:root{--primary-color:#3b82f6;--secondary-color:#60a5fa;--background-color:#f0f9ff;--text-color:#1f2937;--white:#fff;--card-shadow:0 10px 20px rgba(0,0,0,.1);--hover-shadow:0 15px 30px rgba(59,130,246,.2)}html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;margin:0;padding:0;background:linear-gradient(135deg,var(--background-color),#e0f2fe);color:var(--text-color);line-height:1.6;min-height:100vh}.calculator-container{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;padding:20px;animation:fadeIn .5s ease-out}.question-card{background-color:var(--white);border-radius:16px;box-shadow:var(--card-shadow);padding:clamp(20px,5vw,40px);width:min(90%,500px);text-align:center;transform:translateY(0);transition:all .3s cubic-bezier(.4,0,.2,1);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid hsla(0,0%,100%,.2)}.question-card:hover{transform:translateY(-5px);box-shadow:var(--hover-shadow)}.answer-buttons{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));grid-gap:15px;gap:15px;margin-top:20px}.answer-button{padding:12px 20px;border:2px solid var(--primary-color);background-color:transparent;color:var(--primary-color);border-radius:12px;cursor:pointer;transition:all .3s ease;font-weight:600;position:relative;overflow:hidden}.answer-button:before{display:none}.answer-button:hover{color:var(--primary-color);transform:none}.result-card{background:linear-gradient(135deg,var(--primary-color),var(--secondary-color));color:var(--white);border-radius:16px;padding:clamp(20px,5vw,40px);text-align:center;width:min(90%,400px);box-shadow:var(--card-shadow);animation:slideUp .5s ease-out}.result-actions{display:flex;flex-wrap:wrap;justify-content:center;gap:15px;margin-top:20px}.btn{padding:12px 24px;border:none;border-radius:12px;cursor:pointer;transition:all .3s ease;font-weight:600;transform:translateY(0)}.btn:hover{transform:translateY(-2px)}.btn-download{background-color:var(--white);color:var(--primary-color)}.btn-restart{background-color:hsla(0,0%,100%,.2);color:var(--white);-webkit-backdrop-filter:blur(5px);backdrop-filter:blur(5px)}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@media (max-width:768px){.answer-buttons{grid-template-columns:1fr}.result-actions{flex-direction:column}.btn{width:100%}}@media (prefers-color-scheme:dark){:root{--background-color:#1a1a1a;--text-color:#fff;--white:#2a2a2a}}.footer{text-align:center;margin-top:20px;padding:10px 0;font-size:14px;color:#666;border-top:1px solid #ddd}.footer a{color:#007bff;text-decoration:none;font-weight:700}.footer a:hover{text-decoration:underline}