.contrast-app {
  display: grid; grid-template-columns: minmax(0, 27rem) minmax(0, 1fr);
  gap: 2rem clamp(2rem, 5vw, 5rem); max-width: 76rem; margin: 1rem auto 0; align-items: start;
}

.pickers { display: grid; grid-template-columns: 1fr auto 1fr; align-items: end; gap: 0.8rem; margin-top: 1.8rem; }
.picker { display: grid; gap: 0.4rem; min-width: 0; }
.picker-row { display: flex; align-items: center; gap: 0.6rem; }
.swap { padding: 0.55rem 1rem; margin-bottom: 0.2rem; }

.swatch {
  flex: none; width: 3.1rem; height: 3.1rem; padding: 0; border: 2px solid var(--mist); border-radius: 50%;
  background: none; cursor: pointer; overflow: hidden;
}
.swatch::-webkit-color-swatch-wrapper { padding: 0; }
.swatch::-webkit-color-swatch { border: 0; border-radius: 50%; }
.swatch::-moz-color-swatch { border: 0; border-radius: 50%; }

.hex {
  width: 100%; min-width: 0; padding: 0.7rem 0.9rem; border-radius: 0.8rem;
  border: 2px solid rgb(255 255 255 / 0.45); background: rgb(255 255 255 / 0.08); color: var(--mist);
  font-family: var(--display); font-variation-settings: "wdth" 100, "wght" 560; font-size: 1.05rem; text-transform: uppercase;
  transition: border-color 0.2s;
}
.hex:hover { border-color: rgb(255 255 255 / 0.8); }
.hex[aria-invalid="true"] { border-color: var(--sun); }
.hex-error { min-height: 1.4em; margin-top: 0.5rem; color: var(--sun); }

.presets { display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem; margin-top: 0.6rem; }
.presets .ui { margin-right: 0.3rem; opacity: 0.85; }
.presets .chip { min-width: 3.1rem; font-size: 1rem; }
.presets .chip:hover { filter: brightness(1.1); }

.result { margin-top: 2.2rem; }
.ratio {
  font-family: var(--display); font-variation-settings: "wdth" 112, "wght" 800;
  font-size: clamp(3.4rem, 8vw, 5.6rem); line-height: 1; letter-spacing: -0.04em; color: var(--sun);
}
.grade { margin-top: 0.4rem; min-height: 2.7em; font-size: 1.3rem; }

.checks { margin-top: 1rem; border-top: 2px solid rgb(255 255 255 / 0.25); }
.checks li {
  display: grid; grid-template-columns: 1fr auto auto; align-items: center; gap: 0.3rem 1rem;
  padding: 0.75rem 0; border-bottom: 2px solid rgb(255 255 255 / 0.25);
}
.check-name { font-size: 1.15rem; }
.check-need { opacity: 0.8; }
.badge { min-width: 4.2rem; padding: 0.3rem 0.8rem; text-align: center; border-radius: 999px; border: 2px solid currentColor; }
.badge.pass { background: var(--sun); border-color: var(--sun); color: var(--ink); }
.note { margin-top: 0.9rem; font-size: 1rem; opacity: 0.8; }

/* Live preview in the chosen colours */
.preview {
  --pfg: #ffd426; --pbg: #2b35ff;
  display: grid; align-content: center; gap: 1.6rem; min-height: 26rem;
  padding: clamp(1.5rem, 4vw, 3.2rem); border-radius: 1.5rem;
  background: var(--pbg); color: var(--pfg); outline: 2px solid rgb(255 255 255 / 0.25); outline-offset: 2px;
  position: sticky; top: 1rem;
}
.pv-large { font-family: var(--display); font-variation-settings: "wdth" 108, "wght" 800; font-size: clamp(2rem, 4.5vw, 3.4rem); line-height: 1; letter-spacing: -0.03em; }
.pv-body { max-width: 34rem; font-family: var(--display); font-variation-settings: "wdth" 100, "wght" 400; font-size: 1rem; line-height: 1.55; }
.pv-row { display: flex; flex-wrap: wrap; align-items: center; gap: 1rem; }
.pv-button {
  padding: 0.7rem 1.4rem; border: 2px solid var(--pfg); border-radius: 999px;
  font-family: var(--display); font-variation-settings: "wdth" 105, "wght" 620; font-size: 0.95rem;
}
.pv-icon { width: 1.6rem; height: 1.6rem; border-radius: 50%; border: 3px solid var(--pfg); }
.pv-note { font-family: var(--display); font-variation-settings: "wdth" 100, "wght" 500; font-size: 0.95rem; }

@media (max-width: 900px) {
  .contrast-app { grid-template-columns: minmax(0, 1fr); }
  .preview { position: static; order: -1; min-height: 18rem; }
}
@media (max-width: 520px) {
  .pickers { grid-template-columns: 1fr; }
  .swap { justify-self: start; }
}