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

:root {
    --primary-color: #c41e3a;
    --primary-hover: #a01830;
    --primary-light: #fef2f2;
    --bg-color: #f5f0eb;
    --sidebar-bg: #faf8f5;
    --chat-bg: #f5f0eb;
    --message-user-bg: #c41e3a;
    --message-assistant-bg: #ffffff;
    --text-primary: #2c1810;
    --text-secondary: #5a4a42;
    --text-muted: #8b7355;
    --border-color: #d4c4b5;
    --success-color: #2e7d32;
    --warning-color: #f57c00;
    --error-color: #c62828;
    --paper-bg: #fffcf9;
    --shadow-lg: 0 4px 20px rgba(196, 30, 58, 0.15);
    --shadow-soft: 0 2px 8px rgba(140, 100, 80, 0.1);
}

body {
    font-family: 'Georgia', 'Noto Serif SC', 'SimSun', serif;
    background: var(--bg-color);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

/* 应用容器 */
.app-container {
    display: flex;
    height: 100vh;
    background: linear-gradient(180deg, #f5f0eb 0%, #e8dfd5 100%);
}

/* 侧边栏 */
.sidebar {
    width: 260px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
}

.sidebar.collapsed {
    transform: translateX(-260px);
    position: absolute;
    z-index: -1;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 2px solid var(--border-color);
    background: linear-gradient(135deg, #fffcf9 0%, #faf8f5 100%);
}

.sidebar-header h2 {
    font-size: 16px;
    color: var(--text-primary);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.btn-new-chat {
    width: 100%;
    padding: 10px 16px;
    background: var(--primary-color);
    border: none;
    border-radius: 6px;
    color: white;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.btn-new-chat:hover {
    background: var(--primary-hover);
    box-shadow: var(--shadow-soft);
}

.chat-list {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
}

.chat-list::-webkit-scrollbar {
    width: 6px;
}

.chat-list::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.chat-item {
    padding: 12px 14px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-bottom: 5px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border: 1px solid transparent;
}

.chat-item:hover {
    background: var(--primary-light);
    border-color: var(--border-color);
}

.chat-item.active {
    background: var(--primary-light);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-soft);
}

.chat-item-title {
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 170px;
    color: var(--text-primary);
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.chat-item-delete {
    opacity: 0;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    transition: all 0.2s ease;
    font-size: 12px;
}

.chat-item:hover .chat-item-delete {
    opacity: 1;
}

.chat-item-delete:hover {
    background: rgba(196, 30, 58, 0.1);
    color: var(--primary-color);
}

/* 主聊天区域 */
.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--paper-bg);
    position: relative;
}

/* 顶部标题栏 */
.chat-header {
    padding: 15px 24px;
    background: linear-gradient(135deg, #fffcf9 0%, #faf8f5 100%);
    border-bottom: 2px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-soft);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 15px;
}

.btn-toggle-sidebar {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 20px;
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.btn-toggle-sidebar:hover {
    background: var(--primary-light);
    color: var(--primary-color);
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    font-size: 24px;
}

#currentChatTitle {
    font-size: 20px;
    font-weight: 600;
    color: var(--primary-color);
    font-family: 'Noto Serif SC', 'SimSun', serif;
    letter-spacing: 2px;
}

.header-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-secondary);
    padding: 6px 14px;
    background: var(--primary-light);
    border-radius: 20px;
    border: 1px solid rgba(196, 30, 58, 0.2);
}

.status-dot {
    width: 8px;
    height: 8px;
    background: var(--success-color);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

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

/* 消息容器 */
.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    background: var(--paper-bg);
}

.messages-container::-webkit-scrollbar {
    width: 8px;
}

.messages-container::-webkit-scrollbar-track {
    background: var(--bg-color);
}

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

/* 欢迎消息 */
.welcome-message {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px;
}

.welcome-icon {
    font-size: 70px;
    margin-bottom: 15px;
}

.welcome-message h2 {
    font-size: 26px;
    margin-bottom: 8px;
    color: var(--primary-color);
    font-family: 'Noto Serif SC', 'SimSun', serif;
    letter-spacing: 3px;
}

.welcome-message p {
    color: var(--text-secondary);
    margin-bottom: 30px;
    font-size: 15px;
    font-style: italic;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-top: 20px;
}

.feature-item {
    padding: 14px 20px;
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.2s ease;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.feature-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-soft);
    transform: translateY(-2px);
}

/* 消息气泡 */
.message {
    display: flex;
    gap: 12px;
    max-width: 80%;
    animation: messageSlide 0.3s ease;
}

@keyframes messageSlide {
    from {
        opacity: 0;
        transform: translateY(15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    flex-shrink: 0;
    border: 2px solid var(--border-color);
}

