:root {
  color-scheme: light dark;
  --bg-page: #0b0e14;
  --bg-panel: rgba(20, 25, 35, 0.84);
  --bg-button: rgba(255, 255, 255, 0.06);
  --bg-button-hover: rgba(255, 255, 255, 0.12);
  --bg-button-active: #f57823;
  --fg-button-active: #0b0e14;
  --text-primary: #f3f5f8;
  --text-muted: #9aa4b4;
  --border-subtle: rgba(255, 255, 255, 0.13);
  --brand-color: #f57823;
  --brand-green: #7cc142;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-page: #eef1f6;
    --bg-panel: rgba(255, 255, 255, 0.88);
    --bg-button: rgba(15, 23, 42, 0.06);
    --bg-button-hover: rgba(15, 23, 42, 0.11);
    --bg-button-active: #d95d08;
    --fg-button-active: #ffffff;
    --text-primary: #0f172a;
    --text-muted: #475569;
    --border-subtle: rgba(15, 23, 42, 0.14);
    --brand-color: #d95d08;
  }
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  inline-size: 100%;
  block-size: 100%;
  background: var(--bg-page);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  accent-color: var(--brand-color);
  overflow: hidden;
}

.app-shell {
  position: relative;
  inline-size: 100%;
  block-size: 100%;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.top-header {
  z-index: 10;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.85rem 1.25rem;
  background: var(--bg-panel);
  backdrop-filter: blur(14px);
  border-block-end: 1px solid var(--border-subtle);
}

.brand-title {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.coin-badge {
  inline-size: 0.75rem;
  block-size: 0.75rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-green), var(--brand-color));
  box-shadow: 0 0 0 2px var(--border-subtle);
}

.brand-title h1 {
  margin: 0;
  font-size: 1rem;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.brand-subtitle {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Accessible composite toolbar per modern-web-guidance `toolbar` */
[role="toolbar"] {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
}

[role="toolbar"] [role="group"] {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem;
}

[role="toolbar"] [role="separator"] {
  inline-size: 0;
  block-size: 1.35rem;
  margin-inline: 0.25rem;
  border-inline-start: 1px solid var(--border-subtle);
}

.tb-btn {
  appearance: none;
  min-inline-size: 2rem;
  min-block-size: 2rem;
  padding: 0.35rem 0.68rem;
  border: 1px solid var(--border-subtle);
  border-radius: 0.5rem;
  background: var(--bg-button);
  color: var(--text-primary);
  font-size: 0.78rem;
  font-weight: 550;
  line-height: 1.2;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
}

@media (pointer: coarse) {
  .tb-btn {
    min-inline-size: 2.75rem;
    min-block-size: 2.75rem;
    padding: 0.5rem 0.85rem;
  }
}

@media (hover: hover) {
  .tb-btn:hover {
    background: var(--bg-button-hover);
  }
}

@media (prefers-reduced-motion: no-preference) {
  .tb-btn {
    transition: background-color 0.14s ease, border-color 0.14s ease, transform 0.1s ease;
  }
}

.tb-btn:focus-visible {
  outline: 2px solid var(--brand-color);
  outline-offset: 2px;
}

/* Style toggled state strictly from ARIA attribute so visual and accessible state never diverge */
.tb-btn[aria-pressed="true"] {
  background: var(--bg-button-active);
  color: var(--fg-button-active);
  border-color: transparent;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.2);
  font-weight: 650;
}

@media (forced-colors: active) {
  .tb-btn {
    color: ButtonText;
    border-color: ButtonText;
  }
  .tb-btn[aria-pressed="true"] {
    background: Highlight;
    color: HighlightText;
    forced-color-adjust: none;
  }
}

.viewport-wrap {
  position: relative;
  inline-size: 100%;
  block-size: 100%;
  min-block-size: 0;
  overflow: hidden;
  background: radial-gradient(circle at 50% 42%, rgba(148, 163, 184, 0.16), transparent 68%);
}

