:root{--bg: #14141c;--header-bg: #1e1e2a;--panel-bg: rgba(20, 20, 30, .85);--border: #33334a;--text: #e8e8f0;--accent: turquoise}*{font-family:Verdana}body{background-color:var(--bg);color:var(--text);width:100vw;height:100vh;box-sizing:border-box;margin:0;overflow:hidden;display:grid;grid-template-rows:10vh 1fr;grid-template-columns:1fr;grid-template-areas:"header" "main";justify-content:center;align-items:center;justify-items:center}#headerContainer{grid-area:header;background-color:var(--header-bg);border-bottom:1px solid var(--border);width:100%;height:100%;margin:0;display:flex;flex-direction:row;justify-content:center;align-items:center}h1{margin:0;font-size:1.5rem;letter-spacing:.02em}#simWrapper{grid-area:main;position:relative;width:75vw;height:75vh}canvas{display:block;width:100%;height:100%;border:1px solid var(--border);box-sizing:border-box}.lil-gui.autoPlace{top:calc(17.5vh + 16px);right:calc(12.5vw + 16px)}#startOverlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:100;background:#0a0a14eb;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:16px;color:#fff;font-family:Arial,sans-serif}#startOverlay.hidden{display:none}#startTitle{font-size:1.8rem;margin:0;color:#40e0d0}#startSubtitle{margin:0;color:#aaa;font-size:.95rem;max-width:420px;text-align:center}#startBtn{margin-top:8px;padding:14px 40px;font-size:1.1rem;font-weight:700;background:#40e0d0;color:#111;border:none;border-radius:8px;cursor:pointer;transition:background .2s}#startBtn:hover{background:#00e5d4}#startBtn:disabled{background:#555;color:#999;cursor:not-allowed}#loadingMsg{display:none;color:#aaa;font-size:.9rem;margin:0}#gpuWarning{display:none;background:#c8640040;border:1px solid orange;border-radius:8px;padding:14px 20px;max-width:460px;font-size:.88rem;color:#ffd580;line-height:1.5}#gpuWarning p{margin:6px 0 0}#gpuWarning code{background:#ffffff26;padding:1px 5px;border-radius:3px;font-size:.85rem}#instructions{position:absolute;top:16px;left:16px;z-index:2;box-sizing:border-box;width:240px;background-color:var(--panel-bg);color:var(--text);border:1px solid var(--border);padding:15px;border-radius:8px;font-family:Arial,sans-serif;pointer-events:none}#instructions h2{margin-top:0;font-size:1em;color:var(--accent)}#instructions ul{list-style-type:none;padding-left:0}#instructions li{margin-bottom:10px;font-size:.9em}#instructions strong{display:block}