:root {
  --bg: #f0f0f0;
  --card: #fff;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
  --fg: #333;
  --btn-bg: #007bff;
  --btn-fg: #fff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--fg);
  display: flex;
  flex-direction: column;
  align-items: center;
}
header {
  width: 100%;
  background: var(--card);
  box-shadow: var(--shadow);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
header h1 { margin: 0; font-size: 1.5rem; }
header select {
  padding: .5rem;
  font-size: 1rem;
}
.container {
  width: 100%;
  max-width: 900px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.card {
  background: var(--card);
  border-radius: 10px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
}
.fields div {
  margin-bottom: .75rem;
}
.audio-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-top: 1rem;
}
.audio-buttons button {
  flex: 1 1 calc(20% - .5rem);
  padding: .6rem;
  background: var(--btn-bg);
  color: var(--btn-fg);
  border: none;
  border-radius: 5px;
  cursor: pointer;
  text-align: center;
}
.audio-buttons button:active {
  transform: scale(.97);
}
@media (min-width: 600px) {
  header h1 { font-size: 2rem; }
  .fields {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
  .audio-buttons button { flex: 1; }
}