidebar-controls {
    display: flex;
    align-items: center;
}

.sidebar.collapsed .sidebar-controls {
    display: none;
}

/* Theme Toggle Button in Sidebar */
.theme-toggle-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
    background: var(--bg-tertiary);
    transform: rotate(15deg);
}

.theme-toggle-btn .sun-icon {
    display: block;
}

.theme-toggle-btn .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle-btn .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle-btn .moon-icon {
    display: block;
}

/* Sidebar Collapse Button */
.sidebar-collapse-btn {
    position: absolute;
    right: -12px;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 24px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    box-shadow: var(--shadow-sm);
    z-index: 101;
    transition: all 0.3s ease;
}

.sidebar-collapse-btn:hover {
    color: var(--text-primary);
    transform: translateY(-50%) scale(1.1);
}

.sidebar.collapsed .sidebar-collapse-btn {
    transform: translateY(-50%) rotate(180deg);
}

.sidebar-nav {
    padding: 24px 0;
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.2s ease;
    position: relative;
    white-space: nowrap;
    overflow: hidden;
}

.sidebar.collapsed .nav-item {
    padding: 12px;
    justify-content: center;
}

.sidebar.collapsed .nav-item span {
    /* Text label */
    display: none;
    /* In case implementation wrapped text in span */
    /* Or just hide text if simple text node */
}

/* Since HTML structure is SVG + Text Node, we need to hide text node 
   but CSS can't target text nodes directly.
   However, we can set font-size 0 for collapsed state */

.sidebar.collapsed .nav-item {
    font-size: 0;
}

.sidebar.collapsed .nav-item svg {
    margin-right: 0;
    /* Adjust svg size if needed, but inheriting is fine */
}

.nav-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--accent-color);
    transform: scaleY(0);
    transition: transform 0.2s ease;
}

.nav-item:hover,
.nav-item.active {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-item.active::before {
    transform: scaleY(1);
}

/* ==================== Main Container ==================== */
.main-container {
    margin-left: 240px;
    min-height: 100vh;
    padding-bottom: 40px;
    transition: margin-left 0.3s ease;
}

.main-container.expanded {
    /* Applied when sidebar is collapsed */
    margin-left: 80px;
}

/* ==================== Header ==================== */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 24px 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 90;
    backdrop-filter: blur(10px);
}

.header-banner h1 {
    font-family: 'Cinzel Decorative', Georgia, serif;
    font-size: 32px;
    font-weight: 700;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 50%, var(--text-primary) 100%);
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.2)) drop-shadow(0 0 20px rgba(0, 0, 0, 0.08));
    animation: titleShine 4s ease-in-out infinite;
}

@keyframes titleShine {
    0%, 100% { background-position: 0% center; }
    50% { background-position: 100% center; }
}

.user-avatar-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--border-color);
    background: var(--bg-primary);
    cursor: pointer;
    overflow: hidden;
    transition: all 0.3s ease;
}

.user-avatar-btn:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.user-avatar-btn img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ==================== Pages ==================== */
.page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 32px;
}

.page-header {
    margin-bottom: 32px;
}

.page-header h2 {
    font-size: 32px;
    font-weight: 700;
}

/* ==================== Carousel ==================== */
.carousel {
    position: relative;
    width: 100%;
    height: 300px;
    border-radius: 16px;
    overflow: hidden;
    margin-bottom: 32px;
    box-shadow: var(--shadow-md);
}

.carousel-track {
    position: relative;
    width: 100%;
    height: 100%;
}

.carousel-item {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.carousel-item.active {
    opacity: 1;
}

.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    transition: all 0.3s ease;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
}

.carousel-btn:hover {
    background: rgba(255, 255, 255, 1);
    transform: translateY(-50%) scale(1.1);
}

.carousel-btn.prev {
    left: 16px;
}

.carousel-btn.next {
    right: 16px;
}

.carousel-dots {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    z-index: 10;
}

.carousel-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s ease;
}

.carousel-dot.active {
    width: 24px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.9);
}

/* ==================== Search Bar ==================== */
.search-container {
    display: flex;
    gap: 12px;
    margin-bottom: 32px;
}

