* {
    padding: 0;
    margin: 0;
}

@keyframes pulse {

    0%,
    100% {
        box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
        border: 1px solid transparent;
    }

    50% {
        box-shadow: 0 0 15px rgba(0, 0, 0, 0.6);
        border: 1px solid #ff6a00;
    }
}
/* 渐变色按钮样式 */
.gradient-button {
    display: inline-block;
    padding: 10px 20px;
    font-size: 16px;
    font-weight: bold;
    text-align: center;
    text-decoration: none;
    border-radius: 5px;
    cursor: pointer;
    background: linear-gradient(to right, #ff6a00, #ee0979);
    color: #fff;
    border: none;
    outline: none;
    transition: background 0.3s ease;
}

/* 鼠标悬停时的效果 */
.gradient-button:hover {
    background: linear-gradient(to right, #ff6a00, #c837ab);
}

/* 鼠标悬停时的效果 */
#hdxq:hover {
    background: linear-gradient(to right, #00B4DB, #0083B0);
}

.main {
    display: flex;
    max-width: 750px;
    height: 100vh;
    background: url(../img/bg.jpg) top center no-repeat;
    background-size: 100% auto;
    margin: 0 auto;
    text-align: center;
    flex-wrap: wrap;
    align-content: center;
    justify-content: center;
}

.main a{
    width: 80%;
    height: 35px;
    line-height: 35px;
    margin: 25px 0;
}
.main img {
    width: 50%;
    text-align: left;
}
.topimg{
    position: fixed;
    top: 0;
    width: 100%;
    max-width: 750px;
}