/* Reset & base layout */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  background: #0f172a;  /* deep navy */
  color: #e5e7eb;       /* soft gray */
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  padding: 40px 16px;
}

/* App container */
.container {
  background: #020617;     /* near-black panel */
  border: 1px solid #1f2937;
  border-radius: 16px;
  padding: 28px 32px;
  max-width: 720px;
  width: 100%;
  box-shadow: 0 30px 60px rgba(0,0,0,.45);
}

/* Headings */
h1 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 26px;
  text-align: center;
}

.subtitle {
  margin-top: 0;
  margin-bottom: 20px;
  font-size: 14px;
  color: #9ca3af;
  text-align: center;
}

.subtitle2 {
  margin-top: 0;
  margin-bottom: 0px;
  font-size: 10px;
  color: #9ca3af;
  text-align: center;
}

/* Form layout */
form {
  display:grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 12px;
  align-items: center;
}

label {
  font-size: 20px;
  color: #9ca3af;
  text-align: center;
  font-weight: bold;
}

input, select {
  width: 100%;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid #374151;
  background: #020617;
  color: #e5e7eb;
  font-size: 16px;
  text-align: center;
}

/* Full-width rows */
.full {
  grid-column: 1 / -1;
}

/* Button */
button {
  margin-top: 12px;
  padding: 10px 14px;
  border-radius: 12px;
  border: none;
  background: #2563eb;
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: transform .3s, background .3s;
    font-size: 16px
}

button:hover {
  background: #1d4ed8;
  transform: translateY(-4px);

}

#result {
  margin-top: 18px;
  font-size: 38px;
  text-align: center;
}

@media (max-width: 700px) {
  body {
    padding: 24px 12px;
  }

  .container {
    padding: 20px 16px;
  }

  h1 {
    font-size: 22px;
  }

  form {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  label {
    font-size: 16px;
  }

  input,
  select,
  button {
    font-size: 15px;
  }

  #result {
    font-size: 28px;
  }
}