@font-face{font-family:IRANSansX;src:url('../fonts/IRANSansXFaNum-Regular.woff2') format('woff2');font-display:swap}
@font-face{font-family:IRANSansX;src:url('../fonts/IRANSansXFaNum-Bold.woff2') format('woff2');font-weight:700;font-display:swap}
:root{--ink:#182b38;--muted:#5d7280;--line:#d8e3e8;--paper:#fff;--canvas:#f5f8f9;--blue:#1768a8;--blue-dark:#125685;--soft:#eaf5fa;--green:#116c4e;--red:#a4383e}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{scroll-behavior:smooth}
body{margin:0;background:var(--canvas);color:var(--ink);font:15px/1.85 IRANSansX,Tahoma,sans-serif}
button,input,select{font:inherit}
button{cursor:pointer;border:1px solid var(--line);border-radius:8px;background:var(--paper);color:var(--ink);padding:10px 17px}
button:hover:not(:disabled){background:var(--soft);border-color:#93bdd1}
button:disabled{cursor:not-allowed;opacity:.55}
button.primary{background:var(--blue);border-color:var(--blue);color:white;font-weight:700}
button.primary:hover:not(:disabled){background:var(--blue-dark);border-color:var(--blue-dark)}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
:where(a,button,input,select):focus-visible{outline:3px solid #f4a63a;outline-offset:3px}
.skip-link{position:absolute;top:-100px;right:12px;z-index:20;padding:8px 14px;background:white}
.skip-link:focus{top:12px}
.site-header{background:#123954;color:white}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:24px;max-width:1120px;margin:auto;padding:13px 23px}
.brand{display:flex;align-items:center;gap:10px;color:white;font-weight:700;font-size:17px;line-height:1.3}
.brand:hover{text-decoration:none}
.brand small{display:block;font-size:11px;font-weight:400;color:#c9dce7;margin-top:4px}
.brand-icon{display:grid;place-items:center;flex:none;width:39px;height:42px;border-radius:7px;background:#3c94c8;color:white;font-size:27px}
.site-header nav{display:flex;gap:4px;flex-wrap:wrap}
.site-header nav a{color:#e5f3fa;padding:6px 12px;border-radius:6px;font-size:13px}
.site-header nav a:hover,.site-header nav a[aria-current]{background:#fff2;text-decoration:none}
.page-shell{max-width:1120px;margin:0 auto;padding:30px 23px 45px;display:grid;gap:18px}
.intro{padding:13px 5px 9px}
.eyebrow{margin:0;color:var(--blue);font-size:12px;font-weight:700;letter-spacing:.01em}
.intro h1{font-size:clamp(27px,3.6vw,38px);line-height:1.4;margin:5px 0 9px}
.intro>p:not(.eyebrow){max-width:790px;margin:0;color:var(--muted)}
.intro-points{display:flex;flex-wrap:wrap;gap:8px;margin-top:17px}
.intro-points span{background:#e5eff3;border:1px solid #d4e3ea;border-radius:20px;padding:4px 12px;font-size:12px}
.card{background:var(--paper);border:1px solid var(--line);border-radius:12px;box-shadow:0 4px 18px #193d5210;padding:24px}
.section-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:15px;margin-bottom:18px}
.section-heading h2{font-size:21px;line-height:1.5;margin:2px 0 0}
.offline-status{font-size:11px;color:var(--green);white-space:nowrap}
.settings-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:13px}
.settings-grid label{display:grid;align-content:start;gap:6px;font-weight:700;font-size:13px}
.settings-grid input,.settings-grid select{width:100%;min-width:0;min-height:43px;padding:8px 10px;border:1px solid #b8cdd7;border-radius:7px;background:white;color:var(--ink)}
.settings-grid input:focus,.settings-grid select:focus{border-color:var(--blue)}
.optional{font-size:11px;color:var(--muted);font-weight:400}
.helper{font-size:12px;color:var(--muted);margin:12px 0 0}
.actions,.teacher-actions{display:flex;align-items:center;gap:9px;flex-wrap:wrap}
.actions{margin-top:18px}
.status{min-height:23px;margin:12px 0 0;color:var(--green);font-size:12px}
.status.error{color:var(--red)}
.progress{display:inline-block;border:1px solid #b9d3e0;background:var(--soft);border-radius:16px;color:var(--blue-dark);padding:3px 11px;font-size:12px;white-space:nowrap}
.topic-chip{display:inline-block;background:#e7f2f6;color:var(--blue-dark);border-radius:4px;padding:2px 9px;font-size:12px;font-weight:700}
.quiz h3{font-size:19px;line-height:1.7;margin:12px 0 17px}
.options{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;border:0;padding:0;margin:0 0 17px}
.options legend{font-size:12px;color:var(--muted);margin-bottom:9px}
.option{display:flex;align-items:center;gap:10px;min-width:0;border:1px solid var(--line);border-radius:8px;padding:11px 13px;cursor:pointer}
