:root{--bg:#0f1724;--card:#ffffff;--accent:#ffd93d}
*{box-sizing:border-box}
body{margin:0;font-family:Arial, Helvetica, sans-serif;background:linear-gradient(135deg,#0b1220,#102238);color:#fff;min-height:100vh;display:flex;flex-direction:column;align-items:center;padding:24px}
.header{max-width:900px;width:100%;display:flex;align-items:center;gap:16px;margin-bottom:20px}
.brand{width:64px;height:64px;border-radius:8px;background:var(--accent);display:flex;align-items:center;justify-content:center;color:#011; font-weight:700}
.calc-wrap{background:rgba(255,255,255,0.03);padding:20px;border-radius:10px;max-width:480px;width:100%}
.calc-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:12px}
.calc-btn{padding:16px;border-radius:8px;border:none;background:rgba(255,255,255,0.04);color:inherit;font-weight:700;cursor:pointer}
#calc-display{width:100%;padding:12px;border-radius:8px;border:none;background:rgba(0,0,0,0.12);color:inherit;font-size:1.2rem}
.back{margin-top:12px;display:inline-block;text-decoration:none;color:#ffd93d}
/* Fade in */
body{opacity:0;transition:opacity .35s ease-in}
body.page-loaded{opacity:1}