/* SONIDO BLANCO — diseño nocturno calmado */
:root {
  --bg-0: #070b14;
  --bg-1: #0c1322;
  --bg-card: rgba(18, 27, 46, 0.72);
  --line: rgba(139, 157, 195, 0.16);
  --txt: #e8edf6;
  --txt-soft: #93a3bf;
  --accent: #8fb8e8;
  --accent-deep: #4a5d8a;
  --glow: rgba(143, 184, 232, 0.35);
  --radius: 16px;
  --tr: 220ms cubic-bezier(0.33, 1, 0.68, 1);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  background:
    radial-gradient(1100px 600px at 15% -10%, #16223d 0%, transparent 60%),
    radial-gradient(900px 500px at 90% 0%, #101b31 0%, transparent 55%),
    radial-gradient(1200px 800px at 50% 115%, #0f1830 0%, transparent 65%),
    var(--bg-0);
  color: var(--txt);
  line-height: 1.65;
  min-height: 100vh;
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
}

.hero__waves {
  position: absolute;
  inset: auto 0 0;
  width: 100%;
  height: 130px;
  opacity: 0.55;
  pointer-events: none;
  mask-image: linear-gradient(to top, #000 30%, transparent);
  -webkit-mask-image: linear-gradient(to top, #000 30%, transparent);
}

.nav {
  display: flex;
  justify-content: center;
  padding: 1.4rem 1rem 0;
}

.nav__brand {
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.nav__brand--soft { color: var(--accent); }

.hero__inner {
  max-width: 720px;
  margin: clamp(1.6rem, 5vw, 4rem) auto 0;
  padding: 0 1.25rem;
  text-align: center;
  animation: rise 420ms var(--tr) both;
}

.hero__kicker {
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.1rem;
}

.hero__title {
  font-size: clamp(2.2rem, 6vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.12;
  background: linear-gradient(180deg, #ffffff 40%, #aebfd9);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__sub {
  margin-top: 1.1rem;
  color: var(--txt-soft);
  max-width: 34rem;
  margin-inline: auto;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: none; }
}

/* ---------- Player ---------- */
.player {
  position: relative;
  z-index: 1;
  max-width: 620px;
  margin: clamp(1.4rem, 4vw, 2.8rem) auto 0;
  padding: 0 1rem;
  animation: rise 420ms 60ms var(--tr) both;
}

.player__card {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 6px);
  backdrop-filter: blur(14px);
  box-shadow: 0 24px 60px -24px rgba(0, 0, 0, 0.7), inset 0 1px 0 rgba(255, 255, 255, 0.05);
  padding: clamp(1.25rem, 3vw, 1.9rem);
  display: grid;
  gap: 1.35rem;
}

.noise-types {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.6rem;
}

.noise-btn {
  appearance: none;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--txt-soft);
  padding: 0.85rem 0.5rem;
  cursor: pointer;
  display: grid;
  justify-items: center;
  gap: 0.3rem;
  transition: border-color var(--tr), background var(--tr), transform var(--tr), color var(--tr), box-shadow var(--tr);
  min-height: 88px;
  font-family: inherit;
}

.noise-btn svg { width: 26px; height: 26px; }
.noise-btn span { font-weight: 600; color: inherit; }
.noise-btn small { font-size: 0.66rem; opacity: 0.75; letter-spacing: 0.04em; }

.noise-btn:hover { border-color: rgba(143, 184, 232, 0.45); color: var(--txt); transform: translateY(-2px); }

.noise-btn.is-active {
  border-color: var(--accent);
  color: var(--txt);
  background: linear-gradient(160deg, rgba(143, 184, 232, 0.14), rgba(74, 93, 138, 0.08));
  box-shadow: 0 0 0 1px var(--accent), 0 8px 28px -10px var(--glow);
}

.player__controls {
  display: flex;
  align-items: center;
  gap: 1.1rem;
}

.play-btn {
  flex-shrink: 0;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  color: #0a1120;
  background: linear-gradient(145deg, #bcd7f7, var(--accent));
  box-shadow: 0 10px 32px -8px var(--glow), inset 0 1px 0 rgba(255, 255, 255, 0.55);
  display: grid;
  place-items: center;
  transition: transform var(--tr), box-shadow var(--tr);
}

.play-btn:hover { transform: scale(1.06); box-shadow: 0 14px 40px -8px var(--glow); }
.play-btn:active { transform: scale(0.97); }
.play-btn svg { width: 30px; height: 30px; }
.is-hidden { display: none; }

