:root {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #172033;
  background: #f5f7fb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.app {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(280px, 420px) 1fr;
  gap: 2rem;
  padding: 2rem;
  align-items: center;
}

.panel,
.preview {
  background: #ffffff;
  border: 1px solid #dde3ef;
  border-radius: 24px;
  box-shadow: 0 12px 40px rgba(23, 32, 51, 0.08);
}

.panel {
  padding: 2rem;
}

.preview {
  padding: 2rem;
  display: grid;
  place-items: center;
}

h1 {
  margin: 0 0 0.5rem;
}

.intro {
  margin-top: 0;
  color: #5f6c80;
}

label {
  display: grid;
  gap: 0.4rem;
  margin: 1rem 0;
  font-weight: 600;
}

input,
select,
button {
  font: inherit;
}

input[type="url"],
select {
  width: 100%;
  border: 1px solid #cbd5e1;
  border-radius: 12px;
  padding: 0.8rem 0.9rem;
}

input[type="color"] {
  width: 56px;
  height: 44px;
  border: 1px solid #cbd5e1;
  border-radius: 12px;
  background: #ffffff;
  padding: 0.2rem;
}

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 1rem;
}

.colour-row {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 0.5rem;
  align-items: center;
}

.hex-input {
  width: 100%;
  border: 1px solid #cbd5e1;
  border-radius: 12px;
  padding: 0.8rem 0.9rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  text-transform: uppercase;
}

.hex-input:invalid,
.hex-input.invalid {
  border-color: #b42318;
}

.checkbox {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

#status {
  min-height: 1.5rem;
  color: #b42318;
}

.buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

button {
  cursor: pointer;
  border: 0;
  border-radius: 999px;
  padding: 0.8rem 1rem;
  background: #172033;
  color: #ffffff;
  font-weight: 700;
}

button:hover {
  opacity: 0.9;
}

canvas {
  width: min(100%, 512px);
  height: auto;
  image-rendering: crisp-edges;
}

@media (max-width: 820px) {
  .app {
    grid-template-columns: 1fr;
    padding: 1rem;
  }
}