:root {
  --bg: #f6f7fb;
  --panel: #ffffff;
  --panel-2: #f9fafb;
  --text: #172033;
  --muted: #687386;
  --border: #dce2ea;
  --primary: #2563eb;
  --primary-2: #1d4ed8;
  --success: #14845f;
  --warning: #b7791f;
  --danger: #dc2626;
  --info: #0f766e;
  --shadow: 0 12px 32px rgba(24, 35, 56, 0.08);
  color-scheme: light;
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

* { box-sizing: border-box; }
body { margin: 0; color: var(--text); background: var(--bg); }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }

.app-shell { min-height: 100vh; display: flex; flex-direction: column; }
.topbar { background: var(--primary); color: #fff; box-shadow: var(--shadow); }
.topbar-inner { max-width: 1100px; margin: 0 auto; padding: 12px 16px; display: flex; align-items: center; gap: 12px; }
.brand-mark { width: 40px; height: 40px; border-radius: 8px; background: rgba(255,255,255,.16); display: grid; place-items: center; font-weight: 800; }
.brand-text { min-width: 0; flex: 1; }
.brand-title { font-size: 18px; font-weight: 800; line-height: 1.2; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.brand-subtitle { font-size: 12px; opacity: .78; margin-top: 2px; }
.main { width: 100%; max-width: 1100px; margin: 0 auto; padding: 18px 16px 28px; flex: 1; }
.footer { border-top: 1px solid var(--border); color: var(--muted); text-align: center; font-size: 12px; padding: 12px; }

.login-wrap { min-height: 100vh; display: grid; place-items: center; padding: 24px; background: linear-gradient(135deg, #eff6ff, #f8fafc 48%, #ecfdf5); }
.login-card { width: min(440px, 100%); background: var(--panel); border: 1px solid var(--border); border-radius: 8px; padding: 24px; box-shadow: var(--shadow); }
.login-title { font-size: 24px; font-weight: 800; margin: 0 0 6px; }
.login-desc { margin: 0 0 18px; color: var(--muted); font-size: 14px; }
.tabs { display: flex; gap: 6px; padding: 4px; background: var(--panel-2); border: 1px solid var(--border); border-radius: 8px; margin-bottom: 16px; }
.tab { flex: 1; border: 0; background: transparent; border-radius: 6px; padding: 8px 10px; color: var(--muted); }
.tab.active { background: #fff; color: var(--primary); box-shadow: 0 1px 3px rgba(0,0,0,.08); }

.grid { display: grid; gap: 14px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.grid-5 { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 14px; }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: 8px; box-shadow: 0 1px 2px rgba(24,35,56,.04); }
.panel-pad { padding: 16px; }
.hero { background: linear-gradient(135deg, #2563eb, #0f766e); color: #fff; border-radius: 8px; padding: 18px; box-shadow: var(--shadow); }
.hero h2 { margin: 0 0 4px; font-size: 24px; }
.hero p { margin: 0; opacity: .86; font-size: 14px; }
.stat { text-align: center; background: rgba(255,255,255,.13); border-radius: 8px; padding: 10px 6px; }
.stat strong { display: block; font-size: 24px; }
.stat span { display: block; font-size: 12px; opacity: .82; }

.nav-card { border: 1px solid var(--border); background: var(--panel); border-radius: 8px; padding: 16px; text-align: left; min-height: 120px; transition: transform .15s, border-color .15s, box-shadow .15s; }
.nav-card:hover { transform: translateY(-2px); border-color: #b9c7dc; box-shadow: var(--shadow); }
.nav-icon { width: 34px; height: 34px; border-radius: 8px; display: grid; place-items: center; color: #fff; font-weight: 800; margin-bottom: 12px; }
.nav-card h3 { margin: 0 0 4px; font-size: 17px; }
.nav-card p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.45; }
.c-primary { background: var(--primary); }
.c-success { background: var(--success); }
.c-info { background: var(--info); }
.c-warning { background: var(--warning); }
.c-muted { background: #64748b; }

.section-head { display: flex; align-items: center; gap: 10px; justify-content: space-between; margin-bottom: 14px; }
.section-head h2 { margin: 0; font-size: 22px; }
.section-head p { margin: 4px 0 0; color: var(--muted); font-size: 13px; }
.actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.form { display: grid; gap: 12px; }
.field { display: grid; gap: 6px; }
.field label { font-size: 13px; color: #334155; font-weight: 650; }
.field input, .field select, .field textarea {
  width: 100%; border: 1px solid var(--border); border-radius: 8px; padding: 10px 11px; background: #fff; color: var(--text);
  min-height: 40px;
}
.field textarea { resize: vertical; min-height: 84px; }
.field input:focus, .field select:focus, .field textarea:focus { outline: 2px solid rgba(37, 99, 235, .16); border-color: var(--primary); }
.hint { color: var(--muted); font-size: 12px; line-height: 1.45; }
.error { color: var(--danger); background: #fef2f2; border: 1px solid #fecaca; border-radius: 8px; padding: 9px 11px; font-size: 13px; }
.ok { color: var(--success); background: #ecfdf5; border: 1px solid #bbf7d0; border-radius: 8px; padding: 9px 11px; font-size: 13px; }

