:root{--bg: #f3f3f1;--surface: #ffffff;--line: #c7c7c3;--line-strong: #7b7b76;--text: #151515;--muted: #575754;--focus: #2167b4}*{box-sizing:border-box;border-radius:0}body{margin:0;min-height:100vh;background:linear-gradient(180deg,#f8f8f7 0%,var(--bg) 100%);color:var(--text);font-family:IBM Plex Sans,Noto Sans JP,sans-serif;line-height:1.5}#root{min-height:100vh;display:grid;place-items:center;padding:24px}.panel{width:100%;max-width:640px;background:var(--surface);border:2px solid var(--line);box-shadow:0 1px #fff,0 0 0 1px #e7e7e5 inset}.page-shell{padding:24px}h1{margin:0 0 12px;font-size:1.5rem;font-weight:600;letter-spacing:.01em}p{margin:0;color:var(--muted)}.button{margin-top:20px;border:1px solid var(--line-strong);background:#f0f0ee;color:var(--text);padding:10px 14px;font:inherit;cursor:pointer}.button-primary{background:#e4ecf6;border-color:#5f7ea2}.button:focus-visible{outline:2px solid var(--focus);outline-offset:2px}@media(max-width:640px){#root{place-items:stretch;padding:0}.panel{max-width:none;min-height:100vh;border-left:0;border-right:0}.page-shell{padding:20px}}