:root {
  color-scheme: light;
  --bg: #f6f3ee;
  --panel: #fffdf8;
  --ink: #1e293b;
  --muted: #64748b;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --border: #e2e8f0;
  --shadow: 0 24px 60px rgba(15, 23, 42, 0.14);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top left, #e0f2fe 0, transparent 28rem), var(--bg);
  color: var(--ink);
}
.app {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}
header, footer {
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
header { border-bottom: 1px solid rgba(226, 232, 240, 0.8); }
.brand { font-weight: 700; letter-spacing: .01em; }
.meta { color: var(--muted); font-size: .95rem; }
main {
  padding: 1.25rem;
  display: grid;
  place-items: center;
}
.slide {
  width: min(calc(100vw - 2.5rem), calc((100vh - 11rem) * 16 / 9));
  aspect-ratio: 16 / 9;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 24px;
  box-shadow: var(--shadow);
  padding: clamp(1.1rem, 3vw, 3.2rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
  max-height: 100%;
}
.slide-id { color: var(--accent); font-weight: 700; margin-bottom: .5rem; font-size: clamp(1rem, 1.5vw, 1.35rem); }
h1 {
  font-size: clamp(1.8rem, 3.8vw, 4.2rem);
  line-height: 1.04;
  margin: 0 0 1.15rem;
  max-width: 18ch;
}
ul, ol {
  font-size: clamp(1.05rem, 1.9vw, 1.9rem);
  line-height: 1.22;
  padding-left: 1.25em;
  margin: 0;
  max-width: 42ch;
}
li { margin: .52rem 0; }
.step { opacity: 1; transform: none; }
.visual {
  margin-top: 1.4rem;
  border: 2px dashed #bfdbfe;
  background: #eff6ff;
  color: #1e40af;
  border-radius: 18px;
  padding: .85rem 1rem;
  font-size: clamp(.82rem, 1.05vw, 1.05rem);
  max-width: 68rem;
}
.controls { display: flex; gap: .6rem; align-items: center; flex-wrap: wrap; }
button {
  border: 0;
  border-radius: 999px;
  padding: .75rem 1rem;
  background: var(--ink);
  color: white;
  font-weight: 700;
  cursor: pointer;
}
button.secondary { background: var(--accent-soft); color: #1d4ed8; }
button.playing { background: #16a34a; }
button:disabled { opacity: .4; cursor: not-allowed; }
.progress { color: var(--muted); }
audio { display: none; }
@media (max-width: 760px) {
  header, footer { align-items: flex-start; flex-direction: column; }
  main { padding: .75rem; }
  .slide {
    width: min(calc(100vw - 1.5rem), calc((100vh - 13rem) * 16 / 9));
    border-radius: 18px;
  }
}