@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@300;400;500&family=Playfair+Display:wght@400;700;900&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --ink: #1a1208;
  --paper: #f5f0e8;
  --cream: #ede8dc;
  --accent: #c8502a;
  --accent2: #4a7c59;
  --light-rule: #d4cec0;
  --shadow: rgba(26,18,8,0.12);
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'DM Mono', monospace;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Ruled paper lines */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: repeating-linear-gradient(
    transparent,
    transparent 27px,
    var(--light-rule) 27px,
    var(--light-rule) 28px
  );
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
}

header {
  position: relative;
  z-index: 1;
  padding: 2.5rem 3rem 1.5rem;
  border-bottom: 3px solid var(--ink);
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
}

header h1 {
  font-family: 'Playfair Display', serif;
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1;
}

header h1 em {
  font-style: normal;
  color: var(--accent);
}

header span {
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  opacity: 0.5;
  padding-bottom: 0.3em;
}

.layout {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 0;
  flex: 1;
}

/* Left panel */
.panel {
  border-right: 2px solid var(--ink);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  background: var(--cream);
}

.section-label {
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  opacity: 0.45;
  margin-bottom: 0.5rem;
}

/* Upload zone */
.upload-zone {
  border: 2px dashed var(--ink);
  border-radius: 0;
  padding: 2rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
  position: relative;
  background: var(--paper);
}
.upload-zone:hover, .upload-zone.drag-over {
  background: #fff;
  border-color: var(--accent);
}
.upload-zone input { display: none; }

.upload-icon {
  display: block;
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
  line-height: 1;
}
.upload-zone p {
  font-size: 0.75rem;
  line-height: 1.6;
  opacity: 0.6;
}
.upload-zone p strong { opacity: 1; color: var(--accent); }

.thumb-preview {
  width: 100%;
  max-height: 150px;
  object-fit: contain;
  margin-top: 0.75rem;
  display: none;
  border: 1px solid var(--light-rule);
}

/* Slider */
.slider-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.5rem;
}
.slider-row input[type=range] {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 3px;
  background: var(--ink);
  outline: none;
  cursor: pointer;
}
.slider-row input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent);
  border: 2px solid var(--ink);
  cursor: pointer;
  border-radius: 0;
}
.slider-row input[type=range]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--accent);
  border: 2px solid var(--ink);
  cursor: pointer;
  border-radius: 0;
}
.colour-count {
  font-family: 'Playfair Display', serif;
  font-size: 1.6rem;
  font-weight: 700;
  min-width: 2ch;
  text-align: right;
  color: var(--accent);
}

.smooth-label {
  font-family: 'Playfair Display', serif;
  font-style: italic;
  font-size: 0.9rem;
  font-weight: 400;
  min-width: 5ch;
  text-align: right;
  color: var(--accent);
}

.hint {
  font-size: 0.65rem;
  opacity: 0.5;
  margin-top: 0.5rem;
  line-height: 1.4;
}

/* Buttons */
.btn {
  font-family: 'DM Mono', monospace;
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  border: 2px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  padding: 0.85rem 1.5rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, transform 0.1s;
  width: 100%;
}
.btn:hover:not(:disabled) {
  background: var(--accent);
  border-color: var(--accent);
  transform: translateY(-1px);
}
.btn:disabled { opacity: 0.35; cursor: not-allowed; }

/* Options */
.options-stack {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.option-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.7rem;
  cursor: pointer;
  user-select: none;
}
.option-row input[type=checkbox] {
  -webkit-appearance: none;
  appearance: none;
  width: 14px; height: 14px;
  border: 2px solid var(--ink);
  background: var(--paper);
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
}
.option-row input[type=checkbox]:checked {
  background: var(--ink);
}
.option-row input[type=checkbox]:checked::after {
  content: '✓';
  position: absolute;
  color: var(--paper);
  font-size: 9px;
  top: -1px; left: 1px;
}

/* Colour palette list */
.palette-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.palette-entry {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.7rem;
  animation: fadeIn 0.3s ease both;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateX(-6px); }
  to   { opacity: 1; transform: none; }
}

.swatch {
  width: 28px; height: 28px;
  border: 2px solid var(--ink);
  flex-shrink: 0;
}
.palette-num {
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: 1.1rem;
  min-width: 1.4ch;
  color: var(--accent);
}
.palette-hex {
  opacity: 0.55;
  font-size: 0.65rem;
}

/* Main canvas area */
.canvas-area {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: 1.5rem;
  min-height: 0;
  overflow: auto;
}

.empty-state {
  margin: auto;
  text-align: center;
  opacity: 0.3;
}
.empty-state svg { width: 64px; height: 64px; margin-bottom: 1rem; }
.empty-state p {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.output-wrapper {
  position: relative;
  display: inline-block;
  max-width: 100%;
}

#outputCanvas {
  display: block;
  max-width: 100%;
  border: 2px solid var(--ink);
  box-shadow: 6px 6px 0 var(--shadow);
  image-rendering: pixelated;
}

/* Toolbar above the canvas */
.canvas-toolbar {
  display: flex;
  align-items: center;
  gap: 1rem;
  align-self: stretch;
}

.toolbar-spacer { flex: 1; }

.btn-sm {
  font-family: 'DM Mono', monospace;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: 2px solid var(--ink);
  background: transparent;
  color: var(--ink);
  padding: 0.5rem 0.9rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.btn-sm:hover { background: var(--ink); color: var(--paper); }

/* Painted / blank toggle — a dual-labeled pill switch */
.toggle-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  cursor: pointer;
  user-select: none;
}
.toggle-pill input[type=checkbox] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.pill-track {
  position: relative;
  width: 44px;
  height: 22px;
  background: var(--paper);
  border: 2px solid var(--ink);
  transition: background 0.2s;
  flex-shrink: 0;
}
.pill-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 14px;
  height: 14px;
  background: var(--ink);
  transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1), background 0.2s;
}
.toggle-pill input:checked + .pill-track {
  background: var(--accent);
}
.toggle-pill input:checked + .pill-track .pill-thumb {
  transform: translateX(22px);
  background: var(--paper);
}

.pill-labels {
  display: inline-flex;
  gap: 0.35rem;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  align-items: baseline;
}
.pill-option {
  opacity: 0.3;
  transition: opacity 0.2s, color 0.2s;
}
.pill-sep { opacity: 0.2; }

.toggle-pill input:not(:checked) ~ .pill-labels .pill-option[data-state="off"],
.toggle-pill input:checked ~ .pill-labels .pill-option[data-state="on"] {
  opacity: 1;
  color: var(--accent);
  font-weight: 500;
}

/* Progress bar */
.progress-bar-wrap {
  width: 100%;
  max-width: 400px;
  margin: auto;
  text-align: center;
}
.progress-label {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
  opacity: 0.6;
}
.progress-track {
  height: 3px;
  background: var(--light-rule);
  position: relative;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--accent);
  width: 0%;
  transition: width 0.1s;
}
.progress-indeterminate .progress-fill {
  width: 40% !important;
  animation: slide 1s linear infinite;
}
@keyframes slide {
  from { transform: translateX(-150%); }
  to   { transform: translateX(350%); }
}

/* Responsive */
@media (max-width: 700px) {
  .layout { grid-template-columns: 1fr; }
  .panel {
    border-right: none;
    border-bottom: 2px solid var(--ink);
  }
  header { padding: 1.5rem; }
}