/* ==== 图书管理系统 主样式 ==== */
:root{
  --bg:#f5f7fa;--panel:#fff;--text:#1f2328;--muted:#6b7280;--border:#e5e7eb;
  --primary:#2563eb;--primary-dark:#1d4ed8;--danger:#dc2626;--success:#16a34a;--warning:#d97706;
  --radius:10px;--shadow:0 1px 3px rgba(0,0,0,.06),0 1px 2px rgba(0,0,0,.04);
  --sidebar-w:220px;--topbar-h:52px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:-apple-system,"Segoe UI",Roboto,"Helvetica Neue","PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);font-size:14px;line-height:1.55}
a{color:var(--primary);text-decoration:none}
a:hover{color:var(--primary-dark)}
h1,h2,h3{margin:0 0 12px}
h1{font-size:22px}h2{font-size:18px}h3{font-size:15px}

/* ===== 顶栏 ===== */
.topbar{position:fixed;top:0;left:0;right:0;height:var(--topbar-h);background:#fff;border-bottom:1px solid var(--border);display:flex;align-items:center;padding:0 16px;z-index:100;box-shadow:var(--shadow)}
.topbar .brand{font-weight:600;font-size:16px;flex:1;margin-left:8px}
.top-actions{display:flex;align-items:center;gap:14px;font-size:13px}
.top-actions .user{color:#333}
.top-actions .user em{color:var(--primary);font-style:normal;margin-left:4px}
.top-actions .logout{color:var(--muted)}
.top-actions .msg-btn{position:relative;font-size:18px}
.top-actions .msg-btn .badge{position:absolute;top:-6px;right:-8px;background:var(--danger);color:#fff;font-size:10px;padding:1px 5px;border-radius:8px;min-width:14px;text-align:center}
.menu-btn{display:none;background:none;border:0;font-size:22px;cursor:pointer;padding:4px 8px}

/* ===== 侧栏 ===== */
.sidebar{position:fixed;top:var(--topbar-h);left:0;bottom:0;width:var(--sidebar-w);background:#fff;border-right:1px solid var(--border);overflow:auto;z-index:90}
.sidebar nav{padding:12px 8px}
.sidebar a{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:8px;color:#374151;margin-bottom:2px;font-size:14px}
.sidebar a:hover{background:#f3f4f6}
.sidebar a.active{background:#eef4ff;color:var(--primary);font-weight:500}
.sidebar .ic{width:22px;text-align:center}

/* ===== 主区 ===== */
.main{padding:calc(var(--topbar-h) + 16px) 20px 20px calc(var(--sidebar-w) + 20px);min-height:100vh}
.bottom-nav{display:none}
.sidebar-mask{display:none;position:fixed;inset:0;background:rgba(0,0,0,.35);z-index:80}

/* ===== 卡片 & 通用面板 ===== */
.card{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:18px;margin-bottom:16px;box-shadow:var(--shadow)}
.card h2{margin-top:0}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:12px}

/* 指标卡 */
.metric{background:#fff;border:1px solid var(--border);border-radius:10px;padding:16px}
.metric .lbl{color:var(--muted);font-size:12px}
.metric .val{font-size:26px;font-weight:600;margin-top:4px}
.metric .sub{color:var(--muted);font-size:12px;margin-top:2px}
.metric.warn .val{color:var(--warning)}
.metric.err .val{color:var(--danger)}
.metric.ok .val{color:var(--success)}

/* ===== 表单 ===== */
label{display:block;font-size:13px;color:#374151;margin:10px 0 4px}
input[type=text],input[type=password],input[type=email],input[type=number],input[type=date],input[type=datetime-local],input[type=search],select,textarea{
  width:100%;padding:9px 10px;border:1px solid var(--border);border-radius:8px;font-size:14px;background:#fff;box-sizing:border-box;font-family:inherit
}
input:focus,select:focus,textarea:focus{outline:0;border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.15)}
textarea{min-height:80px;resize:vertical}
.row{display:flex;gap:12px}
.row>*{flex:1}
.form-actions{display:flex;gap:10px;margin-top:14px;flex-wrap:wrap}

.btn{display:inline-flex;align-items:center;gap:6px;background:var(--primary);color:#fff;border:0;padding:9px 16px;border-radius:8px;font-size:14px;cursor:pointer;text-decoration:none;font-family:inherit}
.btn:hover{background:var(--primary-dark);color:#fff}
.btn.sm{padding:5px 10px;font-size:12px}
.btn.ghost{background:#eef2f7;color:#333}
.btn.ghost:hover{background:#e5e7eb;color:#111}
.btn.danger{background:var(--danger)}
.btn.danger:hover{background:#b91c1c}
.btn.success{background:var(--success)}
.btn.warn{background:var(--warning)}

/* ===== 表格 ===== */
.table-wrap{overflow-x:auto}
table.data{width:100%;border-collapse:collapse;background:#fff;border-radius:var(--radius);overflow:hidden;font-size:14px}
table.data th,table.data td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--border);vertical-align:middle}
table.data th{background:#f9fafb;color:#374151;font-weight:600;font-size:13px}
table.data tr:last-child td{border-bottom:0}
table.data tr:hover td{background:#fafbfc}
.actions{display:flex;gap:6px;flex-wrap:wrap}

