:root {
  color-scheme: dark;
  --bg-1: #10131d;
  --bg-2: #191f33;
  --card: rgba(255, 255, 255, 0.08);
  --card-strong: rgba(255, 255, 255, 0.14);
  --text: #f3f5ff;
  --muted: #b8bfd8;
  --accent: #7a9dff;
  --accent-strong: #ff7d7d;
  --surface-light-bg: #ffffff;
  --surface-light-text: #16203a;
  --surface-light-border: rgba(17, 25, 40, 0.14);
  --shadow: 0 18px 42px rgba(6, 11, 25, 0.24);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background:
    radial-gradient(circle at top, #263353 0%, var(--bg-1) 45%),
    linear-gradient(180deg, #0d111c 0%, #131a28 100%);
  color: var(--text);
  line-height: 1.5;
}

.page {
  max-width: 980px;
  margin: 0 auto;
  padding: 2rem 1rem 3rem;
  display: grid;
  gap: 1.5rem;
}

.hero { text-align: center; }
.hero h1 { margin: 0.2rem 0 0.4rem; font-size: clamp(2.2rem, 5vw, 3.4rem); }
.eyebrow { margin: 0; color: var(--muted); letter-spacing: 0.08em; text-transform: uppercase; font-size: 0.8rem; }
.subtitle { margin: 0 auto; max-width: 700px; color: var(--muted); }

.metronome,
.content-card,
.content-section {
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}

.metronome,
.content-section {
  border-radius: 1.25rem;
  padding: 1.25rem;
  display: grid;
  gap: 1rem;
}

.section-heading h2,
.content-section h2 {
  margin: 0 0 0.35rem;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
}

.section-heading p,
.content-section > p {
  margin: 0;
  color: var(--muted);
}

.visual-stage {
  position: relative;
  min-height: 170px;
  display: grid;
  justify-items: center;
  align-items: center;
  gap: 0.75rem;
  padding-top: 0.25rem;
}

.visual-element {
  grid-area: 1 / 1;
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease;
}

.pulse {
  width: 104px;
  height: 104px;
  border-radius: 50%;
  background: linear-gradient(160deg, var(--accent), #516ac5);
  box-shadow: 0 0 0 rgba(122, 157, 255, 0.5);
  transform: scale(0.96);
  transition: transform 100ms ease-out, box-shadow 120ms ease-out, background 120ms ease-out, opacity 180ms ease;
}

.number-display {
  font-size: clamp(4rem, 12vw, 6.2rem);
  font-weight: 800;
  letter-spacing: -0.06em;
  color: var(--accent);
  transform: scale(0.86);
  text-shadow: 0 0 24px rgba(122, 157, 255, 0.3);
  transition: transform 120ms ease, color 120ms ease, opacity 180ms ease;
}

.pendulum {
  width: min(280px, 80vw);
  height: 132px;
  position: relative;
  transform-origin: 50% 0;
}

.pendulum-arm {
  position: absolute;
  left: 50%;
  top: 4px;
  width: 4px;
  height: 92px;
  border-radius: 999px;
  background: linear-gradient(180deg, #ebefff, #7a9dff);
  transform-origin: top center;
  transform: translateX(-50%) rotate(var(--swing-angle, 0deg));
  transition: transform 140ms cubic-bezier(0.25, 0.8, 0.25, 1);
}

.pendulum-bob {
  position: absolute;
  left: 50%;
  top: 82px;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: linear-gradient(160deg, var(--accent), #516ac5);
  transform: translateX(calc(-50% + (var(--swing-offset, 0px))));
  transition: transform 140ms cubic-bezier(0.25, 0.8, 0.25, 1), background 120ms ease;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
}

.metronome[data-visual-mode="pulse"] .pulse,
.metronome[data-visual-mode="numbers"] .number-display,
.metronome[data-visual-mode="pendulum"] .pendulum {
  opacity: 1;
}

