/* 重置和基礎樣式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Material Design 3.0 色彩系統 */
    --primary: #1976d2;
    --primary-variant: #1565c0;
    --secondary: #03dac6;
    --secondary-variant: #018786;
    --background: #fafafa;
    --surface: #ffffff;
    --error: #b00020;
    --on-primary: #ffffff;
    --on-secondary: #000000;
    --on-background: #000000;
    --on-surface: #000000;
    --on-error: #ffffff;
    
    /* 聊天專用顏色 */
    --chat-bg: #f5f5f5;
    --message-bg: #ffffff;
    --message-own-bg: #e3f2fd;
    --message-system-bg: #fff3cd;
    --sidebar-bg: #ffffff;
    --hover-bg: #f5f5f5;
    --active-bg: #e3f2fd;
    --border-color: #e0e0e0;
    --text-primary: #212121;
    --text-secondary: #757575;
    --text-hint: #9e9e9e;
    
    /* 陰影系統 */
    --shadow-1: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    --shadow-2: 0 3px 6px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);
    --shadow-3: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
    --shadow-4: 0 14px 28px rgba(0,0,0,0.25), 0 10px 10px rgba(0,0,0,0.22);
    
    /* 動畫時間 */
    --animation-fast: 0.2s;
    --animation-normal: 0.3s;
    --animation-slow: 0.5s;
    
    /* 邊界半徑 */
    --radius-small: 4px;
    --radius-medium: 8px;
    --radius-large: 16px;
    --radius-full: 50%;
    
    /* 間距系統 */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-xxl: 48px;
}

/* Dark theme */
[data-theme="dark"] {
    --background: #121212;
    --surface: #1e1e1e;
    --chat-bg: #0a0a0a;
    --message-bg: #2d2d2d;
    --message-own-bg: #1565c0;
    --message-system-bg: #4a4a00;
    --sidebar-bg: #1e1e1e;
    --hover-bg: #2d2d2d;
    --active-bg: #1565c0;
    --border-color: #333333;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-hint: #666666;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    overflow: hidden;
}

/* 加載畫面 */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--background);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity var(--animation-normal), visibility var(--animation-normal);
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

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

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary);
    border-radius: var(--radius-full);
    animation: spin 1s linear infinite;
    margin: 0 auto var(--space-md);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 登入界面 */
.login-container {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity var(--animation-normal), visibility var(--animation-normal);
}

.login-container.hidden {
    opacity: 0;
    visibility: hidden;
}

.login-card {
    background: var(--surface);
    border-radius: var(--radius-large);
    box-shadow: var(--shadow-4);
    padding: var(--space-xxl);
    width: 100%;
    max-width: 400px;
    margin: var(--space-md);
}

.login-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.app-logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: var(--space-md);
}

.logo-icon {
    width: 64px;
    height: 64px;
    background: var(--primary);
    border-radius: var(--radius-large);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
    color: var(--on-primary);
}

.logo-icon .material-icons-outlined {
    font-size: 32px;
}

.login-header h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: var(--space-xs);
    color: var(--text-primary);
}

.login-subtitle {
    color: var(--text-secondary);
    font-size: 16px;
}

.input-group {
    margin-bottom: var(--space-lg);
}

.input-field {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--background);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: var(--space-sm) var(--space-md);
    transition: border-color var(--animation-fast);
}

.input-field:focus-within {
    border-color: var(--primary);
}

.input-field .material-icons-outlined {
    color: var(--text-hint);
    margin-right: var(--space-sm);
    font-size: 20px;
}

.input-field input {
    border: none;
    outline: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 16px;
    flex: 1;
}

.input-field input::placeholder {
    color: var(--text-hint);
}

.server-config {
    margin-bottom: var(--space-lg);
}

.login-button {
    width: 100%;
    background: var(--primary);
    color: var(--on-primary);
    border: none;
    border-radius: var(--radius-medium);
    padding: var(--space-md);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--animation-fast);
    position: relative;
    overflow: hidden;
}

