:root {
  /* Esquema Material 3 derivado de la semilla púrpura #6750A4 */
  --m3-primary: #6750a4;
  --m3-on-primary: #ffffff;
  --m3-primary-container: #e9ddff;
  --m3-on-primary-container: #22005d;
  --m3-secondary: #625b71;
  --m3-secondary-container: #e8def8;
  --m3-on-secondary-container: #1e192b;
  --m3-tertiary: #7d5260;
  --m3-tertiary-container: #ffd8e4;
  --m3-error: #b3261e;
  --m3-surface: #fef7ff;
  --m3-surface-container: #f3edf7;
  --m3-surface-container-high: #ece6f0;
  --m3-on-surface: #1d1b20;
  --m3-on-surface-variant: #49454f;
  --m3-outline-variant: #cac4d0;
  --m3-inverse-surface: #322f35;
  --m3-inverse-on-surface: #f5eff7;
  --in-tune: #1db954;
  --out-of-tune: #e53935;
  --diff-1: #1db954;
  --diff-2: #43a047;
  --diff-3: #f9a825;
  --diff-4: #ef6c00;
  --diff-5: #e53935;

  /* Formas y movimiento */
  --radius-xs: 10px;
  --radius-s: 16px;
  --radius-m: 24px;
  --radius-l: 32px;
  --ease-emphasized: cubic-bezier(0.2, 0, 0, 1);
  --dur-fast: 150ms;
  --dur-medium: 280ms;
  --dur-slow: 450ms;

  --outfit: 'Outfit', system-ui, -apple-system, 'Segoe UI', sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --m3-primary: #cfbcff;
    --m3-on-primary: #381e72;
    --m3-primary-container: #4f378a;
    --m3-on-primary-container: #e9ddff;
    --m3-secondary: #cbc2db;
    --m3-secondary-container: #4a4458;
    --m3-on-secondary-container: #e8def8;
    --m3-tertiary: #efb8c8;
    --m3-tertiary-container: #633b48;
    --m3-surface: #141218;
    --m3-surface-container: #211f26;
    --m3-surface-container-high: #2b2930;
    --m3-on-surface: #e6e0e9;
    --m3-on-surface-variant: #cac4d0;
    --m3-outline-variant: #49454f;
    --diff-1: #4ade80;
    --diff-2: #86efac;
    --diff-3: #facc15;
    --diff-4: #fb923c;
    --diff-5: #f87171;
  }
}

* {
  box-sizing: border-box;
  margin: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--outfit);
  background: var(--m3-surface);
  color: var(--m3-on-surface);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

code,
pre {
  font-family: 'JetBrains Mono', ui-monospace, 'Cascadia Code', monospace;
}

a {
  color: var(--m3-primary);
}

/* ---------- App bar ---------- */
.app-bar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--m3-surface);
  transition: background var(--dur-medium) var(--ease-emphasized);
}

.app-bar[data-elevated='true'] {
  background: var(--m3-surface-container);
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.16);
}

.app-bar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  max-width: 1120px;
  margin: 0 auto;
  padding: 14px 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 999px;
  background: var(--m3-primary-container);
  color: var(--m3-on-primary-container);
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
}

.brand-version {
  font-size: 12px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--m3-secondary-container);
  color: var(--m3-on-secondary-container);
}

.app-bar-nav {
  display: flex;
  gap: 4px;
}

.app-bar-nav a {
  text-decoration: none;
  color: var(--m3-on-surface-variant);
  font-weight: 600;
  font-size: 14px;
  padding: 8px 14px;
  border-radius: 999px;
  transition: background var(--dur-fast) var(--ease-emphasized);
}

.app-bar-nav a:hover {
  background: color-mix(in srgb, var(--m3-primary) 12%, transparent);
  color: var(--m3-primary);
}

@media (max-width: 640px) {
  .app-bar-nav {
    display: none;
  }
}

/* ---------- Hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
  max-width: 1120px;
  margin: 0 auto;
  padding: 64px 24px 32px;
}

.overline {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12px;
  font-weight: 700;
  color: var(--m3-primary);
  margin-bottom: 12px;
}

