* { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: 'Segoe UI', sans-serif; background: #f0f4f8; min-height: 100vh; color: #1a202c; }
    .nav-link { background: transparent; color: #fff; border: 1px solid #4a5568; border-radius: 6px; padding: 6px 12px; font-size: 12px; cursor: pointer; text-decoration: none; }
    .nav-link.active, .nav-link:hover { background: #2d3748; }

    .container { max-width: 1180px; margin: 32px auto; padding: 0 16px; }
    .section-header { margin-bottom: 24px; display: flex; justify-content: space-between; gap: 16px; align-items: flex-end; }
    .section-title { font-size: 22px; font-weight: 800; }
    .section-subtitle { font-size: 13px; color: #718096; margin-top: 4px; }
    .academy-list { display: grid; gap: 18px; }
    .academy-card { background: #fff; border: 1px solid #e2e8f0; border-radius: 14px; padding: 20px; box-shadow: 0 1px 4px rgba(0,0,0,0.06); }
    .academy-card.hidden-item { border-color: #fc8181; background: #fff5f5; }
    .academy-head { display: flex; justify-content: space-between; gap: 16px; align-items: flex-start; }
    .academy-name { font-size: 18px; font-weight: 800; margin-bottom: 4px; }
    .meta { color: #718096; font-size: 12px; line-height: 1.6; }
    .admin-visit-statistics { display: grid; grid-template-columns: 110px 110px minmax(220px, 360px); gap: 10px; align-items: stretch; margin-top: 14px; }
    .admin-visit-counter, .admin-visit-chart { border: 1px solid #dbe5f0; border-radius: 10px; background: #f8fbff; }
    .admin-visit-counter { display: flex; flex-direction: column; justify-content: center; padding: 10px 12px; }
    .admin-visit-counter span { color: #718096; font-size: 11px; font-weight: 700; }
    .admin-visit-counter strong { margin-top: 3px; color: #1a365d; font-size: 20px; font-variant-numeric: tabular-nums; }
    .admin-visit-chart { min-height: 100px; padding: 4px 8px; }
    .admin-visit-chart svg { display: block; width: 100%; height: 100px; }
    .admin-visit-chart polyline { fill: none; stroke: #319795; stroke-width: 2; }
    .admin-visit-chart circle { fill: #2c7a7b; }
    .admin-visit-chart text { fill: #2f855a; font-size: 9px; font-weight: 800; text-anchor: middle; }
    .admin-visit-chart text.date { fill: #718096; font-size: 8px; font-weight: 500; }
    .pill { display: inline-block; padding: 3px 8px; border-radius: 999px; font-size: 11px; font-weight: 800; margin-left: 6px; }
    .pill-visible { background: #c6f6d5; color: #22543d; }
    .pill-hidden { background: #fed7d7; color: #9b2c2c; }
    .pill-status { background: #edf2f7; color: #4a5568; }
    .toggle-btn { border: none; border-radius: 8px; padding: 9px 12px; color: #fff; cursor: pointer; font-size: 12px; font-weight: 800; min-width: 92px; }
    .toggle-btn.hide { background: #e53e3e; }
    .toggle-btn.show { background: #2f855a; }
    .toggle-btn:disabled { opacity: .55; cursor: wait; }
    .lesson-list { margin-top: 16px; border-top: 1px solid #e2e8f0; padding-top: 12px; display: grid; gap: 10px; }
    .lesson-row { display: grid; grid-template-columns: minmax(180px, 1fr) auto auto; gap: 12px; align-items: center; padding: 12px; border: 1px solid #edf2f7; border-radius: 10px; background: #fff; }
    .lesson-row.hidden-item { border-color: #feb2b2; background: #fffafa; }
    .lesson-name { font-weight: 800; font-size: 14px; }
    .lesson-detail { color: #718096; font-size: 12px; margin-top: 3px; }
    .empty-state { text-align: center; padding: 60px 0; color: #a0aec0; font-size: 14px; background: #fff; border-radius: 14px; border: 1px solid #e2e8f0; }
    @media (max-width: 720px) {
      .section-header, .academy-head { flex-direction: column; align-items: stretch; }
      .lesson-row { grid-template-columns: 1fr; }
      .admin-visit-statistics { grid-template-columns: 1fr 1fr; }
      .admin-visit-chart { grid-column: 1 / -1; }
    }


    @media (max-width: 768px) {
      body { overflow-x: hidden; }
      .container { margin: 20px auto; padding: 0 14px; }
      .academy-card { padding: 18px; }
      .academy-list, .lesson-list { gap: 12px; }
      .lesson-row { grid-template-columns: 1fr; align-items: stretch; }
      .toggle-btn { width: 100%; min-height: 40px; }
    }