:root {
  --bg-darkest: #111111;
  --bg-dark: #1a1a1a;
  --bg-card: #202020;
  --accent: #FFC300;
  --accent-soft: #ffd24d;
  --accent-dim: #b88c00;
  --text: #f4f3ef;
  --text-muted: #9a9a9a;
  --border: #2c2c2c;
  --border-soft: rgba(255, 255, 255, 0.06);
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.45);
  --shadow-soft: 0 8px 24px rgba(0, 0, 0, 0.35);
  --font-display: "Cormorant Garamond", Georgia, "Times New Roman", serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background:
    radial-gradient(1200px 600px at 50% -10%, rgba(255, 195, 0, 0.08), transparent 60%),
    var(--bg-darkest);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
  -webkit-tap-highlight-color: transparent;
  padding-bottom: env(safe-area-inset-bottom);
  position: relative;
  overflow-x: hidden;
}

/* Dezenter Lichtschein im Hintergrund */
.bg-glow {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(600px 300px at 85% 110%, rgba(255, 195, 0, 0.06), transparent 70%),
    radial-gradient(500px 280px at 10% 90%, rgba(120, 80, 200, 0.05), transparent 70%);
}

/* ---------- Header ---------- */
.app-header {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 40px 16px 26px;
}

.brand {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 9vw, 3.6rem);
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: 0.5px;
  color: var(--text);
}

.brand-gen {
  background: linear-gradient(95deg, var(--accent), var(--accent-soft));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.byline {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 4vw, 1.4rem);
  color: var(--text-muted);
  margin-top: 2px;
  letter-spacing: 1px;
}

.byline-name {
  color: var(--accent);
  font-weight: 600;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 12px;
  max-width: 460px;
  margin-left: auto;
  margin-right: auto;
}

/* feine Trennlinie unter dem Header */
.app-header::after {
  content: "";
  display: block;
  width: 90px;
  height: 2px;
  margin: 22px auto 0;
  border-radius: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0.7;
}

/* ---------- Main layout ---------- */
.app-main {
  position: relative;
  z-index: 1;
  max-width: 960px;
  margin: 0 auto;
  padding: 8px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

/* ---------- Panel (gemeinsamer Karten-Look, Glassmorphismus) ---------- */
.panel {
  background: linear-gradient(180deg, rgba(38, 38, 38, 0.9), rgba(26, 26, 26, 0.92));
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

/* ---------- Master panel ---------- */
.master-panel {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.master-controls {
  display: flex;
  gap: 12px;
}

/* ---------- Buttons ---------- */
.btn {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  background: var(--bg-card);
  padding: 13px 16px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: background 0.18s, transform 0.06s, border-color 0.18s, box-shadow 0.18s;
  user-select: none;
}

.btn:active {
  transform: scale(0.97);
}

.btn-master {
  flex: 1;
  background: linear-gradient(95deg, var(--accent), var(--accent-soft));
  color: #161616;
  border-color: transparent;
  font-size: 1.05rem;
  box-shadow: 0 8px 22px rgba(255, 195, 0, 0.22);
}

.btn-master.playing {
  background: var(--bg-card);
  color: var(--accent);
  border-color: var(--accent);
  box-shadow: none;
}

.btn-reset {
  background: var(--bg-card);
  color: var(--text-muted);
}

.btn-reset:hover {
  border-color: var(--accent-dim);
  color: var(--text);
}

/* ---------- Timer ---------- */
.timer-block {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 16px;
  border-top: 1px solid var(--border-soft);
}

.timer-label {
  font-size: 0.74rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.timer-row {
  display: flex;
  gap: 10px;
}

.timer-row input[type="number"] {
  width: 96px;
  flex: 0 0 auto;
}

.btn-timer {
  flex: 1;
  background: var(--bg-card);
  color: var(--text);
}

.btn-timer.active {
  border-color: var(--accent);
  color: var(--accent);
}

.timer-display {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  letter-spacing: 2px;
  text-shadow: 0 0 18px rgba(255, 195, 0, 0.25);
}

