/* Design tokens mirror the original "总是XX" so the look carries over. */
:root {
  --color-ink: #1f3a5f;
  --color-ink-soft: #6b82a3;
  --color-surface: #f5f9ff;
  --color-surface-canvas: #fff;
  --color-border: #d2e4f9;
  --color-error: #e53935;
  --color-clear-bg: #fdecec;
  --color-clear-ink: #d33a3a;
  --color-primary: #64b5f6;
  --color-primary-soft: #64b5f640;
  --color-panel-bg: #f2f8ff;
  --color-panel-border: #64b5f666;
  --color-ios-bg: #f2f2f7;
  --color-ios-separator: #3c3c4333;

  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;

  --font-size-sm: 13px;
  --font-size-md: 15px;
  --font-size-lg: 18px;
  --font-size-xl: 26px;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-full: 999px;

  --duration-fast: 0.12s;
  --duration-base: 0.24s;

  --shadow-card: 0 2px 12px #1f3a5f24;
  --shadow-btn: 0 2px 6px #64b5f666;
}

* { box-sizing: border-box; }

html, body { margin: 0; height: 100%; }

body {
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Noto Sans JP",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-text-size-adjust: 100%;
  overscroll-behavior: none;
}

.app {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Step indicator */

.steps {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin: var(--space-lg) auto var(--space-xl);
  padding: 10px 20px;
  background: var(--color-surface-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--font-size-md);
  color: var(--color-ink-soft);
  box-shadow: var(--shadow-card);
}

.steps[hidden] { display: none; }

.steps__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  transition: color var(--duration-base);
}

.steps__item.is-active { color: var(--color-primary); font-weight: 600; }

.steps__dot {
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 1.5px solid currentColor;
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.steps__item.is-active .steps__dot {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

.steps__line { width: 32px; height: 1px; background: var(--color-border); }

/* Screens */

.screen {
  width: 100%;
  max-width: 720px;
  padding: 0 var(--space-md) var(--space-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.screen[hidden] { display: none; }

.screen__title {
  margin: 0 0 var(--space-md);
  font-size: clamp(30px, 8vw, 43px);
  font-weight: 800;
  letter-spacing: 0.01em;
  text-align: center;
}

.screen__hint {
  margin: 0 0 var(--space-xl);
  color: var(--color-ink-soft);
  font-size: var(--font-size-md);
  text-align: center;
}

/* Shape picker */

.shape-grid-wrap { position: relative; width: 100%; }

.shape-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.shape-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-lg) var(--space-md);
  background: var(--color-surface-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  font: inherit;
  color: var(--color-ink-soft);
  cursor: pointer;
  transition: transform var(--duration-fast), border-color var(--duration-fast),
    box-shadow var(--duration-fast);
}

.shape-card:hover { transform: translateY(-2px); }
.shape-card:active { transform: scale(0.98); }

.shape-card.is-active {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-btn);
}

.shape-card__art {
  width: 100%;
  aspect-ratio: 1;
  max-height: 150px;
  display: grid;
  place-items: center;
  color: var(--color-ink-soft);
}

.shape-card__art svg { width: auto; height: auto; max-width: 100%; max-height: 100%; }

.shape-card__name {
  font-size: var(--font-size-md);
  font-weight: 600;
  text-align: center;
  word-break: break-word;
}

.shape-card__delete {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border: none;
  border-radius: 50%;
  background: var(--color-clear-bg);
  color: var(--color-clear-ink);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
}

/* The refresh button sits over the centre of the 2x2 grid. */
.shuffle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  background: var(--color-surface-canvas);
  color: var(--color-primary);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  transition: transform var(--duration-base);
}

.shuffle:hover { transform: translate(-50%, -50%) rotate(-90deg); }
.shuffle svg { width: 22px; height: 22px; }

/* Mode picker */

.mode-grid {
  width: 100%;
  display: grid;
  gap: var(--space-md);
}

.mode-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-lg);
  background: var(--color-surface-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  font: inherit;
  color: var(--color-ink);
  cursor: pointer;
  transition: transform var(--duration-fast), border-color var(--duration-fast);
}