.option:hover,.option:has(input:checked){border-color:var(--blue);background:var(--soft)}
.option input{flex:none;width:17px;height:17px;accent-color:var(--blue)}
.option span{overflow-wrap:anywhere}
.answer-hint{font-size:12px;color:var(--muted)}
.equation{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;padding:18px 12px;margin:13px 0 20px;border:1px solid var(--line);border-radius:8px;background:#f9fbfc;direction:ltr;text-align:left;font-family:Arial,sans-serif}
.equation-side{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.species{display:inline-flex;align-items:center;gap:3px;white-space:nowrap}
.coefficient{width:46px;height:42px;padding:3px;text-align:center;font:18px Arial,sans-serif;border:1px solid #9bb9c7;border-radius:5px;background:white;color:var(--ink)}
.formula{font:18px/1.6 Arial,sans-serif;unicode-bidi:isolate}
.formula sub{font-size:.65em}
.operator,.arrow{font-size:22px;color:var(--muted)}
.arrow{color:var(--blue-dark)}
.feedback{margin:18px 0 13px;padding:13px 15px;border-radius:8px;line-height:2}
.feedback.correct{background:#e7f6ed;border:1px solid #9bd0b3;color:#125d42}
.feedback.incorrect{background:#fff0ed;border:1px solid #e8b7ac;color:#842e2d}
.feedback.neutral{background:#fff9e8;border:1px solid #ebd29a;color:#65501d}
#next-question{margin-top:5px}
#quiz-summary{padding:12px 0}
#quiz-summary h3{margin:0 0 6px}
.teacher-actions{justify-content:flex-end}
.key-toggle{display:inline-flex;align-items:center;gap:6px;font-size:12px;white-space:nowrap}
.key-toggle input{width:17px;height:17px;accent-color:var(--blue)}
.worksheet{border:1px solid #d2dce1;background:white;padding:27px 28px;margin-top:21px;color:#1b2c36}
.worksheet-header{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;border-bottom:2px solid #446477;padding-bottom:14px}
.worksheet-header h2{font-size:22px;margin:0}
.worksheet-header p{font-size:12px;margin:2px 0 0;color:#4d6673}
.worksheet-fields{display:grid;gap:4px;font-size:12px;white-space:nowrap}
.worksheet-questions,.worksheet-key ol{padding-right:24px;margin:14px 0 0}
.worksheet-questions>li{padding:9px 4px 14px;border-bottom:1px solid #dce5e9;break-inside:avoid}
.sheet-prompt{margin:0 0 8px;font-weight:700}
.sheet-options{display:flex;flex-wrap:wrap;gap:5px 20px;font-size:13px}
.blank{display:inline-block;min-width:28px;border-bottom:1px solid #596d78;font:15px Arial;text-align:center}
.write-line{height:21px;border-bottom:1px dotted #c6d1d6;margin-top:6px}
.worksheet .equation{border:0;background:transparent;justify-content:flex-start;margin:7px 0 0;padding:0}
.worksheet .formula{font-size:16px}
.worksheet-key{margin-top:28px;padding-top:17px;border-top:2px solid #446477}
.worksheet-key h2{font-size:19px;margin:0}
.worksheet-key li{padding:7px 0;break-inside:avoid}
.worksheet-key strong{font-family:Arial,IRANSansX,sans-serif;direction:ltr;unicode-bidi:isolate}
.worksheet-key p{margin:3px 0;font-size:12px}
.notes h2{font-size:17px;margin:0 0 5px}
.notes p{font-size:12px;color:var(--muted);margin:6px 0}
.text-button{padding:2px 0;border:0;color:var(--blue);font-size:12px}
.text-button:hover:not(:disabled){border:0;text-decoration:underline;background:none}
footer{border-top:1px solid var(--line);padding:18px 23px;text-align:center;font-size:11px;color:var(--muted)}

.assignment-notice{border-right:4px solid var(--blue);padding:10px 13px;background:var(--soft);overflow-wrap:anywhere}
.share-box{display:flex;align-items:center;gap:9px;flex-wrap:wrap;padding:12px 0}
.share-box label{width:100%;font-size:12px}.share-box input{flex:1 1 230px;min-width:0;max-width:100%;padding:9px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink);font:13px Arial,sans-serif}
.question-hints{border:1px solid #d8e3e8;padding:12px 15px;border-radius:7px;margin:8px 0 20px;background:#f9fbfc}.question-hints ol{margin:8px 0;padding-right:22px}.question-hints li{padding:5px 0;overflow-wrap:anywhere}
.numeric-answer{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin:15px 0;font-weight:700}.numeric-answer input{padding:10px;width:210px;max-width:100%;direction:ltr;text-align:left;border:1px solid #9bb9c7;border-radius:6px;font:18px Arial,IRANSansX,sans-serif}
.skill-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.skill-card{border:1px solid var(--line);padding:14px;border-radius:8px;min-width:0}.skill-card h3{font-size:16px;margin:0 0 7px}.skill-card p{margin:5px 0;font-size:12px}.skill-card progress{width:100%;height:8px;accent-color:var(--blue)}
