:root{--primary-color:#3b82f6;--accent-color:#10b981;--background:#fff;--surface:#f9fafb;--border:#e5e7eb;--text-primary:#111827;--text-secondary:#6b7280;--error:#ef4444;--shadow:#0000001a}*{box-sizing:border-box;margin:0;padding:0}body{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:var(--background);color:var(--text-primary);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif}#root{flex-direction:column;min-height:100vh;display:flex}.app-header{background-color:var(--primary-color);color:#fff;box-shadow:0 2px 4px var(--shadow);padding:1rem}.header-content{align-items:center;gap:1rem;max-width:800px;margin:0 auto;display:flex}.back-button{color:#fff;cursor:pointer;background:0 0;border:none;border-radius:4px;justify-content:center;align-items:center;padding:.25rem;font-size:1.5rem;transition:background-color .2s;display:flex}.back-button:hover{background-color:#ffffff1a}.header-title{font-size:1.25rem;font-weight:600}.app-content{flex:1;width:100%;max-width:800px;margin:0 auto;padding:1rem}.converter-container{flex-direction:column;gap:1.5rem;display:flex}.tabs{border-bottom:2px solid var(--border);gap:.5rem;display:flex}.tab-button{color:var(--text-secondary);cursor:pointer;background:0 0;border:none;border-bottom:2px solid #0000;margin-bottom:-2px;padding:.75rem 1.5rem;font-size:1rem;transition:all .2s}.tab-button:hover{color:var(--text-primary)}.tab-button.active{color:var(--primary-color);border-bottom-color:var(--primary-color);font-weight:600}.conversion-card{background-color:var(--surface);border:1px solid var(--border);box-shadow:0 1px 3px var(--shadow);border-radius:12px;padding:2rem}.conversion-form{flex-direction:column;gap:1.5rem;display:flex}.input-group{flex-direction:column;gap:.5rem;display:flex}.input-label{color:var(--text-secondary);font-size:.875rem;font-weight:500}.input-wrapper{align-items:center;gap:.5rem;display:flex}.unit-input{border:2px solid var(--border);border-radius:8px;outline:none;flex:1;padding:.75rem;font-size:1.125rem;transition:border-color .2s}.unit-input:focus{border-color:var(--primary-color)}.unit-input:disabled{background-color:var(--surface);color:var(--text-secondary)}.unit-label{background-color:var(--background);border:1px solid var(--border);text-align:center;min-width:80px;color:var(--text-primary);border-radius:8px;padding:.75rem;font-weight:500}.button-group{gap:.75rem;display:flex}.btn{cursor:pointer;border:none;border-radius:8px;flex:1;justify-content:center;align-items:center;gap:.5rem;padding:.75rem 1.5rem;font-size:1rem;font-weight:500;transition:all .2s;display:flex}.btn-primary{background-color:var(--primary-color);color:#fff}.btn-primary:hover{box-shadow:0 4px 6px var(--shadow);background-color:#2563eb;transform:translateY(-1px)}.btn-primary:active{transform:translateY(0)}.btn-secondary{background-color:var(--background);color:var(--text-primary);border:2px solid var(--border)}.btn-secondary:hover{background-color:var(--surface);border-color:var(--primary-color)}.swap-icon{font-size:1.25rem}@media (width<=640px){.app-content{padding:.75rem}.conversion-card{padding:1.5rem}.tabs{overflow-x:auto}.tab-button{flex-shrink:0;padding:.75rem 1rem;font-size:.875rem}.button-group{flex-direction:column}.unit-input{font-size:1rem}}