/* 基础样式与响应式布局 */
body {
    margin: 0;
    font-family: 'Roboto', sans-serif;
    background: radial-gradient(circle, #1A237E, #651FFF);
    color: white;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(26, 35, 126, 0.8);
    padding: 10px 20px;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

header h1 {
    margin: 0;
    font-size: 24px;
    text-align: center;
}

.container {
    flex: 1;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 20px;
    margin-top: 60px;
}

.card {
    background: white;
    color: #1A237E;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    padding: 20px;
    margin-bottom: 20px;
    transition: transform 0.3s ease;
    max-width: calc(33.333% - 20px);
}

.card:hover {
    transform: translateY(-5px);
}

@media (max-width: 1024px) {
    .card {
        max-width: calc(50% - 20px);
    }
}

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

.button-primary {
    background-color: #FF9800;
    color: white;
    border: none;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.button-primary:hover {
    background-color: #E68A00;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    width: 100%;
}

.breadcrumb {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    background: rgba(255, 255, 255, 0.8);
    padding: 10px;
    border-radius: 5px;
}

.breadcrumb-item + .breadcrumb-item::before {
    content: ">";
    margin: 0 5px;
    color: gray;
}

article {
    background: rgba(255, 255, 255, 0.9);
    color: #1A237E;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
}

footer {
    background: #1A237E;
    color: white;
    text-align: center;
    padding: 10px;
}

img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
}

/* 动画效果 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 1.5s ease-in-out;
}