:root{
    --start-color: #e0f7fa;
    --end-color: #fce4ec;
    --y-primary: #7ac8e0;
    --y-secondary:#f7b59c; 
    --y-accent:  #a1d6cc; 
    --y-shadow:  0 4px 18px rgba(0,0,0,.06);
}

.bg{
    background:linear-gradient(135deg, var(--start-color) 0%, var(--end-color) 100%);
}

.top-bar{
    background:linear-gradient(200deg, var(--y-primary) 0%, var(--y-accent) 100%);
    box-shadow:var(--y-shadow);
    padding:1rem 0;
    text-align:center;
    height: 10em;
}
.top-bar h1{
    color:#fff;
    font-size: 2.3rem;
    font-weight:600;
    font-family: "华文行楷";
    margin:0 0 .5rem;
    letter-spacing:1px;
    height: 2em;
    padding-top: 25px;
}
.top-bar nav ul{
    list-style:none;
    padding:0;
    margin:0;
    display:flex;
    justify-content:center;
    gap:1rem;
}
.top-bar nav a{
    color:#fff;
    font-weight:600;
    font-family: "楷体";
    text-decoration:none;
    padding:.5rem 1.2rem;
    border:2px solid rgba(255,255,255,.6);
    border-radius:24px;
    transition:all .3s;
    background:transparent;   
}
.top-bar nav a:hover{
    background:var(--y-card);
    color:var(--y-primary);
    border-color:var(--y-card);
    box-shadow:0 0 12px rgba(255,255,255,.7);
}

section,
.members{
    margin: 0 auto 0 0;
    width:auto;
}
section,
.member,
.head{
    margin-left: 0;
    width: 650px;
}
section,
.member,
.second{
    margin-right: 0;
    width: 650px;
    margin-top: 0;
}
section,
.members,
.title{
    font-family: "楷体";
    font-size: 20px;
    margin-top: 20px; 
    margin-bottom: 20px;
    text-align: center;
}
section,
.members,
.member{
    background:var(--start-color);
    border-radius:var(--end-color);
    box-shadow:var(--y-shadow);
    padding:2rem;
    margin-bottom:2rem;
    transform:translateY(0);
    transition:transform .3s, box-shadow .3s;
    font-size: 20px;
    text-align: left;
    width:auto;
    margin-left: 0;
}
.member-row{
  display:grid;
  grid-template-columns:repeat(auto-fit, minmax(300px, 1fr));
  gap:2rem;
}
section:hover,
.member:hover{
    transform:translateY(-4px);
    box-shadow:0 8px 28px rgba(0,0,0,.08);
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1rem 0;
    position: bottom;
    bottom: 0;
    width: 100%;
}

body.dark{
  --y-bg:#181818;
  --y-card:#222;
  --y-text:#ddd;
  background:var(#faf7f0);
}

.theme-switch{
  position:fixed;
  bottom:1.2rem; right:1.2rem;
  width:3rem; height:3rem;
  border-radius:50%;
  background:var(--y-primary);
  color:#fff;
  border:none;
  cursor:pointer;
  box-shadow:var(--y-shadow);
  font-size:1.4rem;
  line-height:3rem;
  text-align:center;
  transition:transform .3s;
}
.theme-switch:hover{transform:scale(1.1)}

.back-top{
  position:fixed; bottom:5rem; right:1.2rem;
  width:2.8rem; height:2.8rem;
  border-radius:50%; border:none;
  background:var(--y-accent); color:#fff;
  opacity:0; transition:opacity .3s;
  cursor:pointer; font-size:1.2rem;
}

html{--scroll-pct:0;}
body:before{
  content:'';
  position:fixed; top:0; left:0; height:4px;
  width:calc(var(--scroll-pct)*100%);
  background:var(--y-secondary); z-index:9999;
}