*{box-sizing:border-box}body{margin:0;font-family:Segoe UI,Hiragino Sans,Meiryo,sans-serif;background:#f5f6f8;color:#1a1a2e}.app{display:flex;flex-direction:column;height:100vh}.header{display:flex;align-items:center;gap:16px;padding:8px 16px;background:#1a1a2e;color:#fff}.header h1{font-size:18px;margin:0}.header nav button{margin-right:8px;padding:6px 12px;border:none;border-radius:4px;background:transparent;color:#cbd5e1;cursor:pointer}.header nav button.active{background:#3b3b5c;color:#fff}.signin{margin-left:auto}.signin input{padding:6px 8px;border:none;border-radius:4px;min-width:220px}.auth-buttons{display:flex;gap:8px}.btn-login{padding:6px 16px;border:2px solid #818cf8;border-radius:999px;background:transparent;color:#c7d2fe;font-weight:600;cursor:pointer}.btn-login:hover{background:#818cf826}.btn-signup{padding:6px 16px;border:none;border-radius:999px;background:#4f46e5;color:#fff;font-weight:600;cursor:pointer}.btn-signup:hover{background:#6159ea}main{flex:1;overflow:hidden;display:flex;flex-direction:column}.auth-page{flex:1;display:grid;place-content:center;padding:24px 12px;overflow-y:auto}.auth-card{background:#fff;border:1px solid #ddd;border-radius:12px;padding:32px 36px;width:360px;max-width:100%;text-align:center;box-shadow:0 8px 24px #1a1a2e14}.auth-card h2{margin:0 0 20px}.btn-provider{display:flex;align-items:center;justify-content:center;gap:10px;width:100%;padding:10px 16px;margin-bottom:10px;border:2px solid #dadce0;border-radius:6px;background:#fff;color:#1a1a2e;font-size:14px;font-weight:600;cursor:pointer}.btn-provider:hover{background:#f8f9fa}.auth-notice{color:#b45309;background:#fef3c7;border-radius:6px;padding:8px;margin:12px 0 0}.auth-terms{color:#666;font-size:12px;margin:16px 0 0}.auth-switch{margin:16px 0 0;font-size:13px;color:#444}.auth-link{border:none;background:none;color:#4f46e5;font-weight:600;cursor:pointer;text-decoration:underline;padding:0 4px}.chat{display:flex;flex-direction:column;height:100%;max-width:900px;width:100%;margin:0 auto;padding:12px}.toolbar{display:flex;gap:12px;align-items:center;margin-bottom:8px}.log{flex:1;overflow-y:auto;background:#fff;border:1px solid #ddd;border-radius:6px;padding:12px}.msg{margin-bottom:12px}.msg .role{font-size:12px;font-weight:700;color:#666}.msg .content{white-space:pre-wrap;line-height:1.6}.msg.user .content{background:#eef2ff;border-radius:6px;padding:8px}.composer{display:flex;gap:8px;margin-top:8px}.composer textarea{flex:1;min-height:64px;padding:8px;border:1px solid #ccc;border-radius:6px;resize:vertical}.composer button,.toolbar button{padding:8px 16px;border:none;border-radius:6px;background:#4f46e5;color:#fff;cursor:pointer}.error{color:#b91c1c;margin:8px 0}.download{max-width:700px;margin:0 auto;padding:24px 12px}.app-card{background:#fff;border:1px solid #ddd;border-radius:6px;padding:16px;margin-top:12px}.app-card button{padding:8px 16px;border:none;border-radius:6px;background:#4f46e5;color:#fff;cursor:pointer}