效果图：
van-popup背景颜色渐变
使用深度修改样式不生效，直接在 custom-style里面修改即可；
<van-popup position="bottom"custom-style="height:25%;background:linear-gradient(95deg, #F8FCFF -0.03%, #EDF5FF
64.44%, #F8FCFF 133.06%);" 在这里设置渐变背景round show="{{ showLogin }}" bind:close="onLoginClose"><button open-type="getPhoneNumber" open-type是微信原生自带class="wx-login-btn wx-btn" bindgetphonenumber="wxLogin">手机号快捷登录</button><checkbox-group class="certificate" style="width: 90%;margin:24rpx 40rpx;"><checkbox checked="{{isagree}}" class="checkbox" value="{{sms}}"></checkbox><view class="certificate-txt">阅读并同意<text class="txt" bindtap="openUrl" data-num='lending006'>《用户信息授权书》</text>、<text class="txt" bindtap="openUrl" data-num='lending008'>《卖家云SaaS系统服务协议》</text></view></checkbox-group>
</van-popup>样式代码，包括同意协议勾选前后的样式，
.herad .wx-login-btn {margin: 80rpx 0 64rpx 0;height: 96rpx;line-height: 96rpx;font-size: 30rpx;border-radius: 6rpx;width: 90%;color: #fff;right: 0;display: flex;justify-content: center;align-items: center;position: flex;bottom: 0;left: 0;padding: 0;margin-left: 5%;text-align: center;/* padding-left: -5rpx; */border-top-left-radius: 50rpx;border-bottom-left-radius: 50rpx;border-top-right-radius: 50rpx;border-bottom-right-radius: 50rpx;letter-spacing: 3rpx;
}.wx-btn {background: var(--blue, linear-gradient(90deg, #1463FF 0%, #7214FF 100%));box-shadow: 0rpx 8rpx 20rpx 0rpx rgba(20, 72, 255, 0.20);
}
.wx-btn:hover{box-shadow: 10rpx 10rpx 32rpx #91c9f4;
}
.certificate {display: flex;align-items: flex-start;justify-content: space-between;margin-top: 24rpx;font-size: 30rpx;color: #666666;
}
.checkbox .wx-checkbox-input {border-radius: 10rpx;/* 圆角 */width: 40rpx;/* 背景的宽 */height: 40rpx;border: none;
}
.checkbox .wx-checkbox-input {background:#E7E7E7
}
.checkbox .wx-checkbox-input.wx-checkbox-input-checked {background:#E7E7E7
}
.checkbox .wx-checkbox-input.wx-checkbox-input-checked::before {width: 40rpx;height: 40rpx;line-height: 40rpx;text-align: center;font-size: 20rpx;color: #7B7B7B;background: transparent;transform: translate(-50%, -50%) scale(1);-webkit-transform: translate(-50%, -50%) scale(1);
}
.certificate-txt{color: #222;font-size: 24rpx;}
.txt {color: #1F6DF2;font-size: 24rpx;
}
