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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 顶部栏 */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    margin-bottom: 20px;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: white;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo svg {
    width: 32px;
    height: 32px;
}

.user-info {
    color: white;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.logout-btn {
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.3);
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.3s;
}

.logout-btn:hover {
    background: rgba(255,255,255,0.3);
}

/* 主内容区 */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* 输入卡片 */
.input-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
}

.input-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #1a1a2e;
}

.textarea-wrapper {
    position: relative;
    margin-bottom: 15px;
}

textarea {
    width: 100%;
    min-height: 120px;
    padding: 15px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-size: 15px;
    resize: vertical;
    font-family: inherit;
    transition: border-color 0.3s;
    outline: none;
}

textarea:focus {
    border-color: #667eea;
}

textarea::placeholder {
    color: #aaa;
}

/* 图片上传区 */
.upload-section {
    margin-bottom: 15px;
}

.upload-area {
    border: 2px dashed #d0d0d0;
    border-radius: 12px;
    padding: 30px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: #fafafa;
}

.upload-area:hover {
    border-color: #667eea;
    background: #f5f7ff;
}

.upload-area.has-image {
    border-style: solid;
    border-color: #667eea;
    background: #f5f7ff;
}

.upload-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 10px;
    opacity: 0.5;
}

.upload-text {
    color: #666;
    font-size: 14px;
}

.upload-hint {
    color: #999;
    font-size: 12px;
    margin-top: 5px;
}

.image-preview {
    display: none;
    position: relative;
    max-width: 300px;
    margin: 0 auto;
}

.image-preview img {
    max-width: 100%;
    max-height: 200px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.remove-image {
    position: absolute;
    top: -10px;
    right: -10px;
    width: 28px;
    height: 28px;
    background: #ff4757;
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 16px;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.remove-image:hover {
    background: #ff3838;
}

input[type="file"] {
    display: none;
}

/* 发送按钮 */
.send-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.send-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.send-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.send-btn .spinner {
    display: none;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 回答区域 */
.answer-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
    display: none;
    min-height: 100px;
}

.answer-card.show {
    display: block;
    animation: fadeIn 0.5s ease;
}

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

.answer-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid #f0f0f0;
}

.answer-avatar {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
    font-size: 14px;
}

.answer-title {
    font-weight: 600;
    color: #1a1a2e;
}

.answer-status {
    margin-left: auto;
    font-size: 12px;
    color: #999;
    display: flex;
    align-items: center;
    gap: 6px;
}

.typing-dot {
    display: inline-block;
    width: 6px;
    height: 6px;
    background: #667eea;
    border-radius: 50%;
    animation: typing 1.4s infinite;
}

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

@keyframes typing {
    0%, 60%, 100% { transform: translateY(0); }
    30% { transform: translateY(-4px); }
}

.answer-content {
    font-size: 15px;
    line-height: 1.8;
    color: #444;
    white-space: pre-wrap;
    word-wrap: break-word;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: rgba(255,255,255,0.8);
}

.empty-state svg {
    width: 80px;
    height: 80px;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: white;
}

.empty-state p {
    font-size: 14px;
}

/* 提示条 */
.toast {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(-100px);
    background: #333;
    color: white;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 14px;
    z-index: 1000;
    transition: transform 0.3s;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.toast.show {
    transform: translateX(-50%) translateY(0);
}

/* 响应式 */
@media (max-width: 600px) {
    .container {
        padding: 10px;
    }

    .input-card, .answer-card {
        padding: 20px;
        border-radius: 12px;
    }

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