:root{--primary:#000000;--primary-hover:#1d1d1f;--text-primary:#1d1d1f;--text-secondary:#86868b;--text-muted:#999999;--border:#d2d2d7;--border-strong:#333;--bg-primary:#ffffff;--bg-secondary:#ffffff;--bg-subtle:#f5f5f7;--bg-elevated:#fafafa;--accent:#0071e3;--accent-hover:#0077ed;--success:#30d158;--success-bg:#d4f4dd;--success-border:#2d7a2d;--error:#ff3b30;--error-bg:#ffd4d4;--error-border:#c23b22;--warning:#ffc107;--warning-bg:#fff3cd;--warning-border:#e6d700;--highlight:#fffacd;--highlight-border:#e6d700;--shadow-sm:0 1px 3px rgba(0,0,0,0.04);--shadow-md:0 4px 16px rgba(0,0,0,0.08);--shadow-lg:0 8px 32px rgba(0,0,0,0.12);--shadow-neo:3px 3px 0 rgba(0,0,0,0.1);--shadow-neo-sm:2px 2px 0 rgba(0,0,0,0.1);--pro-bg:#fffacd;--pro-border:#e6d700;--pro-text:#000}:root[data-theme=dark]{--primary:#ffffff;--primary-hover:#f0f0f0;--text-primary:#ffffff;--text-secondary:#a8a8a8;--text-muted:#808080;--border:#404040;--border-strong:#555555;--bg-primary:#1a1a1a;--bg-secondary:#252525;--bg-subtle:#2d2d2d;--bg-elevated:#333333;--accent:#4a9eff;--accent-hover:#5aa8ff;--success:#3ed15f;--success-bg:#1f3d2f;--success-border:#3ed15f;--error:#ff5449;--error-bg:#3d1f1f;--error-border:#ff5449;--warning:#ffc844;--warning-bg:#3d3a1f;--warning-border:#d4c200;--highlight:#3d3a1f;--highlight-border:#d4c200;--shadow-sm:0 1px 3px rgba(0,0,0,0.3);--shadow-md:0 4px 16px rgba(0,0,0,0.5);--shadow-lg:0 8px 32px rgba(0,0,0,0.7);--shadow-neo:3px 3px 0 rgba(255,255,255,0.08);--shadow-neo-sm:2px 2px 0 rgba(255,255,255,0.08);--pro-bg:#3d3a1f;--pro-border:#d4c200;--pro-text:#ffd700}*{box-sizing:border-box}body{min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,SF Pro Text,Helvetica Neue,sans-serif;color:var(--text-primary);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;transition:background-color .2s ease,color .2s ease}.app-header,body{background:var(--bg-primary)}.app-header{border-bottom:1px solid var(--border);padding:16px 0}.app-footer,.app-header{transition:background-color .2s ease,border-color .2s ease}.app-footer{border-top:1px solid var(--border);background:var(--bg-subtle);padding:24px 0;margin-top:auto}.card{border:2px solid var(--border-strong);border-radius:8px;background:var(--bg-secondary);box-shadow:var(--shadow-neo);transition:all .2s ease}.btn-primary{background:var(--primary)!important;color:white!important;border-color:var(--primary)!important}.btn-primary:hover{background:var(--primary-hover)!important;border-color:var(--primary-hover)!important;color:white!important}.btn-primary:disabled{opacity:.6;cursor:not-allowed}.badge{border-radius:6px;padding:4px 10px;font-weight:500;font-size:.75rem;border:1px solid var(--border)}.progress{border-radius:8px;overflow:hidden;background:var(--bg-subtle)}.progress-bar{background:var(--primary)}.option-card{border:2px solid var(--border-strong);border-radius:6px;padding:16px 18px;margin-bottom:10px;cursor:pointer;transition:all .15s ease;background:var(--bg-secondary);color:var(--text-primary);font-size:16px;font-weight:400;box-shadow:var(--shadow-neo-sm)}.option-card:hover{border-color:var(--primary);box-shadow:var(--shadow-neo);transform:translate(-1px,-1px)}.option-card.selected{border-color:var(--highlight-border);background:var(--highlight);box-shadow:var(--shadow-neo)}.option-card.correct{border-color:var(--success-border);background:var(--success-bg);box-shadow:var(--shadow-neo)}.option-card.incorrect{border-color:var(--error-border);background:var(--error-bg);box-shadow:var(--shadow-neo)}.custom-checkbox{width:22px;height:22px;border:2px solid var(--border-strong);border-radius:3px;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:all .15s ease;background:var(--bg-secondary);box-shadow:1px 1px 0 rgba(0,0,0,.1)}.custom-checkbox.checked{background:var(--primary);border-color:var(--primary);color:var(--bg-primary)}@keyframes