:root {
  --background: #f6f8fa;
  --primary: #1a2238;
  --secondary: #9daaf2;
  --accent: #ff6a3d;
  --success: #4ad991;
  --danger: #ff4e4e;
  --white: #fff;
  --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
}

body {
  font-family: 'Segoe UI', 'Lato', Helvetica, Arial, sans-serif;
  font-size: 18px;
  background: linear-gradient(135deg, var(--secondary) 0%, var(--background) 100%);
  color: var(--primary);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

main {
  padding: 20px;
}

h1 {
  text-align: center;
  color: var(--accent);
  letter-spacing: 2px;
  font-weight: 800;
  margin-bottom: 24px;
}

.container {
  width: 95%;
  max-width: 480px;
  background: var(--white);
  padding: 32px 28px;
  border-radius: 18px;
  box-shadow: var(--shadow);
  color: var(--primary);
  transition: box-shadow 0.3s;
}

.container:hover {
  box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.22);
}

label,
legend {
  font-weight: 600;
  color: var(--primary);
}

.input-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

button {
  cursor: pointer;
  background: linear-gradient(90deg, var(--accent) 60%, var(--secondary) 100%);
  color: var(--white);
  border: none;
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 1rem;
  font-weight: 600;
  margin-right: 8px;
  box-shadow: 0 2px 8px rgba(255, 106, 61, 0.08);
  transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
}

button:hover, button:focus {
  background: linear-gradient(90deg, var(--secondary) 0%, var(--accent) 100%);
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 4px 16px rgba(255, 106, 61, 0.18);
  outline: none;
}

input,
select {
  padding: 10px;
  border: 1.5px solid var(--secondary);
  border-radius: 6px;
  font-size: 1rem;
  margin-bottom: 10px;
  background: var(--background);
  color: var(--primary);
  transition: border 0.2s;
}

input:focus,
select:focus {
  border: 1.5px solid var(--accent);
  outline: none;
}

fieldset {
  margin-bottom: 22px;
  padding: 18px;
  border: 1.5px solid var(--secondary);
  border-radius: 10px;
  background: rgba(157, 170, 242, 0.06);
}

.output {
  border: 2px solid var(--primary);
  padding: 24px 16px;
  margin-top: 24px;
  text-align: center;
  background: var(--background);
  color: var(--primary);
  border-radius: 12px;
  box-shadow: 0 2px 12px rgba(26, 34, 56, 0.07);
  transition: box-shadow 0.2s;
}

.hide {
  display: none;
}

.output span {
  font-weight: bold;
  font-size: 1.5em;
  letter-spacing: 1px;
}

.surplus {
  color: var(--danger);
}

.deficit {
  color: var(--success);
}

@media (max-width: 600px) {
  .container {
    padding: 16px 6px;
    max-width: 98vw;
  }
  input,
  select,
  button {
    font-size: 16px;
  }
}