:root{font-family:system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;color:#333;background-color:#f8f9fa;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{margin:0;padding:0;display:flex;flex-direction:column;align-items:center;min-height:100vh;box-sizing:border-box}#app{width:100%;margin:0 auto;padding:20px;text-align:center;box-sizing:border-box;display:flex;flex-direction:column;gap:15px}h1{font-size:2.2em;line-height:1.1;margin-bottom:.5em}#numberline-container{width:100%;border:1px solid #ccc;box-sizing:border-box}#numberline-svg{display:block;width:100%}#controls{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin:15px 0}button{border-radius:8px;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;cursor:pointer;transition:border-color .25s;background-color:#e9ecef;color:#333}button:hover{border-color:#646cff}button:focus,button:focus-visible{outline:4px auto -webkit-focus-ring-color}#feedback-area{margin-top:10px;padding:10px;border-radius:4px;min-height:1.5em}#feedback-area.info{background-color:#e7f3ff;color:#00529b;border:1px solid #b8dcfc}#feedback-area.success{background-color:#d4edda;color:#155724;border:1px solid #c3e6cb}#feedback-area.warning{background-color:#fff3cd;color:#856404;border:1px solid #ffeeba}#feedback-area.error{background-color:#f8d7da;color:#721c24;border:1px solid #f5c6cb}#score-display{font-weight:700;font-size:1.2em}.correct-answer-highlight{stroke:#5cb85c}.tick text{fill:currentColor}.tick.major line{stroke:#333}.tick.minor line{stroke:#aaa}@media (prefers-color-scheme: dark){.tick.major line{stroke:#ccc}.tick.minor line{stroke:#666}}.axis-line{stroke:#333}@media (prefers-color-scheme: dark){.axis-line{stroke:#ccc}}.draggable-marker line,.draggable-marker circle{stroke:#d9534f;fill:#d9534f}@media (prefers-color-scheme: dark){.draggable-marker line,.draggable-marker circle{stroke:#e57373;fill:#e57373}}.feedback-line-correct{stroke:#5cb85c}.feedback-text-correct{fill:#5cb85c}.feedback-text-user{fill:#d9534f}