body {
  margin: 0;
  min-height: 100vh;
  background: #050912;
  color: #f8fbff;
  font-family: "Space Grotesk", "Inter", system-ui, -apple-system, sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(1rem, 5vw, 3rem);
}

.shell {
  width: min(600px, 100%);
}

header h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3rem);
}

header p {
  margin-top: 0.3rem;
  color: #93a8c4;
}

.panel {
  margin-top: 1.5rem;
  background: radial-gradient(circle at top, rgba(36, 64, 118, 0.9), rgba(6, 12, 25, 0.98));
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 28px;
  padding: 2rem;
  box-shadow: 0 40px 60px rgba(2, 6, 23, 0.55);
}

label {
  display: block;
  margin-bottom: 0.8rem;
  font-weight: 600;
}

input,
select {
  width: 100%;
  border-radius: 18px;
  border: 1px solid rgba(148, 163, 184, 0.3);
  padding: 0.8rem 1rem;
  background: rgba(8, 12, 28, 0.8);
  color: #f8fbff;
  margin-top: 0.5rem;
}

.modes {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.modes label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 500;
}

button {
  width: 100%;
  border: none;
  border-radius: 20px;
  padding: 0.9rem;
  margin-top: 0.4rem;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  background: linear-gradient(135deg, #ff8a00, #fd1d1d);
  color: #050912;
}

.result {
  margin-top: 1.5rem;
  padding: 1.2rem;
  border-radius: 24px;
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.result .line {
  margin: 0.4rem 0;
}

.final {
  margin-top: 1rem;
  font-weight: 700;
  font-size: 1.1rem;
}