.pulse.active {
  transform: scale(1.08);
  box-shadow: 0 0 32px rgba(122, 157, 255, 0.6);
}

.pulse.accent,
.number-display.accent,
.pendulum.accent .pendulum-bob {
  background: linear-gradient(160deg, var(--accent-strong), #ff5d73);
  color: var(--accent-strong);
}

.number-display.active { transform: scale(1); }

.beat-label {
  grid-area: 2 / 1;
  margin: 0;
  color: var(--muted);
  font-weight: 600;
  text-align: center;
}

.beat-label.is-hidden { display: none; }

.toggle-btn {
  width: min(220px, 100%);
  justify-self: center;
  border: 0;
  border-radius: 999px;
  padding: 0.85rem 1rem;
  background: linear-gradient(135deg, #7a9dff, #5f7de0);
  color: #fff;
  font-weight: 700;
  cursor: pointer;
}

.beat-indicators {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.beat-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transition: transform 100ms ease, background 100ms ease;
}

.beat-dot.active { transform: scale(1.2); background: var(--accent); }
.beat-dot.accent { background: var(--accent-strong); }

.controls-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
}

.control-block {
  background: rgba(0, 0, 0, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 0.9rem;
  padding: 0.9rem;
  display: grid;
  gap: 0.65rem;
}

.signature-block { gap: 0.85rem; }

label,
legend { color: var(--muted); font-size: 0.95rem; }

fieldset { margin: 0; min-width: 0; }
legend { padding: 0; }
input, select, button { font: inherit; }

input[type="number"],
select {
  width: 100%;
  border-radius: 0.7rem;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  padding: 0.58rem 0.65rem;
}

input[type="range"] { width: 100%; }

.tempo-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.45rem;
}

.tap-row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.6rem;
  align-items: center;
}

.small-btn {
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  border-radius: 0.7rem;
  padding: 0.35rem 0.7rem;
  cursor: pointer;
}

.tap-btn { font-weight: 700; }

.signature-groups,
.content-grid,
.faq-list {
  display: grid;
  gap: 0.85rem;
}

.signature-group h3,
.content-card h3 {
  margin: 0;
  font-size: 1rem;
}

.signature-group h3 { color: var(--text); }

.signature-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(74px, 1fr));
  gap: 0.55rem;
  margin-top: 0.5rem;
}

.signature-option {
  position: relative;
  display: block;
  cursor: pointer;
}

.signature-option input {
  position: absolute;
  inset: 0;
  opacity: 0;
}

.signature-option span {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border-radius: 0.8rem;
  border: 1px solid var(--surface-light-border);
  background: var(--surface-light-bg);
  color: var(--surface-light-text);
  font-weight: 700;
  transition: transform 100ms ease, border-color 100ms ease, background 100ms ease, color 100ms ease;
}

.signature-option input:checked + span {
  background: linear-gradient(135deg, #7a9dff, #5f7de0);
  border-color: rgba(122, 157, 255, 0.75);
  color: #fff;
  transform: translateY(-1px);
}

.signature-option input:focus-visible + span,
.toggle-btn:focus-visible,
.small-btn:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 2px solid rgba(122, 157, 255, 0.95);
  outline-offset: 2px;
}

.toggle-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.toggle-row label {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.hint { margin: 0; color: var(--muted); font-size: 0.82rem; }
.wide-hint { flex-basis: 100%; }

.content-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.content-card {
  border-radius: 1rem;
  padding: 1rem;
}

.content-card p,
.steps-list {
  margin: 0.5rem 0 0;
  color: var(--muted);
}

.steps-list {
  padding-left: 1.25rem;
}

.steps-list li + li { margin-top: 0.55rem; }

.footer { text-align: center; color: var(--muted); }

@media (max-width: 820px) {
  .controls-grid,
  .content-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .metronome,
  .content-section {
    padding: 1rem;
  }

  .tap-row {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}