/* ===== 全体 ===== */
*{
box-sizing:border-box;
margin:0;
padding:0;
}

html{
font-size:14px;
}

body{
font-family:"Zen Old Mincho",serif;
background:url(back/2.jpg);
color:#111;
line-height:1.6;
}

/* ===== Header ===== */
.site-header{
position:fixed;
top:0;
width:100%;
background:rgba(255,255,255,0.9);
backdrop-filter:blur(8px);
z-index:1000;
}

.header-inner{
max-width:1100px;
margin:auto;
display:flex;
justify-content:space-between;
align-items:center;
padding:12px 20px;
}

.brand-main{
font-size:18px;
letter-spacing:2px;
}

.brand-sub{
font-size:12px;
opacity:0.7;
}

.header-nav a{
text-decoration:none;
color:#111;
font-size:14px;
padding:6px 12px;
border:1px solid #ccc;
border-radius:20px;
transition:0.2s;
}

.header-nav a:hover{
background:#111;
color:#fff;
}

/* ===== Main ===== */
main{
max-width:800px;
margin:110px auto 40px;
padding:20px;
background:rgba(255,255,255,0.4);
border-radius:10px;
}

/* ===== Panel ===== */
.panel{
background:#fff;
padding:25px;
border-radius:10px;
box-shadow:0 5px 15px rgba(0,0,0,0.05);
}

h2{
text-align:center;
font-size:24px;
margin-bottom:20px;
}

/* ===== 目次（縦一列） ===== */
.itiran{
display:flex;
flex-direction:column;
gap:10px;
max-width:500px;
margin:0 auto;
}

.card{
display:block;
text-align:left;
padding:10px 14px;
font-size:16px;
text-decoration:none;
color:#111;
border-bottom:1px solid #ccc;
transition:0.2s;
}

/* ホバー（控えめ） */
.card:hover{
background:rgba(0,0,0,0.05);
padding-left:18px;
}

/* ===== Footer ===== */
.site-footer{
text-align:center;
background:#1b2a3a;
color:#fff;
font-size:0.85rem;
padding:25px;
margin-top:40px;
}

/* ===== TOPボタン ===== */
.back-to-top{
position:fixed;
bottom:25px;
right:25px;
width:50px;
height:50px;
background:#1b2a3a;
color:#fff;
text-align:center;
line-height:50px;
border-radius:50%;
text-decoration:none;
}

.back-to-top:hover{
opacity:0.7;
}

/* ===== スマホ対応 ===== */
@media (max-width:767px){

.header-inner{
padding:10px 15px;
}

main{
margin-top:100px;
padding:15px;
}

h2{
font-size:20px;
}

.card{
font-size:15px;
}

}