:root{
  --bg:#f5f6f8; --card:#fff; --ink:#1f2329; --sub:#6b7280;
  --brand:#07c160; --brand-d:#06ad56; --line:#e5e7eb; --danger:#e64340;
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg);color:var(--ink);padding:24px;line-height:1.5}
a{color:inherit;text-decoration:none}
header{display:flex;align-items:center;justify-content:space-between;margin-bottom:24px;flex-wrap:wrap;gap:12px}
h1{font-size:22px}
.muted{color:var(--sub);font-size:13px}
.btn{display:inline-block;background:var(--brand);color:#fff;border:none;padding:10px 18px;
  border-radius:10px;cursor:pointer;font-size:14px;transition:.15s}
.btn:hover{background:var(--brand-d)}
.btn.ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn.ghost:hover{border-color:var(--brand);color:var(--brand)}

/* 门户网格 */
.shelf{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:18px}
.book-card{background:var(--card);border-radius:14px;padding:16px;cursor:pointer;
  box-shadow:0 1px 3px rgba(0,0,0,.06);transition:.15s;display:flex;flex-direction:column;gap:10px}
.book-card:hover{transform:translateY(-3px);box-shadow:0 6px 18px rgba(0,0,0,.1)}
.cover{font-size:42px;height:96px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,#eef2f7,#dfe6ef);border-radius:10px}
.title{font-weight:600}
.author{color:var(--sub);font-size:13px}

/* 居中卡片 */
.center{max-width:560px;margin:40px auto;background:#fff;padding:32px;border-radius:16px;
  box-shadow:0 4px 20px rgba(0,0,0,.06);text-align:center}
.center h2{margin-bottom:8px}
.entry{display:flex;gap:14px;justify-content:center;margin-top:22px;flex-wrap:wrap}

/* 模拟扫码二维码 */
.qr{width:180px;height:180px;margin:18px auto;display:grid;
  grid-template-columns:repeat(11,1fr);grid-template-rows:repeat(11,1fr);gap:2px;padding:8px;
  background:#fff;border:1px solid var(--line);border-radius:12px}
.qr i{background:#1f2329;border-radius:1px}
.qr i.off{background:transparent}

/* 用户选择 */
.userpick{display:flex;gap:10px;justify-content:center;margin:16px 0;flex-wrap:wrap}
.userpick label{border:1px solid var(--line);padding:8px 16px;border-radius:20px;cursor:pointer;font-size:14px}
.userpick input{display:none}
.userpick input:checked + span{border-color:var(--brand);color:var(--brand);font-weight:600}
.userpick span{display:block}

/* 书内三种网格 */
.book-head{display:flex;align-items:flex-end;gap:16px;margin-bottom:20px;flex-wrap:wrap}
.book-head .big{font-size:48px}
.chapter{background:#fff;padding:14px 16px;border-radius:10px;box-shadow:0 1px 3px rgba(0,0,0,.05)}
.chapter h3{font-size:15px;margin-bottom:6px}
.chapter p{color:var(--sub);font-size:13px;line-height:1.7}
.tag{display:inline-block;font-size:12px;color:var(--brand);border:1px solid var(--brand);
  border-radius:10px;padding:1px 8px;margin-top:8px}
.l-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.l-list{display:flex;flex-direction:column;gap:10px}
.l-list .chapter{display:flex;gap:14px;align-items:center}
.l-list .no{font-size:20px;font-weight:700;color:var(--brand);min-width:32px}
.l-masonry{columns:3;column-gap:16px}
.l-masonry .chapter{break-inside:avoid;margin-bottom:16px}
@media(max-width:720px){
  .l-grid,.l-masonry{grid-template-columns:1fr;columns:1}
}

/* 无权限 */
.deny{max-width:480px;margin:48px auto;text-align:center;background:#fff;padding:32px;
  border-radius:16px;box-shadow:0 4px 20px rgba(0,0,0,.06)}
.deny .icon{font-size:48px;margin-bottom:8px}
.invite{display:flex;gap:8px;margin-top:18px;justify-content:center}
.invite input{padding:9px 12px;border:1px solid var(--line);border-radius:9px;font-size:14px;width:160px}
.msg{margin-top:12px;font-size:13px;min-height:18px}
.msg.ok{color:var(--brand)}
.msg.err{color:var(--danger)}