:root {
  color-scheme: dark;
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #0b1020;
  color: #edf1ff;
}

* { box-sizing: border-box; }
body { margin: 0; }
a { color: #8fd5f5; }
.stem-wrap { max-width: 1180px; margin: 0 auto; padding: 28px 24px 80px; }
.stem-header { display: flex; justify-content: space-between; align-items: center; gap: 24px; flex-wrap: wrap; }
.stem-brand { font-weight: 800; font-size: 1.3rem; color: #fff; text-decoration: none; }
.stem-language { display: flex; align-items: center; gap: 10px; }
.stem-language label { color: #b9c7df; font-size: .9rem; }
.stem-language select {
  min-width: 150px;
  padding: 9px 36px 9px 12px;
  border: 1px solid #52647f;
  border-radius: 12px;
  background: #141d32;
  color: #edf1ff;
  font: inherit;
  cursor: pointer;
}
.stem-hero { margin: 64px 0 36px; max-width: 780px; }
.stem-hero h1 { font-size: clamp(2rem, 5vw, 3.6rem); line-height: 1.13; letter-spacing: -.03em; margin: 16px 0; }
.stem-intro { font-size: 1.14rem; line-height: 1.7; color: #c7d3e8; }
.stem-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.stem-card, .stem-info { background: #141d32; border: 1px solid #32405b; border-radius: 22px; padding: 26px; }
.stem-step { color: #98e5cb; font-weight: 800; font-size: .85rem; }
.stem-card h2, .stem-info h2 { font-size: 1.25rem; margin: 12px 0; }
.stem-card p:not(.stem-step), .stem-info p { color: #c1cee3; line-height: 1.65; }
.stem-card audio { width: 100%; margin: 16px 0; }
.stem-download { display: inline-block; padding: 10px 14px; border-radius: 12px; background: #283d58; color: #d8f4ff; text-decoration: none; font-weight: 650; }
.stem-info { margin-top: 18px; }
.stem-limit { border-color: #6a5838; }
.stem-more { margin-top: 34px; }
.stem-more h2 { font-size: 1.45rem; }
.stem-tool-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.stem-tool { display: flex; flex-direction: column; gap: 10px; padding: 20px; border: 1px solid #32405b; border-radius: 16px; background: #141d32; text-decoration: none; }
.stem-tool strong { color: #8fd5f5; }
.stem-tool span { color: #c1cee3; line-height: 1.55; }
.stem-tool:hover { border-color: #8fd5f5; }
.stem-cta { display: inline-block; margin-top: 30px; border-radius: 12px; padding: 14px 22px; background: #98e5cb; color: #10222b; font-weight: 800; text-decoration: none; }
.stem-wrap a:focus-visible, .stem-language select:focus-visible { outline: 3px solid #fff; outline-offset: 3px; }

@media (max-width: 760px) {
  .stem-wrap { padding: 20px 16px 56px; }
  .stem-hero { margin: 42px 0 26px; }
  .stem-grid, .stem-tool-grid { grid-template-columns: 1fr; }
  .stem-card, .stem-info { padding: 22px; }
  .stem-header { gap: 12px; }
}