/* 状态徽章 */
.tag{display:inline-block;padding:2px 8px;border-radius:12px;font-size:12px;background:#eef2f7;color:#374151}
.tag.ok{background:#dcfce7;color:#166534}
.tag.warn{background:#fef3c7;color:#92400e}
.tag.err{background:#fee2e2;color:#b91c1c}
.tag.info{background:#dbeafe;color:#1d4ed8}

/* Flash */
.flash{padding:10px 14px;border-radius:8px;margin-bottom:12px;font-size:14px;border:1px solid transparent}
.flash-ok{background:#ecfdf5;color:#065f46;border-color:#a7f3d0}
.flash-err{background:#fef2f2;color:#b91c1c;border-color:#fecaca}
.flash-info{background:#eff6ff;color:#1d4ed8;border-color:#bfdbfe}

/* 分页 */
.pager{display:flex;gap:6px;justify-content:center;margin-top:16px;flex-wrap:wrap}
.pager a,.pager span{padding:6px 10px;border:1px solid var(--border);border-radius:6px;background:#fff;color:#374151;font-size:13px;text-decoration:none}
.pager .cur{background:var(--primary);color:#fff;border-color:var(--primary)}
.pager .dis{color:#9ca3af}

/* 搜索栏 */
.toolbar{display:flex;gap:10px;margin-bottom:14px;flex-wrap:wrap;align-items:center}
.toolbar form{display:flex;gap:8px;flex:1;flex-wrap:wrap}
.toolbar input,.toolbar select{max-width:220px}

/* 认证页 */
.auth-wrap{max-width:400px;margin:60px auto;background:#fff;padding:32px;border-radius:12px;box-shadow:0 4px 20px rgba(0,0,0,.08)}
.auth-wrap h1{text-align:center;margin-bottom:6px}
.auth-wrap .sub{color:var(--muted);text-align:center;margin-bottom:24px;font-size:13px}
.auth-links{text-align:center;margin-top:16px;font-size:13px}
body.auth-page{background:linear-gradient(135deg,#eef2ff 0%,#f5f7fa 60%);min-height:100vh}
body.auth-page .topbar,body.auth-page .sidebar,body.auth-page .bottom-nav{display:none}
body.auth-page .main{padding:0}

/* 扫码页 */
.scan-page{padding:0!important}
.scan-video{width:100%;max-width:600px;margin:0 auto;display:block;border-radius:10px;background:#000}
.scan-result{background:#fff;border-radius:10px;padding:16px;margin-top:16px}
.scan-hint{color:var(--muted);font-size:13px;margin-bottom:10px;text-align:center}

/* 消息列表 */
.msg-item{background:#fff;border:1px solid var(--border);border-radius:10px;padding:14px;margin-bottom:8px}
.msg-item.unread{border-left:3px solid var(--primary)}
.msg-item .msg-t{font-weight:600;margin-bottom:6px}
.msg-item .msg-meta{color:var(--muted);font-size:12px}

/* 图书卡片（网格） */
.book-card{background:#fff;border:1px solid var(--border);border-radius:10px;overflow:hidden;display:flex;flex-direction:column}
.book-card .cover{width:100%;height:180px;background:#f3f4f6 center/cover no-repeat}
.book-card .info{padding:12px;flex:1;display:flex;flex-direction:column}
.book-card .info h3{font-size:14px;margin-bottom:4px;line-height:1.3;max-height:2.6em;overflow:hidden}
.book-card .info .a{color:var(--muted);font-size:12px;flex:1}
.book-card .info .b{display:flex;justify-content:space-between;margin-top:8px;font-size:12px}

/* ===== 响应式 ===== */
@media (max-width:900px){
  .menu-btn{display:block}
  .sidebar{transform:translateX(-100%);transition:transform .2s}
  .sidebar.open{transform:translateX(0)}
  .sidebar-mask.show{display:block}
  .main{padding:calc(var(--topbar-h) + 14px) 14px 76px 14px}
  .bottom-nav{display:flex;position:fixed;bottom:0;left:0;right:0;height:60px;background:#fff;border-top:1px solid var(--border);z-index:100}
  .bottom-nav a{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;color:#6b7280;font-size:11px;gap:2px;text-decoration:none}
  .bottom-nav a .ic{font-size:20px}
  .bottom-nav a.active{color:var(--primary)}
  .top-actions .user{display:none}

  /* 表格转卡片 */
  table.data,table.data thead,table.data tbody,table.data th,table.data td,table.data tr{display:block}
  table.data thead{display:none}
  table.data tr{background:#fff;border:1px solid var(--border);border-radius:10px;margin-bottom:10px;padding:8px 12px}
  table.data td{border:0;padding:6px 0;text-align:right;position:relative;padding-left:40%}
  table.data td::before{content:attr(data-label);position:absolute;left:0;top:6px;color:var(--muted);font-size:12px;text-align:left}
  table.data td.actions{padding-left:0;text-align:left;flex-wrap:wrap;justify-content:flex-start;display:flex}
  .toolbar input,.toolbar select{max-width:100%}
}
@media (max-width:480px){
  .auth-wrap{margin:20px 12px;padding:22px}
  .row{flex-direction:column;gap:0}
}