fadeInSlide{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}.bg-light{background-color:var(--bg-subtle)!important}.bg-white{background-color:var(--bg-secondary)!important}.text-dark{color:var(--text-primary)!important}.text-muted{color:var(--text-muted)!important}.text-secondary{color:var(--text-secondary)!important}.border{border-color:var(--border)!important}.border-dark{border-color:#333!important}.btn-dark{background-color:var(--primary)!important;border-color:var(--primary)!important;color:var(--bg-primary)!important}.btn-dark:hover{background-color:var(--primary-hover)!important;border-color:var(--primary-hover)!important}.btn-outline-dark{color:var(--text-primary)!important;border-color:var(--border-strong)!important}.btn-outline-dark:hover{background-color:var(--bg-elevated)!important;color:var(--text-primary)!important;border-color:var(--primary)!important}.badge.bg-warning{background-color:#ffc107!important;color:#000!important}.alert-warning{background-color:var(--warning-bg)!important;border-color:var(--warning-border)!important}.alert-danger,.alert-warning{color:var(--text-primary)!important}.alert-danger{background-color:var(--error-bg)!important;border-color:var(--error-border)!important}.alert-info{background-color:var(--bg-subtle)!important;border-color:var(--border-strong)!important;color:var(--text-primary)!important}.dropdown-menu,.form-control,.form-select,.modal-content{background-color:var(--bg-secondary)!important;color:var(--text-primary)!important;border-color:var(--border-strong)!important}.form-control:focus,.form-select:focus{background-color:var(--bg-secondary)!important;color:var(--text-primary)!important;border-color:var(--primary)!important}.card-diagram *{color:#000!important}.card-diagram svg text,.card-diagram svg tspan,.card-diagram text,.card-diagram tspan{fill:#000!important;color:#000!important}.card-diagram svg circle[stroke],.card-diagram svg line[stroke],.card-diagram svg path[stroke],.card-diagram svg polygon[stroke],.card-diagram svg polyline[stroke],.card-diagram svg rect[stroke]{stroke:#000!important}.card-diagram svg rect[fill*="#c"],.card-diagram svg rect[fill*="#d"],.card-diagram svg rect[fill*="#e"],.card-diagram svg rect[fill*=blue],.card-diagram svg rect[fill="#e3f2fd"]{fill:#f5f5f5!important}.card-diagram svg marker path,.card-diagram svg marker polygon{fill:#000!important;stroke:#000!important}.homepage-grid{background-image:linear-gradient(90deg,rgba(0,0,0,.05) 1px,transparent 0),linear-gradient(180deg,rgba(0,0,0,.05) 1px,transparent 0);background-size:20px 20px}:root[data-theme=dark] .homepage-grid{background-image:linear-gradient(90deg,rgba(255,255,255,.1) 1px,transparent 0),linear-gradient(180deg,rgba(255,255,255,.1) 1px,transparent 0);background-size:20px 20px}@media (max-width:768px){.card-question{font-size:20px!important}.option-card{font-size:14px;padding:14px 16px}}.FeedbackModal_overlay__MRkij{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.75);display:flex;align-items:center;justify-content:center;z-index:10000;padding:20px}.FeedbackModal_modal__C4uZS{background:#fff;border:3px solid #000;box-shadow:8px 8px 0 #000;max-width:600px;width:100%;max-height:90vh;overflow-y:auto;position:relative}.FeedbackModal_header__ezXCo{padding:24px;border-bottom:3px solid #000;background:#fffacd}.FeedbackModal_headerLabel__dDOd_{font-size:16px;font-weight:700;color:#000;margin-bottom:12px;padding-bottom:12px;border-bottom:3px solid #000}.FeedbackModal_title__WkxiG{font-size:20px;font-weight:700;color:#000;margin:0;line-height:1.4}.FeedbackModal_body__3jdUc{padding:24px}.FeedbackModal_subtitle__d3tbk{font-size:14px;font-weight:600;color:#333;margin-bottom:20px}.FeedbackModal_optionsContainer__3ak_j{display:flex;flex-direction:column;gap:12px}.FeedbackModal_option__66btP{display:flex;align-items:flex-start;padding:16px;border:3px solid #000;background:#fff;cursor:pointer;transition:none;position:relative;gap:12px}.FeedbackModal_option__66btP:hover{background:#f5f5f5}.FeedbackModal_option__66btP.FeedbackModal_optionSelected__oP72u{background:#000;color:#fff;box-shadow:3px 3px 0 #000;transform:translate(-2px,-2px)}.FeedbackModal_checkbox__FhrRV{width:22px;height:22px;border:3px solid #000;cursor:pointer;flex-shrink:0;margin-top:2px;background:#fff;-moz-appearance:none;appearance:none;-webkit-appearance:none;position:relative}.FeedbackModal_option__66btP.FeedbackModal_optionSelected__oP72u .FeedbackModal_checkbox__FhrRV{background:#fff;border-color:#fff}.FeedbackModal_option__66btP.FeedbackModal_optionSelected__oP72u .FeedbackModal_checkbox__FhrRV:after{content:"✓";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);color:#000;font-size:16px;font-weight:900}.FeedbackModal_optionText__6NUr4{flex:1 1;font-size:15px;font-weight:500;line-height:1.4}.FeedbackModal_checkmark__pVZyQ{display:none}.FeedbackModal_promotionalContent__dgVkS{text-align:center}.FeedbackModal_description__MFRPZ{font-size:16px;font-weight:500;color:#333;line-height:1.6;margin-bottom:28px}.FeedbackModal_btnAction__soOE8{width:100%;padding:18px 32px;background:#000;color:#fff;border:3px solid #000;font-weight:700;font-size:18px;cursor:pointer;box-shadow:4px 4px 0 #000;transition:all .1s ease;font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,Helvetica Neue,sans-serif;display:inline-flex;align-items:center;justify-content:center;gap:10px}.FeedbackModal_btnAction__soOE8:hover:not(:disabled){transform:translate(2px,2px);box-shadow:1px 1px 0 #000}.FeedbackModal_btnAction__soOE8:disabled{opacity:.5;cursor:not-allowed}.FeedbackModal_actionIcon__RFyPG{font-size:22px;line-height:1}.FeedbackModal_btnSecondary__Sbk9D{width:100%;padding:14px 28px;background:#fff;color:#000;border:3px solid #000;font-weight:600;font-size:16px;cursor:pointer;box-shadow:3px 3px 0 #000;transition:all .1s ease;font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,Helvetica Neue,sans-serif;display:inline-flex;align-items:center;justify-content:center;gap:10px;margin-top:16px}.FeedbackModal_btnSecondary__Sbk9D:hover:not(:disabled){transform:translate(2px,2px);box-shadow:1px 1px 0 #000}.FeedbackModal_btnSecondary__Sbk9D:disabled{opacity:.5;cursor:not-allowed}.FeedbackModal_youtubeContainer__e62sg{display:flex;flex-direction:column;align-items:center;gap:16px;width:100%}.FeedbackModal_youtubeSubscribeBtn__Xh30g{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 24px;background:#FF0000;color:#fff;border:3px solid #000;border-radius:2px;font-weight:700;font-size:16px;text-decoration:none;box-shadow:3px 3px 0 #000;transition:all .1s ease;font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,Helvetica Neue,sans-serif;cursor:pointer}.FeedbackModal_youtubeSubscribeBtn__Xh30g:hover{transform:translate(2px,2px);box-shadow:1px 1px 0 #000;color:#fff}.FeedbackModal_youtubeIcon__CcFeN{font-size:18px;line-height:1;display:flex;align-items:center;flex-shrink:0}.FeedbackModal_youtubeText___2Gxm{letter-spacing:.5px;text-transform:uppercase;font-size:14px}.FeedbackModal_footer__gNeqB{padding:24px;border-top:3px solid #000;display:flex;flex-direction:column;gap:12px}.FeedbackModal_btnSubmit__2q5sI{width:100%;padding:16px 24px;background:#000;color:#fff;border:3px solid #000;font-weight:700;font-size:16px;cursor:pointer;box-shadow:3px 3px 0 #000;transition:all .1s ease;font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,Helvetica Neue,sans-serif}.FeedbackModal_btnSubmit__2q5sI:hover:not(:disabled){transform:translate(2px,2px);box-shadow:0 0 0 #000}.FeedbackModal_btnSubmit__2q5sI:disabled{opacity:.5;cursor:not-allowed}.FeedbackModal_btnDismiss__XGyqf{width:100%;padding:14px 24px;background:#fff;color:#666;border:2px solid #ddd;font-weight:600;font-size:14px;cursor:pointer;transition:all .1s ease;font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,Helvetica Neue,sans-serif}.FeedbackModal_btnDismiss__XGyqf:hover:not(:disabled){border-color:#999;color:#333}.FeedbackModal_btnDismiss__XGyqf:disabled{opacity:.5;cursor:not-allowed}@media (max-width:768px){.FeedbackModal_modal__C4uZS{max-height:95vh}.FeedbackModal_body__3jdUc,.FeedbackModal_footer__gNeqB,.FeedbackModal_header__ezXCo{padding:20px}.FeedbackModal_title__WkxiG{font-size:16px}.FeedbackModal_option__66btP{padding:14px}.FeedbackModal_optionText__6NUr4{font-size:14px}}