@charset "utf-8";
.slideshow {
    overflow: hidden;
    position: relative;
    min-width: 960px;
    height: 700px;
}
.slideshow img {
    display: none;
    position: absolute;
    left: 50%;
    margin-left: -800px;
}

/* JavsScript 無効時 */
.no-js .slideshow img:first-child {
    display: inline;
}
.righttext{
    text-align: right;
}
.lefttext{
    text-align: left;
}
.centertext{
    text-align: center;
}

body {
    background-image: url("../images/tokei.jpg"); 
    background-size: cover;        
    background-repeat: no-repeat; 
    background-position: center;  
    background-attachment: fixed;  
    color: white;
}
.bold{
    font-weight:bold;
    color: green;
    font-size: 20px;
}
.title{
    position: relative;
    width: 1600px;
    height: 700px;

}
.chenge1{
    position: absolute;
    opacity: 1;
}
.chenge2{
    position: absolute;
    opacity: 0;
}
button{
    color: white;
    background-color: black;
}
#error{
    opacity: 1;
    color: red;
}
  
nav ul{
    list-style-type: none;

    display: flex;
     font-size: 18px;
     margin: auto;
    padding: auto;
    justify-content: center;
    width: 900px;
    box-sizing: border-box;
}
nav a{
    display: block;
    padding: 6px 20px;
     color: silver;  
    text-decoration: none;
    border-right: 3px solid #cccccc;
    border-bottom: 3px solid #cccccc;
    border-top: 3px solid #525050;
    border-left: 3px solid #525050;
    background-color: black;
    transition: color 2s linear;
}
nav a:hover{
    color:red;
}