:root {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #18212f;
  background: #f4f6f8;
}
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; background: #f4f6f8; }
.shell { width: min(100%, 760px); margin: 0 auto; padding: 18px 14px 40px; }
.card {
  background: white;
  border-radius: 18px;
  padding: 30px 26px;
  box-shadow: 0 8px 30px rgba(0,0,0,.08);
  min-height: 560px;
}
.progress {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  margin: 6px 4px 18px;
}
.progress span {
  height: 7px;
  border-radius: 999px;
  background: #dfe4ea;
}
.progress span.active { background: #34495e; }
.progress span.done { background: #7f8c8d; }
h1 { font-size: 34px; margin: 0 0 14px; line-height: 1.25; }
h2 { font-size: 28px; margin: 0 0 16px; line-height: 1.3; }
h3 { margin-top: 22px; font-size: 21px; }
p, li { line-height: 1.7; font-size: 18px; }
.lead { font-size: 19px; color: #304055; margin-top: 2px; }
.zh-help { color: #4b5a6c; font-size: 16px; }
.big { font-size: 42px; font-weight: 800; text-align: center; margin: 24px 0; }
.question { font-size: 29px; line-height: 1.45; font-weight: 800; margin: 28px 0; }
.status { text-align: center; font-size: 22px; font-weight: 900; letter-spacing: .02em; margin: 18px 0 6px; }
.status.listen { color: #2c3e50; }
.status.ready { color: #8a6d1d; }
.status.record { color: #b42318; }
.status.saved { color: #237a43; }
.timer { font-size: 62px; font-variant-numeric: tabular-nums; font-weight: 900; text-align: center; margin: 10px 0 20px; }
button {
  width: 100%;
  border: 0;
  border-radius: 14px;
  padding: 16px 18px;
  font-size: 20px;
  font-weight: 800;
  cursor: pointer;
  background: #18212f;
  color: white;
  margin-top: 14px;
}
button.secondary { background: #eef1f4; color: #18212f; }
button:disabled { opacity: .45; cursor: not-allowed; }
input[type="text"] {
  width: 100%;
  padding: 15px 16px;
  font-size: 20px;
  border: 1px solid #ccd3db;
  border-radius: 12px;
  margin: 10px 0 4px;
}
.notice { padding: 16px 18px; border-radius: 14px; background: #f7f8fa; margin: 16px 0; border-left: 5px solid #d8dee6; }
.notice.highlight { background: #fff7db; border-left-color: #f0b429; }
.notice.warning { background: #fff1f1; border-left-color: #d64545; }
.keyline { font-size: 20px; margin: 8px 0; }
.emphasis { color: #8b1e1e; font-weight: 900; }
.quote { font-size: 22px; font-weight: 800; text-align: center; margin: 12px 0 6px; }
.compact-list { margin: 8px 0 0 0; padding-left: 22px; }
.checkline { display: flex; gap: 10px; align-items: flex-start; margin-top: 18px; }
.checkline input { margin-top: 6px; transform: scale(1.25); }
.product-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0; }
.product-grid div { background: #f6f7f9; border-radius: 12px; padding: 14px; font-size: 17px; }
.points { padding-left: 22px; }
.points li { margin-bottom: 10px; }
.mic-meter { height: 18px; border-radius: 999px; background: #edf0f3; overflow: hidden; margin: 16px 0; }
.mic-meter > div { height: 100%; width: 0%; background: currentColor; transition: width .08s linear; }
audio { width: 100%; margin-top: 12px; }
.small { font-size: 14px; color: #6c7785; }
.prototype { font-size: 12px; text-align:center; color:#7a8490; margin-top:20px; }
@media (max-width: 520px) {
  .shell { padding: 10px 8px 24px; }
  .card { min-height: calc(100vh - 30px); border-radius: 14px; padding: 24px 18px; }
  h1 { font-size: 31px; }
  h2 { font-size: 26px; }
  p, li { font-size: 17px; }
  .lead, .keyline { font-size: 18px; }
  .question { font-size: 24px; }
  .timer { font-size: 56px; }
  button { font-size: 19px; }
  .product-grid { grid-template-columns: 1fr; }
}
.form-error {
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: 10px;
  background: #fff1f1;
  border-left: 5px solid #d64545;
  color: #8b1e1e;
  font-size: 16px;
  font-weight: 700;
}
.practice-flow { text-align: center; }
.practice-flow p { font-size: 21px; margin: 6px 0; }
.short-note { color: #4b5a6c; font-size: 16px; margin-top: -2px; }
.save-state { font-weight: 800; }
.save-state.ok { color: #237a43; }
.save-state.pending { color: #8a6d1d; }