#coin-canvas {
  display: block;
  inline-size: 100%;
  block-size: 100%;
  touch-action: none;
  cursor: grab;
}

#coin-canvas:active {
  cursor: grabbing;
}

.hud-pill {
  position: absolute;
  inset-block-start: 0.85rem;
  inset-inline-start: 1.25rem;
  pointer-events: none;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  font-size: 0.75rem;
  color: var(--text-muted);
  background: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  backdrop-filter: blur(10px);
}

.bottom-bar {
  z-index: 10;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 1.25rem;
  background: var(--bg-panel);
  backdrop-filter: blur(14px);
  border-block-start: 1px solid var(--border-subtle);
}

.slider-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.25rem;
}

.slider-field {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.78rem;
}

.slider-field label {
  color: var(--text-muted);
  font-weight: 500;
  white-space: nowrap;
}

.slider-readout {
  min-inline-size: 2.6rem;
  font-variant-numeric: tabular-nums;
  font-size: 0.75rem;
  color: var(--text-primary);
}

/* Native accessible range slider per modern-web-guidance `slider` */
input[type="range"].styled-slider {
  --slider-track-size: 0.38rem;
  --slider-thumb-size: 1rem;
  --slider-track-radius: 999px;
  --slider-thumb-radius: 50%;
  --slider-track-color: rgba(148, 163, 184, 0.32);
  --slider-fill-color: var(--brand-color);
  --slider-thumb-color: var(--slider-fill-color);
  --slider-direction: to right;

  --attr-min: attr(min type(<number>), 0);
  --attr-max: attr(max type(<number>), 100);
  --control-value: attr(value type(<number>), 50);
  --slider-progress: calc(
    progress(var(--control-value), var(--attr-min), var(--attr-max)) * 100%
  );

  appearance: none;
  inline-size: 7.5rem;
  block-size: 2rem;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  cursor: pointer;
}

input[type="range"].styled-slider:dir(rtl) {
  --slider-direction: to left;
}

@supports not (opacity: progress(1, 0, 100)) {
  input[type="range"].styled-slider {
    --slider-progress: calc(
      (var(--control-value) - var(--attr-min)) /
      (var(--attr-max) - var(--attr-min)) * 100%
    );
  }
}

input[type="range"].styled-slider::-webkit-slider-runnable-track {
  block-size: var(--slider-track-size);
  border: 0;
  border-radius: var(--slider-track-radius);
  background: linear-gradient(
    var(--slider-direction),
    var(--slider-fill-color) var(--slider-progress),
    var(--slider-track-color) var(--slider-progress)
  );
}

input[type="range"].styled-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  inline-size: var(--slider-thumb-size);
  block-size: var(--slider-thumb-size);
  margin-block-start: calc((var(--slider-track-size) - var(--slider-thumb-size)) / 2);
  border: 0;
  border-radius: var(--slider-thumb-radius);
  background: var(--slider-thumb-color);
}

input[type="range"].styled-slider::-moz-range-track {
  block-size: var(--slider-track-size);
  border: 0;
  border-radius: var(--slider-track-radius);
  background: var(--slider-track-color);
}

input[type="range"].styled-slider::-moz-range-progress {
  block-size: var(--slider-track-size);
  border-radius: var(--slider-track-radius);
  background: var(--slider-fill-color);
}

input[type="range"].styled-slider::-moz-range-thumb {
  inline-size: var(--slider-thumb-size);
  block-size: var(--slider-thumb-size);
  border: 0;
  border-radius: var(--slider-thumb-radius);
  background: var(--slider-thumb-color);
}

input[type="range"].styled-slider:focus-visible {
  outline: 2px solid var(--slider-fill-color);
  outline-offset: 4px;
}

.spec-note {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.sr-only {
  position: absolute;
  inline-size: 1px;
  block-size: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}