/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

/* 登录界面 */
.login-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}

.login-box {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    text-align: center;
    min-width: 350px;
    max-width: 90%;
    animation: fadeInUp 0.5s;
}

.login-box h2 {
    margin-bottom: 10px;
    color: #333;
    font-size: 24px;
}

.login-desc {
    color: #666;
    margin-bottom: 30px;
    font-size: 14px;
}

.login-box input {
    width: 100%;
    padding: 14px 16px;
    margin: 10px 0;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.3s;
    outline: none;
}

.login-box input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.login-box button {
    width: 100%;
    padding: 14px;
    margin-top: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s;
}

.login-box button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

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

/* 主容器 */
.container {
    width: 100%;
    max-width: 1400px;
    height: 85vh;
    min-height: 600px;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    display: flex;
    overflow: hidden;
    animation: fadeIn 0.5s;
}

/* 侧边栏 */
.sidebar {
    width: 300px;
    background: #f8f9fa;
    border-right: 1px solid #e0e0e0;
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 25px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.sidebar-header h2 {
    font-size: 18px;
    margin-bottom: 12px;
    font-weight: 600;
}

.current-user {
    display: flex;
    align-items: center;
    font-size: 14px;
    opacity: 0.95;
    padding: 8px 12px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
}

.status-dot {
    width: 10px;
    height: 10px;
    background: #4caf50;
    border-radius: 50%;
    margin-right: 10px;
    animation: pulse 2s infinite;
}

/* 用户列表 */
.user-list {
    flex: 1;
    overflow-y: auto;
    padding: 15px;
}

.empty-users {
    text-align: center;
    color: #999;
    padding: 40px 20px;
    font-size: 14px;
}

.user-item {
    padding: 14px 16px;
    margin: 8px 0;
    background: white;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.user-item:hover {
    background: #e3f2fd;
    transform: translateX(5px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.user-item.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.user-item .status {
    width: 8px;
    height: 8px;
    background: #4caf50;
    border-radius: 50%;
    margin-right: 12px;
    flex-shrink: 0;
}

.user-item.active .status {
    background: #fff;
}

.user-item .user-name {
    flex: 1;
}

/* 未读消息徽章 */
.unread-badge {
    margin-left: auto;
    background: #f44336;
    color: white;
    font-size: 11px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 10px;
    min-width: 18px;
    text-align: center;
    flex-shrink: 0;
}

.user-item.active .unread-badge {
    background: rgba(255, 255, 255, 0.3);
}

/* 聊天区域 */
.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: #fafafa;
}

.chat-header {
    padding: 20px 25px;
    background: white;
    border-bottom: 1px solid #e0e0e0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chat-header h3 {
    font-size: 18px;
    color: #333;
    font-weight: 600;
}

.logout-btn {
    padding: 8px 20px;
    background: #f44336;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
}

.logout-btn:hover {
    background: #d32f2f;
    transform: translateY(-2px);
}

/* 消息区域 */
.messages {
    flex: 1;
    padding: 25px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

.welcome-screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #999;
}

.welcome-icon {
    font-size: 80px;
    margin-bottom: 20px;
    animation: bounce 2s infinite;
}

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

/* 消息样式 */
.message {
    margin: 12px 0;
    display: flex;
    animation: slideIn 0.3s ease-out;
}

.message.sent {
    justify-content: flex-end;
}

.message.received {
    justify-content: flex-start;
}

.message-wrapper {
    max-width: 65%;
    display: flex;
    flex-direction: column;
}

.message-sender {
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 4px;
    padding: 0 4px;
    opacity: 0.8;
    letter-spacing: 0.3px;
}

.message.sent .message-sender {
    text-align: right;
    color: #667eea;
}

.message.received .message-sender {
    text-align: left;
    color: #555;
}

.message-content {
    padding: 12px 16px;
    border-radius: 18px;
    word-wrap: break-word;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    position: relative;
}

.message.received .message-content {
    background: white;
    color: #333;
    border-bottom-left-radius: 4px;
}

.message.sent .message-content {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-bottom-right-radius: 4px;
}

.message-text {
    font-size: 15px;
    line-height: 1.5;
    margin-bottom: 6px;
}

