*{font-size: 15px}
body {background-color:#1e1e1e;}
.container {position: relative;  /* 创建定位基准 */}


/* 基础样式 */
.xietaiji {
  font-size: 2.3vh;
  font-family: Arial, sans-serif;
  text-align: center;
  animation: colorSwitch 10s infinite alternate;
}
/* 关键帧动画 */
@keyframes colorSwitch {
  0% {opacity: 1;color: rgb(23, 23, 23); /* 深灰色 */}
  50% {opacity: 1;color: rgb(213, 213, 213); /* 保持深灰色 */}
  100% {opacity: 1;color: rgb(23, 23, 23); /* 浅灰色 */}
}

h1{position: absolute;margin-top: 17vh;left: 50%; transform: translateX(-50%); 
    transition: color 1s;text-align: center;font-size: 2.3vh;}

a:link {color: #d5d5d5;text-decoration:none;font-size: 15px;text-align: center;}
a:visited {color: #535353;text-decoration:none;font-size: 15px;text-align: center;}
h2{color: rgb(122, 122, 122);text-align: center;}
h3,p{color: rgb(212, 212, 212);text-align: center;}
.content{text-align: center;}
#message{width: 500px;}
#submit{color: rgb(60, 67, 76);}