* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: #f4f6fa;
  color: #1f2933;
  font-size: 14px;
}
.btn-wecom {
  display: inline-block;
  background: #07c160 !important;
  border-color: #07c160 !important;
  color: #fff !important;
  font-weight: 600;
}
.btn-wecom:hover { background: #06ad56 !important; }
.divider {
  text-align: center;
  margin: 16px 0;
  color: #94a3b8;
  position: relative;
}
.divider::before {
  content: ""; position: absolute; left: 0; right: 0; top: 50%;
  border-top: 1px solid #e2e8f0; z-index: 0;
}
.divider span {
  position: relative; z-index: 1; background: #fff; padding: 0 12px;
}
.switch-row {
  display: flex; align-items: center; gap: 8px; margin: 6px 0 14px; font-weight: 600;
}
hr { border: none; border-top: 1px solid #e2e8f0; margin: 18px 0; }
a { color: #2563eb; text-decoration: none; }
.nav {
  display: flex;
  align-items: center;
  background: #1e293b;
  padding: 0 24px;
  height: 54px;
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 10;
}
.nav-item {
  color: #cbd5e1;
  padding: 0 16px;
  line-height: 54px;
  font-size: 14px;
}
.nav-item:hover, .nav-item.active { color: #fff; background: #334155; }
.nav-right { margin-left: auto; display: flex; align-items: center; gap: 14px; }
.nav-user { color: #e2e8f0; }
.btn-link { color: #93c5fd; }
.container { max-width: 1080px; margin: 24px auto; padding: 0 20px; }
h1 { font-size: 22px; margin: 0 0 18px; }
h3 { margin: 0 0 12px; font-size: 16px; }
.card {
  background: #fff;
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 18px;
  box-shadow: 0 1px 3px rgba(0,0,0,.06);
}
.form { max-width: 460px; }
.form-row { display: flex; flex-direction: column; margin-bottom: 14px; }
.form-row label { margin-bottom: 6px; color: #475569; }
.form-inline { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
input, select, textarea {
  padding: 8px 10px;
  border: 1px solid #d1d9e6;
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: #2563eb; }
textarea { width: 100%; min-height: 70px; resize: vertical; }
.btn {
  background: #2563eb; color: #fff; border: none; padding: 9px 18px;
  border-radius: 6px; cursor: pointer; font-size: 14px;
}
.btn:hover { background: #1d4ed8; }
.btn-sm {
  background: #eef2ff; color: #2563eb; border: 1px solid #c7d2fe;
  padding: 5px 12px; border-radius: 6px; cursor: pointer; font-size: 13px; display: inline-block;
}
.btn-sm:hover { background: #e0e7ff; }
.btn-sm.danger { background: #fef2f2; color: #dc2626; border-color: #fecaca; }
.alert { padding: 12px 16px; border-radius: 8px; margin-bottom: 16px; }
.alert-info { background: #eff6ff; color: #1e40af; }
.alert-red { background: #fef2f2; color: #b91c1c; }
.alert-green { background: #ecfdf5; color: #047857; }
.hint { color: #64748b; font-size: 13px; margin: 6px 0 14px; }
.tbl { width: 100%; border-collapse: collapse; font-size: 13px; }
.tbl th, .tbl td { padding: 9px 10px; border-bottom: 1px solid #eef1f5; text-align: left; }
.tbl th { background: #f8fafc; color: #475569; font-weight: 600; }
.tbl tr:hover td { background: #fafbff; }
.tbl tr.row-red td { background: #fef2f2; }
.tbl tr.row-red:hover td { background: #fee2e2; }
.tbl tr.row-green td { background: #f0fdf4; }
.tbl tr.row-green:hover td { background: #dcfce7; }
.stats { display: flex; gap: 16px; margin-bottom: 18px; flex-wrap: wrap; }
.stat { background: #fff; border-radius: 10px; padding: 18px 22px; flex: 1; min-width: 160px; box-shadow: 0 1px 3px rgba(0,0,0,.06); }
.stat .num { font-size: 28px; font-weight: 700; color: #2563eb; }
.stat .lab { color: #64748b; margin-top: 4px; }
.course-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px,1fr)); gap: 16px; }
.course-card { background: #fff; border-radius: 10px; padding: 16px; box-shadow: 0 1px 3px rgba(0,0,0,.06); }
.course-title { font-weight: 600; font-size: 15px; margin-bottom: 8px; }
.course-meta { color: #64748b; font-size: 13px; margin-bottom: 8px; }
.course-desc { color: #475569; font-size: 13px; margin-bottom: 12px; }
.bar { height: 8px; background: #e2e8f0; border-radius: 4px; overflow: hidden; margin: 6px 0; }
.bar span { display: block; height: 100%; background: #2563eb; }
.lesson-list { list-style: none; padding: 0; margin: 0; }
.lesson-item { display: flex; align-items: center; gap: 12px; padding: 10px 0; border-bottom: 1px solid #eef1f5; }
.lesson-item .lt { font-weight: 500; flex: 1; }
.lt-type { color: #64748b; font-size: 13px; }
.viewer video, .viewer iframe, .doc-frame { width: 100%; border: none; border-radius: 8px; background: #000; }
.viewer video { max-height: 520px; }
.doc-frame { height: 70vh; }
.richtext { padding: 10px; background: #f8fafc; border-radius: 8px; line-height: 1.7; }
.badge { padding: 2px 9px; border-radius: 10px; font-size: 12px; }
.badge-green { background: #dcfce7; color: #166534; }
.badge-gray { background: #e2e8f0; color: #475569; }
.badge-red { background: #fee2e2; color: #991b1b; }
.badge-blue { background: #dbeafe; color: #1e40af; }
.question { border: 1px solid #e2e8f0; border-radius: 8px; padding: 14px; margin-bottom: 12px; }
.q-head { font-weight: 600; margin-bottom: 8px; }
.q-score { color: #2563eb; font-weight: 400; font-size: 13px; margin-left: 6px; }
.opt { display: block; margin: 6px 0; cursor: pointer; }
.fill-input, .question textarea { width: 100%; margin-top: 4px; }
.question.correct { border-color: #22c55e; background: #f0fdf4; }
.question.wrong { border-color: #ef4444; background: #fef2f2; }
.question.pending { border-color: #f59e0b; background: #fffbeb; }
.q-ans { font-size: 13px; color: #475569; margin-top: 4px; }
.score-box { background: #fff; border-radius: 10px; padding: 24px; text-align: center; margin-bottom: 18px; box-shadow: 0 1px 3px rgba(0,0,0,.06); }
.score-num { font-size: 42px; font-weight: 800; color: #2563eb; }
.timer { background: #fef3c7; color: #92400e; padding: 8px 14px; border-radius: 8px; display: inline-block; margin-bottom: 14px; font-weight: 600; }
.foot { text-align: center; color: #94a3b8; font-size: 12px; padding: 24px; }