/* SECTION: Design tokens */
:root {
  /* Color palette */
  --color-bg: #050814;
  --color-surface: #0b1022;
  --color-surface-soft: #101731;
  --color-border-subtle: #222845;
  --color-text: #f5f6ff;
  --color-text-muted: #a7b0d8;
  --color-accent: #ff5f6c;
  --color-accent-soft: rgba(255, 95, 108, 0.18);
  --color-accent-strong: #ffb347;
  --color-chip-high: #ffefc2;
  --color-chip-low: #050814;

  /* Wave gradient colors (for legend & possible UI usage) */
  --color-wave-negative: #0a2342;
  --color-wave-zero: #050814;
  --color-wave-positive: #ff5f6c;

  /* Shadows & borders */
  --shadow-soft: 0 18px 45px rgba(0, 0, 0, 0.55);
  --radius-lg: 20px;
  --radius-md: 12px;
  --radius-pill: 999px;

  /* Typography */
  --font-sans: "Space Grotesk", system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.85rem;
  --font-size-base: 0.95rem;
  --font-size-lg: 1.1rem;
  --font-size-xl: 1.7rem;
  --font-size-xxl: 2.3rem;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;

  /* Spacing */
  --space-2: 0.25rem;
  --space-4: 0.5rem;
  --space-6: 0.75rem;
  --space-8: 1rem;
  --space-10: 1.25rem;
  --space-12: 1.5rem;
  --space-16: 2rem;

  /* Motion */
  --transition-fast: 0.16s ease-out;
  --transition-med: 0.22s ease-out;
}

/* SECTION: Global layout */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  min-height: 100vh;
  font-family: var(--font-sans);
  background: radial-gradient(circle at top, #151b34 0, #050814 50%, #02030a 100%);
  color: var(--color-text);
  display: flex;
  flex-direction: column;
}

code {
  font-family: "SF Mono", ui-monospace, Menlo, Monaco, Consolas, "Liberation Mono",
    "Courier New", monospace;
  background: rgba(10, 14, 40, 0.8);
  padding: 0 var(--space-2);
  border-radius: 4px;
  font-size: 0.8em;
}

.app-header {
  padding: var(--space-12) var(--space-16) var(--space-8);
}

.app-main {
  flex: 1;
  padding: 0 var(--space-16) var(--space-12);
  display: grid;
  grid-template-columns: minmax(0, 3fr) minmax(0, 2.3fr);
  gap: var(--space-12);
}

.app-footer {
  padding: var(--space-8) var(--space-16) var(--space-10);
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* SECTION: Header */
.branding {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.logo-mark {
  width: 40px;
  height: 40px;
  border-radius: 16px;
  background: radial-gradient(circle at 30% 20%, #ffb347, #ff5f6c 40%, #4b1d5b 90%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fffaf0;
  font-size: 1.4rem;
  font-weight: var(--font-weight-bold);
  box-shadow: 0 0 25px rgba(255, 95, 108, 0.6);
}

.app-title {
  margin: 0 0 2px;
  font-size: var(--font-size-xxl);
  letter-spacing: -0.04em;
}

.app-tagline {
  margin: 0;
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

/* SECTION: Panels */
.panel {
  background: linear-gradient(145deg, rgba(8, 12, 35, 0.98), rgba(6, 10, 28, 0.98));
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-subtle);
  box-shadow: var(--shadow-soft);
  padding: var(--space-10);
}

.panel-visual {
  display: flex;
  flex-direction: column;
}

.panel-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-10);
}

.panel-title {
  margin: 0 0 var(--space-2);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-medium);
}

.panel-subtitle {
  margin: 0;
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
}

.canvas-header {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
}

.canvas-wrapper {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.06);
  background: radial-gradient(circle at center, #141b3a 0, #050814 60%);
}

#waveCanvas {
  display: block;
  width: 100%;
  height: auto;
  background: transparent;
  cursor: crosshair;
}