/* ---------- Number inputs ---------- */
input[type="number"] {
  background: var(--bg-darkest);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 11px;
  font-size: 1rem;
  font-family: var(--font-body);
  text-align: center;
  -moz-appearance: textfield;
}

input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(255, 195, 0, 0.12);
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* ---------- Oscillators ---------- */
.oscillators {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.osc-card {
  display: flex;
  flex-direction: column;
  gap: 18px;
  position: relative;
  overflow: hidden;
}

.osc-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0.6;
}

.osc-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.osc-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text);
}

.btn-play {
  background: var(--bg-darkest);
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: 10px 20px;
}

.btn-play.playing {
  background: linear-gradient(95deg, var(--accent), var(--accent-soft));
  color: #161616;
}

/* ---------- Control groups ---------- */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.control-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.control-label {
  font-size: 0.74rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.freq-input-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
}

.freq-number {
  width: 104px;
}

.unit {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.vol-value {
  color: var(--accent);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ---------- Sliders ---------- */
.slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--accent-dim), #333 60%);
  outline: none;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, var(--accent-soft), var(--accent));
  cursor: pointer;
  border: 2px solid #161616;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
}

.slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, var(--accent-soft), var(--accent));
  cursor: pointer;
  border: 2px solid #161616;
}

/* ---------- Solfeggio-Box im Oszillator ---------- */
.solfeggio-box {
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 14px;
  background:
    linear-gradient(180deg, rgba(255, 195, 0, 0.04), rgba(255, 255, 255, 0.01));
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.solfeggio-box-head {
  display: flex;
  align-items: center;
  gap: 10px;
}

.solfeggio-box-title {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 1.4px;
  text-transform: uppercase;
  color: var(--accent);
  white-space: nowrap;
}

.solfeggio-box-head::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(255, 195, 0, 0.4), transparent);
}

.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.preset-btn {
  --c: var(--accent);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid color-mix(in srgb, var(--c) 45%, transparent);
  color: var(--text);
  border-radius: 999px;
  padding: 7px 13px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.16s ease;
  position: relative;
}

.preset-btn::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c);
  margin-right: 7px;
  vertical-align: middle;
  box-shadow: 0 0 8px color-mix(in srgb, var(--c) 70%, transparent);
}

.preset-btn:hover {
  border-color: var(--c);
  background: color-mix(in srgb, var(--c) 14%, transparent);
}

.preset-btn.active {
  background: var(--c);
  border-color: var(--c);
  color: #fff;
  font-weight: 700;
  box-shadow: 0 4px 16px color-mix(in srgb, var(--c) 45%, transparent);
}

.preset-btn.active::before {
  background: #fff;
  box-shadow: none;
}

.preset-desc {
  font-size: 0.84rem;
  color: var(--text-muted);
  min-height: 1.2em;
  transition: color 0.2s;
}

.preset-desc.has-value {
  color: var(--text);
}

.preset-desc .desc-freq {
  font-weight: 700;
  color: var(--desc-c, var(--accent));
}

/* ---------- Waveform buttons ---------- */
.waveform-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.wave-btn {
  background: var(--bg-darkest);
  border: 1px solid var(--border);
  color: var(--text-muted);
  border-radius: 8px;
  padding: 11px 4px;
  font-size: 0.82rem;
  font-weight: 500;
  font-family: var(--font-body);
  cursor: pointer;
  transition: all 0.16s;
}

.wave-btn:hover {
  border-color: var(--accent-dim);
  color: var(--text);
}

.wave-btn.active {
  background: linear-gradient(95deg, var(--accent), var(--accent-soft));
  color: #161616;
  border-color: transparent;
  font-weight: 700;
}

/* ---------- Solfeggio-Referenz (Übersicht) ---------- */
.solfeggio-guide {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.guide-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 5vw, 2rem);
  font-weight: 700;
  color: var(--text);
  text-align: center;
}

.guide-intro {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
  max-width: 560px;
  margin: 0 auto;
}

.guide-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}

.guide-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-soft);
  border-left: 4px solid var(--c, var(--accent));
  transition: background 0.16s, transform 0.06s;
}