.search-input {
    flex: 1;
    padding: 14px 20px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 16px;
    transition: all 0.3s ease;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.search-btn {
    padding: 14px 24px;
    background: var(--accent-color);
    color: var(--bg-primary);
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.search-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ==================== Create Post Container ==================== */
.create-post-container {
    margin-bottom: 32px;
    text-align: center;
}

/* ==================== Posts Grid ==================== */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.post-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    animation: fadeInUp 0.5s ease;
}

.post-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-color);
}

.post-card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.post-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
}

.post-user-info {
    flex: 1;
}

.post-nickname {
    font-weight: 600;
    font-size: 15px;
    color: var(--text-primary);
}

.post-time {
    font-size: 13px;
    color: var(--text-tertiary);
}

.post-content {
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 12px;
    color: var(--text-secondary);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.post-image {
    width: 100%;
    border-radius: 12px;
    margin-bottom: 12px;
    max-height: 200px;
    object-fit: cover;
}

.post-stats {
    display: flex;
    gap: 20px;
    font-size: 14px;
    color: var(--text-tertiary);
    align-items: center;
}

/* 首页帖子卡片中的点赞按钮 */
.post-stats .like-btn {
    padding: 6px 12px;
    font-size: 14px;
    background: transparent;
    border: 1px solid var(--border-color);
}

.post-stats .like-btn:hover {
    background: var(--bg-secondary);
}

.post-actions {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

/* ==================== Buttons ==================== */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-danger {
    background: var(--error-color);
    color: white;
}

.btn-danger:hover {
    background: #d32f2f;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 13px;
}

/* ==================== Pagination ==================== */
.pagination {
    display: flex;
    justify-content: center;
    gap: 8px;
    align-items: center;
}

.pagination button {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.pagination button:hover:not(:disabled) {
    background: var(--accent-color);
    color: var(--bg-primary);
}

.pagination button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.pagination button.active {
    background: var(--accent-color);
    color: var(--bg-primary);
}

/* ==================== Modals ==================== */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: var(--overlay);
    animation: fadeIn 0.3s ease;
}

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

.modal-content {
    background: var(--bg-primary);
    border-radius: 16px;
    padding: 32px;
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: slideUp 0.3s ease;
    box-shadow: var(--shadow-lg);
}

.modal-large {
    max-width: 800px;
}

.close {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 28px;
    font-weight: bold;
    color: var(--text-tertiary);
    cursor: pointer;
    transition: all 0.3s ease;
}

.close:hover {
    color: var(--text-primary);
    transform: rotate(90deg);
}

/* ==================== Forms ==================== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 15px;
    transition: all 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.form-group textarea {
    resize: vertical;
}

.image-preview {
    margin-top: 12px;
    max-width: 100%;
}

.image-preview img {
    max-width: 100%;
    border-radius: 8px;
}

/* ==================== Auth Tabs ==================== */
.auth-tabs,
.admin-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    border-bottom: 2px solid var(--border-color);
}

.auth-tab,
.admin-tab {
    padding: 12px 24px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.auth-tab::after,
.admin-tab::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-color);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.auth-tab.active,
.admin-tab.active {
    color: var(--text-primary);
}

.auth-tab.active::after,
.admin-tab.active::after {
    transform: scaleX(1);
}

.auth-message {
    margin-top: 16px;
    padding: 12px;
    border-radius: 8px;
    text-align: center;
}

.auth-message.error {
    background: rgba(244, 67, 54, 0.1);
    color: var(--error-color);
}

.auth-message.success {
    background: rgba(76, 175, 80, 0.1);
    color: var(--success-color);
}

/* ==================== Post Detail ==================== */
.post-detail {
    animation: fadeIn 0.3s ease;
}

.post-detail-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.post-detail-avatar {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    object-fit: cover;
}

.post-detail-content {
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 20px;
    white-space: pre-wrap;
}

.post-detail-image {
    width: 100%;
    border-radius: 12px;
    margin-bottom: 20px;
}

.post-detail-stats {
    display: flex;
    align-items: center;
    gap: 24px;
    margin-bottom: 24px;
    padding: 16px;
    background: var(--bg-secondary);
    border-radius: 12px;
}

.like-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 15px;
}

.like-btn:hover {
    border-color: #ff4757;
    color: #ff4757;
}

.like-btn.liked {
    background: #ff4757;
    color: white;
    border-color: #ff4757;
}

