/* 全局样式设置 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(135deg, #0f2027, #203a43, #2c5364); /* 主背景渐变，避免纯白色 */
    color: #ffffff;
    line-height: 1.6;
    overflow-x: hidden; /* 防止横向滚动条出现 */
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(32, 58, 67, 0.9);
    padding: 15px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar a {
    color: #ffffff;
    margin: 0 15px;
    text-decoration: none;
    font-size: 1rem;
    transition: color 0.3s ease;
}

.navbar a:hover {
    color: #ff9800; /* 辅助色用于高亮 */
}

/* 首屏样式 */
.header {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    text-align: center;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(32, 58, 67, 0.5);
}

.header-content {
    position: relative;
    z-index: 1;
}

.header h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #ffffff;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

.header p {
    font-size: 1.2rem;
    color: #dddddd;
}

/* 章节导航样式 */
.section-nav {
    position: fixed;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 999;
}

.section-nav a {
    background: #20a0ff;
    color: #ffffff;
    padding: 10px 15px;
    border-radius: 50%;
    text-decoration: none;
    font-size: 0.9rem;
    transition: background 0.3s ease;
}

.section-nav a:hover {
    background: #ff5722; /* 点缀色用于吸引注意 */
}

/* 模块样式 */
.section {
    padding: 100px 40px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.section:nth-child(even) {
    background: rgba(255, 255, 255, 0.05);
}

.section h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: #ffffff;
}

.section p {
    max-width: 800px;
    font-size: 1rem;
    color: #dddddd;
    margin-bottom: 20px;
}

/* 图片样式 */
.section img {
    width: 320px;
    height: 320px;
    border-radius: 15px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.section img:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 16px rgba(0,0,0,0.5);
}

/* 卡片布局 */
.card-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    width: 100%;
    max-width: 1200px;
}

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

.card:hover {
    transform: translateY(-10px);
}

.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 15px;
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #20a0ff; /* 辅助色用于标题 */
}

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

/* 用户反馈样式 */
.feedback {
    background: rgba(255, 255, 255, 0.05);
    padding: 30px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 20px;
    max-width: 800px;
    margin: 20px 0;
}

.feedback img {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid #20a0ff;
}

.feedback blockquote {
    font-style: italic;
    color: #dddddd;
    position: relative;
    padding-left: 20px;
}

.feedback blockquote::before {
    content: '“';
    position: absolute;
    left: 0;
    top: -5px;
    font-size: 2rem;
    color: #ff9800; /* 点缀色用于引号 */
}

/* 按钮样式 */
.button {
    background-color: #20a0ff;
    border: none;
    padding: 15px 30px;
    color: #ffffff;
    font-size: 1rem;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.3s ease;
}

.button:hover {
    background-color: #ff5722;
    transform: scale(1.05);
}

/* 折叠区域样式 */
.collapsible {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 15px;
    width: 100%;
    max-width: 800px;
    margin: 20px 0;
}

.collapsible summary {
    cursor: pointer;
    font-size: 1.2rem;
    color: #20a0ff;
}

.collapsible details p {
    margin-top: 10px;
    font-size: 1rem;
    color: #dddddd;
}

/* 关键帧动画 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 2s ease-in-out;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar {
        padding: 10px 20px;
    }

    .navbar a {
        margin: 0 10px;
        font-size: 0.9rem;
    }

    .header h1 {
        font-size: 2rem;
    }

    .header p {
        font-size: 1rem;
    }

    .section {
        padding: 80px 20px;
    }

    .section-nav {
        right: 10px;
    }

    .section-nav a {
        padding: 8px 12px;
        font-size: 0.8rem;
    }

    .card img {
        height: 150px;
    }

    .feedback {
        flex-direction: column;
        text-align: center;
    }

    .feedback img {
        margin-bottom: 10px;
    }
}