.mode-card:hover { transform: translateY(-2px); border-color: var(--color-primary); }

.mode-card__demo { width: 100%; max-width: 420px; height: auto; }

.mode-card__badge {
  position: absolute;
  top: 58%;
  left: 50%;
  transform: translateX(-50%);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: #fff;
  font-size: var(--font-size-sm);
  font-weight: 600;
  box-shadow: var(--shadow-btn);
  pointer-events: none;
}

.mode-card__name { font-size: var(--font-size-lg); font-weight: 700; }

.mode-card__desc {
  color: var(--color-ink-soft);
  font-size: var(--font-size-sm);
  text-align: center;
}

/* Drawing stage */

.screen--draw {
  position: fixed;
  inset: 0;
  max-width: none;
  padding: 0;
  background: var(--color-surface-canvas);
}

.stage__bg {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 12vh;
  gap: var(--space-md);
  pointer-events: none;
  user-select: none;
}

.stage__title {
  margin: 0;
  font-size: clamp(34px, 9vw, 62px);
  font-weight: 800;
  opacity: 0.18;
  text-align: center;
}

.stage__hint {
  margin: 0;
  padding: 0 var(--space-lg);
  color: var(--color-ink-soft);
  font-size: var(--font-size-md);
  text-align: center;
  opacity: 0.75;
  transition: opacity var(--duration-base);
}

.stage__bg.is-hidden { opacity: 0; transition: opacity var(--duration-base); }

.stage__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  touch-action: none;
  cursor: crosshair;
}

/* Zoom pill */

.zoom {
  position: absolute;
  top: max(var(--space-md), env(safe-area-inset-top));
  right: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 8px 12px;
  background: var(--color-surface-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-card);
}

.zoom[hidden] { display: none; }
.zoom__pct { font-size: var(--font-size-sm); font-weight: 700; }

.zoom__reset {
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  padding: 0;
  border: none;
  background: none;
  color: var(--color-ink-soft);
  cursor: pointer;
}

.zoom__reset svg { width: 16px; height: 16px; }

/* Toolbar */

.toolbar {
  position: absolute;
  left: 50%;
  bottom: max(var(--space-lg), env(safe-area-inset-bottom));
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: calc(100vw - var(--space-lg));
  padding: 10px 16px;
  background: var(--color-surface-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-card);
  overflow-x: auto;
  scrollbar-width: none;
}

.toolbar::-webkit-scrollbar { display: none; }

.toolbar__palette { display: flex; align-items: center; gap: 10px; }

.toolbar__divider {
  flex: none;
  width: 1px;
  height: 22px;
  background: var(--color-border);
}

.swatch {
  flex: none;
  width: 28px;
  height: 28px;
  padding: 0;
  border: 2px solid transparent;
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px #1f3a5f1a;
  cursor: pointer;
  transition: transform var(--duration-fast), border-color var(--duration-fast);
}

.swatch.is-active {
  border-color: var(--color-primary);
  transform: scale(1.1);
}

/* The "any colour" swatch wraps a native colour input. */
.swatch--any {
  position: relative;
  display: grid;
  place-items: center;
  overflow: hidden;
  background: conic-gradient(#f44336, #ffeb3b, #4caf50, #00bcd4, #3f51b5, #9c27b0, #f44336);
}

.swatch--any input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  border: none;
  padding: 0;
  cursor: pointer;
}

.tool {
  flex: none;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: none;
  border-radius: var(--radius-sm);
  background: none;
  color: var(--color-ink);
  cursor: pointer;
  transition: background var(--duration-fast), opacity var(--duration-fast);
}

.tool:hover:not(:disabled) { background: var(--color-panel-bg); }
.tool:disabled { opacity: 0.3; cursor: default; }
.tool svg { width: 20px; height: 20px; }

