body {
    font-family: sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
}

header {
    background-color: #35424a;
    color: #ffffff;
    padding: 1rem 0;
    text-align: center;
    margin-bottom: 20px;
}

header h1 {
    margin: 0;
    padding-bottom: 5px;
}

header p {
    margin: 0;
    font-size: 0.9em;
}

main {
    max-width: 800px;
    margin: 20px auto;
    padding: 0 20px;
}

#crypto-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); /* 响应式网格布局 */
    gap: 20px; /* 网格间距 */
}

.crypto-card {
    background-color: #ffffff;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    text-align: center;
}

.crypto-card img {
    width: 40px;
    height: 40px;
    margin-bottom: 10px;
}

.crypto-card h2 {
    margin-top: 0;
    margin-bottom: 10px;
    font-size: 1.2em;
}

.price {
    font-size: 1.3em;
    font-weight: bold;
    margin: 10px 0;
    color: #333;
}

.change {
    font-size: 1em;
    font-weight: bold;
}

.positive {
    color: #28a745; /* 绿色 */
}

.negative {
    color: #dc3545; /* 红色 */
}

.loading {
    text-align: center;
    padding: 30px;
    font-style: italic;
    color: #666;
    grid-column: 1 / -1; /* 让加载提示占据整行 */
}

footer {
    text-align: center;
    margin-top: 40px;
    padding: 15px;
    background-color: #35424a;
    color: #ffffff;
    font-size: 0.8em;
}