.login-button:hover {
    background: var(--primary-variant);
    transform: translateY(-1px);
    box-shadow: var(--shadow-2);
}

.login-button:active {
    transform: translateY(0);
}

.login-button.loading {
    pointer-events: none;
}

.login-button .button-text {
    opacity: 1;
    transition: opacity var(--animation-fast);
}

.login-button.loading .button-text {
    opacity: 0;
}

.button-loading {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    opacity: 0;
    transition: opacity var(--animation-fast);
}

.login-button.loading .button-loading {
    opacity: 1;
}

.mini-spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid white;
    border-radius: var(--radius-full);
    animation: spin 1s linear infinite;
}

.login-footer {
    margin-top: var(--space-lg);
    text-align: center;
}

.connection-status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    color: var(--text-secondary);
    font-size: 14px;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: var(--radius-full);
    background: var(--text-hint);
    transition: background var(--animation-fast);
}

.status-dot.connected {
    background: var(--secondary);
}

.status-dot.error {
    background: var(--error);
}

/* 主聊天界面 */
.chat-container {
    display: flex;
    height: 100vh;
    background: var(--background);
    transition: opacity var(--animation-normal), visibility var(--animation-normal);
}

.chat-container.hidden {
    opacity: 0;
    visibility: hidden;
}

/* 左側邊欄 */
.sidebar {
    width: 280px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform var(--animation-normal);
}

.sidebar-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
}

.user-avatar .material-icons-outlined {
    font-size: 24px;
}

.user-details h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 2px;
}

.user-status {
    font-size: 12px;
    color: var(--text-secondary);
}

.user-status.online {
    color: var(--secondary);
}

.sidebar-actions {
    display: flex;
    gap: var(--space-xs);
}

.action-btn {
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    border-radius: var(--radius-medium);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
}

.action-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

.search-bar {
    padding: var(--space-md);
}

.search-input {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    padding: var(--space-sm) var(--space-md);
    transition: border-color var(--animation-fast);
}

.search-input:focus-within {
    border-color: var(--primary);
}

.search-input .material-icons-outlined {
    color: var(--text-hint);
    margin-right: var(--space-sm);
    font-size: 20px;
}

.search-input input {
    border: none;
    outline: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 14px;
    flex: 1;
}

.search-input input::placeholder {
    color: var(--text-hint);
}

.chat-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-xs);
}

.chat-item {
    display: flex;
    align-items: center;
    padding: var(--space-md);
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: background var(--animation-fast);
    margin-bottom: var(--space-xs);
}

.chat-item:hover {
    background: var(--hover-bg);
}

.chat-item.active {
    background: var(--active-bg);
}

.chat-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    margin-right: var(--space-md);
}

.chat-avatar .material-icons-outlined {
    font-size: 20px;
}

.chat-info {
    flex: 1;
    min-width: 0;
}

.chat-name {
    font-weight: 500;
    font-size: 15px;
    margin-bottom: 2px;
    color: var(--text-primary);
}

.chat-preview {
    font-size: 13px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.chat-meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: var(--space-xs);
}

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

.unread-badge {
    background: var(--primary);
    color: var(--on-primary);
    font-size: 11px;
    font-weight: 600;
    padding: 2px 6px;
    border-radius: var(--radius-full);
    min-width: 16px;
    text-align: center;
}

/* 主聊天區域 */
.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--chat-bg);
}

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

.channel-info {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    margin-right: var(--space-sm);
}

.channel-avatar {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-medium);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
}

.channel-avatar .material-icons-outlined {
    font-size: 20px;
}

.channel-details h2 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 2px;
    color: var(--text-primary);
}

.channel-details p {
    font-size: 13px;
    color: var(--text-secondary);
}

.chat-actions {
    display: flex;
    gap: var(--space-xs);
}

.messages-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-lg);
    scroll-behavior: smooth;
}

