:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--page-background:#f5f5f5;--surface-background:#fff;--text-color:#242424;--muted-text:#666;--primary-background:#333;--primary-text:#fff;--border-color:#d9d9d9;--disabled-background:#e5e5e5;--disabled-border:#d4d4d4;--disabled-text:#737373;--focus-color:#e3a008;--answer-border:#858585;--error-background:#fff0ef;--error-border:#b4433c;--error-text:#7d201b;--blank-border:#737373;--molecule-name:#525252;--molecule-background:var(--surface-background);--correct-background:#237a3b;--correct-text:#17642d;--incorrect-background:#b53b34;--incorrect-text:#9b2f2a;color:var(--text-color);background:var(--page-background);font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-size:18px;line-height:1.45}@media (prefers-color-scheme:dark){:root:not([data-theme]){--lightningcss-light: 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;--lightningcss-dark:initial;color-scheme:dark;--page-background:#171717;--surface-background:#222;--text-color:#f2f2f2;--muted-text:#b3b3b3;--primary-background:#e5e5e5;--primary-text:#171717;--border-color:#404040;--disabled-background:#303030;--disabled-border:#454545;--disabled-text:#999;--focus-color:#f4bf4f;--answer-border:#858585;--error-background:#351c1d;--error-border:#e07a73;--error-text:#ffb8b3;--blank-border:#a3a3a3;--molecule-name:#ccc;--correct-background:#237a3b;--correct-text:#62d27f;--incorrect-background:#b53b34;--incorrect-text:#ff837b}:root[data-theme=light]{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}*{box-sizing:border-box}[hidden]{display:none!important}html,body{min-height:100%;margin:0}body{background:var(--page-background);overflow-x:hidden}button,input{font:inherit}button,.file-picker{min-height:44px}button{border:1px solid var(--primary-background);color:var(--primary-text);background:var(--primary-background);cursor:pointer;touch-action:manipulation;border-radius:10px;padding:.55rem .9rem;font-size:.9rem;font-weight:600}button:disabled{color:var(--disabled-text);background:var(--disabled-background);border-color:var(--disabled-border);cursor:not-allowed}button:focus-visible,.icon-button:focus-visible,input:focus-visible,.file-picker:focus-within{outline:3px solid var(--focus-color);outline-offset:2px}.app-shell{width:min(2400px,100%);padding:max(1.25rem, env(safe-area-inset-top)) max(1rem, env(safe-area-inset-right)) max(1.5rem, env(safe-area-inset-bottom)) max(1rem, env(safe-area-inset-left));margin:0 auto}.app-header{border-bottom:1px solid var(--border-color);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:.75rem;margin-bottom:2rem;padding-bottom:1rem;display:flex}.brand{letter-spacing:-.04em;align-items:center;gap:.45rem;font-size:1.1rem;font-weight:750;display:inline-flex}.brand-mark{width:32px;height:32px}.theme-toolbar{justify-content:flex-end;gap:.15rem;margin-left:auto;display:flex}.icon-button{width:44px;height:44px;color:var(--muted-text);touch-action:manipulation;background:0 0;border:1px solid #0000;border-radius:10px;flex:0 0 44px;justify-content:center;align-items:center;padding:10px;text-decoration:none;display:inline-flex;position:relative}.icon-button:hover,.icon-button:focus-visible{color:var(--text-color);border-color:var(--border-color);background:var(--surface-background)}.theme-toggle{border-color:var(--border-color);background:var(--surface-background);margin-left:.35rem}.icon-button svg{fill:none;stroke:currentColor;stroke-width:1.75px;stroke-linecap:round;stroke-linejoin:round;width:22px;height:22px}.icon-button:after{content:attr(aria-label);z-index:2;width:max-content;max-width:180px;color:var(--primary-text);background:var(--primary-background);pointer-events:none;visibility:hidden;border-radius:6px;padding:.4rem .6rem;font-size:.78rem;line-height:1.35;position:absolute;top:calc(100% + 8px);right:0}.icon-button:first-child:after{left:0;right:auto}.icon-button:focus-visible:after{visibility:visible}@media (hover:hover){.icon-button:hover:after{visibility:visible}}.theme-toggle[data-next-theme=dark] .sun-icon,.theme-toggle[data-next-theme=light] .moon-icon{display:none}.screen{width:100%}#import-screen{border:1px solid var(--border-color);background:var(--surface-background);text-align:center;border-radius:20px;max-width:680px;margin:clamp(2rem,8vh,6rem) auto 0;padding:clamp(1.5rem,5vw,3rem);box-shadow:0 2px 4px #00000005,0 16px 40px #0000000a}h1,h2,p{margin-top:0}h1{letter-spacing:-.04em;margin-bottom:.75rem;font-size:clamp(1.65rem,5vw,2.25rem);font-weight:650;line-height:1.15}.intro{color:var(--muted-text);margin-bottom:1.5rem;font-size:.95rem}.file-picker{border:1.5px dashed var(--blank-border);width:100%;color:var(--text-color);background:var(--page-background);cursor:pointer;border-radius:14px;flex-direction:column;justify-content:center;align-items:center;gap:.65rem;padding:1.75rem 1rem;font-weight:600;display:inline-flex}.file-icon{fill:none;width:28px;height:28px;stroke:var(--muted-text);stroke-width:1.5px;stroke-linecap:round;stroke-linejoin:round;margin-bottom:.25rem}.file-hint{color:var(--muted-text);font-size:.78rem;font-weight:400}@media (hover:hover){.file-picker:hover{border-color:var(--text-color);background:var(--surface-background)}button:not(:disabled):not(.icon-button):hover{box-shadow:inset 0 0 0 1px}}.file-picker input{opacity:0;pointer-events:none;width:1px;height:1px;position:absolute}.status{min-height:1.5rem;color:var(--muted-text);margin:1rem 0 0;font-size:.78rem}.error-message{border:1px solid var(--error-border);color:var(--error-text);background:var(--error-background);text-align:left;white-space:pre-wrap;border-radius:8px;margin:1rem 0 0;padding:.8rem}.study-header{justify-content:space-between;align-items:center;gap:1rem;margin-bottom:1.25rem;display:flex}.section-label{color:var(--muted-text);letter-spacing:.1em;text-transform:uppercase;margin-bottom:.6rem;font-size:.72rem;font-weight:600}.study-header h1{overflow-wrap:anywhere;margin-bottom:0;font-size:clamp(1.4rem,3vw,1.85rem)}.progress{border:1px solid var(--border-color);background:var(--surface-background);color:var(--muted-text);white-space:nowrap;font-variant-numeric:tabular-nums;border-radius:100px;flex:none;margin:0;padding:.45rem 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.secondary-button{color:var(--primary-background);background:var(--surface-background)}.rating-controls{border-top:1px solid var(--border-color);flex-wrap:wrap;align-items:center;gap:.75rem 1.25rem;margin-top:1rem;padding-top:1rem;display:flex}.rating-controls p{color:var(--muted-text);margin:0;font-size:.85rem}.rating-buttons{flex-wrap:wrap;gap:.75rem;display:flex}.rating-button{background:var(--surface-background);flex:auto;min-width:130px}.correct-button{color:var(--correct-text);border-color:var(--correct-text)}.incorrect-button{color:var(--incorrect-text);border-color:var(--incorrect-text)}.rating-button.selected{color:#fff;font-weight:700}.correct-button.selected{background:var(--correct-background)}.incorrect-button.selected{background:var(--incorrect-background)}.rating-controls .rating-status{min-height:1.4rem;color:var(--muted-text);margin:.65rem 0 0 auto;font-size:.9rem}.progress-dialog{border:1px solid var(--border-color);width:min(720px,100% - 2rem);max-height:calc(100vh - 2rem);color:var(--text-color);background:var(--surface-background);border-radius:18px;padding:1.25rem;overflow:auto}.confirm-dialog{border:1px solid var(--border-color);width:min(480px,100% - 2rem);color:var(--text-color);background:var(--surface-background);border-radius:18px;padding:1.25rem}.progress-dialog::backdrop,.confirm-dialog::backdrop{background:#0000008c}.dialog-actions{flex-wrap:wrap;justify-content:flex-end;gap:.65rem;display:flex}.dialog-actions .secondary-button,.confirm-dialog .secondary-button{color:var(--primary-background);background:var(--surface-background)}.confirm-dialog h2{margin-bottom:.75rem;font-size:1.3rem}.confirm-actions{margin-top:1.25rem}.progress-list{grid-template-columns:repeat(auto-fill,minmax(72px,1fr));gap:.5rem;margin:1rem 0 0;padding:0;list-style:none;display:grid}.progress-list li{border:1px solid var(--border-color);background:var(--page-background);border-radius:7px;justify-content:center;align-items:center;gap:.25rem;min-height:44px;padding:0 .55rem 0 0;display:inline-flex}.progress-question-number{border:0;border-right:1px solid var(--border-color);min-width:2.5rem;min-height:44px;color:var(--text-color);text-underline-offset:.15em;background:0 0;border-radius:6px 0 0 6px;align-self:stretch;padding:.35rem .45rem;font-weight:700;text-decoration:none}.progress-question-number[aria-current=true]{color:var(--primary-text);background:var(--primary-background);text-decoration:none}.progress-status{text-align:center;min-width:1.2rem;font-size:1.1rem;font-weight:700}.progress-status.correct{color:var(--correct-text)}.progress-status.incorrect{color:var(--incorrect-text)}.progress-status.unattempted{color:var(--muted-text)}.progress-copy-status{min-height:1.4rem;color:var(--muted-text);margin:.75rem 0 0;font-size:.9rem}.content-rows{gap:1.25rem;display:grid}.reaction-row-scroll{overscroll-behavior-x:contain;-webkit-overflow-scrolling:touch;width:100%;max-width:100%;overflow:auto 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var(--error-border);min-height:120px;color:var(--error-text);background:var(--error-background);text-align:center;overflow-wrap:anywhere;border-radius:8px;flex-direction:column;justify-content:center;padding:.75rem;display:flex}.molecule-error strong{margin-bottom:.35rem}.molecule-error-detail{margin-top:.25rem;font-size:.82rem}.blank-item{border:2px dashed var(--blank-border);border-radius:12px;justify-content:center;align-items:center;min-height:84px;display:flex}.blank-short{width:130px}.blank-medium{width:190px}.blank-large{width:min(300px,100vw - 3rem);min-height:150px}.arrow-item{flex-direction:column;justify-content:center;align-items:stretch;gap:.3rem;width:260px;min-width:220px;display:flex}.arrow-annotations{flex-direction:column;align-items:center;gap:.3rem;min-height:1.5rem;display:flex}.arrow-glyph{color:var(--text-color);text-align:center;font-size:2.7rem;line-height:1;display:block}.annotation-text{white-space:pre-wrap;text-align:center;width:100%}.annotation-blank{white-space:pre-wrap;justify-content:center;align-items:flex-end;gap:.35rem;width:100%;display:inline-flex}.blank-line{border-bottom:2px solid var(--text-color);height:1.3rem;display:inline-block}.line-short{width:90px}.line-medium{width:150px}.line-large{width:230px}.controls{flex-wrap:wrap;gap:.5rem;max-width:1100px;margin:1.25rem auto 0;display:flex}.controls button{flex:140px}#previous-button:not(:disabled),#next-button:not(:disabled){color:var(--text-color);background:var(--surface-background);border-color:var(--border-color)}.controls 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