2 状态平滑的动画

   @keyframes panoramic {
            to {
                background-position: 100% 0;
            }
        }
        .panoramic {
            width: 150px;
            height: 150px;
            background: url("10.jfif");
            background-size: auto 100%;
            animation: panoramic 10s linear infinite alternate;
            animation-play-state: paused;
        }
        .panoramic:hover,
        .panoramic:focus {
            animation-play-state: running;
        }