:root{--primary: #d32f2f;--primary-dark: #b71c1c;--secondary: #1976d2;--secondary-dark: #1565c0;--background: #fafafa;--surface: #ffffff;--surface-dark: #f5f5f5;--text-primary: #212121;--text-secondary: #757575;--border: #e0e0e0;--success: #388e3c}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:var(--background);color:var(--text-primary)}.container{max-width:800px;margin:0 auto;padding:0 16px}.header{text-align:center;padding:48px 0 32px;border-bottom:2px solid var(--border)}.header h1{font-size:2.5rem;color:var(--primary);margin-bottom:8px;font-weight:700}.subtitle{font-size:1rem;color:var(--text-secondary);font-weight:300}.main{padding:32px 0}.calculator{background:var(--surface);border-radius:8px;padding:24px;box-shadow:0 2px 4px #0000001a}.section{margin-bottom:32px}.section h2{font-size:1.25rem;margin-bottom:16px;color:var(--text-primary);font-weight:600;border-bottom:1px solid var(--border);padding-bottom:8px}.button-group{display:flex;gap:12px;margin-bottom:16px}.btn{flex:1;padding:12px 16px;font-size:1rem;font-weight:500;border:2px solid var(--border);border-radius:4px;background:var(--surface);color:var(--text-primary);cursor:pointer;transition:all .3s ease}.btn:hover{border-color:var(--secondary);color:var(--secondary)}.btn-active{background:var(--primary);color:#fff;border-color:var(--primary)}.btn-active:hover{background:var(--primary-dark);border-color:var(--primary-dark)}.btn-primary{background:var(--secondary);color:#fff;border-color:var(--secondary);font-size:1.1rem;font-weight:600;padding:14px 24px}.btn-primary:hover{background:var(--secondary-dark);border-color:var(--secondary-dark)}.btn-secondary{background:var(--surface-dark);color:var(--text-primary);border-color:var(--border)}.btn-secondary:hover{background:var(--border)}.input-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px}.input-group{display:flex;flex-direction:column}.input-group label{font-size:.9rem;font-weight:500;margin-bottom:6px;color:var(--text-secondary)}.input-group input{padding:10px 12px;font-size:1rem;border:1px solid var(--border);border-radius:4px;background:var(--surface);color:var(--text-primary);transition:border-color .3s ease}.input-group input:focus{outline:none;border-color:var(--secondary);box-shadow:0 0 0 2px #1976d21a}.button-section{display:flex;gap:12px;justify-content:center}.button-section .btn{flex:0 1 auto;min-width:150px}.result-section{background:linear-gradient(135deg,#d32f2f0d,#1976d20d);border:2px solid var(--primary);border-radius:8px;padding:24px;margin-top:32px}.result-section h2{border-bottom-color:var(--primary);color:var(--primary)}.result-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:16px;margin-top:16px}.result-item{background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:16px;text-align:center}.result-label{display:block;font-size:.85rem;color:var(--text-secondary);margin-bottom:8px;font-weight:500}.result-value{display:block;font-size:1.75rem;font-weight:700;color:var(--primary);font-family:Courier New,monospace}.result-value.highlight{color:var(--success)}.footer{text-align:center;padding:32px 0 16px;color:var(--text-secondary);font-size:.85rem;border-top:2px solid var(--border);margin-top:48px}.footer p{margin-bottom:8px}.footer-version{font-size:.75rem;margin-top:16px}@media (max-width: 600px){.header h1{font-size:1.75rem}.subtitle{font-size:.9rem}.input-grid{grid-template-columns:1fr}.button-group,.button-section{flex-direction:column}.button-section .btn{width:100%}.result-grid{grid-template-columns:1fr}.calculator{padding:16px}}