/* 中文图书管理系统 - UI 效果图样式 */
:root {
  --primary: #4f6ef7;
  --primary-dark: #3b56d9;
  --primary-light: #eef1fe;
  --success: #2e9e5b;
  --danger: #d9534f;
  --warning: #f0a020;
  --text: #2b2f36;
  --text-sub: #7a8290;
  --border: #e4e7ec;
  --bg: #f5f6f8;
  --card: #ffffff;
  --radius: 10px;
  --shadow: 0 2px 10px rgba(20, 30, 60, .06);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 14px;
}
a { text-decoration: none; color: var(--primary); }

/* 顶部导航 */
.navbar {
  background: #fff;
  border-bottom: 1px solid var(--border);
  height: 60px;
  display: flex;
  align-items: center;
  padding: 0 28px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.navbar .brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 10px;
}
.navbar .brand .logo {
  width: 32px; height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), #7b96ff);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
}
.navbar .menu { display: flex; gap: 6px; margin-left: 32px; }
.navbar .menu a {
  padding: 8px 14px;
  border-radius: 8px;
  color: var(--text-sub);
  font-weight: 500;
  transition: .15s;
}
.navbar .menu a.active, .navbar .menu a:hover { background: var(--primary-light); color: var(--primary); }
.navbar .spacer { flex: 1; }
.navbar .user { display: flex; align-items: center; gap: 12px; }
.navbar .avatar {
  width: 34px; height: 34px; border-radius: 50%;
  background: var(--primary-light); color: var(--primary);
  display: flex; align-items: center; justify-content: center; font-weight: 700;
}
.navbar .user .name { font-weight: 500; }
.navbar .logout { color: var(--text-sub); font-size: 13px; }
.navbar .logout:hover { color: var(--danger); }

/* 布局容器 */
.container { max-width: 1100px; margin: 24px auto; padding: 0 28px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.card .card-header {
  padding: 16px 22px;
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  font-weight: 600;
}
.card .card-body { padding: 22px; }

/* 页面标题栏 */
.page-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.page-head h1 { font-size: 22px; font-weight: 700; }
.page-head .sub { color: var(--text-sub); font-size: 13px; margin-top: 2px; }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 16px;
  border-radius: 8px;
  border: none;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: .15s;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { filter: brightness(.95); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { filter: brightness(.95); }
.btn-outline { background: #fff; color: var(--text-sub); border: 1px solid var(--border); }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-sm { padding: 6px 12px; font-size: 12px; }

/* 表单 */
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-weight: 500; margin-bottom: 6px; font-size: 13px; }
.form-group label .req { color: var(--danger); }
.form-control {
  width: 100%;
  padding: 10px 13px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  transition: .15s;
  background: #fff;
}
.form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }
.form-error { color: var(--danger); font-size: 12px; margin-top: 5px; }
.form-text { color: var(--text-sub); font-size: 12px; margin-top: 4px; }
.form-row { display: flex; gap: 18px; }
.form-row .form-group { flex: 1; }

/* 表格 */
table { width: 100%; border-collapse: collapse; }
th, td { padding: 13px 16px; text-align: left; font-size: 13px; }
thead th {
  background: #fafbfc;
  color: var(--text-sub);
  font-weight: 600;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
tbody tr { border-bottom: 1px solid var(--border); transition: .1s; }
tbody tr:hover { background: #fafbff; }
td .actions { display: flex; gap: 6px; }
.tag {
  display: inline-block; padding: 3px 10px; border-radius: 20px;
  font-size: 12px; font-weight: 500;
}
.tag-blue { background: var(--primary-light); color: var(--primary); }
.tag-green { background: #e6f7ee; color: var(--success); }
.tag-orange { background: #fdf1e3; color: var(--warning); }
.tag-gray { background: #f0f2f5; color: var(--text-sub); }

/* 搜索栏 */
.toolbar { display: flex; gap: 10px; margin-bottom: 18px; align-items: center; }
.toolbar .search-input { flex: 1; max-width: 340px; }
.toolbar .spacer { flex: 1; }

