/* Apple-inspired theme tokens */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
  --font-mono: 'SFMono-Regular', ui-monospace, Menlo, Monaco, Consolas, monospace;

  /* Shape scale */
  --shape-xs:   4px;
  --shape-sm:   8px;
  --shape-md:   12px;
  --shape-lg:   16px;
  --shape-xl:   28px;
  --shape-full: 9999px;

  --radius-sm: 8px;
  --radius-md: 10px;
  --radius-lg: 12px;
  --radius-xl: 12px;

  --md-easing-standard: cubic-bezier(0.22, 1, 0.36, 1);
  --md-easing-decelerate: cubic-bezier(0, 0, 0.2, 1);
  --md-easing-accelerate: cubic-bezier(0.4, 0, 1, 1);
  --md-duration-short2: 220ms;
  --md-duration-short4: 320ms;
  --md-duration-medium2: 420ms;
  --md-duration-medium4: 500ms;
  --transition: 420ms ease-in-out;
}

[data-theme="dark"] {
  --md-primary: #0a84ff;
  --md-on-primary: #ffffff;
  --md-primary-container: #173a66;
  --md-on-primary-container: #d8ebff;
  --md-secondary: #ebebf5;
  --md-on-secondary: #1c1c1e;
  --md-secondary-container: #2f4157;
  --md-on-secondary-container: #e9f2ff;
  --md-error: #ff453a;
  --md-on-error: #ffffff;
  --md-error-container: #5c1e1b;
  --md-on-error-container: #ffd8d6;
  --md-background: #1c1c1e;
  --md-on-background: #ffffff;
  --md-surface: #1c1c1e;
  --md-on-surface: #ffffff;
  --md-surface-variant: #3a3a3c;
  --md-on-surface-variant: rgba(235, 235, 245, 0.6);
  --md-surface-lowest: #1c1c1e;
  --md-surface-low: #2c2c2e;
  --md-surface-container: #3a3a3c;
  --md-surface-high: #2c2c2e;
  --md-surface-highest: #3a3a3c;
  --md-outline: rgba(255, 255, 255, 0.15);
  --md-outline-variant: rgba(255, 255, 255, 0.1);
  --md-scrim: #000000;
  --md-success: #30d158;
  --state-hover: rgba(10, 132, 255, 0.12);
  --state-focus: rgba(10, 132, 255, 0.22);
  --state-pressed: rgba(10, 132, 255, 0.18);

  /* ── Legacy aliases for app compatibility ── */
  --bg-base:         var(--md-background);
  --bg-surface:      var(--md-surface-low);
  --bg-raised:       var(--md-surface-container);
  --bg-overlay:      var(--md-surface-high);
  --border:          var(--md-outline-variant);
  --border-focus:    var(--md-primary);
  --text-primary:    var(--md-on-surface);
  --text-secondary:  rgba(235, 235, 245, 0.6);
  --text-muted:      rgba(235, 235, 245, 0.3);
  --input-bg:        var(--md-surface-highest);
  --input-hover:     var(--md-surface-highest);
  --accent:          var(--md-primary);
  --accent-hover:    #5aa9ff;
  --accent-muted:    rgba(10, 132, 255, 0.2);
  --danger:          var(--md-error);
  --danger-hover:    #E46962;
  --success:         var(--md-success);
  --preview-dark:    var(--md-surface-lowest);
  --preview-light:   #E6E1E5;
}

[data-theme="light"] {
  --md-primary:             #6750A4;
  --md-on-primary:          #FFFFFF;
  --md-primary-container:   #EADDFF;
  --md-on-primary-container:#21005D;

  --md-secondary:           #625B71;
  --md-on-secondary:        #FFFFFF;
  --md-secondary-container: #E8DEF8;
  --md-on-secondary-container: #1D192B;

  --md-error:               #B3261E;
  --md-on-error:            #FFFFFF;
  --md-error-container:     #F9DEDC;
  --md-on-error-container:  #410E0B;

  --md-background:          #FFFBFE;
  --md-on-background:       #1C1B1F;
  --md-surface:             #FFFBFE;
  --md-on-surface:          #1C1B1F;
  --md-surface-variant:     #E7E0EC;
  --md-on-surface-variant:  #49454F;
  --md-surface-lowest:      #FFFFFF;
  --md-surface-low:         #F7F2FA;
  --md-surface-container:   #F3EDF7;
  --md-surface-high:        #ECE6F0;
  --md-surface-highest:     #E6E0E9;

  --md-outline:             #79747E;
  --md-outline-variant:     #CAC4D0;
  --md-success:             #1A7D3E;

  --state-hover:   rgba(103, 80, 164, 0.08);
  --state-focus:   rgba(103, 80, 164, 0.12);
  --state-pressed: rgba(103, 80, 164, 0.12);

