/* 現代極簡黑白灰主題：淺色為主、髮絲線邊框、藥丸按鈕、大量留白。
   跟隨系統深色模式（同為黑白灰）。Mobile-first 單欄版面。 */

.van-gogh-filter-wrapper {
  --bg: #fafafa;
  --surface: #ffffff;
  --text: #111111;
  --text-2: #6b6b6b;
  --line: #e5e5e5;
  --line-strong: #cfcfcf;
  --accent: #111111;
  /* 黑就是強調色 */
  --accent-contrast: #ffffff;
  --radius: 14px;
  --shadow: 0 10px 32px rgba(0, 0, 0, 0.08);
}

@media (prefers-color-scheme: dark) {
  .van-gogh-filter-wrapper {
    --bg: #0e0e0e;
    --surface: #171717;
    --text: #f2f2f2;
    --text-2: #969696;
    --line: #2a2a2a;
    --line-strong: #3d3d3d;
    --accent: #f2f2f2;
    --accent-contrast: #111111;
    --shadow: 0 10px 32px rgba(0, 0, 0, 0.5);
  }
}

.van-gogh-filter-wrapper main {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 56px;
}

.van-gogh-filter-wrapper header {
  text-align: center;
  margin-bottom: 32px;
}

.van-gogh-filter-wrapper h1 {
  font-size: 1.3rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

#subtitle {
  color: var(--text-2);
  margin-top: 6px;
  font-size: 0.9rem;
}

.muted {
  color: var(--text-2);
  font-size: 0.85rem;
}

/* 狀態機顯示控制 */
#screen-idle,
#screen-preview,
#screen-studio {
  display: none;
}

body[data-state="idle"] #screen-idle {
  display: block;
}

body[data-state="preview"] #screen-preview {
  display: block;
}

body[data-state="painting"] #screen-studio,
body[data-state="done"] #screen-studio {
  display: block;
}

body[data-state="painting"] #done-controls {
  display: none;
}

body[data-state="done"] #progress-area {
  display: none;
}

/* 上傳區 */
#dropzone {
  border: 1.5px dashed var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 72px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, transform 0.15s;
}

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

#dropzone:active {
  transform: scale(0.995);
}

.drop-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  border: 1.5px solid var(--line-strong);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  font-weight: 300;
  color: var(--text-2);
}

#dropzone:hover .drop-icon {
  border-color: var(--text);
  color: var(--text);
}

#drop-hint {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
}

/* 預覽 */
.preview-wrap {
  position: relative;
}

#preview-img,
#debug-canvas,
#tone-canvas {
  width: 100%;
  border-radius: var(--radius);
  display: block;
}

#debug-canvas,
#tone-canvas {
  position: absolute;
  inset: 0;
  height: 100%;
}

.controls {
  margin-top: 24px;
}

.slider-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 10px;
}

.slider-row label {
  flex: 0 0 7.5em;
  font-size: 0.9rem;
  font-weight: 600;
}

/* 每個滑桿下方的一行說明 */
.slider-hint {
  color: var(--text-2);
  font-size: 0.78rem;
  line-height: 1.55;
  margin: -4px 0 16px;
}

/* 進階調整（摺疊） */
#advanced,
#tone-panel {
  margin: 10px 0 6px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 0 16px;
}

#advanced[open],
#tone-panel[open] {
  padding-bottom: 6px;
}

#advanced summary,
#tone-panel summary {
  cursor: pointer;
  padding: 13px 0;
  color: var(--text-2);
  font-size: 0.9rem;
  font-weight: 600;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

#advanced summary::-webkit-details-marker,
#tone-panel summary::-webkit-details-marker {
  display: none;
}

#advanced summary::after,
#tone-panel summary::after {
  content: "+";
  font-size: 1.1rem;
  font-weight: 400;
  transition: transform 0.15s;
}

#advanced[open] summary::after,
#tone-panel[open] summary::after {
  content: "−";
}

#advanced summary:hover,
#tone-panel summary:hover {
  color: var(--text);
}

#advanced .slider-row:first-of-type,
#tone-panel .slider-row:first-of-type {
  margin-top: 4px;
}

.slider-row input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  height: 28px;
  /* 觸控友善 */
}

.slider-row output {
  flex: 0 0 3.4em;
  text-align: right;
  color: var(--text-2);
  font-size: 0.85rem;
  font-variant-numeric: tabular-nums;
}

/* 按鈕：主要＝實心黑（深色模式為白），次要＝髮絲線描邊 */
.van-gogh-filter-wrapper .btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.van-gogh-filter-wrapper button {
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 13px 24px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--text);
  cursor: pointer;
  min-height: 46px;
  /* 觸控友善 */
  transition: border-color 0.15s, opacity 0.15s, transform 0.1s;
}

.van-gogh-filter-wrapper button:hover {
  border-color: var(--text);
}

.van-gogh-filter-wrapper button:active {
  transform: scale(0.98);
}

.van-gogh-filter-wrapper button:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 2px;
}

.van-gogh-filter-wrapper button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-contrast);
  flex: 1 1 auto;
}

.van-gogh-filter-wrapper button.primary:hover {
  opacity: 0.82;
}

.van-gogh-filter-wrapper button.small {
  padding: 7px 16px;
  min-height: 0;
  font-size: 0.85rem;
}

/* 色調濾鏡 chips（preview 控制區最上方） */
#filter-row {
  margin-bottom: 10px;
}

.filter-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 8px;
}

#filter-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

#filter-chips .chip {
  padding: 8px 14px;
  min-height: 0;
  font-size: 0.85rem;
  border-radius: 999px;
}

#filter-chips .chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-contrast);
  font-weight: 600;
}

/* 畫布：p5 建立在渲染解析度，CSS 縮放顯示 */
.canvas-wrap canvas {
  width: 100% !important;
  height: auto !important;
  display: block;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* 進度條（DOM 元素，不畫進 canvas） */
#progress-area {
  margin-top: 18px;
}

#progress-bar {
  height: 3px;
  background: var(--line);
  border-radius: 2px;
  overflow: hidden;
}

#progress-fill {
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.15s linear;
}

.progress-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 12px;
  color: var(--text-2);
  font-size: 0.9rem;
}

/* 窄螢幕微調 */
@media (max-width: 420px) {

  #dropzone {
    padding: 56px 18px;
  }

  .slider-row label {
    flex: 0 0 6.8em;
    font-size: 0.85rem;
  }
}