.welcome-message {
    text-align: center;
    padding: var(--space-xxl);
    color: var(--text-secondary);
}

.welcome-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-full);
    background: var(--primary);
    color: var(--on-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-md);
}

.welcome-icon .material-icons-outlined {
    font-size: 32px;
}

.welcome-message h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.welcome-message p {
    font-size: 16px;
}

/* 訊息樣式 */
.message {
    margin-bottom: var(--space-lg);
    display: flex;
    opacity: 0;
    animation: messageSlideIn var(--animation-normal) forwards;
}

@keyframes messageSlideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.own {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    margin: 0 var(--space-md);
    flex-shrink: 0;
    font-size: 12px;
    font-weight: 600;
}

.message-content {
    flex: 1;
    max-width: 70%;
}

.message-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-xs);
}

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

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

.message-text {
    background: var(--message-bg);
    padding: var(--space-md);
    border-radius: var(--radius-large);
    font-size: 15px;
    line-height: 1.4;
    word-wrap: break-word;
    box-shadow: var(--shadow-1);
}

.message.own .message-text {
    background: var(--message-own-bg);
    color: var(--text-primary);
}

.message.system .message-text {
    background: var(--message-system-bg);
    color: var(--text-primary);
    text-align: center;
    font-style: italic;
}

/* 正在輸入指示器 */
.typing-indicator {
    padding: var(--space-md) var(--space-lg);
    display: none;
    align-items: center;
    gap: var(--space-sm);
    color: var(--text-secondary);
    font-size: 14px;
}

.typing-indicator.visible {
    display: flex;
}

.typing-dots {
    display: flex;
    gap: 4px;
}

.typing-dot {
    width: 6px;
    height: 6px;
    border-radius: var(--radius-full);
    background: var(--text-hint);
    animation: typingBounce 1.4s infinite;
}

.typing-dot:nth-child(1) { animation-delay: 0s; }
.typing-dot:nth-child(2) { animation-delay: 0.2s; }
.typing-dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes typingBounce {
    0%, 60%, 100% { transform: translateY(0); }
    30% { transform: translateY(-10px); }
}

/* 輸入區域 */
.input-area {
    background: var(--surface);
    border-top: 1px solid var(--border-color);
    padding: var(--space-md) var(--space-lg);
    position: relative;
}
.file-drop-zone {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(25, 118, 210, 0.1);
    border: 2px dashed var(--primary);
    border-radius: var(--radius-large);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 10;
    backdrop-filter: blur(4px);
}

.file-drop-zone.dragover {
    display: flex;
    animation: dropZonePulse 0.5s ease-in-out infinite alternate;
}

@keyframes dropZonePulse {
    from { background: rgba(25, 118, 210, 0.1); }
    to { background: rgba(25, 118, 210, 0.2); }
}

.drop-zone-content {
    text-align: center;
    color: var(--primary);
}

.drop-zone-content .material-icons-outlined {
    font-size: 64px;
    margin-bottom: var(--space-md);
}

.drop-zone-content p {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.drop-hint {
    font-size: 14px !important;
    opacity: 0.7;
    font-weight: normal !important;
}

/* 文件預覽區域 */
.file-preview-area {
    display: none;
    padding: var(--space-md);
    background: var(--surface);
    border-top: 1px solid var(--border-color);
    max-height: 200px;
    overflow-y: auto;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.file-preview-area.show {
    display: flex;
}

.file-preview-item {
    position: relative;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: var(--space-sm);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    max-width: 300px;
    transition: all var(--animation-fast);
}

.file-preview-item:hover {
    box-shadow: var(--shadow-1);
}

.file-preview-item.uploading {
    opacity: 0.7;
}

.file-thumbnail {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-medium);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    flex-shrink: 0;
}

.file-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-medium);
}

.file-thumbnail .material-icons-outlined {
    font-size: 24px;
}

.file-info {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-size {
    font-size: 12px;
    color: var(--text-secondary);
}

