:root{--bg:#f5f4f0;--surface:#fff;--text:#222;--muted:#6b6b6b;--border:#dedcd6;--accent:#5b4b8a;--danger:#b3261e;color:var(--text);background:var(--bg);font-family:system-ui,-apple-system,Segoe UI,Roboto,Hiragino Sans,Noto Sans JP,sans-serif}*{box-sizing:border-box}body{min-height:100vh;margin:0}a{color:var(--accent)}h1{margin:0 0 1rem;font-size:1.25rem}.centered{place-items:center;min-height:100vh;padding:1rem;display:grid}.card{background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:1.5rem}.login-form{gap:1rem;width:min(100%,24rem);display:grid}.login-form label{gap:.25rem;font-size:.875rem;display:grid}input{font:inherit;border:1px solid var(--border);border-radius:6px;padding:.5rem .625rem}button{font:inherit;background:var(--accent);color:#fff;cursor:pointer;border:0;border-radius:6px;padding:.5rem 1rem}button:disabled{opacity:.6;cursor:default}.link-button{color:var(--accent);background:0 0;padding:0;text-decoration:underline}.error{color:var(--danger);margin:0}.muted{color:var(--muted)}.shell{grid-template-rows:auto 1fr;min-height:100vh;display:grid}.topbar{background:var(--surface);border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;gap:1rem;padding:.75rem 1rem;display:flex}.nav{gap:1rem;display:flex}.nav a{color:var(--muted);text-decoration:none}.nav a[data-status=active]{color:var(--text);font-weight:600}.session{align-items:center;gap:.75rem;font-size:.875rem;display:flex}.content{width:100%;max-width:64rem;margin:0 auto;padding:1.5rem 1rem}