:root{
  --blue-900:#0052CC; --blue-700:#1769E0; --blue-400:#4C9AFF; --blue-050:#EAF1FF;
  --bg:#F4F6F8; --surface:#FFFFFF; --text:#172B4D; --muted:#5E6C84; --line:#DFE4EA;
  --danger:#DE350B; --ok:#00875A; --wait:#FF8B00;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0E1621; --surface:#16202E; --text:#E6ECF5; --muted:#93A1B4; --line:#26344A; --blue-050:#132238;
  }
}
:root[data-theme="dark"]{
  --bg:#0E1621; --surface:#16202E; --text:#E6ECF5; --muted:#93A1B4; --line:#26344A; --blue-050:#132238;
}
*{box-sizing:border-box;}
html{scroll-padding-top:env(safe-area-inset-top,0px);}
body{margin:0;background:var(--bg);color:var(--text);font-family:'Inter',sans-serif;min-height:100%;}
h1,h2,h3,.brand{font-family:'Sora',sans-serif;}
img{max-width:100%;}
button{font-family:inherit;cursor:pointer;}
a{color:inherit;text-decoration:none;}

.topbar{display:none;position:sticky;top:0;z-index:20;background:var(--surface);border-bottom:1px solid var(--line);
  padding:12px 28px;padding-top:calc(env(safe-area-inset-top,0px)+12px);align-items:center;justify-content:space-between;}
.brand{font-weight:800;font-size:20px;color:var(--blue-900);display:flex;align-items:center;gap:8px;}
.nav-links{display:flex;gap:6px;background:var(--bg);padding:4px;border-radius:12px;}
.nav-btn{display:flex;align-items:center;gap:8px;padding:9px 16px;border:none;border-radius:9px;background:transparent;color:var(--muted);font-weight:600;font-size:14px;}
.nav-btn.active{background:var(--surface);color:var(--blue-900);box-shadow:0 1px 3px rgba(0,0,0,.08);}
.top-actions{display:flex;gap:10px;align-items:center;}
.avatar{width:34px;height:34px;border-radius:50%;background:var(--blue-050);color:var(--blue-900);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:13px;flex:none;}

.bottombar{position:fixed;left:0;right:0;bottom:0;z-index:20;background:var(--surface);border-top:1px solid var(--line);
  display:flex;padding-bottom:env(safe-area-inset-bottom,0px);}
.bottombar .nav-btn{flex:1;flex-direction:column;border-radius:0;gap:3px;padding:9px 0 8px;font-size:11px;}
.bottombar .nav-btn.active{background:transparent;color:var(--blue-900);}

main{max-width:1080px;margin:0 auto;padding:18px 16px 90px;}
.screen{display:none;}
.screen.active{display:block;}
.pagehead{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:14px;gap:10px;flex-wrap:wrap;}
.pagehead h1{font-size:21px;margin:0;}
.pagehead p{margin:2px 0 0;color:var(--muted);font-size:13px;}

.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:16px;margin-bottom:12px;}
.post-head{display:flex;gap:10px;align-items:center;margin-bottom:8px;}
.post-head .who{font-weight:600;font-size:14px;}
.post-head .meta{font-size:12px;color:var(--muted);}
.post-body{font-size:14px;line-height:1.55;white-space:pre-wrap;}
.tag{display:inline-block;font-size:11.5px;font-weight:600;color:var(--blue-900);background:var(--blue-050);padding:3px 9px;border-radius:7px;margin-top:8px;}
.composer{display:flex;gap:10px;margin-bottom:16px;}
.composer input{flex:1;border:1px solid var(--line);background:var(--bg);border-radius:11px;padding:12px 14px;color:var(--text);font-size:14px;}
.composer input:focus{outline:2px solid var(--blue-400);outline-offset:1px;}
.btn{border:none;border-radius:10px;padding:11px 18px;font-weight:600;font-size:14px;}
.btn-primary{background:var(--blue-900);color:#fff;}
.btn-primary:hover{background:var(--blue-700);}
.btn-ghost{background:var(--bg);color:var(--text);border:1px solid var(--line);}
.btn-danger{background:#FFEBE6;color:var(--danger);}
.btn[disabled]{opacity:.55;cursor:default;}

.filters{display:flex;gap:8px;overflow-x:auto;padding-bottom:12px;margin-bottom:6px;}
.filters select,.filters input{border:1px solid var(--line);background:var(--surface);border-radius:9px;padding:9px 12px;font-size:13px;color:var(--text);flex:none;min-width:130px;}
.filters input[type="text"]{min-width:200px;flex:1;}
.grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;}
.book{background:var(--surface);border:1px solid var(--line);border-radius:14px;overflow:hidden;display:flex;flex-direction:column;}
.book .thumb{position:relative;aspect-ratio:3/4;background:var(--blue-050);}
.book .thumb img{width:100%;height:100%;object-fit:cover;display:block;}
.book .wm{position:absolute;bottom:6px;right:6px;font-size:10px;font-weight:700;color:#fff;background:rgba(0,82,204,.6);padding:2px 7px;border-radius:6px;}
.book .info{padding:10px 12px 12px;}
.book .title{font-size:13.5px;font-weight:600;line-height:1.3;margin:0 0 4px;}
.book .price{color:var(--blue-900);font-weight:700;font-size:14px;}
.book .price.free{color:var(--ok);}
.status-pill{font-size:10.5px;font-weight:700;padding:3px 8px;border-radius:20px;display:inline-block;margin-top:6px;border:none;}
.status-pill.available{background:#E3FCEF;color:var(--ok);}
.status-pill.pending{background:#FFF0E1;color:var(--wait);}
.status-pill.sold{background:#F0F1F4;color:var(--muted);}
.book .actions{display:flex;gap:6px;padding:0 12px 12px;}
.book .actions button{flex:1;font-size:11.5px;padding:7px 4px;border-radius:8px;}