.btn { border: 1px solid transparent; background: var(--primary); color: #fff; border-radius: 8px; min-height: 38px; padding: 8px 12px; display: inline-flex; align-items: center; justify-content: center; gap: 6px; font-weight: 650; }
.btn:hover { background: var(--primary-2); }
.btn.secondary { background: #fff; color: var(--text); border-color: var(--border); }
.btn.secondary:hover { background: var(--panel-2); }
.btn.ghost { background: transparent; color: inherit; border-color: rgba(255,255,255,.5); }
.btn.danger { background: var(--danger); }
.btn.success { background: var(--success); }
.btn.small { min-height: 30px; padding: 5px 9px; font-size: 12px; }
.btn.icon { width: 38px; padding: 0; }
.btn:disabled { opacity: .55; cursor: not-allowed; }

.table-wrap { overflow: auto; border: 1px solid var(--border); border-radius: 8px; background: #fff; }
table { width: 100%; border-collapse: collapse; min-width: 760px; }
th, td { padding: 10px 11px; border-bottom: 1px solid var(--border); text-align: left; font-size: 13px; vertical-align: top; }
th { background: #f8fafc; color: #475569; font-weight: 750; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
.badge { display: inline-flex; align-items: center; justify-content: center; border-radius: 999px; padding: 3px 8px; font-size: 12px; font-weight: 700; white-space: nowrap; }
.badge.borrowed { background: #eff6ff; color: var(--primary); }
.badge.returned { background: #f1f5f9; color: #475569; }
.badge.admin { background: #fef3c7; color: #92400e; }
.empty { color: var(--muted); text-align: center; padding: 28px; font-size: 14px; }

.toolbar { display: grid; grid-template-columns: 1.3fr repeat(4, minmax(120px, .55fr)); gap: 8px; margin-bottom: 12px; }
.toolbar input, .toolbar select { border: 1px solid var(--border); border-radius: 8px; padding: 9px 10px; min-height: 38px; background: #fff; }
.modal-backdrop { position: fixed; inset: 0; background: rgba(15, 23, 42, .38); display: grid; place-items: center; padding: 16px; z-index: 20; }
.modal { width: min(620px, 100%); max-height: 86vh; overflow: auto; background: #fff; border-radius: 8px; border: 1px solid var(--border); box-shadow: var(--shadow); padding: 16px; }
.modal h3 { margin: 0 0 12px; }
.dropzone { border: 1.5px dashed #b6c2d2; border-radius: 8px; background: #f8fafc; padding: 22px; text-align: center; }
.dropzone input { margin-top: 10px; }
.split { display: grid; grid-template-columns: 320px minmax(0, 1fr); gap: 14px; align-items: start; }
.notice-list { margin: 0; padding-left: 18px; color: var(--muted); font-size: 13px; line-height: 1.7; }
.scanner-modal { max-width: 720px; }
.scanner-box { position: relative; overflow: hidden; border-radius: 8px; background: #0f172a; aspect-ratio: 16 / 10; display: grid; place-items: center; }
.scanner-box video { width: 100%; height: 100%; object-fit: cover; }
.scanner-box::after { content: ""; position: absolute; inset: 18%; border: 2px solid rgba(255,255,255,.88); border-radius: 8px; box-shadow: 0 0 0 999px rgba(15, 23, 42, .28); }
.scan-line { position: absolute; left: 20%; right: 20%; top: 50%; height: 2px; background: #22c55e; box-shadow: 0 0 12px #22c55e; animation: scan 1.8s ease-in-out infinite; }
@keyframes scan {
  0%, 100% { transform: translateY(-90px); opacity: .6; }
  50% { transform: translateY(90px); opacity: 1; }
}

@media (max-width: 860px) {
  .grid-5, .grid-3, .grid-2, .split { grid-template-columns: 1fr; }
  .toolbar { grid-template-columns: 1fr; }
  .topbar-inner { align-items: flex-start; }
  .brand-title { white-space: normal; }
}

@media print {
  .topbar, .footer, .actions, .no-print { display: none !important; }
  .main { max-width: none; padding: 0; }
  body { background: #fff; }
  .panel { border: 0; box-shadow: none; }
}