:root {
  --hdc-bg: #f5f5f5;
  --hdc-card: #ffffff;
  --hdc-fg: #0a0a0a;
  --hdc-muted: #6b6b6f;
  --hdc-border: #e7e7e8;
  --hdc-accent: #0a0a0a;
  --hdc-accent-fg: #ffffff;
  --hdc-track: #e2e2e3;
  --hdc-shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 12px 24px -12px rgba(0, 0, 0, 0.12);
  --hdc-radius-lg: 20px;
  --hdc-radius-md: 12px;
  --hdc-radius-sm: 8px;
  --hdc-radius-pill: 999px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --hdc-bg: #0a0a0a;
    --hdc-card: #161616;
    --hdc-fg: #f5f5f5;
    --hdc-muted: #9a9a9d;
    --hdc-border: #2a2a2c;
    --hdc-accent: #f5f5f5;
    --hdc-accent-fg: #0a0a0a;
    --hdc-track: #2c2c2e;
    --hdc-shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 16px 32px -16px rgba(0, 0, 0, 0.6);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--hdc-bg);
  color: var(--hdc-fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.hdc-tester {
  width: 100%;
  padding: 40px 24px 64px;
}

/* ---------- toolbar ---------- */

.hdc-toolbar {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.hdc-status {
  color: var(--hdc-muted);
  font-size: 13px;
  margin: 0 0 16px;
}

.hdc-toolbar__controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

.hdc-invert-btn {
  appearance: none;
  border: 1px solid var(--hdc-border);
  background: transparent;
  color: var(--hdc-fg);
  font-size: 13px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: var(--hdc-radius-pill);
  cursor: pointer;
  transition: background-color 120ms ease, color 120ms ease, border-color 120ms ease;
}

.hdc-invert-btn:hover {
  border-color: color-mix(in srgb, var(--hdc-fg) 30%, var(--hdc-border));
}

.hdc-invert-btn[aria-pressed="true"] {
  background: var(--hdc-accent);
  color: var(--hdc-accent-fg);
  border-color: var(--hdc-accent);
}

.hdc-invert-btn:focus-visible {
  outline: 2px solid var(--hdc-fg);
  outline-offset: 2px;
}

.hdc-select {
  appearance: none;
  -webkit-appearance: none;
  min-width: 220px;
  padding: 9px 36px 9px 14px;
  font-size: 13px;
  font-weight: 500;
  border: 1px solid var(--hdc-border);
  border-radius: var(--hdc-radius-pill);
  background-color: var(--hdc-card);
  color: var(--hdc-fg);
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6' fill='none'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%236b6b6f' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  transition: border-color 150ms ease;
}

.hdc-select:hover { border-color: color-mix(in srgb, var(--hdc-fg) 25%, var(--hdc-border)); }
.hdc-select:focus-visible { outline: 2px solid var(--hdc-fg); outline-offset: 2px; }

/* ---------- searchable font picker ---------- */

.hdc-font-picker {
  position: relative;
}

.hdc-font-picker__btn {
  display: block;
  width: 100%;
}

.hdc-font-picker__btn span {
  display: block;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  text-align: left;
}

.hdc-font-panel {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: 320px;
  max-width: 90vw;
  background: var(--hdc-card);
  border: 1px solid var(--hdc-border);
  border-radius: var(--hdc-radius-md);
  box-shadow: var(--hdc-shadow);
  overflow: hidden;
  z-index: 20;
}

.hdc-font-search {
  display: block;
  width: 100%;
  box-sizing: border-box;
  padding: 12px 14px;
  font-size: 13px;
  border: none;
  border-bottom: 1px solid var(--hdc-border);
  background: transparent;
  color: var(--hdc-fg);
  outline: none;
}

.hdc-font-search::placeholder {
  color: var(--hdc-muted);
}

.hdc-font-listbox {
  list-style: none;
  margin: 0;
  padding: 6px;
  max-height: 280px;
  overflow-y: auto;
}

.hdc-font-option {
  padding: 8px 10px;
  font-size: 13px;
  border-radius: var(--hdc-radius-sm);
  cursor: pointer;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.hdc-font-option:hover,
.hdc-font-option.is-highlighted {
  background: var(--hdc-track);
}

