:root{--ink:#143d70;--line:#c9dce9;--surface:#fff;--page:#eef4f8}*{box-sizing:border-box}body{margin:0;background:var(--page);color:var(--ink);font-family:Arial,sans-serif}.viewer-shell{max-width:1280px;margin:0 auto;padding:16px}.viewer-head{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:12px}.viewer-head a{color:var(--ink);font-weight:700}.viewer-head p{margin:0;font-weight:700;text-align:right}.slide-stage{display:grid;place-items:center;position:relative;width:min(100%,calc((100vh - 165px)*16/9));min-height:0;aspect-ratio:16/9;margin:0 auto;background:#fff;border:1px solid var(--line);overflow:hidden}.slide-stage img{display:block;width:100%;height:100%;max-width:none;max-height:none;object-fit:contain}.viewer-controls{display:flex;align-items:center;justify-content:center;gap:14px;padding:14px}.viewer-controls button{border:1px solid #92b8d7;border-radius:10px;background:#fff;color:var(--ink);font:inherit;font-weight:700;padding:10px 18px;cursor:pointer}.viewer-controls button:last-child{background:var(--ink);color:#fff}.viewer-controls button:disabled{cursor:not-allowed;opacity:.5}.viewer-status{min-width:110px;text-align:center;font-weight:700}.viewer-message{margin:32px auto;max-width:600px;background:#fff;padding:20px;border:1px solid var(--line);border-radius:12px}@media(max-width:700px){.viewer-shell{padding:8px}.viewer-head{align-items:flex-start;flex-direction:column;gap:5px}.viewer-head p{text-align:left}.slide-stage{width:100%;min-height:0}.slide-stage img{max-height:none}.viewer-controls{gap:8px}.viewer-controls button{padding:10px 13px}}.knowledge-check{max-width:900px;margin:14px auto 0;background:#fff;border:2px solid #b8d3e6;border-radius:16px;padding:18px}.check-topline{display:flex;justify-content:space-between;gap:12px;align-items:center;font-size:.95rem}.knowledge-check h2{margin:12px 0 14px;font-size:1.25rem}.check-options{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.check-option{border:1px solid #92b8d7;border-radius:12px;background:#f8fbfd;color:#143d70;padding:13px;font:inherit;font-weight:700;cursor:pointer}.check-option.is-correct{border-color:#2d8a57;background:#eaf7ef}.check-option.is-wrong{border-color:#bd4b4b;background:#fff0f0}.check-feedback{margin:12px 0 0;font-weight:700}.check-feedback.correct{color:#236c45}.check-feedback.wrong{color:#9b3030}@media(max-width:700px){.check-options{grid-template-columns:1fr}.check-topline{align-items:flex-start;flex-direction:column}}.parent-note{max-width:980px;margin:14px auto 0;padding:13px 16px;background:#fff8df;border-left:5px solid #e3a518;border-radius:8px;color:#4e3b08;font-weight:700;line-height:1.45}\n
.slide-stage.student-check-slide img{clip-path:inset(0 0 15% 0)}


/* Classroom slides are presentation-only: no printable slide surface. */
#slide-image {
  -webkit-user-drag: none;
  user-select: none;
  -webkit-user-select: none;
}
@media print {
  body * { visibility: hidden !important; }
  body::before {
    content: "SkillrHub teacher slides are available for on-screen teaching only.";
    visibility: visible !important;
    display: block;
    padding: 2rem;
    font: 700 18px/1.4 system-ui, sans-serif;
  }
}