.navigation {
    background-color: #C8102E;
    color: #000000;
    padding: 7px 0px 0px 0px;
    text-align: center; 
} 

nav ul {
    list-style: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin: 0 10px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    position: relative;
    transition: color 0.3s ease;
}

nav ul li a::before {
    content: "";
    position: absolute;
    width: 100%;
    height: 3px;
    background-color: #fff;
    bottom: -5px;
    left: 0;
    transform: scaleX(0);
    transform-origin: bottom right;
    transition: transform 0.3s ease;
}

nav ul li a:hover::before {
    transform: scaleX(1);
    transform-origin: bottom left;
}

nav ul li a:hover {
    color: #ff6347;
}









.navigation a {
    text-decoration: line-through; /* 真ん中の線を引く */ 
}