.volume {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--txt-soft);
}
.volume > svg { width: 22px; height: 22px; flex-shrink: 0; }
#vol-out { font-size: 0.82rem; font-variant-numeric: tabular-nums; min-width: 3ch; text-align: right; }

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 999px;
  background: linear-gradient(to right, var(--accent) var(--fill, 40%), rgba(255, 255, 255, 0.12) var(--fill, 40%));
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #fff;
  border: 2px solid var(--accent);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.45);
  transition: transform 150ms ease;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.15); }
input[type="range"]::-moz-range-thumb {
  width: 20px; height: 20px; border-radius: 50%;
  background: #fff; border: 2px solid var(--accent); cursor: pointer;
}

.mix-row, .timer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.7rem;
}

.mix-row__label, .timer-row__label {
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--txt-soft);
  min-width: 100%;
}

.chips { display: flex; gap: 0.55rem; flex-wrap: wrap; }
.mix-chips, .timer-chips { display: flex; gap: 0.55rem; flex-wrap: wrap; }

.chip {
  appearance: none;
  font-family: inherit;
  font-size: 0.86rem;
  color: var(--txt-soft);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.5rem 1rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  min-height: 44px;
  transition: all var(--tr);
}

.chip svg { width: 17px; height: 17px; }
.chip:hover { color: var(--txt); border-color: rgba(143, 184, 232, 0.45); }

.chip.is-active {
  color: var(--txt);
  border-color: var(--accent);
  background: rgba(143, 184, 232, 0.13);
  box-shadow: 0 0 14px -4px var(--glow);
}

.timer-status { font-size: 0.78rem; color: var(--accent); min-height: 1.2em; letter-spacing: 0.05em; }

button:focus-visible, a:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ---------- Contenido ---------- */
.content-block {
  max-width: 780px;
  margin: 0 auto;
  padding: clamp(2.2rem, 6vw, 3.6rem) 1.25rem;
}

.content-block h2 {
  font-size: clamp(1.35rem, 3vw, 1.7rem);
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

.content-block h3 { margin: 1.4rem 0 0.6rem; }

.content-block p { color: var(--txt-soft); margin-bottom: 0.9rem; }
.content-block strong { color: var(--txt); }

.content-block ul, .content-block ol { padding-left: 1.3rem; color: var(--txt-soft); }
.content-block li { margin-bottom: 0.45rem; }

.steps { list-style: none; padding: 0 !important; counter-reset: none; display: grid; gap: 0.8rem; }

.steps li {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.8rem 1rem;
}

.steps span {
  flex-shrink: 0;
  width: 30px; height: 30px;
  border-radius: 50%;
  display: grid; place-items: center;
  font-size: 0.82rem; font-weight: 700;
  color: var(--accent);
  background: rgba(143, 184, 232, 0.12);
  border: 1px solid var(--line);
}

.tips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.9rem;
  margin-top: 1.2rem;
}

.tip-card {
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.2rem;
  transition: border-color var(--tr), transform var(--tr);
}

.tip-card:hover { border-color: rgba(143, 184, 232, 0.4); transform: translateY(-3px); }
.tip-card h3 { margin: 0 0 0.5rem; font-size: 1.02rem; }
.tip-card p { margin: 0; font-size: 0.92rem; }

details {
  border: 1px solid var(--line);
  border-radius: 12px;
  margin-bottom: 0.7rem;
  background: rgba(255, 255, 255, 0.025);
  overflow: hidden;
}

summary {
  cursor: pointer;
  padding: 1rem 1.2rem;
  font-weight: 600;
  list-style-position: inside;
  transition: color var(--tr);
}
summary:hover { color: var(--accent); }
details[open] summary { color: var(--accent); border-bottom: 1px solid var(--line); }
details p { padding: 0.9rem 1.2rem 1.1rem; margin: 0; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--line);
  padding: clamp(2rem, 5vw, 3rem) 1.25rem;
  text-align: center;
}

.footer__cta { font-size: 1.05rem; font-weight: 600; margin-bottom: 1rem; }

.footer nav { display: flex; justify-content: center; gap: 1.6rem; margin-bottom: 1.2rem; }

.footer a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  letter-spacing: 0.05em;
}
.footer a:hover { text-decoration: underline; }

.footer__copy { font-size: 0.8rem; color: var(--txt-soft); }

@media (max-width: 420px) {
  .noise-btn { min-height: 76px; }
  .player__controls { gap: 0.8rem; }
  .play-btn { width: 56px; height: 56px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}