:root{--fg:#1a1a1a;--muted:#666;--border:#d4d4d4;--accent:#1f6feb;--warn-bg:#fff8e1;--warn-border:#e0b400;--error-bg:#fdecea;--error-border:#d93025;--bg:#fff;--surface:#fafafa}@media (prefers-color-scheme:dark){:root{--fg:#e8e8e8;--muted:#a0a0a0;--border:#3a3a3a;--accent:#58a6ff;--warn-bg:#3a2f00;--warn-border:#8a7000;--error-bg:#3a1a18;--error-border:#b3261e;--bg:#121212;--surface:#1c1c1c}}*{box-sizing:border-box}body{color:var(--fg);background:var(--bg);margin:0;padding:2rem 1rem;font-family:system-ui,-apple-system,Hiragino Sans,Noto Sans JP,sans-serif;line-height:1.7}main{max-width:720px;margin:0 auto}h1{margin:0 0 .5rem;font-size:1.5rem}h2{margin:1.5rem 0 .5rem;font-size:1rem}.lead{color:var(--muted);margin-top:0}.hint{color:var(--muted);font-size:.85rem}.drop-zone{border:2px dashed var(--border);text-align:center;border-radius:8px;padding:2.5rem 1rem;transition:border-color .15s,background .15s}.drop-zone.dragover{border-color:var(--accent);background:var(--surface)}.drop-zone p{margin:.35rem 0}.button{border:1px solid var(--border);background:var(--surface);color:var(--fg);font:inherit;cursor:pointer;border-radius:6px;padding:.5rem 1.25rem;display:inline-block}.button.primary{background:var(--accent);border-color:var(--accent);color:#fff;font-weight:600}.button:disabled{opacity:.5;cursor:not-allowed}.summary{grid-template-columns:max-content 1fr;gap:.5rem 1rem;display:grid}.summary dt{color:var(--muted);font-size:.9rem}.summary dd{margin:0}.summary label{margin-right:1rem}.message{border-left:4px solid;border-radius:6px;margin:.5rem 0;padding:.75rem 1rem;font-size:.9rem}.message.warn{background:var(--warn-bg);border-color:var(--warn-border)}.message.error{background:var(--error-bg);border-color:var(--error-border)}.message.info{background:var(--surface);border-color:var(--border);color:var(--muted)}.message ul{margin:.5rem 0 0;padding-left:1.25rem}pre#preview{background:var(--surface);border:1px solid var(--border);white-space:pre;border-radius:6px;max-height:24rem;padding:1rem;font-family:ui-monospace,SF Mono,Menlo,Consolas,monospace;font-size:.85rem;overflow-x:auto}