:root{--primary-color:#4caf50;--secondary-color:#2196f3;--background-color:#fff;--text-color:#333;--card-bg:#f5f5f5;--input-bg:#fff;--shadow-color:rgba(0,0,0,.1)}.dark-mode{--primary-color:#66bb6a;--secondary-color:#42a5f5;--background-color:#1a1a1a;--text-color:#fff;--card-bg:#2d2d2d;--input-bg:#3d3d3d;--shadow-color:rgba(0,0,0,.3)}*{margin:0;padding:0;box-sizing:border-box;transition:background-color .3s , color .3s}body{font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;background-color:var(--background-color);color:var(--text-color);line-height:1.6}.container{max-width:800px;margin:2rem auto;padding:0 1rem}h1{text-align:center;margin-bottom:2rem;color:var(--primary-color);font-size:2.5rem;text-shadow:2px 2px 4px var(--shadow-color)}.calculator{background-color:var(--card-bg);padding:2rem;border-radius:15px;box-shadow:0 8px 16px var(--shadow-color);margin-bottom:2rem}.input-group{margin-bottom:1.5rem}label{display:block;margin-bottom:.5rem;color:var(--text-color);font-weight:500}input,select{width:100%;padding:.8rem;border:2px solid var(--primary-color);border-radius:8px;background-color:var(--input-bg);color:var(--text-color);font-size:1rem;transition:all .3s ease}input:focus,select:focus{outline:none;box-shadow:0 0 0 3px rgba(76,175,80,.2)}.calculate-btn{width:100%;padding:1rem;background-color:var(--primary-color);color:#fff;border:none;border-radius:8px;font-size:1.1rem;cursor:pointer;transition:all .3s ease}.calculate-btn:hover{background-color:#45a049;transform:translateY(-2px)}.result{background-color:var(--card-bg);padding:2rem;border-radius:15px;box-shadow:0 8px 16px var(--shadow-color)}.result-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1.5rem;margin:2rem 0}.result-item{text-align:center;padding:1rem;background-color:var(--input-bg);border-radius:8px;box-shadow:0 4px 8px var(--shadow-color)}.result-item h3{color:var(--primary-color);margin-bottom:.5rem}.health-advice{margin-top:2rem;padding:1rem;background-color:var(--input-bg);border-radius:8px;box-shadow:0 4px 8px var(--shadow-color)}.reset-btn{display:block;width:100%;padding:1rem;background-color:var(--secondary-color);color:#fff;border:none;border-radius:8px;font-size:1.1rem;cursor:pointer;margin-top:1rem;transition:all .3s ease}.reset-btn:hover{background-color:#1976d2;transform:translateY(-2px)}.theme-switch{position:fixed;top:1rem;right:1rem}.theme-label{cursor:pointer;padding:.5rem;border-radius:50%;background-color:var(--card-bg);box-shadow:0 2px 4px var(--shadow-color)}#theme-toggle{display:none}.sun,.moon{font-size:1.5rem}.dark-mode .sun{display:none}.light-mode .moon{display:none}@media (max-width:600px){.container{margin:1rem auto}.result-grid{grid-template-columns:1fr}h1{font-size:2rem}}