.hdc-font-option[aria-selected="true"] {
  font-weight: 600;
}

.hdc-font-option-empty {
  padding: 10px;
  font-size: 13px;
  color: var(--hdc-muted);
}

/* ---------- preview ---------- */

.hdc-preview-card {
  background: var(--hdc-card);
  color: var(--hdc-fg);
  border: 1px solid var(--hdc-border);
  border-radius: var(--hdc-radius-lg);
  box-shadow: var(--hdc-shadow);
  padding: 56px 40px;
  min-height: 220px;
  display: flex;
  align-items: center;
  transition: background-color 150ms ease, color 150ms ease;
}

.hdc-preview-card.is-inverted {
  background: var(--hdc-fg);
  color: var(--hdc-bg);
  border-color: var(--hdc-fg);
}

.hdc-preview-card.is-inverted .hdc-preview {
  caret-color: var(--hdc-bg);
}

.hdc-preview {
  width: 100%;
  outline: none;
  font-size: 48px;
  line-height: 1.2;
  letter-spacing: 0;
  word-break: break-word;
  caret-color: var(--hdc-fg);
}

.hdc-preview:focus-visible {
  box-shadow: none;
}

/* ---------- controls panel ---------- */

.hdc-panel {
  background: var(--hdc-card);
  border: 1px solid var(--hdc-border);
  border-radius: var(--hdc-radius-md);
  box-shadow: var(--hdc-shadow);
  padding: 14px 24px;
  margin-bottom: 16px;
}

.hdc-sliders {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.hdc-control__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 6px;
}

.hdc-control label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--hdc-muted);
}

.hdc-control__value {
  font-size: 13px;
  font-weight: 500;
  color: var(--hdc-fg);
  font-variant-numeric: tabular-nums;
}

/* custom range slider */

.hdc-control input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  border-radius: var(--hdc-radius-pill);
  background: linear-gradient(
    to right,
    var(--hdc-accent) 0%,
    var(--hdc-accent) var(--hdc-fill, 0%),
    var(--hdc-track) var(--hdc-fill, 0%),
    var(--hdc-track) 100%
  );
  cursor: pointer;
  outline: none;
}

.hdc-control input[type="range"]::-webkit-slider-runnable-track {
  height: 4px;
  background: transparent;
  border-radius: var(--hdc-radius-pill);
}

.hdc-control input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  margin-top: -6px;
  border-radius: 50%;
  background: var(--hdc-accent);
  border: 2px solid var(--hdc-card);
  box-shadow: 0 0 0 1px var(--hdc-border), 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform 120ms ease;
}

.hdc-control input[type="range"]:hover::-webkit-slider-thumb { transform: scale(1.1); }
.hdc-control input[type="range"]:active::-webkit-slider-thumb { transform: scale(1.15); }

.hdc-control input[type="range"]::-moz-range-track {
  height: 4px;
  background: transparent;
  border-radius: var(--hdc-radius-pill);
}

.hdc-control input[type="range"]::-moz-range-progress {
  height: 4px;
  background: var(--hdc-accent);
  border-radius: var(--hdc-radius-pill);
}

.hdc-control input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--hdc-accent);
  border: 2px solid var(--hdc-card);
  box-shadow: 0 0 0 1px var(--hdc-border), 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform 120ms ease;
}

.hdc-control input[type="range"]:hover::-moz-range-thumb { transform: scale(1.1); }
.hdc-control input[type="range"]:focus-visible::-webkit-slider-thumb { outline: 2px solid var(--hdc-fg); outline-offset: 2px; }

/* ---------- narrow screens ---------- */

@media (max-width: 700px) {
  .hdc-sliders {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 560px) {
  .hdc-tester { padding: 24px 16px 48px; }
  .hdc-preview-card { padding: 32px 24px; min-height: 160px; }
  .hdc-panel { padding: 14px 18px; }
  .hdc-toolbar__controls { width: 100%; }
  .hdc-font-picker { min-width: 0; flex: 1; }
  .hdc-select { min-width: 0; }
  .hdc-font-panel { width: 100%; right: 0; }
}