.guide-item:hover {
  background: rgba(255, 255, 255, 0.04);
}

.guide-freq {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--c, var(--accent));
  min-width: 86px;
  line-height: 1.2;
}

.guide-effect {
  font-size: 0.9rem;
  color: var(--text);
  padding-top: 3px;
}

.guide-note {
  text-align: center;
  font-size: 0.76rem;
  color: var(--text-muted);
  font-style: italic;
  margin-top: 2px;
}

/* ---------- Musik-Player ---------- */
.music-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: relative;
  overflow: hidden;
}

.music-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, #3ec47a, var(--accent), transparent);
  opacity: 0.6;
}

.music-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.music-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text);
}

.music-badge {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: #3ec47a;
  border: 1px solid rgba(62, 196, 122, 0.4);
  background: rgba(62, 196, 122, 0.08);
  padding: 4px 10px;
  border-radius: 999px;
  white-space: nowrap;
}

.music-intro {
  color: var(--text-muted);
  font-size: 0.86rem;
}

/* Track-Auswahl */
.track-select {
  width: 100%;
  background: var(--bg-darkest);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  padding: 13px 14px;
  font-size: 0.95rem;
  font-family: var(--font-body);
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 24 24' fill='none' stroke='%23FFC300' stroke-width='3'><path d='M6 9l6 6 6-6'/></svg>");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 40px;
}

.track-select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(255, 195, 0, 0.12);
}

/* Transport-Steuerung */
.music-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.btn-music-ctrl {
  flex: 0 0 auto;
  width: 52px;
  height: 52px;
  padding: 0;
  font-size: 1.2rem;
  border-radius: 50%;
  background: var(--bg-card);
  color: var(--text);
}

.btn-music-ctrl:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-music-ctrl[aria-pressed="true"] {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(255, 195, 0, 0.08);
}

.btn-music-play {
  flex: 1;
  max-width: 220px;
  height: 52px;
  background: linear-gradient(95deg, var(--accent), var(--accent-soft));
  color: #161616;
  border-color: transparent;
  font-size: 1rem;
  box-shadow: 0 8px 22px rgba(255, 195, 0, 0.22);
}

.btn-music-play.playing {
  background: var(--bg-card);
  color: var(--accent);
  border-color: var(--accent);
  box-shadow: none;
}

.btn-music-play:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  background: var(--bg-card);
  color: var(--text-muted);
  box-shadow: none;
}

/* Fortschritt */
.music-progress-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.music-time {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  min-width: 38px;
  text-align: center;
}

.music-seek {
  flex: 1;
}

.music-seek:disabled {
  opacity: 0.5;
}

/* Eigene Musik */
.music-own {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  padding-top: 14px;
  border-top: 1px solid var(--border-soft);
}

.btn-own-music {
  background: var(--bg-card);
  border: 1px dashed var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: border-color 0.15s, color 0.15s;
}

.btn-own-music:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.own-music-name {
  font-size: 0.82rem;
  color: var(--text-muted);
  word-break: break-word;
}

.music-hint {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-style: italic;
  min-height: 1em;
}

.music-hint.error {
  color: #e06c5a;
  font-style: normal;
}

/* ---------- Einführung (ausklappbar) ---------- */
.intro-panel {
  padding: 0;
  overflow: hidden;
}

.intro-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: transparent;
  border: none;
  color: var(--text);
  padding: 18px 22px;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 1.02rem;
  font-weight: 600;
}

.intro-toggle-label {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px 9px;
  text-align: left;
}

.intro-toggle-label::before {
  content: "\2139\FE0F"; /* ℹ️ Info */
  color: var(--accent);
}

.intro-toggle-hint {
  font-weight: 500;
  font-size: 0.82rem;
  color: var(--accent);
  opacity: 0.85;
}

.intro-chevron {
  color: var(--accent);
  font-size: 0.9rem;
  transition: transform 0.25s ease;
}

.intro-panel.collapsed .intro-chevron {
  transform: rotate(-90deg);
}

.intro-body {
  padding: 0 22px 22px;
  max-height: 1000px;
  overflow: hidden;
  transition: max-height 0.4s ease, opacity 0.25s ease, padding 0.3s ease;
  opacity: 1;
}