.canvas-fallback {
  display: none;
}

/* SECTION: Controls */
.controls-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.control-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-8);
}

.control-column {
  flex: 1;
  min-width: 180px;
}

.control-label {
  margin: 0 0 var(--space-4);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.11em;
  color: var(--color-text-muted);
}

.control-hints {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

.control-hints li + li {
  margin-top: var(--space-2);
}

.key {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.2rem;
  padding: 0 var(--space-2);
  border-radius: 4px;
  background: rgba(9, 15, 39, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.16);
  font-size: 0.7rem;
}

.sliders-row {
  align-items: flex-end;
}

.slider-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.slider-value {
  font-size: var(--font-size-xs);
  color: var(--color-text);
  opacity: 0.9;
}

input[type="range"] {
  width: 100%;
  -webkit-appearance: none;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(255, 95, 108, 0.4), rgba(53, 121, 255, 0.2));
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #ff5f6c;
  border: 2px solid #ffe7d9;
  box-shadow: 0 0 12px rgba(255, 95, 108, 0.7);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.05);
  box-shadow: 0 0 18px rgba(255, 95, 108, 0.8);
}

input[type="range"]::-moz-range-track {
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(255, 95, 108, 0.4), rgba(53, 121, 255, 0.2));
}

input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #ff5f6c;
  border: 2px solid #ffe7d9;
  box-shadow: 0 0 12px rgba(255, 95, 108, 0.7);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: background-color var(--transition-med),
    color var(--transition-med),
    border-color var(--transition-med),
    transform var(--transition-fast),
    box-shadow var(--transition-fast);
}

.btn.primary {
  background: linear-gradient(120deg, #ff5f6c, #ffb347);
  color: #1a0b12;
  box-shadow: 0 0 18px rgba(255, 95, 108, 0.75);
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 0 24px rgba(255, 95, 108, 0.95);
}

.btn.ghost {
  background: rgba(12, 18, 50, 0.9);
  border-color: rgba(255, 255, 255, 0.12);
  color: var(--color-text);
}

.btn.ghost:hover {
  background: rgba(16, 24, 65, 0.95);
}

.toggles {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: center;
}

.checkbox {
  display: inline-flex;
  align-items: center;
  gap: var(--space-4);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.checkbox input[type="checkbox"] {
  width: 14px;
  height: 14px;
  border-radius: 4px;
}

/* Explanation & legend */
.explanation {
  padding-top: var(--space-4);
  border-top: 1px dashed rgba(255, 255, 255, 0.08);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.legend {
  list-style: none;
  margin: var(--space-4) 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.chip {
  display: inline-flex;
  width: 18px;
  height: 10px;
  border-radius: 999px;
  margin-right: var(--space-4);
  border: 1px solid rgba(255, 255, 255, 0.35);
}

.chip-high {
  background: radial-gradient(circle at 30% 20%, var(--color-chip-high), var(--color-accent));
}

.chip-low {
  background: radial-gradient(circle at 30% 20%, #070a16, #00010a);
}

.tip {
  margin-top: var(--space-6);
  padding: var(--space-4) var(--space-6);
  border-radius: 8px;
  background: linear-gradient(120deg, rgba(255, 95, 108, 0.08), rgba(255, 179, 71, 0.04));
  color: var(--color-text);
  border: 1px solid rgba(255, 95, 108, 0.25);
}

/* SECTION: Responsiveness */
@media (max-width: 900px) {
  .app-main {
    grid-template-columns: minmax(0, 1fr);
    padding: 0 var(--space-8) var(--space-10);
  }

  .app-header {
    padding: var(--space-10) var(--space-8) var(--space-6);
  }

  .panel {
    padding: var(--space-8);
  }

  .app-title {
    font-size: 1.8rem;
  }
}

@media (max-width: 600px) {
  .branding {
    align-items: flex-start;
  }

  .logo-mark {
    width: 34px;
    height: 34px;
    font-size: 1.1rem;
  }

  .control-row {
    flex-direction: column;
  }
}