:root {
  --bg: #f4f6fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #2563eb;
  --green: #16a34a;
  --red: #dc2626;
  --amber: #f59e0b;
  --border: #e5e7eb;
  --radius: 16px;
  --shadow: 0 2px 12px rgba(17, 24, 39, .06);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}
.container { max-width: 480px; margin: 0 auto; padding: 20px 16px 40px; }

.page-head { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.page-head h1 { font-size: 20px; }
.back { text-decoration: none; color: var(--primary); font-size: 16px; padding: 4px 8px 4px 0; }

.card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px; margin-bottom: 16px; }
.card h2 { font-size: 17px; margin-bottom: 12px; }

.btn {
  display: block; width: 100%; border: none; border-radius: 12px;
  padding: 14px 16px; font-size: 16px; font-weight: 600; cursor: pointer;
  background: var(--primary); color: #fff; transition: filter .15s, transform .05s;
}
.btn:active { transform: scale(.98); }
.btn:hover { filter: brightness(1.05); }
.btn.secondary { background: #eef2ff; color: var(--primary); }
.btn.green { background: var(--green); }
.btn.ghost { background: #fff; color: var(--primary); border: 1px solid var(--border); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-row { display: flex; gap: 10px; }
.btn-row .btn { flex: 1; }

.field { margin-bottom: 14px; }
.field label { display: block; font-size: 14px; color: var(--muted); margin-bottom: 6px; }
.field input[type="text"], .field input[type="password"], .field input[type="number"], .field select {
  width: 100%; padding: 12px 14px; font-size: 16px; border: 1px solid var(--border);
  border-radius: 10px; background: #fafbfc; outline: none; color: var(--text);
}
.field input:focus, .field select:focus { border-color: var(--primary); background: #fff; }

.equip-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 16px; }
.equip-item {
  display: flex; align-items: center; gap: 12px; padding: 12px 14px;
  border: 1.5px solid var(--border); border-radius: 12px; cursor: pointer; background: #fff;
}
.equip-item.selected { border-color: var(--primary); background: #eff6ff; }
.equip-item.disabled { opacity: .5; cursor: not-allowed; }
.equip-emoji { font-size: 26px; }
.equip-info { flex: 1; }
.equip-name { font-size: 16px; font-weight: 600; }
.equip-left { font-size: 13px; color: var(--muted); }
.equip-left.low { color: var(--amber); font-weight: 600; }
.equip-left.out { color: var(--red); }
.equip-radio { width: 20px; height: 20px; border-radius: 50%; border: 2px solid var(--border); flex: none; }
.equip-item.selected .equip-radio { border-color: var(--primary); background: radial-gradient(circle, var(--primary) 0 55%, transparent 60%); }

.qty-row { display: flex; align-items: center; gap: 12px; justify-content: center; margin: 16px 0; }
.qty-btn { width: 44px; height: 44px; border-radius: 10px; border: 1px solid var(--border); background: #fafbfc; font-size: 22px; cursor: pointer; color: var(--text); }
.qty-num { font-size: 20px; font-weight: 700; min-width: 40px; text-align: center; }

.alert { padding: 12px 14px; border-radius: 10px; margin-bottom: 14px; font-size: 14px; }
.alert.error { background: #fef2f2; color: var(--red); }
.alert.info { background: #eff6ff; color: var(--primary); }

.hidden { display: none !important; }

/* 入口页 */
.hero { text-align: center; padding: 28px 8px 8px; }
.hero .icon { font-size: 52px; }
.hero h1 { font-size: 24px; margin: 10px 0 6px; }
.hero p { color: var(--muted); font-size: 15px; margin-bottom: 24px; }
.hero .btn { margin-bottom: 12px; padding: 18px; font-size: 17px; }
.hero a.btn { text-decoration: none; }
.admin-link { display: block; text-align: center; color: var(--muted); font-size: 13px; margin-top: 18px; text-decoration: none; }

/* 成功页 */
.success { text-align: center; padding: 30px 10px; }
.success .check { font-size: 60px; }
.success h2 { font-size: 20px; margin: 12px 0 8px; }
.success .summary { color: var(--muted); font-size: 15px; margin-bottom: 22px; }
.success a.btn { text-decoration: none; }

/* 归还列表 */
.return-item { display: flex; align-items: center; gap: 12px; padding: 12px 14px; border: 1.5px solid var(--border); border-radius: 12px; margin-bottom: 10px; cursor: pointer; background: #fff; }
.return-item.selected { border-color: var(--green); background: #f0fdf4; }
.return-info { flex: 1; }
.return-name { font-size: 16px; font-weight: 600; }
.return-time { font-size: 13px; color: var(--muted); }
.return-check { width: 20px; height: 20px; border-radius: 6px; border: 2px solid var(--border); flex: none; }
.return-item.selected .return-check { background: var(--green); border-color: var(--green); }
.return-item.selected .return-check::after { content: "✓"; color: #fff; font-size: 13px; display: block; text-align: center; line-height: 19px; }

/* 后台 */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 16px; }
.tab { padding: 9px 14px; border-radius: 999px; border: 1px solid var(--border); background: #fff; font-size: 14px; cursor: pointer; color: var(--muted); }
.tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 13px; }
th, td { padding: 8px 6px; border-bottom: 1px solid var(--border); text-align: left; white-space: nowrap; }
th { color: var(--muted); font-weight: 600; }
tr.overdue td { background: #fffbeb; }
.badge { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 12px; }
.badge.open { background: #fef3c7; color: #92400e; }
.badge.returned { background: #dcfce7; color: #166534; }
.small-btn { padding: 5px 10px; border-radius: 8px; border: none; background: var(--primary); color: #fff; font-size: 12px; cursor: pointer; }
.small-btn.ghost { background: #fff; color: var(--primary); border: 1px solid var(--border); }
.toolbar { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.toolbar input, .toolbar select { flex: 1; min-width: 120px; padding: 9px 10px; border: 1px solid var(--border); border-radius: 8px; font-size: 14px; background: #fff; }
.empty { text-align: center; color: var(--muted); padding: 30px 0; }

.qr-box { text-align: center; }
.qr-box img { width: min(320px, 80vw); height: auto; border: 8px solid #fff; border-radius: 12px; box-shadow: var(--shadow); }
.qr-url { margin-top: 12px; font-size: 13px; color: var(--muted); word-break: break-all; background: #fafbfc; padding: 10px; border-radius: 8px; }

.switch { display: flex; align-items: center; gap: 8px; margin-bottom: 14px; }
.switch input { width: 18px; height: 18px; }
.switch label { font-size: 15px; }
.muted { color: var(--muted); font-size: 13px; }
.spacer { height: 8px; }