.display {
  font-size: clamp(38px, 5.6vw, 58px);
  line-height: 1.05;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.lede {
  font-size: clamp(16px, 2vw, 18px);
  color: var(--m3-on-surface-variant);
  max-width: 52ch;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  transition: transform var(--dur-fast) var(--ease-emphasized),
    box-shadow var(--dur-medium) var(--ease-emphasized);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn.filled {
  background: var(--m3-primary);
  color: var(--m3-on-primary);
  box-shadow: 0 2px 6px color-mix(in srgb, var(--m3-primary) 35%, transparent);
}

.btn.tonal {
  background: var(--m3-secondary-container);
  color: var(--m3-on-secondary-container);
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 36px;
  max-width: 560px;
}

.stat {
  background: var(--m3-surface-container);
  border-radius: var(--radius-m);
  padding: 14px 16px;
}

.stat dt {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  color: var(--m3-on-surface-variant);
}

.stat dd {
  font-size: 26px;
  font-weight: 800;
}

/* ---------- Mockup de móvil ---------- */
.hero-device {
  display: grid;
  place-items: center;
}

.phone {
  width: 252px;
  border-radius: 38px;
  padding: 12px;
  background: var(--m3-inverse-surface);
  box-shadow: 0 24px 60px rgb(0 0 0 / 0.28);
  transform: rotate(2deg);
}

.phone-notch {
  width: 84px;
  height: 18px;
  margin: 0 auto 8px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--m3-on-surface) 30%, transparent);
}

.phone-screen {
  background: var(--m3-surface);
  border-radius: 28px;
  padding: 14px;
  min-height: 380px;
}

.phone-title {
  font-weight: 800;
  font-size: 18px;
  margin-bottom: 10px;
}

.phone-search {
  height: 38px;
  border-radius: 999px;
  background: var(--m3-surface-container-high);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  padding: 0 14px;
  font-size: 12px;
  color: var(--m3-on-surface-variant);
}

.phone-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.mini-card {
  background: var(--m3-surface-container);
  border-radius: var(--radius-s);
  padding: 8px;
  text-align: center;
}

.mini-card .mini-name {
  font-weight: 700;
  font-size: 13px;
}

/* ---------- Secciones ---------- */
.section {
  max-width: 1120px;
  margin: 0 auto;
  padding: 56px 24px 8px;
}

.headline {
  font-size: clamp(26px, 3.6vw, 34px);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
}

.section-lede {
  color: var(--m3-on-surface-variant);
  max-width: 68ch;
  margin-bottom: 28px;
}

.subhead {
  font-size: 20px;
  font-weight: 700;
  margin: 28px 0 14px;
}

/* ---------- Funciones ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px;
}

.feature {
  background: var(--m3-surface-container);
  border-radius: var(--radius-m);
  padding: 22px;
  transition: transform var(--dur-medium) var(--ease-emphasized),
    background var(--dur-medium) var(--ease-emphasized);
}

.feature:hover {
  transform: translateY(-4px);
  background: var(--m3-surface-container-high);
}

.feature .icon {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-s);
  background: var(--m3-primary-container);
  color: var(--m3-on-primary-container);
  margin-bottom: 14px;
}

.feature h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 6px;
}

.feature p {
  font-size: 14px;
  color: var(--m3-on-surface-variant);
}

/* ---------- Banco de acordes ---------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.chip {
  border: 1px solid var(--m3-outline-variant);
  background: transparent;
  color: var(--m3-on-surface-variant);
  border-radius: 999px;
  padding: 7px 16px;
  font: inherit;
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-emphasized),
    color var(--dur-fast) var(--ease-emphasized);
}

.chip[aria-selected='true'] {
  background: var(--m3-secondary-container);
  color: var(--m3-on-secondary-container);
  border-color: transparent;
}

.chord-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(168px, 1fr));
  gap: 16px;
}

.chord-card {
  background: var(--m3-surface-container);
  border-radius: var(--radius-m);
  padding: 14px;
  text-align: center;
  border: 0;
  font: inherit;
  color: inherit;
  cursor: pointer;
  transition: transform var(--dur-medium) var(--ease-emphasized),
    box-shadow var(--dur-medium) var(--ease-emphasized);
}

.chord-card:hover {
  transform: translateY(-4px) scale(1.01);
  box-shadow: 0 10px 28px rgb(0 0 0 / 0.14);
}