.like-icon {
    transition: transform 0.3s ease;
}

.like-btn.liked .like-icon {
    animation: heartBeat 0.5s ease;
}

/* ==================== Comments ==================== */
.comments-section {
    margin-top: 32px;
    padding-top: 24px;
    border-top: 2px solid var(--border-color);
}

.comments-section h3 {
    margin-bottom: 20px;
    font-size: 20px;
}

.comment-form {
    margin-bottom: 32px;
}

.comment {
    display: flex;
    gap: 16px;
    padding: 16px;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin-bottom: 16px;
    animation: fadeInUp 0.5s ease;
}

.comment-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
}

.comment-content-wrapper {
    flex: 1;
}

.comment-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.comment-nickname {
    font-weight: 600;
    font-size: 15px;
}

.comment-time {
    font-size: 13px;
    color: var(--text-tertiary);
}

.comment-content {
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: 8px;
    white-space: pre-wrap;
}

.comment-image {
    max-width: 300px;
    border-radius: 8px;
    margin-top: 8px;
}

/* ==================== User Center ==================== */
.user-profile {
    display: flex;
    align-items: center;
    gap: 24px;
    background: var(--bg-secondary);
    padding: 32px;
    border-radius: 16px;
    margin-bottom: 24px;
}

.user-profile-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
}

.user-profile-info h3 {
    font-size: 24px;
    margin-bottom: 8px;
}

.user-profile-info p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

/* ==================== Admin Panel ==================== */
.admin-search {
    margin-bottom: 24px;
}

.admin-search input {
    width: 100%;
    padding: 12px 20px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 16px;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-secondary);
    border-radius: 12px;
    overflow: hidden;
}

.admin-table th,
.admin-table td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

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

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

.admin-table img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
}

/* ==================== Loading ==================== */
.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-tertiary);
    font-size: 16px;
}

/* ==================== Animations ==================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

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

@keyframes slideUp {
    from {
        transform: translateY(100px);
        opacity: 0;
    }

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

@keyframes heartBeat {

    0%,
    100% {
        transform: scale(1);
    }

    25% {
        transform: scale(1.3);
    }

    50% {
        transform: scale(1.1);
    }

    75% {
        transform: scale(1.2);
    }
}

/* ==================== Chatroom Styles ==================== */
.chatroom-container {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 200px);
    background-color: var(--bg-secondary);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    background-color: var(--bg-primary);
}

.chat-message {
    display: flex;
    gap: 12px;
    animation: slideInUp 0.3s ease;
}

.chat-message-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
}

.chat-message-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.chat-message-header {
    display: flex;
    align-items: center;
    gap: 8px;
}

.chat-message-nickname {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 14px;
}

.chat-message-time {
    font-size: 12px;
    color: var(--text-tertiary);
}

.chat-message-text {
    background-color: var(--bg-secondary);
    padding: 10px 14px;
    border-radius: 12px;
    color: var(--text-primary);
    word-wrap: break-word;
    max-width: 80%;
}

.chat-input-container {
    display: flex;
    gap: 12px;
    padding: 16px;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

#chatInput {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 14px;
    resize: none;
    transition: border-color 0.3s ease;
}

#chatInput:focus {
    outline: none;
    border-color: var(--accent-color);
}

#sendMessageBtn {
    padding: 12px 24px;
    white-space: nowrap;
    align-self: flex-end;
}

/* 滚动条样式 */
.chat-messages::-webkit-scrollbar {
    width: 8px;
}

.chat-messages::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.chat-messages::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

.chat-messages::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

/* ==================== Responsive Design ==================== */
@media (max-width: 768px) {
    .sidebar {
        width: 60px;
    }

    .sidebar-header,
    .nav-item span {
        display: none;
    }

    .main-container {
        margin-left: 60px;
    }

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

    .header h1 {
        font-size: 20px;
        letter-spacing: 0.1em;
    }

    .carousel {
        height: 200px;
    }

    .chatroom-container {
        height: calc(100vh - 150px);
    }

    .chat-message-text {
        max-width: 90%;
    }

    .chat-input-container {
        flex-direction: column;
    }

    #sendMessageBtn {
        align-self: stretch;
    }
}