/* Wichtiger Kompatibilitäts-Hinweis */
.intro-notice {
  margin: 0 0 18px;
  padding: 14px 16px;
  background: rgba(255, 195, 0, 0.08);
  border: 1px solid rgba(255, 195, 0, 0.28);
  border-radius: 12px;
}

.intro-notice-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 10px;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text);
}

.intro-notice-title::before {
  content: "\26A0\FE0F"; /* ⚠️ */
}

.intro-notice-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
}

.intro-notice-list li {
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--text-muted);
}

.intro-notice-list strong {
  color: var(--text);
  font-weight: 600;
}

.intro-notice-dev {
  display: inline-block;
  margin-right: 6px;
  padding: 2px 9px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  color: #161616;
  background: linear-gradient(135deg, var(--accent), var(--accent-soft));
  vertical-align: 1px;
}

.intro-panel.collapsed .intro-body {
  max-height: 0;
  opacity: 0;
  padding-top: 0;
  padding-bottom: 0;
}

.intro-steps {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin: 0 0 14px;
  padding: 0;
}

.intro-steps li {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.intro-step-num {
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  color: #161616;
  background: linear-gradient(135deg, var(--accent), var(--accent-soft));
  box-shadow: 0 4px 12px rgba(255, 195, 0, 0.22);
}

.intro-steps strong {
  display: block;
  color: var(--text);
  font-size: 0.96rem;
  margin-bottom: 2px;
}

.intro-steps p {
  color: var(--text-muted);
  font-size: 0.85rem;
  line-height: 1.45;
}

.intro-tip {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
  padding: 12px 14px;
  background: rgba(255, 195, 0, 0.06);
  border-left: 2px solid var(--accent);
  border-radius: 8px;
}

/* ---------- Timer-Panel ---------- */
.timer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 6px;
}

.timer-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text);
}

.timer-badge {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-muted);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 999px;
}

.timer-desc {
  color: var(--text-muted);
  font-size: 0.86rem;
  margin-bottom: 14px;
}

.timer-panel .timer-row {
  align-items: center;
}

.timer-unit {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-right: 4px;
}

.timer-panel .timer-display {
  margin-top: 14px;
}

/* ---------- Frequenz-Wirkungen Hinweis (in "So funktioniert's") ---------- */
.intro-freq-hint {
  margin: 20px 0;
  padding: 16px 18px;
  background: rgba(255, 195, 0, 0.05);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
}

.intro-freq-hint p {
  margin: 0;
  line-height: 1.6;
}

.intro-freq-hint p:first-child {
  margin-bottom: 6px;
}

.intro-freq-hint strong {
  color: var(--accent-soft);
  font-weight: 600;
}

/* ---------- Musik-Link in der Musik-Karte ---------- */
.music-external-link {
  text-align: center;
  margin: 16px 0 4px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.music-external-link a {
  color: var(--accent-soft);
  text-decoration: none;
  transition: color 0.2s ease;
}

.music-external-link a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ---------- Promo-Panels (Musik-Empfehlung + Spenden) ---------- */
.promo-grid {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.promo-panel {
  position: relative;
  text-align: center;
  padding: 30px 26px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* Dezenter Farbschimmer oben an jeder Promo-Karte */
.promo-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: var(--radius) var(--radius) 0 0;
}

/* Musik-Empfehlung: kühler, sanfter Akzent */
.music-promo {
  background:
    radial-gradient(420px 200px at 50% -40%, rgba(120, 160, 255, 0.10), transparent 70%),
    linear-gradient(160deg, rgba(120, 160, 255, 0.045), rgba(120, 160, 255, 0.015));
  border: 1px solid rgba(140, 170, 255, 0.18);
}
.music-promo::before {
  background: linear-gradient(90deg, transparent, #8ab0ff, transparent);
}

/* Spenden: warmer Gold-Akzent */
.donate-panel {
  background:
    radial-gradient(420px 200px at 50% -40%, rgba(255, 195, 0, 0.12), transparent 70%),
    linear-gradient(160deg, rgba(255, 195, 0, 0.05), rgba(255, 195, 0, 0.015));
  border: 1px solid rgba(255, 195, 0, 0.22);
}
.donate-panel::before {
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.promo-icon {
  font-size: 2.4rem;
  line-height: 1;
  margin-bottom: 14px;
  filter: drop-shadow(0 3px 10px rgba(255, 195, 0, 0.25));
}

