:root{color-scheme:dark;--bg: #0f172a;--fg: #f9fafb;--accent: #3b82f6;--panel-bg: #1e293b;--card-bg: #1e1e1e;--border: #334155}body{background-color:var(--bg);color:var(--fg);font-family:system-ui,sans-serif;margin:0}.skip-link{position:absolute;top:-40px;left:0;background:var(--accent);color:var(--bg);padding:.5rem 1rem;z-index:100}.skip-link:focus{top:0}a{color:var(--accent)}a:focus-visible,button:focus-visible,.card:focus-visible{outline:2px solid var(--accent);outline-offset:2px}header nav{display:flex;gap:1rem;align-items:center}button{background:var(--accent);color:var(--bg);border:none;padding:.5rem 1rem;cursor:pointer;border-radius:.25rem}button:hover{filter:brightness(1.1)}#file,#upload,#loadSample,#schemaBox,#summaryBox,#sampleBox,#cleanForm,#dash,#exportPng,#exportPdf{background:var(--panel-bg);padding:1rem;border-radius:.5rem;margin-bottom:1rem;display:flex;flex-direction:column;gap:1rem}#dash{display:grid;grid-template-columns:1fr;gap:1rem}@media (min-width: 640px){#dash{grid-template-columns:repeat(2,1fr)}}.card{background:var(--card-bg);border:1px solid var(--border);padding:1rem;border-radius:.5rem;position:relative;display:flex;flex-direction:column}.card .controls{position:absolute;top:.5rem;right:.5rem;display:flex;flex-direction:column;gap:.25rem}.card .controls button{background:transparent;color:var(--fg);border:1px solid var(--border);padding:.25rem;line-height:1}.card .controls button:hover,.card .controls button:focus-visible{background:var(--accent);color:var(--bg)}.card .controls button:focus-visible{outline:2px solid var(--accent);outline-offset:2px}