.message.user .message-avatar {
    background: var(--primary-color);
}

.message.assistant .message-avatar {
    background: #fff;
}

.message-content {
    padding: 14px 18px;
    border-radius: 12px;
    line-height: 1.7;
    font-size: 15px;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.message.user .message-content {
    background: var(--message-user-bg);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.assistant .message-content {
    background: var(--message-assistant-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-bottom-left-radius: 4px;
    box-shadow: var(--shadow-soft);
}

.message-content pre {
    background: var(--bg-color);
    padding: 12px;
    border-radius: 6px;
    overflow-x: auto;
    margin: 10px 0;
    border: 1px solid var(--border-color);
}

.message-content code {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 13px;
}

.message-content p {
    margin-bottom: 10px;
}

.message-content p:last-child {
    margin-bottom: 0;
}

/* 输入区域 */
.input-container {
    padding: 16px 24px;
    background: linear-gradient(135deg, #fffcf9 0%, #faf8f5 100%);
    border-top: 2px solid var(--border-color);
    box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.05);
}

.input-wrapper {
    display: flex;
    gap: 10px;
    align-items: flex-end;
    background: #fff;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    padding: 8px 8px 8px 16px;
    transition: all 0.2s ease;
}

.input-wrapper:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(196, 30, 58, 0.1);
}

.input-wrapper textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 15px;
    resize: none;
    max-height: 120px;
    outline: none;
    padding: 8px 0;
    line-height: 1.5;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.input-wrapper textarea::placeholder {
    color: var(--text-muted);
}

.btn-send {
    padding: 10px 22px;
    background: var(--primary-color);
    border: none;
    border-radius: 8px;
    color: white;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.btn-send:hover:not(:disabled) {
    background: var(--primary-hover);
    box-shadow: var(--shadow-soft);
}

.btn-send:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-send svg {
    transition: transform 0.2s ease;
}

.btn-send:hover:not(:disabled) svg {
    transform: translateX(3px);
}

.input-footer {
    text-align: center;
    margin-top: 8px;
    font-size: 12px;
    color: var(--text-muted);
    font-style: italic;
}

/* 警告容器 */
.warning-container {
    padding: 0 24px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.warning-container.show {
    max-height: 80px;
    padding: 10px 24px;
}

.warning-message {
    padding: 10px 14px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    font-family: 'Noto Serif SC', 'SimSun', serif;
}

.warning-message.warning {
    background: rgba(245, 124, 0, 0.1);
    border: 1px solid var(--warning-color);
    color: var(--warning-color);
}

.warning-message.danger {
    background: rgba(198, 40, 40, 0.1);
    border: 1px solid var(--error-color);
    color: var(--error-color);
}

/* 加载动画 */
.loading-dots {
    display: inline-flex;
    gap: 4px;
}

.loading-dots span {
    width: 8px;
    height: 8px;
    background: var(--primary-color);
    border-radius: 50%;
    animation: bounce 1.4s infinite;
}

.loading-dots span:nth-child(2) {
    animation-delay: 0.2s;
}

.loading-dots span:nth-child(3) {
    animation-delay: 0.4s;
}

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

/* 响应式设计 - 手机端适配 */
@media (max-width: 768px) {
    .sidebar {
        position: absolute;
        z-index: 100;
        height: 100%;
        box-shadow: var(--shadow-lg);
    }

    .sidebar.collapsed {
        transform: translateX(-100%);
    }

    .chat-header {
        padding: 12px 16px;
    }

    #currentChatTitle {
        font-size: 16px;
    }

    .header-status {
        display: none;
    }

    .feature-list {
        grid-template-columns: 1fr;
    }

    .feature-item {
        padding: 12px 16px;
    }

    .message {
        max-width: 90%;
    }

    .message-content {
        font-size: 14px;
        padding: 12px 14px;
    }

    .input-container {
        padding: 12px 16px;
    }

    .input-wrapper textarea {
        font-size: 14px;
    }

    .btn-send {
        padding: 10px 16px;
        font-size: 13px;
    }

    .btn-send span {
        display: none;
    }

    .welcome-message {
        padding: 20px;
    }

    .welcome-icon {
        font-size: 60px;
    }

    .welcome-message h2 {
        font-size: 22px;
    }
}

/* 小屏手机适配 */
@media (max-width: 375px) {
    .chat-header {
        padding: 10px 12px;
    }

    .logo-icon {
        font-size: 20px;
    }

    #currentChatTitle {
        font-size: 14px;
        letter-spacing: 1px;
    }

    .messages-container {
        padding: 16px;
    }

    .feature-item {
        font-size: 13px;
        padding: 10px 14px;
    }
}