:root{color-scheme:light dark;--bg:#f5f6fa;--panel:#fff;--ink:#17283c;--muted:#43546a;--line:#1f558a;--shade:#dceafa;--border:#718096;--accent:#a02839}
@media(prefers-color-scheme:dark){:root{--bg:#111b28;--panel:#1b2a3c;--ink:#eef4ff;--muted:#c6d3e4;--line:#8dc8ff;--shade:#304861;--border:#9bacbf;--accent:#ffadb8}}
:root[data-theme=light]{color-scheme:light;--bg:#f5f6fa;--panel:#fff;--ink:#17283c;--muted:#43546a;--line:#1f558a;--shade:#dceafa;--border:#718096;--accent:#a02839}
:root[data-theme=dark]{color-scheme:dark;--bg:#111b28;--panel:#1b2a3c;--ink:#eef4ff;--muted:#c6d3e4;--line:#8dc8ff;--shade:#304861;--border:#9bacbf;--accent:#ffadb8}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.65 system-ui,sans-serif}main{max-width:980px;margin:auto;padding:18px}section,header{background:var(--panel);border:1px solid var(--border);border-radius:12px;padding:20px;margin-bottom:18px}h1{font-size:1.8rem}h2{font-size:1.25rem}p{overflow-wrap:anywhere}button,select{font:inherit;color:var(--ink);background:var(--bg);border:1px solid var(--border);border-radius:6px;padding:8px;max-width:100%}button{cursor:pointer;margin:8px 0}button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--accent);outline-offset:3px}label{display:block}#controls{display:grid;grid-template-columns:1fr 1fr;gap:14px}.slider input{width:100%;min-height:32px;accent-color:var(--line)}output{font-variant-numeric:tabular-nums}.checks{display:flex;gap:18px;flex-wrap:wrap}input[type=checkbox]{width:20px;height:20px;vertical-align:middle}#formula{font-size:1.2rem;font-weight:650}#plot{width:100%;height:auto;display:block;color:var(--ink)}#feedback{font-weight:650}footer{color:var(--muted)}[hidden]{display:none!important}@media(max-width:500px){main{padding:10px}section,header{padding:14px}#controls{grid-template-columns:1fr}h1{font-size:1.5rem}}