/* 全局样式设置 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif; /* 使用现代无衬线字体，提升可读性 */
    background: linear-gradient(135deg, #1e3c72, #2a5298); /* 渐变背景，体现科技感 */
    color: #ffffff;
    line-height: 1.6;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.7); /* 半透明背景，增强层次感 */
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 30px;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.navbar .logo {
    font-size: 1.5em;
    font-weight: bold;
}

.navbar ul {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
}

.navbar ul li {
    margin-left: 20px;
}

.navbar ul li a {
    color: #ffffff;
    text-decoration: none;
    font-size: 1em;
    transition: color 0.3s;
}

.navbar ul li a:hover {
    color: #ffa500; /* 橙色悬停效果，吸引注意 */
}

/* 横幅样式 */
.banner {
    height: 100vh;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center center/cover;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    animation: fadeInBackground 5s ease-in-out infinite alternate;
}

@keyframes fadeInBackground {
    from { opacity: 1; }
    to { opacity: 0.8; }
}

.banner::after {
    content: "这是一个网页样式设计参考";
    position: absolute;
    bottom: 20px;
    right: 30px;
    background: rgba(0, 0, 0, 0.5);
    padding: 10px 20px;
    border-radius: 20px;
    font-size: 1em;
    color: #ffffff;
    animation: slideIn 2s ease-out;
}

@keyframes slideIn {
    from { transform: translateX(100%); }
    to { transform: translateX(0); }
}

.banner h1 {
    font-size: 3em;
    text-align: center;
    color: #ffffff;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
    animation: zoomIn 2s ease-out forwards;
}

@keyframes zoomIn {
    from { transform: scale(0.5); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

/* 核心功能展示区 */
.core-features {
    padding: 80px 20px;
    background: linear-gradient(135deg, #2a5298, #1e3c72);
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

.feature-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    width: 300px;
    margin: 20px;
    padding: 30px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 12px rgba(0,0,0,0.4);
}

.feature-card img {
    width: 100%;
    height: auto;
    border-radius: 10px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.5em;
    margin-bottom: 15px;
    color: #ffffff;
}

.feature-card p {
    font-size: 1em;
    color: #dddddd;
}

/* 数据展示区 */
.data-section {
    padding: 80px 20px;
    background: #ffffff;
    color: #333333;
}

.data-section h2 {
    text-align: center;
    font-size: 2em;
    margin-bottom: 40px;
    color: #1e3c72;
}

.data-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.data-card {
    background: #f0f8ff;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s, background-color 0.3s;
}

.data-card:hover {
    transform: translateY(-5px);
    background-color: #e6f7ff;
}

.data-card h4 {
    font-size: 1.2em;
    margin-bottom: 10px;
    color: #1e3c72;
}

.data-card p {
    font-size: 1em;
    color: #555555;
}

/* 用户反馈区 */
.feedback-section {
    padding: 80px 20px;
    background: linear-gradient(135deg, #1e3c72, #2a5298);
    color: #ffffff;
}

.feedback-section h2 {
    text-align: center;
    font-size: 2em;
    margin-bottom: 40px;
}

.feedback-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
}

.feedback-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 20px;
    width: 300px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feedback-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 12px rgba(0,0,0,0.3);
}

.feedback-card p {
    font-size: 1em;
    color: #dddddd;
}

.feedback-card .user {
    margin-top: 15px;
    font-weight: bold;
    color: #ffa500;
}

/* 底部信息区 */
.footer {
    padding: 40px 20px;
    background: #1e3c72;
    color: #ffffff;
    text-align: center;
}

.footer p {
    margin: 10px 0;
    font-size: 0.9em;
}

.footer a {
    color: #ffa500;
    text-decoration: none;
    margin: 0 10px;
    transition: color 0.3s;
}

.footer a:hover {
    color: #ffffff;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar ul {
        flex-direction: column;
        background: rgba(0, 0, 0, 0.9);
        position: absolute;
        top: 60px;
        right: 0;
        width: 200px;
        display: none;
    }

    .navbar ul.active {
        display: flex;
    }

    .navbar ul li {
        margin: 15px 0;
    }

    .banner h1 {
        font-size: 2em;
    }

    .feature-card, .data-card, .feedback-card {
        width: 100%;
    }
}

/* 按钮样式 */
.button {
    display: inline-block;
    padding: 10px 20px;
    background: #ffa500;
    color: #ffffff;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: background 0.3s, transform 0.3s;
    text-decoration: none;
    font-size: 1em;
}

.button:hover {
    background: #ff8c00;
    transform: scale(1.05);
}

/* 图片装饰样式 */
.decorative-images {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-top: 40px;
}

.decorative-images img {
    width: 100px;
    height: 100px;
    border-radius: 15px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    transition: transform 0.3s, box-shadow 0.3s;
}

.decorative-images img:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 12px rgba(0,0,0,0.4);
}