/* Screen-only presentation: worksheet printing and drawing coordinates stay in the original engine. */
@media screen {
    :root { --primary: #3559d8; --primary-dark: #2545b7; --bg-viewport: #f7f9fc; }
    body { background: #f7f9fc; color: #26334d; }
    button, input, select, textarea { font: inherit; }
    button, a, input, select, textarea { -webkit-tap-highlight-color: rgba(53,89,216,.12); }
    :is(button, a, input, select, textarea):focus-visible { outline: 3px solid #6485ec; outline-offset: 3px; }
    .modoo-navbar { position: relative; background: #fff; color: #1b2b4d; padding: 22px max(24px, env(safe-area-inset-right)) 16px max(24px, env(safe-area-inset-left)); box-shadow: none; border-bottom: 1px solid #e6eaf2; }
    .nav-container { max-width: 1240px; gap: 20px; }
    .nav-brand { min-width: 0; }
    .brand-logo-badge { width: 46px; height: 46px; border-radius: 15px; background: #eef2ff; box-shadow: none; }
    .brand-title { flex-wrap: wrap; font-size: 21px; letter-spacing: -.8px; }
    .brand-sub-badge { background: transparent; padding: 0; color: #637499; font-size: 11px; letter-spacing: 0; }
    .version-tag { display: none; }
    .brand-desc { color: #66738a; margin-top: 3px; font-size: 12px; }
    .nav-actions { width: 100%; gap: 8px; padding-top: 16px; border-top: 1px solid #edf0f5; }
    .nav-actions .nav-btn { min-height: 42px; padding: 9px 12px; border: 1px solid #e3e8f1; border-radius: 11px; background: #fff; color: #43516b; box-shadow: none; font-size: 12px; transition: background .18s, border-color .18s; }
    .nav-actions .nav-btn:hover { background: #eef2ff; border-color: #becbf3; transform: none; }
    .nav-actions .btn-account, .nav-actions .btn-storage { background: #eef2ff; color: #3559d8; border-color: #dce4ff; }
    .auto-save-pill { background: #edf8f2; color: #27684f; border: 1px solid #d8ebdf; font-size: 11px; }
    .studio-welcome { width: min(1240px, calc(100% - 48px)); margin: 32px auto 28px; padding: 46px 52px; display: grid; grid-template-columns: 1.2fr 1fr; align-items: center; gap: 24px; border: 1px solid #e5e9f3; border-radius: 28px; background: radial-gradient(ellipse at 90% 20%, #e4eaff 0, transparent 55%), linear-gradient(120deg, #fffdf7, #f0f4ff); overflow: hidden; }
    .studio-eyebrow { font-size: 10px; font-weight: 800; letter-spacing: 2px; color: #6173a2; }
    .studio-intro h1 { margin: 17px 0; font-size: clamp(28px, 3.1vw, 43px); letter-spacing: -1.8px; line-height: 1.35; color: #1b2c4e; font-weight: 800; }
    .studio-intro h1 em { color: #3559d8; font-style: normal; }
    .studio-intro p { color: #6a7589; font-size: 14px; line-height: 1.9; word-break: keep-all; }
    .studio-start { display: inline-flex; gap: 28px; align-items: center; margin-top: 24px; padding: 13px 20px; color: white; background: #3559d8; border-radius: 12px; text-decoration: none; font-size: 14px; font-weight: 700; box-shadow: 0 8px 18px #3559d822; }
    .studio-start:hover { background: #2545b7; }
    .studio-tags { display: flex; flex-wrap: wrap; gap: 8px 16px; margin-top: 21px; font-size: 11px; color: #78839a; }
    .studio-tags span::before { content: '✓'; margin-right: 5px; color: #6b87b4; }
    .studio-mobile-break { display: none; }
    .studio-art { position: relative; min-height: 265px; display: grid; place-items: center; }
    .studio-note { position: relative; z-index: 1; width: 285px; padding: 27px; background: #ffffffed; border: 1px solid #fff; border-radius: 20px; box-shadow: 0 24px 48px #5265a31a; transform: rotate(-7deg); }
    .note-caption { font-size: 8px; letter-spacing: 1.4px; color: #98a3ba; }
    .studio-note strong { display: block; margin: 13px 0 22px; color: #354364; font-size: 17px; }
    .note-equation { font-size: 27px; font-weight: 800; color: #3c547a; white-space: nowrap; }
    .note-equation span { font-size: 20px; color: #a5b2ca; }