.file-progress {
    width: 100%;
    height: 3px;
    background: var(--background);
    border-radius: var(--radius-small);
    margin-top: 4px;
    overflow: hidden;
}

.file-progress-bar {
    height: 100%;
    background: var(--primary);
    border-radius: var(--radius-small);
    transition: width var(--animation-fast);
}

.remove-file-btn {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 20px;
    height: 20px;
    background: var(--error);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    transition: all var(--animation-fast);
}

.remove-file-btn:hover {
    transform: scale(1.1);
}

/* 附件選項菜單 */
.attachment-options {
    position: absolute;
    bottom: 100%;
    left: 0;
    background: var(--surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    box-shadow: var(--shadow-3);
    padding: var(--space-sm);
    display: none;
    flex-direction: column;
    gap: var(--space-xs);
    min-width: 180px;
    z-index: 100;
}

.attachment-options.show {
    display: flex;
    animation: slideUp var(--animation-fast) ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.attachment-option {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: background var(--animation-fast);
    color: var(--text-primary);
}

.attachment-option:hover {
    background: var(--hover-bg);
}

.attachment-option .material-icons-outlined {
    font-size: 20px;
    color: var(--text-secondary);
}

.attachment-option span:last-child {
    font-size: 14px;
    font-weight: 500;
}

.input-container {
    display: flex;
    align-items: flex-end;
    gap: var(--space-md);
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-large);
    padding: var(--space-md);
    transition: border-color var(--animation-fast);
}

.input-container:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(25, 118, 210, 0.1);
}

.attachment-menu .attachment-btn {
    width: 36px;
    height: 36px;
    border: none;
    background: transparent;
    border-radius: var(--radius-full);
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.attachment-menu .attachment-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

.message-input-wrapper {
    flex: 1;
    display: flex;
    align-items: flex-end;
    gap: var(--space-sm);
}

.message-input {
    flex: 1;
    min-height: 20px;
    max-height: 100px;
    overflow-y: auto;
    border: none;
    outline: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 15px;
    line-height: 1.4;
    resize: none;
    word-wrap: break-word;
}

.message-input:empty::before {
    content: attr(data-placeholder);
    color: var(--text-hint);
    pointer-events: none;
}

.emoji-picker-btn button {
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    border-radius: var(--radius-full);
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.emoji-picker-btn button:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

.send-btn {
    width: 36px;
    height: 36px;
    background: var(--primary);
    color: var(--on-primary);
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--animation-fast);
}

.send-btn:hover {
    background: var(--primary-variant);
    transform: scale(1.05);
}

.send-btn:active {
    transform: scale(0.95);
}

.send-btn:disabled {
    background: var(--text-hint);
    cursor: not-allowed;
    transform: none;
}

/* 右側邊欄 */
.member-sidebar {
    width: 240px;
    background: var(--sidebar-bg);
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.member-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-color);
}

.member-header h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--text-primary);
}

.member-count {
    font-size: 13px;
    color: var(--text-secondary);
}

.member-categories {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-md);
}

.member-category {
    margin-bottom: var(--space-lg);
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.category-header .material-icons-outlined {
    font-size: 14px;
    color: var(--secondary);
}

.category-header .count {
    margin-left: auto;
    background: var(--background);
    padding: 2px 6px;
    border-radius: var(--radius-full);
    font-size: 11px;
}

.member-list {
    padding-left: var(--space-md);
}

.member-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: background var(--animation-fast);
}

.member-item:hover {
    background: var(--hover-bg);
}

.member-avatar {
    width: 28px;
    height: 28px;
    border-radius: var(--radius-full);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    font-size: 10px;
    font-weight: 600;
}

.member-name {
    font-size: 14px;
    color: var(--text-primary);
}

/* 通知系統 */
.notification-container {
    position: fixed;
    top: var(--space-lg);
    right: var(--space-lg);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.notification {
    background: var(--surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: var(--space-md);
    box-shadow: var(--shadow-3);
    min-width: 300px;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    animation: notificationSlideIn var(--animation-normal) ease-out;
}

