/* 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 */
    background: linear-gradient(135deg, #1E3A8A 70%, #F3F4F6 25%, #FF7506 5%);
    color: #333333;
    line-height: 1.6;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(30, 58, 138, 0.9);
    padding: 15px 20px;
    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: #F3F4F6;
    text-decoration: none;
    margin: 0 10px;
    font-weight: 500;
    transition: color 0.3s ease;
}
.navbar a:hover {
    color: #FF7506;
}

/* 主容器样式 */
.container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(500px, 1fr));
    gap: 40px;
    padding: 100px 20px 40px 20px; /* 顶部留出导航栏空间 */
    background-color: #F3F4F6;
}

/* 卡片样式 */
.card {
    background-color: #FFFFFF;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}
.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.2);
}

/* 图片样式 */
.card img {
    width: 100%;
    height: auto;
    border-bottom: 1px solid #E5E7EB;
    transition: transform 0.3s ease;
}
.card img:hover {
    transform: scale(1.05);
}

/* 内容区域样式 */
.card-content {
    padding: 20px;
}
.card-content h2 {
    font-size: 1.8em;
    margin-bottom: 10px;
    color: #1E3A8A;
}
.card-content h3 {
    font-size: 1.6em;
    margin-bottom: 10px;
    color: #22C55E;
}
.card-content p {
    font-size: 1.6em;
    margin-bottom: 15px;
}

/* 按钮样式 */
.button {
    background: linear-gradient(45deg, #1E3A8A, #22C55E);
    border: none;
    padding: 10px 20px;
    color: #FFFFFF;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s ease;
}
.button:hover {
    background: linear-gradient(45deg, #FF7506, #22C55E);
}

/* 悬停效果 */
.hover-effect:hover {
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
    transform: scale(1.02);
    transition: all 0.3s ease;
}

/* 代码块样式 */
pre {
    background: #F3F4F6;
    padding: 15px;
    border-radius: 8px;
    overflow: auto;
    position: relative;
}
pre code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.4em;
    color: #1E3A8A;
}
pre code::before {
    content: "代码示例";
    position: absolute;
    top: -25px;
    left: 0;
    background: #1E3A8A;
    color: #FFFFFF;
    padding: 5px 10px;
    border-radius: 4px 4px 0 0;
    font-size: 1.2em;
}

/* SVG 动画样式 */
.svg-animation circle {
    stroke-dasharray: 502;
    stroke-dashoffset: 502;
    animation: draw 2s forwards;
}
@keyframes draw {
    to {
        stroke-dashoffset: 0;
    }
}

/* 时间轴样式 */
.timeline {
    position: relative;
    padding: 20px 0;
    list-style: none;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #1E3A8A;
    transform: translateX(-50%);
}
.timeline-item {
    position: relative;
    width: 50%;
    padding: 20px 40px;
}
.timeline-item:nth-child(odd) {
    left: 0;
}
.timeline-item:nth-child(even) {
    left: 50%;
}
.timeline-icon {
    position: absolute;
    top: 20px;
    right: -10px;
    width: 20px;
    height: 20px;
    background: #FF7506;
    border-radius: 50%;
}
.timeline-content {
    background: #FFFFFF;
    padding: 10px 20px;
    border-radius: 6px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    opacity: 0;
    transition: opacity 0.6s ease;
}
.timeline-content.visible {
    opacity: 1;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        align-items: flex-start;
        padding: 15px;
    }
    .container {
        grid-template-columns: 1fr;
    }
    .timeline::before {
        left: 20px;
    }
    .timeline-item {
        width: 100%;
        padding: 20px 20px 20px 60px;
    }
    .timeline-icon {
        left: 0;
        right: auto;
    }
}