:root{--brand:#22181c;--brand-dark:#22181c;--accent:#b45309;--accent-hover:#92400e;--accent-soft:rgba(180,83,9,.09);--accent-border:rgba(180,83,9,.26)}body{background:radial-gradient(circle at 100% 0,rgba(180,83,9,.06),transparent 28rem),var(--bg,#f6f8fb)}.study-tabs{grid-template-columns:repeat(4,minmax(0,1fr))}.tab-btn{min-height:54px}.tab-panel.hidden,.question-source-data,.hidden{display:none!important}.concept-number{display:inline-block;margin-bottom:8px;color:var(--accent);font-size:.74rem;font-weight:900;text-transform:uppercase;letter-spacing:.08em}.lead-concept{font-weight:700;color:var(--brand);font-size:1rem}.notes-section h3{margin-top:18px;color:var(--brand);font-size:1rem}.gk-callout,.comparison-callout,.trap-callout,.exam-focus{padding:14px 16px;border-radius:10px;margin:14px 0;line-height:1.6}.gk-callout{background:#fcf1f5;border-left:4px solid #5c1d3d}.comparison-callout{background:#f6f1f2;border-left:4px solid #b45309}.trap-callout{background:#fffbeb;border-left:4px solid #d97706}.exam-focus{background:var(--accent-soft);border-left:4px solid var(--accent);color:var(--ink2)}.question-type{display:inline-flex;padding:3px 9px;border-radius:999px;background:var(--accent-soft);color:var(--accent);font-size:.72rem;font-weight:850;text-transform:uppercase;letter-spacing:.04em}.quiz-answer-input,.quiz-answer-textarea{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:9px;background:var(--paper);color:var(--ink);font:inherit}.quiz-answer-textarea{min-height:96px;resize:vertical}.quiz-check-btn{margin-top:10px;padding:9px 14px;border:0;border-radius:8px;background:var(--brand);color:#fff;font-weight:800;cursor:pointer}.revision-comparisons{display:flex;flex-direction:column;gap:12px}.revision-comparison{padding:14px 16px;border:1px solid var(--line);border-radius:10px;background:var(--paper-card)}.revision-comparison>div{display:flex;gap:9px;align-items:center;flex-wrap:wrap;color:var(--brand)}.revision-comparison span{color:var(--muted);font-size:.78rem}.test-question-card .test-option-btn{width:100%;text-align:left}.generation-notice{margin:16px 0;padding:14px 16px;border:1px solid #f59e0b;border-left:4px solid #d97706;border-radius:10px;background:#fffbeb;color:#78350f;display:grid;gap:4px}@media(max-width:680px){.study-tabs{grid-template-columns:repeat(2,minmax(0,1fr))}.tab-btn{font-size:.78rem}.tab-btn span:first-child{display:none}}