.notification.success {
    border-color: var(--secondary);
}

.notification.error {
    border-color: var(--error);
}

.notification .material-icons-outlined {
    font-size: 20px;
}

.notification.success .material-icons-outlined {
    color: var(--secondary);
}

.notification.error .material-icons-outlined {
    color: var(--error);
}

@keyframes notificationSlideIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* 模態框 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    transition: opacity var(--animation-normal), visibility var(--animation-normal);
}

.modal.hidden {
    opacity: 0;
    visibility: hidden;
}

.modal-content {
    background: var(--surface);
    border-radius: var(--radius-large);
    box-shadow: var(--shadow-4);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: transform var(--animation-normal);
}

.modal:not(.hidden) .modal-content {
    transform: scale(1);
}

.modal-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
}

.close-btn {
    width: 32px;
    height: 32px;
    background: none;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--space-lg);
}

.settings-section {
    margin-bottom: var(--space-xl);
}

.settings-section h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--text-primary);
}

.setting-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) 0;
}

.setting-item label {
    color: var(--text-primary);
    font-size: 15px;
}

.setting-item select,
.setting-item input[type="checkbox"] {
    margin-left: var(--space-md);
}

.setting-item select {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: var(--space-sm) var(--space-md);
    color: var(--text-primary);
}

/* 響應式設計 */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        z-index: 100;
        transform: translateX(-100%);
        box-shadow: var(--shadow-4);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .member-sidebar {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex !important;
    }
    
    .chat-header {
        padding: var(--space-md);
    }
    
    .input-area {
        padding: var(--space-md);
    }
    
    .messages-container {
        padding: var(--space-md);
    }
    
    .notification-container {
        top: var(--space-sm);
        right: var(--space-sm);
        left: var(--space-sm);
    }
    
    .notification {
        min-width: auto;
    }
    
    .modal-content {
        margin: var(--space-md);
        width: calc(100% - 32px);
    }
}

@media (max-width: 480px) {
    .login-card {
        padding: var(--space-lg);
    }
    
    .logo-icon {
        width: 48px;
        height: 48px;
    }
    
    .logo-icon .material-icons-outlined {
        font-size: 24px;
    }
    
    .welcome-icon {
        width: 48px;
        height: 48px;
    }
    
    .welcome-icon .material-icons-outlined {
        font-size: 24px;
    }
    
    .message-text {
        max-width: 85%;
    }
}

/* 滾動條樣式 */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--background);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-small);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-hint);
}

/* 選取效果 */
::selection {
    background: rgba(25, 118, 210, 0.2);
}

/* 圖片預覽模態框 */
.image-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 3000;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity var(--animation-normal), visibility var(--animation-normal);
}

.image-modal.hidden {
    opacity: 0;
    visibility: hidden;
}

.image-modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(4px);
}

.image-modal-content {
    position: relative;
    background: var(--surface);
    border-radius: var(--radius-large);
    max-width: 90vw;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow-4);
}

.image-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-color);
}

.image-info h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.image-info p {
    font-size: 14px;
    color: var(--text-secondary);
}

.image-modal-actions {
    display: flex;
    gap: var(--space-sm);
}

.modal-action-btn {
    width: 40px;
    height: 40px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-action-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

.image-modal-body {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    min-height: 300px;
}

.image-modal-body img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: var(--radius-medium);
    box-shadow: var(--shadow-2);
}

/* 截圖工具樣式 */
.screenshot-modal-content {
    width: 90%;
    max-width: 600px;
}

.screenshot-options {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.screenshot-option-btn {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: all var(--animation-fast);
    text-align: left;
}

.screenshot-option-btn:hover {
    background: var(--hover-bg);
    border-color: var(--primary);
}

.screenshot-option-btn .material-icons-outlined {
    font-size: 32px;
    color: var(--primary);
}

