*{margin:0;padding:0;box-sizing:border-box;font-family:Segoe UI}
body{background:#f4f6ff}
.header{background:linear-gradient(120deg,#5f2cff,#00c6ff);padding:15px;color:#fff}
.nav{display:flex;justify-content:space-between;align-items:center;width:90%;margin:auto}
nav a{color:#fff;margin-left:20px;text-decoration:none}
.hero{text-align:center;padding:120px 20px;color:#fff;background:linear-gradient(120deg,#5f2cff,#00c6ff)}
.btn{display:inline-block;margin-top:20px;background:#fff;color:#5f2cff;padding:12px 30px;border-radius:30px;text-decoration:none}
.container{width:90%;max-width:500px;margin:auto}
.calc-box{background:#fff;padding:40px;margin-top:80px;border-radius:15px;text-align:center;box-shadow:0 10px 25px rgba(0,0,0,.1)}
input,select,button{width:100%;padding:15px;margin:15px 0;border-radius:10px;border:1px solid #ddd}
button{background:#5f2cff;color:#fff;border:none;font-weight:bold;cursor:pointer}
.result{margin-top:20px;font-size:20px;font-weight:bold}