* {
   box-sizing: border-box;
   margin: 0;
   padding: 0;
}

body {
   font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
   display: flex;
   flex-direction: column;
   align-items: center;
   justify-content: center;
   min-height: 100vh;
   background: linear-gradient(135deg, #00D4FF 0%, #001014 100%);
}
nav {
   width: 3rem;
   height: 3rem;
   background: #001014;
   margin: 10px;
   border-radius: 100%;
   aspect-ratio: 1;
   display: flex;
   justify-content: center;
   align-items: center;
   color: white;
   font-size: 1.5rem;
   padding: 10px;
   position: fixed;
   top: 0;
   right: 0;
   z-index: 1000;
   transition: all 300ms;

   &:hover {
      background: #0ea5e9;
      /* color: #001014; */
   }
}

main {
   text-align: center;
   background: white;
   padding: 25px;
   border-radius: 16px;
   box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
   gap: 25px;
}

#display {
   font-size: 3rem;
   font-weight: bold;
   color: #333;
   display: flex;
   align-items: center;
   justify-content: center;
   background: #f8f9fa;
   border-radius: 8px;
}

#button {
   padding: 12px 24px;
   font-size: 1.1em;
   cursor: pointer;
   border-radius: 8px;
   outline: 0;
   border: none;
   color: white;
   transition: all 0.3s ease-in-out, transform 0.2s ease;
   box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
   background: linear-gradient(135deg, #00D4FF 0%, #00BFFF 100%);

   &:hover {
      transform: translateY(-2px);
      background: linear-gradient(135deg, #00BFFF 0%, #001014 100%);
   }
}

input[type="number"] {
   height: 2.5rem;
   color: black;
   background: #fbfdff;
   border-radius: 8px;
   padding: 10px;
   margin: 5px;
   border: 2px solid #00bfff33;
   /* text-align: center; */
   margin-bottom: 10px;
   font-size: 1em;
   outline: none;

   &:hover {
      border: 2px solid #00bfff65;
   }
}