    .note-equation b { font-size: 24px; color: #4464d9; }
    .note-line { height: 5px; background: #edf1f8; border-radius: 5px; margin-top: 22px; }
    .note-line.short { width: 65%; margin-top: 9px; }
    .note-check { display: block; color: #548876; font-size: 11px; margin-top: 20px; }
    .studio-orbit { position: absolute; border-radius: 50%; border: 1px solid #cdd7f0; width: 310px; height: 310px; }
    .orbit-two { width: 380px; height: 380px; opacity: .5; }
    .studio-spark { position: absolute; z-index: 2; font-size: 40px; }
    .spark-one { top: -4px; right: 34px; color: #eab66a; }
    .spark-two { bottom: 8px; left: 12px; color: #7d94dc; transform: rotate(15deg); }
    .studio-float { position: absolute; z-index: 2; bottom: 0; right: 0; display: flex; gap: 10px; align-items: center; border: 1px solid #fff; background: #ffffffed; padding: 14px 20px; border-radius: 14px; color: #506bba; box-shadow: 0 10px 30px #5265a318; }
    .studio-float span { font-size: 12px; font-weight: 700; }
    .toolbar-toggle-bar { width: min(1240px, calc(100% - 48px)); margin: 0 auto; padding: 16px 22px; background: #fff; border: 1px solid #e3e8f1; border-radius: 18px 18px 0 0; box-shadow: none; gap: 12px; }
    .modoo-toolbar-bar { width: min(1240px, calc(100% - 48px)); margin: 0 auto; background: #fff; padding: 22px; border: 1px solid #e3e8f1; border-top: 0; border-radius: 0 0 18px 18px; box-shadow: 0 8px 24px #253b6510; scroll-margin-top: 20px; }
    .modoo-toolbar-bar { max-height: none; overflow: visible; }
    .modoo-toolbar-bar.collapsed { padding-top: 0; padding-bottom: 0; border-bottom: 0; overflow: hidden; }
    .toolbar-toggle-bar { position: relative; top: auto; }
    .toolbar-inner { align-items: flex-start; gap: 20px 16px; }
    .tool-group { flex-wrap: wrap; min-width: 0; align-items: flex-start; }
    .tool-group > .tool-label { width: 100%; font-size: 11px; color: #74819a; letter-spacing: .3px; }
    .tool-group-grow { min-width: 180px; }
    .modoo-select { min-height: 44px; max-width: 100%; border: 1px solid #e0e6f0; border-radius: 10px; background: #f9fbfe; font-size: 14px; }
    .level-btn-group { flex-wrap: wrap; gap: 3px; }
    .level-chip, .col-chip { min-height: 38px; }
    .tool-toggles { width: 100%; border-top: 1px solid #edf0f5; padding-top: 16px; align-items: center; }
    .checkbox-inline { min-height: 36px; }
    .toggle-actions { flex-wrap: wrap; }
    .toggle-actions button { min-height: 40px; border-radius: 9px; }
    .page-viewport { padding: 26px 24px calc(64px + env(safe-area-inset-bottom)); gap: 28px; }
    .print-sub-bar { width: 100%; max-width: 1040px; flex-wrap: wrap; gap: 12px; }
    .print-sub-right { flex-wrap: wrap; gap: 8px; }
    .btn-sub-action { min-height: 40px; border-radius: 9px; }
    .a4-sheet-wrapper { max-width: 1040px; border-radius: 20px; border: 1px solid #e5eaf2; box-shadow: 0 10px 40px #2438570a; }
    .questions-grid.grid-col-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .question-card { min-width: 0; overflow-wrap: anywhere; }
    .nav-container, .toolbar-inner, .studio-intro, .worksheet-header-right { min-width: 0; }
    .a4-sheet-wrapper { width: 100%; min-width: 0; }
    .question-card img, .question-card svg { max-width: 100%; }
    .worksheet-title-row, .worksheet-header-right { flex-wrap: wrap; gap: 16px; }
    .modal-overlay { padding: max(16px, env(safe-area-inset-top)) max(12px, env(safe-area-inset-right)) max(16px, env(safe-area-inset-bottom)) max(12px, env(safe-area-inset-left)); }
    /* Override legacy mobile !important sizes; keep dialogs inside the safe viewport. */
    .modal-card { border-radius: 22px; width: 100% !important; max-height: calc(100vh - 32px) !important; max-height: calc(100dvh - max(16px, env(safe-area-inset-top)) - max(16px, env(safe-area-inset-bottom))) !important; border: 1px solid #e4e9f2; }
