/* ════════════════════════ 后台管理样式 ════════════════════════ */

/* ── 登录页 ─────────────────────────────────────────── */
.admin-login {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #E8F4FD 0%, #F0F7FF 50%, #E6FAF8 100%);
  padding: 20px;
}
.admin-login-card {
  width: 100%; max-width: 360px;
  display: flex; flex-direction: column; align-items: center;
  gap: 14px;
  padding: 40px 32px;
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-pop);
}
.admin-login-logo {
  width: 56px; height: 56px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%;
  background: var(--color-primary-light); color: var(--color-primary);
}
.admin-login-logo svg { width: 30px; height: 30px; }
.admin-login-card h1 { font-size: 1.4rem; margin: 0; }
.admin-login-card .sub { color: var(--color-text-secondary); font-size: 0.85rem; margin: -8px 0 6px; }
.admin-login-card input[type=password] {
  width: 100%; padding: 11px 14px; font-size: 0.95rem;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
}
.admin-login-card button {
  width: 100%; padding: 11px; font-size: 0.95rem; font-weight: 600;
  border: none; border-radius: var(--radius-sm);
  background: var(--color-primary); color: #fff; cursor: pointer;
  transition: filter .15s ease;
}
.admin-login-card button:hover { filter: brightness(1.07); }
.admin-login-error {
  width: 100%; padding: 8px 12px; font-size: 0.85rem;
  color: #C0392B; background: #FDECEA; border-radius: var(--radius-sm);
  text-align: center;
}
.admin-login-back { font-size: 0.82rem; color: var(--color-text-secondary); text-decoration: none; }
.admin-login-back:hover { color: var(--color-primary); }

/* ── 整体布局 ───────────────────────────────────────── */
.admin {
  display: flex;
  min-height: 100vh;
  background: var(--color-bg);
}

/* 侧栏 */
.admin-sidebar {
  width: 220px; flex-shrink: 0;
  display: flex; flex-direction: column;
  background: #fff;
  border-right: 1px solid var(--color-border);
  padding: 18px 14px;
}
.admin-brand {
  display: flex; align-items: center; gap: 10px;
  font-size: 1.05rem; font-weight: 700;
  color: var(--color-text-primary);
  padding: 6px 8px 18px;
}
.admin-brand svg { width: 24px; height: 24px; color: var(--color-primary); }
.admin-nav { display: flex; flex-direction: column; gap: 4px; flex: 1; }
.admin-nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 11px 12px;
  border: none; background: transparent;
  border-radius: var(--radius-sm);
  font-size: 0.92rem; color: var(--color-text-secondary);
  cursor: pointer; text-align: left;
  transition: all .15s ease;
}
.admin-nav-item svg { width: 18px; height: 18px; }
.admin-nav-item:hover { background: var(--color-primary-light); color: var(--color-primary); }
.admin-nav-item.active { background: var(--color-primary); color: #fff; }
.admin-sidebar-foot { display: flex; flex-direction: column; gap: 8px; padding-top: 14px; border-top: 1px solid var(--color-border); }
.admin-foot-link { font-size: 0.85rem; color: var(--color-text-secondary); text-decoration: none; padding: 4px 8px; border-radius: var(--radius-sm); }
.admin-foot-link:hover { background: rgba(100,116,139,0.08); color: var(--color-text-primary); }
.admin-foot-link.logout:hover { color: #C0392B; background: #FDECEA; }

/* 主体 */
.admin-main { flex: 1; padding: 24px 28px; overflow-y: auto; height: 100vh; }
.admin-panel { display: none; }
.admin-panel.active { display: block; }
.admin-panel-head {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 18px;
}
.admin-panel-head h2 { font-size: 1.3rem; margin: 0; }
.demo-badge {
  font-size: 0.72rem; font-weight: 600; vertical-align: middle;
  padding: 3px 8px; margin-left: 6px;
  color: #B7791F; background: #FEF3C7; border-radius: 999px;
}

/* 工具栏 */
.admin-toolbar { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.admin-toolbar select, .admin-toolbar input {
  padding: 8px 12px; font-size: 0.88rem;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  background: #fff;
}
.admin-toolbar input { min-width: 200px; }
.admin-count { font-size: 0.82rem; color: var(--color-text-secondary); margin-left: auto; }

/* 表格 */
.admin-table-wrap {
  background: #fff; border-radius: var(--radius-md);
  box-shadow: var(--shadow-xs); overflow: hidden;
}
.admin-table { width: 100%; border-collapse: collapse; font-size: 0.88rem; }
.admin-table thead th {
  text-align: left; padding: 12px 14px;
  font-size: 0.8rem; font-weight: 600; color: var(--color-text-secondary);
  background: #F8FAFC; border-bottom: 1px solid var(--color-border);
}
.admin-table tbody td { padding: 11px 14px; border-bottom: 1px solid #F1F5F9; vertical-align: middle; }
.admin-table tbody tr:hover { background: #F8FAFC; }
.admin-table .cell-name { font-weight: 600; color: var(--color-text-primary); }
.admin-table .cell-def { color: var(--color-text-secondary); max-width: 360px; }
.admin-table .col-act { width: 130px; white-space: nowrap; }
.admin-empty { text-align: center; color: var(--color-text-muted); padding: 28px 0 !important; }
.tag {
  display: inline-block; padding: 2px 9px;
  font-size: 0.76rem; color: var(--color-primary);
  background: var(--color-primary-light); border-radius: 999px;
}
.mini {
  padding: 4px 10px; font-size: 0.78rem;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  background: #fff; cursor: pointer; margin-right: 6px;
  transition: all .15s ease;
}
.mini.edit:hover { border-color: var(--color-primary); color: var(--color-primary); }
.mini.del:hover  { border-color: #E74C3C; color: #E74C3C; }

