*{
  box-sizing: border-box;
}

body{
  margin:0;
  min-height:100vh;
  display:flex;
  justify-content:center;
  align-items:center;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  font-family: -apple-system, BlinkMacSystemFont,
               "SF Pro Display", "Segoe UI", Roboto, Arial;
  color : white;
}

/* Main Card */
.box{
  width:700px;
  padding:18px;
  border-radius:18px;

  background: rgba(255,255,255,0.12);
  backdrop-filter: blur(18px) saturate(180%);
  -webkit-backdrop-filter: blur(18px) saturate(180%);

  box-shadow:
    0 20px 40px rgba(0,0,0,0.35),
    inset 0 0 0 1px rgba(255,255,255,0.15);
}

/* Heading */
h2{
  text-align:center;
  margin:5px 0 15px;
  font-size:45px;
  font-weight:600;
  letter-spacing:0.8px;
}

/* Inputs */
input, select{
  width:100%;
  margin:7px 0;
  padding:10px 12px;
  border-radius:12px;
  border:none;
  outline:none;

  background: white;
  color: black;
  font-size:25px;
}

input::placeholder{
  color: black;
}

/* Range slider */
input[type="range"]{
  padding:0;
}

/* Canvas */
canvas{
  width:100%;
  margin-top:12px;
  border-radius:14px;
  background: rgba(255, 255, 255, 0.308);
}

/* Button – Apple style */
button{
  width:100%;
  margin-top:14px;
  padding:12px;
  border-radius:20px;
  border:none;

  background: linear-gradient(180deg, white, white);
  color : black;
  font-size:35px;
  font-weight:500;
  cursor:pointer;

  box-shadow: 0 8px 20px rgba(0,0,0,0.35);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

button:hover{
  transform: scale(1.03);
  box-shadow: 0 12px 28px rgba(0,0,0,0.45);
}