:root{--bg: #eef2ff;--surface: #ffffff;--border: #e2e8f0;--text: #0f172a;--muted: #64748b;--primary: #2563eb;--primary-hover: #1d4ed8;--shadow-card: 0 2px 12px rgba(15, 23, 42, .06)}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Sukhumvit Set,IBM Plex Sans Thai,Roboto,sans-serif;background:var(--bg);color:var(--text);font-size:14px}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}.page{display:flex;align-items:center;justify-content:center;min-height:100%;padding:24px}.shell-card{background:var(--surface);border:1px solid var(--border);border-radius:16px;box-shadow:var(--shadow-card);padding:40px 48px;text-align:center;max-width:420px}.shell-card h1{margin:16px 0 8px;font-size:24px}.shell-card .sub{margin:0;color:var(--muted)}.brand-mark{width:48px;height:48px;margin:0 auto;border-radius:12px;background:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;letter-spacing:.5px}