.app{width:100%;min-height:100vh;background:#f5f7fa}.calculator-nav{background:#fff;border-bottom:1px solid #e5e7eb;padding:1rem 0;position:sticky;top:0;z-index:100}.nav-container{max-width:1400px;margin:0 auto;padding:0 1rem;display:flex;justify-content:space-between;align-items:center;gap:2rem}.nav-title{font-size:1.5rem;font-weight:700;color:#1f2937;margin:0;white-space:nowrap}.nav-buttons{display:flex;gap:.5rem}.nav-btn{padding:.75rem 1.5rem;background:transparent;border:2px solid transparent;border-radius:6px;color:#6b7280;font-weight:600;cursor:pointer;transition:all .2s;font-size:.875rem;white-space:nowrap}.nav-btn:hover{color:#1f2937;background:#f3f4f6}.nav-btn:focus-visible{outline:2px solid #3b82f6;outline-offset:2px}.nav-btn.active{color:#3b82f6;border-color:#3b82f6;background:#eff6ff}.nav-btn.active:focus-visible{outline:2px solid #3b82f6;outline-offset:2px}.calculator-main{max-width:1400px;margin:0 auto;padding:2rem 1rem}@media(max-width:768px){.nav-container{flex-direction:column;align-items:flex-start;gap:1rem}.nav-buttons{width:100%}.nav-btn{flex:1;padding:.5rem 1rem}.nav-title{font-size:1.25rem}}