.option-info h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.option-info p {
    font-size: 14px;
    color: var(--text-secondary);
}

.screenshot-preview {
    display: none;
    text-align: center;
    padding: var(--space-lg);
    background: var(--background);
    border-radius: var(--radius-medium);
}

.screenshot-preview.show {
    display: block;
}

#screenshotCanvas {
    max-width: 100%;
    max-height: 300px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
}

/* 文件管理器樣式 */
.file-manager-content {
    width: 90%;
    max-width: 800px;
    height: 80vh;
}

.file-search {
    flex: 1;
    max-width: 300px;
    margin: 0 var(--space-md);
}

.file-search input {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    outline: none;
    font-size: 14px;
    color: var(--text-primary);
}

.file-search input:focus {
    border-color: var(--primary);
}

.file-manager-tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--space-md);
}

.tab-btn {
    padding: var(--space-md) var(--space-lg);
    background: none;
    border: none;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    border-bottom: 2px solid transparent;
    transition: all var(--animation-fast);
}

.tab-btn.active,
.tab-btn:hover {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.file-list {
    height: 400px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.file-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: all var(--animation-fast);
}

.file-item:hover {
    background: var(--hover-bg);
    border-color: var(--primary);
}

.file-item-thumbnail {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-medium);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    flex-shrink: 0;
}

.file-item-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-medium);
}

.file-item-info {
    flex: 1;
    min-width: 0;
}

.file-item-name {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 4px;
}

.file-item-meta {
    font-size: 13px;
    color: var(--text-secondary);
}

.file-item-actions {
    display: flex;
    gap: var(--space-xs);
}

.file-action-btn {
    width: 32px;
    height: 32px;
    background: none;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.file-action-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

/* 消息中的文件樣式 */
.message-file {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: var(--space-md);
    margin-top: var(--space-sm);
    display: flex;
    align-items: center;
    gap: var(--space-md);
    cursor: pointer;
    transition: all var(--animation-fast);
    max-width: 400px;
}

.message-file:hover {
    background: var(--hover-bg);
    border-color: var(--primary);
}

.message-file-thumbnail {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-medium);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    flex-shrink: 0;
}

.message-file-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-medium);
}

.message-file-info {
    flex: 1;
    min-width: 0;
}

.message-file-name {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 4px;
}

.message-file-size {
    font-size: 12px;
    color: var(--text-secondary);
}

.message-file-actions {
    display: flex;
    gap: var(--space-xs);
}

.message-file-btn {
    width: 32px;
    height: 32px;
    background: none;
    border: none;
    border-radius: var(--radius-medium);
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--animation-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.message-file-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

/* 圖片消息樣式 */
.message-image {
    margin-top: var(--space-sm);
    max-width: 300px;
    border-radius: var(--radius-medium);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--animation-fast);
}

.message-image:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-2);
}

.message-image img {
    width: 100%;
    height: auto;
    display: block;
}

.message-image-placeholder {
    width: 100%;
    height: 200px;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

/* 拖拽懸停效果 */
.input-area.drag-hover {
    background: rgba(25, 118, 210, 0.05);
}

/* 移動設備優化 */
@media (max-width: 768px) {
    .attachment-options {
        bottom: auto;
        top: 100%;
        left: auto;
        right: 0;
    }
    
    .file-preview-item {
        max-width: 100%;
    }
    
    .image-modal-content {
        max-width: 95vw;
        max-height: 95vh;
        margin: var(--space-md);
    }
    
    .file-manager-content {
        width: 95%;
        height: 90vh;
    }
    
    .file-search {
        max-width: 200px;
    }
}

/* 聚焦樣式 */
button:focus,
input:focus,
select:focus,
[contenteditable]:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* 打印樣式 */
@media print {
    .sidebar,
    .member-sidebar,
    .input-area,
    .chat-header,
    .notification-container {
        display: none !important;
    }
    
    .chat-main {
        width: 100% !important;
    }
}