.chatlist{display:grid;gap:8px;}
.chatrow{display:flex;gap:10px;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:11px 13px;width:100%;text-align:left;}
.chatrow .body{flex:1;min-width:0;}
.chatrow .body .name{font-weight:600;font-size:13.5px;}
.chatrow .body .last{font-size:12.5px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.chat-window{background:var(--surface);border:1px solid var(--line);border-radius:14px;height:440px;display:flex;flex-direction:column;overflow:hidden;margin-top:14px;}
.chat-window .head{padding:12px 14px;border-bottom:1px solid var(--line);font-weight:600;font-size:14px;}
.chat-window .msgs{flex:1;overflow-y:auto;padding:14px;display:flex;flex-direction:column;gap:8px;}
.bubble{max-width:72%;padding:9px 13px;border-radius:14px;font-size:13.5px;line-height:1.4;}
.bubble.in{background:var(--bg);align-self:flex-start;}
.bubble.out{background:var(--blue-900);color:#fff;align-self:flex-end;}
.chat-window .row{display:flex;gap:8px;border-top:1px solid var(--line);padding:10px;}
.chat-window .row input{flex:1;border:1px solid var(--line);border-radius:10px;padding:9px 12px;background:var(--bg);color:var(--text);}
.empty-hint{color:var(--muted);font-size:13.5px;text-align:center;padding:30px 10px;}

.profile-head{display:flex;gap:14px;align-items:center;}
.profile-head .avatar{width:62px;height:62px;font-size:22px;}
.verify-badge{display:inline-flex;align-items:center;gap:5px;font-size:12px;font-weight:600;padding:3px 9px;border-radius:20px;margin-top:5px;}
.verify-badge.VERIFIED{color:var(--ok);background:#E3FCEF;}
.verify-badge.PENDING{color:var(--wait);background:#FFF0E1;}
.verify-badge.REJECTED{color:var(--danger);background:#FFEBE6;}
.tabs-mini{display:flex;gap:6px;margin:16px 0 12px;background:var(--bg);padding:4px;border-radius:11px;overflow-x:auto;}
.tabs-mini button{flex:none;border:none;background:transparent;padding:9px 14px;border-radius:8px;font-weight:600;font-size:13px;color:var(--muted);}
.tabs-mini button.active{background:var(--surface);color:var(--blue-900);}

.overlay{position:fixed;inset:0;background:rgba(10,20,40,.45);display:none;align-items:center;justify-content:center;z-index:50;padding:20px;}
.overlay.show{display:flex;}
.modal{background:var(--surface);border-radius:16px;max-width:420px;width:100%;padding:26px;max-height:88vh;overflow-y:auto;}
.modal h2{margin:0 0 4px;font-size:19px;}
.modal p.sub{color:var(--muted);font-size:13px;margin:0 0 18px;}
.field{margin-bottom:12px;}
.field label{font-size:12.5px;font-weight:600;color:var(--muted);display:block;margin-bottom:5px;}
.field input,.field select,.field textarea{width:100%;border:1px solid var(--line);border-radius:9px;padding:10px 12px;background:var(--bg);color:var(--text);font-size:14px;font-family:inherit;}
.modal .btn{width:100%;margin-top:6px;}
.error-msg{color:var(--danger);font-size:12.5px;margin:-4px 0 10px;min-height:15px;}
.switch-link{text-align:center;font-size:13px;color:var(--muted);margin-top:12px;}
.switch-link button{background:none;border:none;color:var(--blue-900);font-weight:600;font-size:13px;}

.admin-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:16px;}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:13px;padding:14px;}
.stat .num{font-size:22px;font-weight:800;color:var(--blue-900);}
.stat .lbl{font-size:12px;color:var(--muted);margin-top:2px;}
table{width:100%;border-collapse:collapse;font-size:13px;background:var(--surface);border-radius:12px;overflow:hidden;}
th,td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);}
th{color:var(--muted);font-weight:600;font-size:12px;}
.rowbtn{border:none;background:none;color:var(--blue-900);font-weight:600;font-size:12.5px;cursor:pointer;margin-right:8px;}
.rowbtn.danger{color:var(--danger);}
.table-wrap{overflow-x:auto;margin-bottom:20px;}
.icon{width:20px;height:20px;flex:none;}
.toast{position:fixed;bottom:80px;left:50%;transform:translateX(-50%);background:var(--text);color:var(--surface);
  padding:10px 18px;border-radius:10px;font-size:13px;z-index:60;opacity:0;pointer-events:none;transition:opacity .2s;}
.toast.show{opacity:1;}

@media(min-width:820px){
  .topbar{display:flex;}
  .bottombar{display:none;}
  main{padding-top:26px;}
  .grid{grid-template-columns:repeat(4,1fr);}
  .admin-grid{grid-template-columns:repeat(4,1fr);}
  .toast{bottom:24px;}
}