/* 分页 */
.pagination {
  display: flex; gap: 6px; align-items: center; justify-content: flex-end;
  padding: 16px; border-top: 1px solid var(--border);
}
.pagination a, .pagination span {
  padding: 7px 12px; border-radius: 8px; font-size: 13px;
  border: 1px solid var(--border); color: var(--text-sub); background: #fff;
}
.pagination .cur { background: var(--primary); color: #fff; border-color: var(--primary); }
.pagination .info { border: none; background: none; color: var(--text-sub); }

/* 消息条 flash */
.flash { padding: 12px 16px; border-radius: 8px; margin-bottom: 18px; font-size: 13px; display: flex; align-items: center; gap: 8px; }
.flash-success { background: #e6f7ee; color: var(--success); border: 1px solid #c3ecd4; }
.flash-error { background: #fdecec; color: var(--danger); border: 1px solid #f5cccc; }
.flash-info { background: #eef1fe; color: var(--primary); border: 1px solid #d6def9; }

/* 弹窗 */
.overlay {
  position: fixed; inset: 0; background: rgba(20, 30, 60, .4);
  display: flex; align-items: center; justify-content: center; z-index: 200;
}
.modal {
  background: #fff; border-radius: 14px; width: 420px;
  box-shadow: 0 10px 40px rgba(0,0,0,.18); overflow: hidden;
}
.modal .modal-head { padding: 18px 22px; font-weight: 700; font-size: 15px; display: flex; align-items: center; gap: 10px; }
.modal .modal-body { padding: 0 22px 22px; color: var(--text-sub); font-size: 14px; }
.modal .modal-foot { padding: 16px 22px; border-top: 1px solid var(--border); display: flex; justify-content: flex-end; gap: 10px; }
.modal .icon-warn { color: var(--warning); }

/* 登录页（独立布局） */
.login-wrap {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #4f6ef7 0%, #7b96ff 60%, #a9bcff 100%);
}
.login-card {
  background: #fff; width: 400px; border-radius: 16px;
  box-shadow: 0 20px 60px rgba(0,0,0, .22); padding: 40px 36px;
}
.login-card .logo-big {
  width: 60px; height: 60px; border-radius: 16px;
  background: linear-gradient(135deg, var(--primary), #7b96ff);
  color: #fff; font-size: 30px;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 18px;
}
.login-card h2 { text-align: center; font-size: 20px; margin-bottom: 4px; }
.login-card .sub { text-align: center; color: var(--text-sub); font-size: 13px; margin-bottom: 26px; }
.login-card .btn-login { width: 100%; justify-content: center; padding: 12px; font-size: 15px; }
.login-card .hint { background: var(--primary-light); color: var(--primary); border-radius: 8px; padding: 10px 14px; font-size: 12px; margin-bottom: 20px; text-align: center; }
.login-foot { text-align: center; color: var(--text-sub); font-size: 12px; margin-top: 16px; }

/* 统计卡片 */
.stats-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 22px; }
.stat-card { text-align: center; padding: 20px; }
.stat-card .val { font-size: 34px; font-weight: 700; color: var(--primary); }
.stat-card .label { color: var(--text-sub); font-size: 13px; margin-top: 2px; }
.stat-card .icon { font-size: 26px; margin-bottom: 8px; }

/* 面包屑 */
.breadcrumb { font-size: 13px; color: var(--text-sub); margin-bottom: 14px; }
.breadcrumb a { color: var(--text-sub); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .sep { margin: 0 6px; }

/* 柱状图（纯 CSS 模拟） */
.chart { display: flex; align-items: flex-end; gap: 22px; height: 180px; padding: 10px 6px 0; }
.chart .bar-wrap { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: flex-end; height: 100%; }
.chart .bar { width: 70%; background: linear-gradient(180deg, #7b96ff, var(--primary)); border-radius: 6px 6px 0 0; }
.chart .bar-label { font-size: 12px; color: var(--text-sub); margin-top: 8px; }
.chart .bar-val { font-size: 12px; color: var(--primary); font-weight: 600; margin-bottom: 4px; }

.empty { text-align: center; color: var(--text-sub); padding: 46px 0; }
.empty .icon { font-size: 46px; opacity: .35; }