:root{--font-sans:"Inter", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;--color-bg:#fafafa;--color-text:#1e293b;--color-accent:#3b5b73;--color-border:#e2e8f0;--color-danger:#b91c1c}*{box-sizing:border-box}body{font-family:var(--font-sans);background:var(--color-bg);color:var(--color-text);margin:0}input,button{font-family:inherit;font-size:1rem}.auth-shell{border:1px solid var(--color-border);background:#fff;border-radius:8px;max-width:380px;margin:10vh auto;padding:2rem}.field{flex-direction:column;gap:.25rem;margin-bottom:1rem;display:flex}.field input{border:1px solid var(--color-border);border-radius:6px;padding:.5rem .75rem}.btn-primary{background:var(--color-accent);color:#fff;cursor:pointer;border:none;border-radius:6px;width:100%;padding:.6rem}.btn-primary:disabled{opacity:.6;cursor:not-allowed}.error-text{color:var(--color-danger);font-size:.875rem}