.tool--danger { color: var(--color-clear-ink); }
.tool--danger:hover:not(:disabled) { background: var(--color-clear-bg); }

/* Sheets */

.sheet {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: var(--space-md);
}

.sheet[hidden] { display: none; }

.sheet__backdrop { position: absolute; inset: 0; background: #1f3a5f66; }

.sheet__panel {
  position: relative;
  display: flex;
  flex-direction: column;
  width: min(460px, 100%);
  max-height: min(760px, 88dvh);
  background: var(--color-ios-bg);
  border-radius: 18px;
  box-shadow: 0 12px 40px #1f3a5f3d;
  overflow: hidden;
}

.sheet__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-md) var(--space-sm);
}

.sheet__title { margin: 0; font-size: var(--font-size-lg); font-weight: 700; }

.sheet__close {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border: none;
  border-radius: 50%;
  background: var(--color-border);
  color: var(--color-ink);
  font-size: 19px;
  line-height: 1;
  cursor: pointer;
}

.sheet__body {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 0 var(--space-md) var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.sheet__actions { display: flex; gap: var(--space-sm); }
.sheet__actions .btn { flex: 1; }

.sheet__error {
  margin: 0;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: var(--color-clear-bg);
  color: var(--color-clear-ink);
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.sheet__error[hidden] { display: none; }

/* iOS-style grouped list */

.group { display: flex; flex-direction: column; gap: var(--space-sm); }
.group[hidden] { display: none; }

.group__label {
  margin: 0 var(--space-sm);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-ink-soft);
}

.group__card {
  background: var(--color-surface-canvas);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.group__hint {
  margin: 0 var(--space-sm);
  font-size: 12px;
  line-height: 1.6;
  color: var(--color-ink-soft);
}

.cell {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  width: 100%;
  padding: 12px var(--space-md);
  border: none;
  background: none;
  font: inherit;
  color: inherit;
  text-align: left;
  text-decoration: none;
}

.cell + .cell { border-top: 1px solid var(--color-ios-separator); }

.cell--pick, .cell--action, .cell--link { cursor: pointer; }
.cell--action { justify-content: center; font-weight: 600; color: var(--color-primary); }

.cell__text { flex: 1; display: flex; flex-direction: column; gap: 3px; }
.cell__title { font-size: var(--font-size-md); font-weight: 600; }
.cell__desc { font-size: 12px; line-height: 1.5; color: var(--color-ink-soft); }

.cell__value {
  flex: none;
  min-width: 52px;
  text-align: right;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-ink-soft);
  font-variant-numeric: tabular-nums;
}

.cell__check { flex: none; color: var(--color-primary); font-weight: 700; opacity: 0; }
.cell--pick.is-active .cell__check { opacity: 1; }
.cell__chevron { flex: none; color: var(--color-ink-soft); font-size: 20px; }

/* Form controls */

.slider { flex: 1; accent-color: var(--color-primary); }

.switch {
  flex: none;
  width: 20px;
  height: 20px;
  accent-color: var(--color-primary);
}

.select, .input {
  flex: 1;
  font: inherit;
  color: inherit;
  padding: 8px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface-canvas);
}

input[type="color"] {
  flex: none;
  width: 44px;
  height: 30px;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: none;
  cursor: pointer;
}

.width-preview {
  flex: 1;
  height: 40px;
  max-width: 220px;
  border-radius: var(--radius-sm);
  background: var(--color-panel-bg);
}

.palette-editor {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.palette-editor__slot { position: relative; }

.palette-editor__slot input[type="color"] {
  width: 34px;
  height: 34px;
  border-radius: 50%;
}

.palette-editor__remove {
  position: absolute;
  top: -5px;
  right: -5px;
  width: 18px;
  height: 18px;
  display: grid;
  place-items: center;
  border: none;
  border-radius: 50%;
  background: var(--color-clear-bg);
  color: var(--color-clear-ink);
  font-size: 12px;
  line-height: 1;
  cursor: pointer;
}