.music-promo .promo-icon {
  filter: drop-shadow(0 3px 10px rgba(120, 160, 255, 0.35));
}

.promo-title {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
  letter-spacing: 0.4px;
}

.donate-panel .promo-title {
  color: var(--accent-soft);
}

.promo-text {
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 420px;
  margin: 0 auto 20px;
  font-size: 0.9rem;
}

/* Gemeinsame Basis für Promo-/Spenden-Buttons */
.btn-promo,
.btn-donate {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 12px 26px;
  font-weight: 600;
  font-size: 0.92rem;
  border: none;
  border-radius: 50px;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  margin-top: auto;
}

/* Musik-Button: kühl, transparent mit blauem Rand */
.btn-promo {
  background: rgba(140, 170, 255, 0.10);
  color: #cfdcff;
  border: 1px solid rgba(140, 170, 255, 0.45);
  box-shadow: 0 4px 14px rgba(80, 110, 200, 0.18);
}
.btn-promo:hover {
  transform: translateY(-2px);
  background: rgba(140, 170, 255, 0.18);
  box-shadow: 0 7px 20px rgba(80, 110, 200, 0.32);
}
.btn-promo:active {
  transform: translateY(0);
}

/* Spenden-Button: voller Gold-Akzent */
.btn-donate {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dim) 100%);
  color: var(--bg-darkest);
  box-shadow: 0 4px 14px rgba(255, 195, 0, 0.28);
}
.btn-donate:hover {
  transform: translateY(-2px);
  box-shadow: 0 7px 22px rgba(255, 195, 0, 0.45);
  background: linear-gradient(135deg, var(--accent-soft) 0%, var(--accent) 100%);
}
.btn-donate:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(255, 195, 0, 0.3);
}

/* ---------- Footer ---------- */
.app-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 26px 16px 36px;
  color: var(--text-muted);
  font-size: 0.78rem;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 0.9rem;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}

/* ---------- Responsive (Tablet/Desktop) ---------- */
@media (min-width: 860px) {
  .app-header {
    padding-top: 56px;
  }

  /* Zwei-Spalten-Layout, das den Platz sinnvoll nutzt:
     Einführung oben über die volle Breite, darunter Frequenz und Musik
     nebeneinander (gleich hoch), dann Timer, Guide und Promo-Panels. */
  .app-main {
    max-width: 1040px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-areas:
      "intro intro"
      "freq  music"
      "timer timer"
      "promo promo"
      "guide guide";
    gap: 18px;
  }

  .intro-panel { grid-area: intro; }
  .oscillators { grid-area: freq; }
  .music-panel { grid-area: music; }
  .timer-panel { grid-area: timer; }
  .promo-grid { grid-area: promo; }
  .solfeggio-guide { grid-area: guide; }

  /* Promo-Karten nebeneinander, gleich hoch */
  .promo-grid {
    flex-direction: row;
  }
  .promo-grid .promo-panel {
    flex: 1;
  }

  /* Frequenz & Musik füllen ihre Spalte auf gleiche Höhe */
  .oscillators,
  .oscillators .osc-card,
  .music-panel {
    height: 100%;
  }

  /* Timer kompakter zentrieren, da volle Breite */
  .timer-panel .timer-row {
    max-width: 520px;
  }

  .guide-list {
    grid-template-columns: 1fr 1fr;
  }
}

/* Sehr breite Bildschirme: Solfeggio-Übersicht dreispaltig */
@media (min-width: 1200px) {
  .guide-list {
    grid-template-columns: 1fr 1fr 1fr;
  }
}

/* Fallback, falls color-mix nicht unterstützt wird */
@supports not (background: color-mix(in srgb, red 50%, transparent)) {
  .preset-btn {
    border-color: var(--c);
  }
  .preset-btn.active {
    background: var(--c);
  }
}