/* ── 弹窗 ───────────────────────────────────────────── */
.admin-modal {
  position: fixed; inset: 0; z-index: 100;
  display: flex; align-items: center; justify-content: center;
  background: rgba(15, 23, 42, 0.42);
  padding: 20px;
}
.admin-modal[hidden] { display: none; }
.admin-modal-box {
  position: relative;
  width: 100%; max-width: 520px; max-height: 90vh; overflow-y: auto;
  background: #fff; border-radius: var(--radius-lg);
  box-shadow: var(--shadow-pop); padding: 24px;
}
.admin-modal-close {
  position: absolute; top: 14px; right: 16px;
  background: none; border: none; font-size: 1.5rem; cursor: pointer;
  color: var(--color-text-secondary);
}
.admin-modal-box h3 { margin: 0 0 16px; font-size: 1.15rem; }
.admin-form { display: flex; flex-direction: column; gap: 12px; }
.admin-form label { display: flex; flex-direction: column; gap: 5px; font-size: 0.85rem; color: var(--color-text-secondary); }
.admin-form input, .admin-form textarea, .admin-form select {
  padding: 9px 12px; font-size: 0.9rem; color: var(--color-text-primary);
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  background: #fff; font-family: inherit;
}
.admin-form textarea { resize: vertical; }
.admin-form-row { display: flex; gap: 12px; }
.admin-form-row label { flex: 1; }

/* 关系管理 */
.admin-relations { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--color-border); }
.admin-relations h4 { margin: 0 0 10px; font-size: 0.95rem; }
.relation-list { list-style: none; display: flex; flex-direction: column; gap: 6px; margin-bottom: 12px; }
.relation-list li {
  display: flex; align-items: center; justify-content: space-between;
  padding: 7px 10px; font-size: 0.85rem;
  background: #F8FAFC; border-radius: var(--radius-sm);
}
.relation-list li.muted { color: var(--color-text-muted); background: none; }
.relation-list b { color: var(--color-secondary); }
.relation-add { display: flex; gap: 8px; align-items: flex-start; }
.relation-add select {
  padding: 8px 10px; font-size: 0.85rem;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm); background: #fff;
}
.rel-target { position: relative; flex: 1; }
.rel-target input {
  width: 100%; padding: 8px 12px; font-size: 0.85rem;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
}
.rel-results {
  display: none;
  position: absolute; top: 100%; left: 0; right: 0; z-index: 5;
  margin-top: 4px; max-height: 200px; overflow-y: auto;
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); box-shadow: var(--shadow-card);
}
.rel-results.open { display: block; }
.rel-results .muted { padding: 8px 12px; color: var(--color-text-muted); font-size: 0.82rem; }
.rel-result-item { padding: 8px 12px; font-size: 0.84rem; cursor: pointer; }
.rel-result-item:hover { background: var(--color-primary-light); }
.admin-modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 20px; }

/* ── 学生学习情况 ───────────────────────────────────── */
.admin-cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px; margin-bottom: 26px;
}
.stat-card {
  background: #fff; border-radius: var(--radius-md);
  box-shadow: var(--shadow-xs); padding: 20px;
}
.stat-value { font-size: 2rem; font-weight: 700; color: var(--color-primary); }
.stat-unit { font-size: 0.9rem; font-weight: 500; color: var(--color-text-secondary); margin-left: 3px; }
.stat-label { font-size: 0.85rem; color: var(--color-text-secondary); margin-top: 4px; }
.stat-label em { color: var(--color-secondary); font-style: normal; }
.admin-progress-block {
  background: #fff; border-radius: var(--radius-md);
  box-shadow: var(--shadow-xs); padding: 20px 22px;
}
.admin-progress-block h3 { margin: 0 0 16px; font-size: 1.05rem; }
.chapter-progress { display: flex; flex-direction: column; gap: 10px; }
.cp-row { display: flex; align-items: center; gap: 12px; font-size: 0.84rem; }
.cp-label { width: 220px; flex-shrink: 0; color: var(--color-text-primary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.cp-bar { flex: 1; height: 10px; background: #EDF2F7; border-radius: 999px; overflow: hidden; }
.cp-fill { height: 100%; background: linear-gradient(90deg, var(--color-primary), var(--color-secondary)); border-radius: 999px; }
.cp-pct { width: 44px; text-align: right; color: var(--color-text-secondary); }
.admin-note { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 18px; }

/* ── 响应式 ─────────────────────────────────────────── */
@media (max-width: 768px) {
  .admin { flex-direction: column; }
  .admin-sidebar { width: 100%; flex-direction: row; flex-wrap: wrap; align-items: center; }
  .admin-nav { flex-direction: row; }
  .admin-main { height: auto; }
  .cp-label { width: 120px; }
}