:root{--color-primary:#0366d6;--color-primary-hover:#0256b9;--color-danger:#c0392b;--color-danger-strong:#b3261e;--color-success:#2c8a2c;--color-warning-bg:#fff8e6;--color-warning-border:#e6c34a;--color-warning-text:#7a5d00;--color-text:#222;--color-text-muted:#666;--color-text-subtle:#888;--color-border:#ccc;--color-border-light:#e0e0e0;--color-surface:#fff;--color-surface-alt:#f6f8fa;--radius-sm:3px;--radius-md:4px;--radius-lg:6px;--radius-xl:8px;--font-family-base:system-ui,sans-serif}body{font-family:var(--font-family-base);color:var(--color-text)}.btn-primary{padding:.45rem 1rem;background:var(--color-primary);color:#fff;border:none;border-radius:var(--radius-md);cursor:pointer;font-size:.9rem}.btn-primary:hover{background:var(--color-primary-hover)}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{display:inline-block;padding:.45rem 1rem;background:var(--color-surface);color:var(--color-text);border:1px solid var(--color-border);border-radius:var(--radius-md);cursor:pointer;font-size:.9rem;text-decoration:none}.btn-secondary:hover{background:var(--color-surface-alt)}.btn-secondary:disabled{opacity:.5;cursor:not-allowed}.badge{padding:.15rem .55rem;border-radius:var(--radius-sm);font-size:.78rem;background:#eee;color:#555;border:1px solid var(--color-border)}.badge.paid{background:#e3f6e3;color:#276927;border-color:#8c8}.badge.open{background:#fdecea;color:var(--color-danger-strong);border-color:#e8a09a}.badge.uncollectible,.badge.void{background:#eee;color:#777}.badge.preview{background:#eef4fd;color:#1a56a0;border-color:#a9c8ef}.alert{padding:.8rem 1rem;border-radius:var(--radius-lg);font-size:.9rem;margin:0 0 1rem}.alert.error{background:#fdecea;border:1px solid #e8a09a;color:var(--color-danger-strong)}.alert.processing{background:var(--color-warning-bg);border:1px solid var(--color-warning-border);color:var(--color-warning-text)}.alert.success{background:#e3f6e3;border:1px solid #8c8;color:#276927}