The goal of this clinical trial is to learn if adding intermittent hypoxic training (IHT) to standard neoadjuvant chemo-immunotherapy can increase the pathologic complete response (pCR) rate in patients aged 18 to 75 of both sexes with resectable stage II-IIIA lung squamous cell carcinoma. The main questions it aims to answer are:Can the addition of IHT to standard neoadjuvant chemo-immunotherapy significantly improve the pathologic complete response (pCR) rate compared to standard therapy alone? Is IHT safe and well-tolerated in this perioperative setting, and can it improve 2-year recurrence-free survival (RFS) without increasing complications? Researchers will compare the experimental group (standard neoadjuvant chemo-immunotherapy combined with IHT) to the control group (standard neoadjuvant chemo-immunotherapy alone) to see if the combination safely enhances anti-tumor immune responses, improves tumor regression, and extends long-term survival. Participants will:Receive standard neoadjuvant chemo-immunotherapy for 4 cycles (21 days per cycle), consisting of nab-paclitaxel, carboplatin, and pembrolizumab. Undergo Intermittent Hypoxic Training (IHT) if randomized to the experimental group, using the FLY-2265 low oxygen system (13% $FiO\_2$ for 5 minutes followed by 21% $FiO\_2$ for 5 minutes per cycle; 10 cycles per session, twice daily) for 7 consecutive days starting on Day 1 of each chemo-immunotherapy cycle. Undergo surgery (VATS lobectomy and systematic lymph node dissection) 3 to 4 weeks after the completion of the 4th cycle, provided that the disease has not progressed. Complete regular post-operative follow-up visits (including chest CT scans, brain MRIs, bone scans, tumor markers, and peripheral blood immune monitoring) for up to 5 years to evaluate long-term outcomes.