.message-info {
    font-size: 11px;
    opacity: 0.7;
    text-align: right;
}

/* 输入区域 */
.input-area {
    padding: 20px 25px;
    background: white;
    border-top: 1px solid #e0e0e0;
    display: flex;
    gap: 12px;
    align-items: center;
}

.input-area input {
    flex: 1;
    padding: 14px 18px;
    border: 2px solid #e0e0e0;
    border-radius: 25px;
    font-size: 15px;
    outline: none;
    transition: all 0.3s;
}

.input-area input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.input-area input:disabled {
    background: #f5f5f5;
    cursor: not-allowed;
}

.input-area button {
    padding: 14px 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
    white-space: nowrap;
}

.input-area button:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(102, 126, 234, 0.3);
}

.input-area button:active:not(:disabled) {
    transform: translateY(0);
}

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

/* 滚动条样式 */
.user-list::-webkit-scrollbar,
.messages::-webkit-scrollbar {
    width: 6px;
}

.user-list::-webkit-scrollbar-track,
.messages::-webkit-scrollbar-track {
    background: transparent;
}

.user-list::-webkit-scrollbar-thumb,
.messages::-webkit-scrollbar-thumb {
    background: #ccc;
    border-radius: 3px;
}

.user-list::-webkit-scrollbar-thumb:hover,
.messages::-webkit-scrollbar-thumb:hover {
    background: #999;
}

/* 工具类 */
.hidden {
    display: none !important;
}

/* 动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

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

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

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

    .container {
        height: 100vh;
        border-radius: 0;
        max-width: 100%;
    }

    .sidebar {
        width: 250px;
    }

    .login-box {
        min-width: 300px;
        padding: 30px 25px;
    }

    .message-wrapper {
        max-width: 80%;
    }

    .input-area {
        padding: 15px;
    }

    .input-area button {
        padding: 14px 24px;
    }
}

@media (max-width: 480px) {
    .sidebar {
        position: absolute;
        left: -250px;
        height: 100%;
        z-index: 100;
        transition: left 0.3s;
    }

    .sidebar.show {
        left: 0;
    }

    .chat-header h3 {
        font-size: 16px;
    }

    .logout-btn {
        padding: 6px 16px;
        font-size: 13px;
    }
}

/* 文件和多媒体样式 */
.attach-btn, .voice-btn {
    padding: 14px 18px;
    background: #f5f5f5;
    color: #666;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 18px;
    transition: all 0.3s;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.attach-btn:hover:not(:disabled), .voice-btn:hover:not(:disabled) {
    background: #e0e0e0;
    transform: scale(1.1);
}

.attach-btn:disabled, .voice-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* 文件消息样式 */
.message-file {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    margin-bottom: 6px;
}

.message.received .message-file {
    background: #f5f5f5;
}

.file-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.file-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px;
    min-width: 0;
}

.file-name {
    font-weight: 600;
    font-size: 14px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.file-size {
    font-size: 12px;
    opacity: 0.7;
}

.download-btn {
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.2);
    color: inherit;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.3s;
    flex-shrink: 0;
}

.message.received .download-btn {
    background: white;
    color: #667eea;
    border-color: #667eea;
}

.download-btn:hover {
    transform: scale(1.05);
    opacity: 0.9;
}

/* 图片消息样式 */
.message-image {
    max-width: 300px;
    max-height: 300px;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s;
    display: block;
    margin-bottom: 8px;
}

.message-image:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* 视频消息样式 */
.message-video {
    max-width: 400px;
    max-height: 300px;
    border-radius: 12px;
    display: block;
    margin-bottom: 8px;
}

/* 音频消息样式 */
.message-audio {
    width: 300px;
    margin-bottom: 8px;
}

/* 语音消息样式 */
.message-voice {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    margin-bottom: 6px;
}

.message.received .message-voice {
    background: #f5f5f5;
}

.voice-icon {
    font-size: 24px;
    flex-shrink: 0;
}

.voice-audio {
    flex: 1;
    height: 32px;
}

.voice-duration {
    font-size: 12px;
    opacity: 0.7;
    flex-shrink: 0;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .message-image {
        max-width: 200px;
        max-height: 200px;
    }
    
    .message-video {
        max-width: 280px;
        max-height: 200px;
    }
    
    .message-audio {
        width: 220px;
    }
    
    .attach-btn, .voice-btn {
        width: 42px;
        height: 42px;
        font-size: 16px;
    }
}