:root {
  --bg: #faf9f7;
  --ink: #1c1917;
  --muted: #78716c;
  --line: #e4e0da;
  --panel: #ffffff;
  --danger: #b4341f;
}

* { box-sizing: border-box; }

/* Class-based display rules would otherwise out-specify the UA [hidden] rule. */
[hidden] { display: none !important; }

body {
  margin: 0;
  padding: 56px 32px 96px;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.6 ui-sans-serif, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

header { max-width: 1080px; margin: 0 auto 48px; }

h1 {
  margin: 0;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.tagline { margin: 6px 0 0; color: var(--muted); font-size: 14px; }

main { max-width: 1080px; margin: 0 auto; }

h2 {
  margin: 0 0 20px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

/* --- upload --- */

#screen-upload { max-width: 560px; }

#dropzone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 240px;
  padding: 40px;
  border: 1px dashed var(--line);
  border-radius: 10px;
  background: var(--panel);
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}

#dropzone:hover, #dropzone.dragging {
  border-color: var(--ink);
  background: #fff;
}

.drop-title { font-size: 16px; font-weight: 500; }
.drop-sub { color: var(--muted); font-size: 13px; }

.field { margin-top: 36px; }
.field + .field { margin-top: 24px; }

.field-label {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  color: var(--muted);
}

.seg { display: flex; gap: 8px; }

.seg button {
  min-width: 44px;
  height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--ink);
  font: inherit;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}

.seg button:hover { border-color: var(--muted); }

.seg button.on {
  background: var(--ink);
  border-color: var(--ink);
  color: #fff;
}

.tips { margin-top: 40px; color: var(--muted); font-size: 13px; }
.tips summary { cursor: pointer; }
.tips ul { margin: 12px 0 0; padding-left: 18px; }
.tips li { margin-bottom: 4px; }

.error { margin-top: 20px; color: var(--danger); font-size: 14px; }

.note {
  margin: 20px 0 0;
  padding: 10px 12px;
  border-left: 2px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

/* --- workspace --- */

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 48px;
  align-items: start;
}

.preview {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px;
  display: flex;
  justify-content: center;
}

.preview canvas {
  max-width: 100%;
  max-height: 68vh;
  height: auto;
  display: block;
  border-radius: 4px;
}

/* --- swatches --- */

.swatches { display: flex; flex-direction: column; gap: 14px; }

.swatch {
  display: flex;
  align-items: center;
  gap: 12px;
}

.swatch input[type="color"] {
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: none;
  cursor: pointer;
}

.swatch input[type="color"]::-webkit-color-swatch-wrapper { padding: 3px; }
.swatch input[type="color"]::-webkit-color-swatch { border: none; border-radius: 5px; }

.swatch-body { flex: 1; min-width: 0; }

.swatch-name { font-size: 12px; color: var(--muted); }

.swatch input[type="text"] {
  width: 100%;
  margin-top: 3px;
  padding: 4px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel);
  color: var(--ink);
  font: 13px/1.4 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.03em;
}

.swatch input[type="text"]:focus { outline: 1px solid var(--ink); border-color: var(--ink); }
.swatch input[type="text"].invalid { border-color: var(--danger); color: var(--danger); }

/* Detected colour; click to reset the pick back to it. */
.swatch-reset {
  flex: none;
  width: 22px;
  height: 22px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 50%;
  cursor: pointer;
}
.swatch-reset:hover { border-color: var(--ink); }

/* --- buttons --- */

.actions { display: flex; flex-direction: column; gap: 8px; margin-top: 32px; }

button.primary, button.ghost {
  padding: 10px 16px;
  border-radius: 8px;
  font: inherit;
  cursor: pointer;
  transition: opacity .15s, border-color .15s;
}

button.primary { border: 1px solid var(--ink); background: var(--ink); color: #fff; }
button.primary:hover { opacity: .85; }
button.primary:disabled { opacity: .35; cursor: default; }

button.ghost { border: 1px solid transparent; background: none; color: var(--muted); }
button.ghost:hover { color: var(--ink); }

.checkbox { display: flex; align-items: center; gap: 8px; font-size: 14px; cursor: pointer; }
.checkbox input { width: 15px; height: 15px; accent-color: var(--ink); }

/* --- processing --- */

.processing {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  background: rgba(250, 249, 247, .92);
  color: var(--muted);
  font-size: 14px;
  z-index: 10;
}

.spinner {
  width: 22px;
  height: 22px;
  border: 2px solid var(--line);
  border-top-color: var(--ink);
  border-radius: 50%;
  animation: spin .7s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 800px) {
  body { padding: 32px 20px 64px; }
  .workspace { grid-template-columns: 1fr; gap: 32px; }
}