.palette-editor__add {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 1.5px dashed var(--color-border);
  border-radius: 50%;
  background: none;
  color: var(--color-ink-soft);
  font-size: 18px;
  cursor: pointer;
}

/* Trace preview */

.trace-preview { display: flex; flex-direction: column; gap: var(--space-sm); }
.trace-preview[hidden] { display: none; }

.trace-preview__box {
  display: grid;
  place-items: center;
  min-height: 180px;
  padding: var(--space-md);
  background: var(--color-surface-canvas);
  border-radius: var(--radius-md);
  color: var(--color-ink);
}

.trace-preview__box svg { width: 100%; max-height: 220px; }

.trace-preview__count {
  margin: 0 var(--space-sm);
  font-size: 12px;
  color: var(--color-ink-soft);
}

.is-busy { opacity: 0.5; pointer-events: none; }

/* Buttons */

.btn {
  font: inherit;
  font-weight: 600;
  padding: 12px var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface-canvas);
  color: var(--color-ink);
  cursor: pointer;
  transition: opacity var(--duration-fast);
}

.btn:disabled { opacity: 0.4; cursor: default; }

.btn--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-btn);
}

@media (min-width: 640px) {
  .mode-grid { grid-template-columns: repeat(2, 1fr); }
}

/* Segmented control */

.segmented {
  display: flex;
  gap: var(--space-xs);
  margin: 0 var(--space-md) var(--space-md);
  padding: 3px;
  background: var(--color-border);
  border-radius: var(--radius-sm);
}

.segmented__item {
  flex: 1;
  padding: 7px 12px;
  border: none;
  border-radius: 4px;
  background: none;
  font: inherit;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-ink-soft);
  cursor: pointer;
}

.segmented__item.is-active {
  background: var(--color-surface-canvas);
  color: var(--color-ink);
  box-shadow: 0 1px 3px #1f3a5f1f;
}

/* Community gallery */

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(132px, 1fr));
  gap: var(--space-sm);
}

.gallery__status {
  margin: 0 var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--color-ink-soft);
  text-align: center;
}

.gallery__status[hidden] { display: none; }

.gallery-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: var(--space-md) var(--space-sm) var(--space-sm);
  background: var(--color-surface-canvas);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font: inherit;
  color: var(--color-ink);
  cursor: pointer;
  transition: border-color var(--duration-fast), transform var(--duration-fast);
}

.gallery-card:hover { border-color: var(--color-primary); transform: translateY(-2px); }

.gallery-card__art {
  width: 100%;
  aspect-ratio: 1;
  max-height: 96px;
  display: grid;
  place-items: center;
}

.gallery-card__art svg { width: auto; height: auto; max-width: 100%; max-height: 100%; }

.gallery-card__name {
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-align: center;
  word-break: break-word;
}

.gallery-card__meta {
  font-size: 11px;
  color: var(--color-ink-soft);
  text-align: center;
}

.gallery-card__report {
  position: absolute;
  top: 4px;
  right: 4px;
  padding: 2px 6px;
  border: none;
  border-radius: var(--radius-sm);
  background: none;
  color: var(--color-ink-soft);
  font-size: 11px;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--duration-fast);
}

.gallery-card:hover .gallery-card__report,
.gallery-card__report:focus-visible { opacity: 1; }
.gallery-card__report:hover { color: var(--color-clear-ink); }

/* Language switcher, pinned to the corner */

.lang-switch {
  position: fixed;
  top: max(12px, env(safe-area-inset-top));
  left: 12px;
  z-index: 50;
  display: flex;
  gap: 2px;
  padding: 3px;
  background: var(--color-surface-canvas);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-card);
}

.lang-switch__btn {
  padding: 5px 10px;
  border: none;
  border-radius: var(--radius-full);
  background: none;
  font: inherit;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-ink-soft);
  cursor: pointer;
}

.lang-switch__btn.is-active {
  background: var(--color-primary);
  color: #fff;
}