:root{--accent: #2563eb;--accent-dark: #1d4ed8;--bg: #f8fafc;--panel: #ffffff;--text: #1e293b;--muted: #64748b;--border: #e2e8f0}*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Hiragino Sans,Noto Sans JP,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}.site-header{display:flex;align-items:center;gap:1.5rem;padding:.6rem 1.2rem;background:var(--panel);border-bottom:1px solid var(--border)}.brand{font-size:1.25rem;font-weight:700;color:var(--accent);text-decoration:none}.tabs{display:flex;gap:.5rem}.tabs a{padding:.35rem .6rem;border-bottom:2px solid transparent;color:var(--muted);text-decoration:none}.tabs a:hover{color:var(--text)}.tabs a.active{color:var(--accent);border-bottom-color:var(--accent);font-weight:600}main{max-width:1100px;margin:0 auto;padding:1.2rem}.columns{display:grid;grid-template-columns:1fr 1fr;gap:2rem}@media(max-width:768px){.columns{grid-template-columns:1fr}}.field{margin-bottom:1rem}.field-label{font-size:.9rem;font-weight:600;color:var(--muted);margin:0 0 .4rem}.settings h2,#tab-about h2{font-size:1.1rem;margin:0 0 .8rem}.input{width:100%;padding:.5rem .7rem;border:1px solid var(--border);border-radius:8px;font:inherit;background:var(--panel);color:inherit}textarea.input{resize:vertical}.input:focus{outline:2px solid var(--accent);outline-offset:-1px}.btn{padding:.45rem 1rem;border:1px solid var(--border);border-radius:8px;background:var(--panel);color:var(--text);font:inherit;cursor:pointer}.btn:hover{border-color:var(--accent)}.btn.active,.btn-primary{background:var(--accent);border-color:var(--accent);color:#fff}.btn-primary:hover:not(:disabled){background:var(--accent-dark)}.btn:disabled{opacity:.55;cursor:not-allowed}.btn-group-wrap{display:flex;flex-wrap:wrap;gap:.4rem}.btn-group{display:inline-flex;border:1px solid var(--border);border-radius:8px;overflow:hidden}.btn-group .btn{border:none;border-radius:0;padding:.3rem .9rem;font-size:.9rem;background:transparent}.btn-group .btn+.btn{border-left:1px solid var(--border)}.btn-group .btn.active{background:var(--accent);color:#fff}.convert-row{display:flex;align-items:center;gap:.8rem}#btn-convert{min-width:11rem;padding:.65rem 1.5rem;font-size:1.05rem;font-weight:700;letter-spacing:.05em;border-radius:10px;box-shadow:0 2px 8px #2563eb4d}.progress{display:inline-flex;align-items:center;gap:.5rem;color:var(--muted)}.progress[hidden]{display:none}.spinner{width:1rem;height:1rem;border:2px solid var(--border);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.param-grid{display:grid;grid-template-columns:1fr 1fr;gap:.8rem}.param-item .field-label{margin-bottom:.3rem}dialog{width:min(90vw,640px);border:1px solid var(--border);border-radius:12px;padding:1.2rem}dialog::backdrop{background:#0006}dialog h2{margin-top:0;font-size:1.1rem}.dialog-buttons{display:flex;justify-content:flex-end;gap:.6rem;margin-top:.8rem}@media(prefers-color-scheme:dark){:root{--bg: #0f172a;--panel: #1e293b;--text: #e2e8f0;--muted: #94a3b8;--border: #334155}}