:root {
  color-scheme: light dark;

  --font-sans:
    "Inter", "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial,
    sans-serif;

  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 40px;
  --space-8: 56px;

  --bg: #f4f6fb;
  --bg-grad-a: rgba(13, 124, 102, 0.08);
  --bg-grad-b: rgba(217, 119, 6, 0.05);
  --panel: #ffffff;
  --panel-muted: #f6f8fc;
  --panel-border: #e1e6f0;
  --ink: #0f1729;
  --ink-soft: #1f2a44;
  --muted: #4a5879;
  --muted-strong: #2c3653;
  --accent: #0d7c66;
  --accent-ink: #ffffff;
  --accent-strong: #095a4a;
  --accent-soft: #d9eee8;
  --accent-ring: rgba(13, 124, 102, 0.35);
  --warning: #b45309;
  --danger: #b91c1c;
  --focus: #2563eb;
  --focus-ring: rgba(37, 99, 235, 0.4);
  --shadow-sm:
    0 1px 2px rgba(15, 23, 41, 0.06), 0 1px 3px rgba(15, 23, 41, 0.04);
  --shadow-md:
    0 6px 16px rgba(15, 23, 41, 0.08), 0 12px 32px rgba(15, 23, 41, 0.06);
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b1220;
  --bg-grad-a: rgba(34, 197, 168, 0.16);
  --bg-grad-b: rgba(217, 119, 6, 0.08);
  --panel: #131c30;
  --panel-muted: #0f172a;
  --panel-border: #223049;
  --ink: #eef2ff;
  --ink-soft: #d7deee;
  --muted: #a6b2cf;
  --muted-strong: #c4cde4;
  --accent: #22c5a8;
  --accent-ink: #06231d;
  --accent-strong: #5fe0c6;
  --accent-soft: rgba(34, 197, 168, 0.18);
  --accent-ring: rgba(34, 197, 168, 0.55);
  --warning: #f59e0b;
  --danger: #f87171;
  --focus: #93c5fd;
  --focus-ring: rgba(147, 197, 253, 0.45);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

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

body {
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% -10%, var(--bg-grad-a), transparent 45%),
    radial-gradient(circle at 110% 110%, var(--bg-grad-b), transparent 40%),
    var(--bg);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.app-shell {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(20px, 4vw, 48px);
  display: grid;
  gap: clamp(20px, 2.8vw, 32px);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  padding: clamp(18px, 2.8vw, 30px) clamp(20px, 3vw, 34px);
  border-radius: 28px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow-md);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  min-width: 0;
}

.brand-logo {
  width: clamp(60px, 7vw, 84px);
  height: clamp(60px, 7vw, 84px);
  border-radius: 20px;
  box-shadow: var(--shadow-md);
  flex: 0 0 auto;
}

.brand-text {
  display: grid;
  gap: 6px;
}

.brand-text h1 {
  margin: 0;
  font-size: clamp(1.35rem, 2vw, 1.8rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.brand-text .eyebrow {
  margin: 0;
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.topbar-actions {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.layout {
  display: grid;
  gap: clamp(22px, 3vw, 34px);
  grid-template-columns: minmax(0, 1fr);
}

.layout > .stack {
  display: grid;
  gap: clamp(22px, 3vw, 34px);
  align-content: start;
  min-width: 0;
}

@media (min-width: 1100px) {
  .layout {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    align-items: start;
  }
}

.panel {
  padding: clamp(22px, 3vw, 36px);
  border-radius: 26px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow-sm);
  min-width: 0;
}

.secondary-panel {
  margin-top: 0;
}

.section-header {
  margin-bottom: var(--space-4);
}

.section-header h2,
.panel-header h2 {
  margin: 0;
  font-size: clamp(1.15rem, 1.6vw, 1.4rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
  flex-wrap: wrap;
}

.eyebrow {
  margin: 0 0 4px;
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-strong);
}

h1 {
  margin: 0;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.intro {
  margin: var(--space-4) 0 var(--space-6);
  color: var(--muted-strong);
  max-width: 64ch;
  font-size: 1.04rem;
  line-height: 1.7;
}

.field-group {
  display: grid;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
  min-width: 0;
}

label {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted-strong);
}

.voice-filters {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}

select,
textarea,
input[type="search"],
input[type="text"] {
  width: 100%;
  font: inherit;
  color: var(--ink);
  background: var(--panel-muted);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  outline: none;
  transition:
    border-color 120ms ease,
    box-shadow 120ms ease,
    background 120ms ease;
}

select:hover,
textarea:hover,
input[type="search"]:hover,
input[type="text"]:hover {
  border-color: var(--muted);
}

select:focus,
textarea:focus,
input[type="search"]:focus,
input[type="text"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-ring);
}

textarea {
  min-height: 168px;
  line-height: 1.65;
  resize: vertical;
}

textarea[readonly] {
  background: var(--panel-muted);
  color: var(--muted-strong);
}

