body {
    font-family: system-ui, sans-serif;
    color: #1a1a1a;
    padding: 20px;
}

/* 容器：宽度自适应，间距整齐 */
.contact-list {
    max-width: 280px;
    margin: 0 auto;
}

/* 用户名效果 */
.username {
    color: #007bff;
    font-weight: bold;
    border-bottom: 2px solid #007bff;
}

/* 每一行的间距和对齐 */
.item {
    margin: 12px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* 数字高亮：纯黑加粗，确保看清 */
.num {
    color: #000;
    font-size: 1.1em;
    margin-left: 5px;
}

/* 基础按钮：边框感，无多余装饰 */
button {
    padding: 4px 10px;
    border: 1px solid #ccc;
    background: #fff;
    border-radius: 4px;
    cursor: pointer;
    font-size: 13px;
}

button:active {
    background: #f0f0f0;
}