    .modal-header { flex-shrink: 0; }
    .modal-header { gap: 12px; }
    .modal-header h3 { min-width: 0; overflow-wrap: anywhere; }
    .modal-close { flex-shrink: 0; min-width: 44px; min-height: 44px; }
    .modal-body { min-height: 0; overflow-wrap: anywhere; }
    .ipad-drawing-dock { max-width: calc(100% - 24px); flex-wrap: wrap; justify-content: center; border-radius: 20px; bottom: calc(16px + env(safe-area-inset-bottom)); }
    .ipad-drawing-dock button { min-height: 36px; }
}
@media screen and (max-width: 900px) {
    /* Supersede the legacy forced single-row mobile navigation. */
    .nav-actions { flex-wrap: wrap !important; overflow: visible !important; }
    .toolbar-toggle-bar { top: auto; }
    .studio-welcome { padding: 32px; grid-template-columns: 1.3fr 1fr; }
    .studio-note { width: 230px; padding: 23px; }
    .note-equation { font-size: 22px; }
    .note-equation b { font-size: 20px; }
    .studio-art { min-height: 245px; }
    .studio-float { right: -12px; }
    .nav-actions .nav-btn { flex: 1 1 auto; justify-content: center; }
    .a4-sheet-wrapper { padding: 30px; }
}
@media screen and (max-width: 600px) {
    .modoo-navbar { padding: 18px 16px 12px; }
    .brand-title { font-size: 19px; }
    .brand-desc { font-size: 10px; }
    .nav-actions { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; }
    .nav-actions .auto-save-pill { grid-column: 1 / -1; justify-self: start; }
    .nav-actions .nav-btn { width: 100%; min-width: 0; padding: 8px 4px; font-size: 10px; min-height: 44px; gap: 4px; white-space: normal; }
    .nav-actions .btn-text { display: inline; }
    .nav-actions .btn-icon { font-size: 12px; }
    .studio-welcome { width: calc(100% - 24px); margin: 18px auto; padding: 28px 23px; grid-template-columns: 1fr; border-radius: 22px; }
    .studio-intro h1 { font-size: 30px; letter-spacing: -1.3px; }
    .studio-intro p { font-size: 12px; }
    .studio-mobile-break { display: inline; }
    .studio-art { display: none; }
    .studio-tags { font-size: 10px; gap: 6px 12px; }
    .studio-eyebrow { font-size: 8px; letter-spacing: 1.6px; }
    .toolbar-toggle-bar, .modoo-toolbar-bar { width: calc(100% - 24px); padding: 16px; }
    .toolbar-toggle-bar { flex-wrap: wrap; }
    .toggle-summary-wrap { min-width: 0; flex-wrap: wrap; }
    .toggle-actions { width: 100%; justify-content: space-between; gap: 6px; }
    .toolbar-inner { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px 10px; }
    .tool-group { width: 100%; min-width: 0; }
    .tool-group-grow, .tool-toggles, .tool-group:has(.level-btn-group) { grid-column: 1 / -1; }
    .tool-group .modoo-select { width: 100%; font-size: 16px; }
    .tool-toggles { gap: 6px 14px; }
    .checkbox-inline { font-size: 12px; }
    .page-viewport { padding: 20px 12px calc(90px + env(safe-area-inset-bottom)); }
    .print-sub-right { width: 100%; }
    .print-sub-right button { flex: 1 1 auto; font-size: 11px; }
    .print-guide-text { font-size: 11px; }
    .a4-sheet-wrapper { padding: 22px 16px; border-radius: 16px; min-height: 0; }
    .questions-grid.grid-col-2 { grid-template-columns: minmax(0, 1fr) !important; }
    .worksheet-title-row { align-items: flex-start; }
    .worksheet-header-right { max-width: 100%; }
    .input-answer { max-width: 100%; min-width: 0; font-size: 16px; }
    .input-answer-row { flex-wrap: wrap; }
    .quick-table-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .modal-body { padding: 16px; }
    .modal-body input, .modal-body select, .modal-body textarea { max-width: 100%; font-size: 16px; }
    .auth-grid { grid-template-columns: minmax(0, 1fr); }
    .recent-ws-card, .gemini-key-input-row { flex-wrap: wrap; }
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}
@media print { .studio-welcome { display: none !important; } }