* {
    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: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 500px;
    padding: 20px;
}

.welcome-box, .form-box {
    background: white;
    border-radius: 16px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 10px;
    font-size: 32px;
}

.subtitle {
    text-align: center;
    color: #666;
    margin-bottom: 30px;
    font-size: 16px;
}

.button-group {
    display: flex;
    gap: 15px;
    margin-bottom: 40px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    text-align: center;
    transition: all 0.3s;
    flex: 1;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #f0f0f0;
    color: #333;
}

.btn-secondary:hover {
    background: #e0e0e0;
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
}

.btn-small {
    padding: 6px 12px;
    font-size: 14px;
}

.features {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.feature {
    text-align: center;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 12px;
}

.feature .icon {
    font-size: 48px;
    display: block;
    margin-bottom: 10px;
}

.feature h3 {
    color: #333;
    margin-bottom: 8px;
    font-size: 18px;
}

.feature p {
    color: #666;
    font-size: 14px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #333;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.form-footer {
    text-align: center;
    margin-top: 20px;
    color: #666;
}

.form-footer a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.form-footer a:hover {
    text-decoration: underline;
}

.message {
    margin-top: 20px;
    padding: 12px;
    border-radius: 8px;
    text-align: center;
    display: none;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

/* 聊天页面样式 */
.chat-container {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background: white;
}

.chat-header {
    background: #667eea;
    color: white;
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.chat-header h2 {
    margin: 0;
    font-size: 24px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-info span {
    font-size: 16px;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: #f5f5f5;
}

.message-item {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
}

.message-item.user {
    align-items: flex-end;
}

.message-item.assistant {
    align-items: flex-start;
}

.message-content {
    max-width: 70%;
    padding: 12px 16px;
    border-radius: 12px;
    word-wrap: break-word;
}

.message-item.user .message-content {
    background: #667eea;
    color: white;
}

.message-item.assistant .message-content {
    background: white;
    color: #333;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

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

.chat-input-container {
    padding: 20px;
    background: white;
    border-top: 1px solid #e0e0e0;
    display: flex;
    gap: 10px;
}

#messageInput {
    flex: 1;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    resize: none;
    font-family: inherit;
}

#messageInput:focus {
    outline: none;
    border-color: #667eea;
}

#sendBtn {
    align-self: flex-end;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .welcome-box, .form-box {
        padding: 30px 20px;
    }
    
    .message-content {
        max-width: 85%;
    }
}