:root {
    --primary-color: #0066cc;
    --secondary-color: #f0f8ff;
    --text-color: #333;
    --background-color: #ffffff;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    margin: 0;
    padding: 0;
}

header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 0;
}

nav ul {
    display: flex;
    justify-content: center;
    list-style-type: none;
    padding: 0;
}

nav ul li {
    margin: 0 1rem;
}

nav ul li a {
    color: white;
    text-decoration: none;
}

.hero {
    background-image: url('path/to/your/hero-image.jpg');
    background-size: cover;
    background-position: center;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: black;
}

.hero h1, .hero p {
    background-color: rgba(255, 255, 255, 0.7); /* 添加半透明白色背景 */
    padding: 10px; /* 添加一些内边距 */
    border-radius: 5px; /* 可选：添加圆角 */
}

.hero h1 {
    color: black;
    font-size: 3rem;
    margin-bottom: 1rem;
    text-shadow: 1px 1px 3px rgba(255, 255, 255, 0.5);
}

.hero p {
    color: black; /* 将段落文字颜色改为黑色 */
    text-shadow: 1px 1px 2px rgba(255, 255, 255, 0.5);
}

section {
    padding: 4rem 2rem;
}

h2 {
    text-align: center;
    color: var(--primary-color);
}

.features {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
}

.feature {
    flex-basis: 30%;
    text-align: center;
    margin-bottom: 2rem;
}

.application-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.news-list article {
    margin-bottom: 2rem;
}

.contact-form, .subscribe-form {
    display: flex;
    flex-direction: column;
    max-width: 500px;
    margin: 0 auto;
}

input, textarea, button {
    margin-bottom: 1rem;
    padding: 0.5rem;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
}

footer {
    background-color: var(--secondary-color);
    padding: 2rem;
    text-align: center;
}

@media (max-width: 768px) {
    .feature {
        flex-basis: 100%;
    }
}

/* AI对话框样式 */
#ai-chat {
    background-color: var(--secondary-color);
    padding: 2rem;
}

.chat-container {
    max-width: 600px;
    margin: 0 auto;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.chat-messages {
    height: 300px;
    overflow-y: auto;
    padding: 1rem;
}

.message {
    margin-bottom: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    max-width: 80%;
}

.user-message {
    background-color: #e6f2ff;
    align-self: flex-end;
    margin-left: auto;
}

.ai-message {
    background-color: #f0f0f0;
    align-self: flex-start;
}

.chat-input {
    display: flex;
    padding: 1rem;
    background-color: #f9f9f9;
}

.chat-input input {
    flex-grow: 1;
    margin-right: 0.5rem;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.chat-input button {
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}