.file-button{display:inline-flex;align-items:center;cursor:pointer;padding:10px 17px;border:1px solid var(--line);border-radius:8px;background:var(--paper);font:inherit;max-width:100%;position:relative}.file-button:focus-within{outline:3px solid #f4a63a;outline-offset:3px}.file-button input{position:absolute;opacity:0;width:100%;height:100%;cursor:pointer;right:0;top:0}
.report-items{padding-right:24px}.report-items li{border-bottom:1px solid var(--line);padding:12px 0;break-inside:avoid;overflow-wrap:anywhere}.report-items p{margin:5px 0}.progress-card:target{outline:3px solid #f4a63a;outline-offset:3px}
.classroom-toolbar{display:flex;align-items:center;gap:20px;flex-wrap:wrap;margin-bottom:18px}.classroom-toolbar label{display:flex;align-items:center;gap:9px;font-size:13px}.classroom-view{--class-font:24px}.classroom-view .quiz h3,.classroom-view .option,.classroom-view .feedback,.classroom-view .question-hints li{font-size:var(--class-font,24px);line-height:1.9}.classroom-view .quiz:fullscreen{overflow:auto;background:white;padding:30px;max-width:none}.classroom-view .numeric-answer{font-size:var(--class-font,24px)}
@media(max-width:850px){.skill-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:600px){.skill-grid{grid-template-columns:1fr}.question-hints{padding:10px}.numeric-answer input{width:100%}.classroom-view .quiz h3,.classroom-view .option,.classroom-view .feedback{font-size:20px}.session-report .actions{width:100%}.file-button{width:100%;justify-content:center}}

@media(max-width:850px){.settings-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.worksheet-header{display:grid}.worksheet-fields{grid-template-columns:repeat(3,auto);gap:15px}}
@media(max-width:600px){body{font-size:14px}.header-inner{padding:11px 13px;flex-wrap:wrap;gap:8px}.site-header nav{width:100%;justify-content:space-between}.site-header nav a{padding:5px 7px;font-size:11px}.page-shell{padding:17px 11px 28px;gap:12px}.intro{padding:5px 3px}.intro h1{font-size:27px}.intro-points span{font-size:11px}.card{padding:17px 14px;border-radius:8px}.section-heading{flex-wrap:wrap;margin-bottom:14px}.section-heading h2{font-size:19px}.settings-grid{gap:10px}.settings-grid label{font-size:12px}.actions button{flex:1 1 100%;min-height:44px}.options{grid-template-columns:1fr}.equation{justify-content:flex-start;overflow-x:auto;flex-wrap:nowrap;max-width:100%;padding:12px 9px}.equation-side{flex-wrap:nowrap}.species{flex:none}.coefficient{width:39px;height:39px}.formula{font-size:16px}.teacher-actions{width:100%;justify-content:space-between}.worksheet{padding:14px 12px;margin-top:14px}.worksheet-fields{grid-template-columns:1fr;gap:0}.sheet-options{gap:3px 13px}.worksheet .equation{overflow-x:auto}.worksheet .formula{font-size:14px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media print{
  @page{size:A4 portrait;margin:14mm}
  :root{--paper:#fff;--canvas:#fff}
  html,body{margin:0;padding:0;background:white;color:black;font-size:10pt;print-color-adjust:exact;-webkit-print-color-adjust:exact}
  .site-header,.intro,.setup,.quiz,.notes,.progress-card,.session-report,footer,.teacher>.section-heading,.teacher>.helper{display:none!important}
  .page-shell{display:block;max-width:none;margin:0;padding:0}
  .teacher:not([hidden]){display:block!important;border:0;box-shadow:none;padding:0;margin:0}
  .teacher[hidden]{display:none!important}
  .worksheet{display:block;border:0;padding:0;margin:0}
  .worksheet-header{display:flex;gap:15px;padding-bottom:7mm}
  .worksheet-header h2{font-size:16pt}
  .worksheet-header p,.worksheet-fields{font-size:9pt}
  .worksheet-questions{padding-right:7mm}
  .worksheet-questions>li{padding:3mm 1mm 5mm}
  .sheet-prompt{font-size:10pt}
  .sheet-options{font-size:9pt}
  .worksheet .equation{overflow:visible;white-space:normal}
  .worksheet .formula{font-size:11pt}
  .worksheet-key{break-before:page;margin-top:0;padding-top:0;border-top:0}
  .worksheet-key h2{font-size:14pt;border-bottom:2px solid #446477;padding-bottom:4mm}
  .worksheet-key li{font-size:10pt}
  .worksheet-key p{font-size:9pt}
  .print-session .teacher{display:none!important}.print-session .session-report{display:block!important;padding:0;margin:0;border:0;box-shadow:none}.print-session .session-report .actions{display:none}.print-session .report-items{font-size:10pt}.print-session .report-items p{font-size:9pt}
}