.chord-card .name {
  font-size: 22px;
  font-weight: 800;
}

.chord-card .quality {
  font-size: 12px;
  color: var(--m3-on-surface-variant);
  margin-bottom: 8px;
}

.chord-card .meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 11px;
  color: var(--m3-on-surface-variant);
}

.stars {
  display: inline-flex;
  gap: 2px;
}

.stars b {
  width: 7px;
  height: 7px;
  border-radius: 999px;
  background: var(--dot, var(--diff-3));
}

.diagram {
  display: block;
  margin: 4px auto 6px;
}

/* ---------- Diseño ---------- */
.design-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.design-card {
  background: var(--m3-surface-container);
  border-radius: var(--radius-m);
  padding: 20px;
}

.design-card h3 {
  font-size: 16px;
  margin-bottom: 12px;
}

.token-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 8px;
}

.token-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--m3-on-surface-variant);
}

.swatch {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  border: 1px solid var(--m3-outline-variant);
}

.difficulty-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 10px;
}

.difficulty-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
}

.pill {
  padding: 4px 10px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 12px;
  background: color-mix(in srgb, var(--pill) 18%, transparent);
  color: var(--pill);
}

.mockups {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.mockup {
  background: var(--m3-surface-container);
  border-radius: var(--radius-l);
  padding: 18px;
  border: 1px solid var(--m3-outline-variant);
}

.mockup h4 {
  font-size: 14px;
  margin-bottom: 12px;
  color: var(--m3-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav-demo {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

.nav-demo span {
  flex: 1;
  text-align: center;
  font-size: 11px;
  padding: 8px 4px;
  border-radius: 999px;
  background: var(--m3-surface-container-high);
  color: var(--m3-on-surface-variant);
}

.nav-demo span[data-active='true'] {
  background: var(--m3-primary);
  color: var(--m3-on-primary);
}

.rail-demo {
  display: flex;
  gap: 12px;
}

.rail-demo nav {
  display: grid;
  gap: 10px;
}

.rail-demo .rail-item {
  width: 46px;
  height: 34px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: var(--m3-surface-container-high);
  font-size: 12px;
}

.rail-demo .rail-item[data-active='true'] {
  background: var(--m3-secondary-container);
}

.rail-demo .rail-content {
  flex: 1;
  border-radius: var(--radius-s);
  background: var(--m3-surface-container-high);
  min-height: 120px;
  display: grid;
  place-items: center;
  font-size: 12px;
  color: var(--m3-on-surface-variant);
}

.live-demo {
  text-align: center;
  padding: 8px 0;
}

.live-note {
  font-size: 44px;
  font-weight: 800;
}

.meter {
  margin: 14px auto 0;
  width: 80%;
  height: 12px;
  border-radius: 999px;
  background: var(--m3-surface-container-high);
  position: relative;
}

.meter i {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 4px;
  border-radius: 999px;
  background: var(--in-tune);
  left: calc(50% - 2px);
  animation: tune 2.4s var(--ease-emphasized) infinite;
}

@keyframes tune {
  0%, 100% { left: calc(38% - 2px); }
  50% { left: calc(62% - 2px); }
}

/* ---------- Arquitectura ---------- */
.arch-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.arch-card {
  background: var(--m3-inverse-surface);
  color: var(--m3-inverse-on-surface);
  border-radius: var(--radius-m);
  padding: 18px;
}

.arch-card h3 {
  font-size: 14px;
  margin-bottom: 10px;
  color: var(--m3-primary);
}

pre.code {
  font-size: 12px;
  line-height: 1.6;
  overflow-x: auto;
  white-space: pre;
}

.footer-note {
  margin-top: 24px;
  padding: 16px 20px;
  border-radius: var(--radius-s);
  background: var(--m3-surface-container);
  font-size: 13px;
  color: var(--m3-on-surface-variant);
}

/* ---------- Footer ---------- */
.footer {
  margin-top: 64px;
  padding: 28px 24px 40px;
  text-align: center;
  font-size: 13px;
  color: var(--m3-on-surface-variant);
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    padding-top: 40px;
  }
  .hero-device {
    order: -1;
  }
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }
}