.voice-picker select#voiceSelect {
  height: 280px;
  padding: 10px;
}

.voice-picker select#voiceSelect option {
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}

.voice-picker select#voiceSelect option:checked {
  background: var(--accent-soft);
  color: var(--ink);
}

.voice-picker select#voiceSelect optgroup {
  font-weight: 700;
  color: var(--accent-strong);
  background: transparent;
}

.voice-count {
  margin: 0;
  font-size: 0.82rem;
  color: var(--muted);
}

.status-grid {
  display: grid;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.status-line {
  margin: 0;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  background: var(--panel-muted);
  border: 1px solid var(--panel-border);
  color: var(--muted-strong);
  font-size: 0.92rem;
  word-break: break-word;
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-4);
  margin-bottom: var(--space-2);
}

button,
#downloadLink {
  font: inherit;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  padding: 12px 20px;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  color: var(--accent-ink);
  background: var(--accent);
  box-shadow: var(--shadow-sm);
  transition:
    transform 120ms ease,
    box-shadow 120ms ease,
    background 120ms ease,
    border-color 120ms ease,
    color 120ms ease;
}

button:hover:not(:disabled),
#downloadLink:hover {
  background: var(--accent-strong);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

button:active:not(:disabled) {
  transform: translateY(0);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  box-shadow: none;
  transform: none;
}

#stopPlaybackButton {
  background: var(--danger);
  color: #ffffff;
}

#cancelGenerateButton {
  background: var(--warning);
  color: #ffffff;
}

#downloadButton,
#sttStopButton,
#sttClearButton,
#sttSendToTtsButton,
#sttSendToTranslateButton,
#translateSwapButton,
#translateClearButton,
#translateSendToTtsButton {
  background: var(--panel-muted);
  color: var(--ink);
  border-color: var(--panel-border);
  box-shadow: none;
}

#downloadButton:hover:not(:disabled),
#sttStopButton:hover:not(:disabled),
#sttClearButton:hover:not(:disabled),
#sttSendToTtsButton:hover:not(:disabled),
#sttSendToTranslateButton:hover:not(:disabled),
#translateSwapButton:hover:not(:disabled),
#translateClearButton:hover:not(:disabled),
#translateSendToTtsButton:hover:not(:disabled) {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--ink);
}

.theme-toggle {
  background: var(--panel-muted);
  color: var(--ink);
  border: 1px solid var(--panel-border);
  box-shadow: none;
  padding: 10px 16px;
  min-height: 42px;
}

.theme-toggle:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
}

#downloadLink {
  margin-top: var(--space-3);
  color: var(--ink);
  background: var(--panel-muted);
  border: 1px solid var(--panel-border);
  box-shadow: none;
}

#downloadLink:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.hint {
  margin: var(--space-5) 0 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.7;
}

.preview-panel {
  margin-top: var(--space-6);
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  background: var(--panel-muted);
  border: 1px solid var(--panel-border);
}

.preview-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-bottom: var(--space-3);
}

.preview-eyebrow {
  margin: 0 0 4px;
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-strong);
}

.preview-panel h2 {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.25;
  word-break: break-word;
  color: var(--ink);
}

.duration-output {
  margin: 0;
  color: var(--muted-strong);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.waveform-canvas {
  display: block;
  width: 100%;
  height: 180px;
  margin-bottom: var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--panel-border);
  background: #ffffff;
}

#previewAudio {
  width: 100%;
  border-radius: var(--radius-md);
}

.translate-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.translate-row .field-group {
  margin-bottom: var(--space-2);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 720px) {
  .app-shell {
    padding: 18px;
  }

  .voice-filters {
    grid-template-columns: 1fr;
  }

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

  .topbar {
    flex-wrap: wrap;
    padding: 18px;
  }

  .brand-logo {
    width: 56px;
    height: 56px;
    border-radius: 16px;
  }

  .panel {
    padding: 20px;
  }

  .action-row button,
  .action-row #downloadLink {
    flex: 1 1 45%;
  }
}

@media (max-width: 440px) {
  .app-shell {
    padding: 14px;
    gap: 16px;
  }

  .topbar,
  .panel,
  .preview-panel {
    border-radius: 20px;
  }

  .brand {
    align-items: flex-start;
  }

  .brand-logo {
    width: 48px;
    height: 48px;
    border-radius: 14px;
  }

  .intro {
    font-size: 0.98rem;
  }

  .action-row button {
    flex: 1 1 100%;
  }
}