  --bg-base:         var(--md-background);
  --bg-surface:      var(--md-surface-low);
  --bg-raised:       var(--md-surface-container);
  --bg-overlay:      var(--md-surface-high);
  --border:          var(--md-outline-variant);
  --border-focus:    var(--md-primary);
  --text-primary:    var(--md-on-surface);
  --text-secondary:  var(--md-on-surface-variant);
  --text-muted:      var(--md-outline);
  --input-bg:        var(--md-surface-highest);
  --input-hover:     var(--md-surface-high);
  --accent:          #0a84ff;
  --accent-hover:    #4F378B;
  --accent-muted:    rgba(103, 80, 164, 0.12);
  --danger:          var(--md-error);
  --danger-hover:    #8C1D18;
  --success:         var(--md-success);
  --preview-dark:    #1C1B1F;
  --preview-light:   #F7F2FA;
}

/* ─── Reset & Base ───────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  font-size: 15px;
  font-optical-sizing: auto;
  background: var(--md-background);
  color: var(--md-on-surface);
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── MD3 Top App Bar ────────────────────────────────────────── */
.app-header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: 64px;
  background: color-mix(in srgb, var(--md-surface-low) 82%, transparent);
  border-bottom: 0.5px solid var(--md-outline);
  /* MD3: elevation via tonal overlay */
  box-shadow: 0 4px 24px rgba(0,0,0,0.5);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
}

a {
  color: var(--accent);
  transition: color var(--transition);
}

a:hover {
  color: var(--accent-hover);
}

.header-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  user-select: none;
}

.brand-logo {
  width: 40px;
  height: 40px;
  background: var(--md-primary-container);
  border-radius: var(--shape-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--md-on-primary-container);
  font-size: 22px;
  font-weight: 700;
  flex-shrink: 0;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3);
  transition: box-shadow var(--transition);
}

.brand-logo:hover {
  box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-title {
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--md-on-surface);
}

.brand-sub {
  font-size: 11px;
  font-weight: 400;
  color: var(--md-on-surface-variant);
  letter-spacing: 0.04em;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* MD3 Icon Button */
.icon-btn,
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: none;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--md-on-surface-variant);
  position: relative;
  overflow: hidden;
  transition: color var(--transition), background var(--transition);
  font-size: 18px;
}

.icon-btn::before,
.theme-toggle::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: currentColor;
  opacity: 0;
  transition: opacity var(--transition);
}

.icon-btn:hover::before,
.theme-toggle:hover::before { opacity: 0.08; }
.icon-btn:active::before,
.theme-toggle:active::before { opacity: 0.12; }
.icon-btn:hover,
.theme-toggle:hover { color: var(--md-on-surface); }

.theme-icon {
  position: absolute;
  transition: opacity var(--transition), transform var(--md-duration-medium2) var(--md-easing-standard);
  display: flex;
  align-items: center;
  justify-content: center;
}

[data-theme="dark"]  .theme-icon--dark  { opacity: 1; transform: rotate(0deg) scale(1); }
[data-theme="dark"]  .theme-icon--light { opacity: 0; transform: rotate(45deg) scale(0.5); }
[data-theme="light"] .theme-icon--dark  { opacity: 0; transform: rotate(-45deg) scale(0.5); }
[data-theme="light"] .theme-icon--light { opacity: 1; transform: rotate(0deg) scale(1); }

/* ─── MD3 Snackbar (Toast) ───────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: var(--md-surface-highest);
  color: var(--md-on-surface);
  font-size: 15px;
  font-weight: 500;
  padding: 14px 24px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  opacity: 0;
  transition: opacity var(--md-duration-short4) var(--md-easing-standard),
              transform var(--md-duration-medium2) var(--md-easing-decelerate);
  pointer-events: none;
  white-space: nowrap;
  box-shadow: 0 3px 5px rgba(0,0,0,0.3), 0 1px 18px rgba(0,0,0,0.15), 0 6px 10px rgba(0,0,0,0.1);
  letter-spacing: 0.01em;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ─── Main Layout ────────────────────────────────────────────── */
.app-layout {
  display: grid;
  grid-template-columns: minmax(320px, 380px) 1fr;
  flex: 1;
  max-width: 1440px;
  margin: 0 auto;
  width: 100%;
  align-items: start;
}

@media (max-width: 960px) {
  .app-layout {
    grid-template-columns: 1fr;
  }
}

/* ─── Controls Panel (Navigation Drawer inspired) ────────────── */
.controls-panel {
  border-right: 0.5px solid var(--md-outline);
  overflow-y: auto;
  max-height: calc(100dvh - 64px);
  position: sticky;
  top: 64px;
  padding: 16px 16px 48px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: color-mix(in srgb, var(--md-surface-low) 82%, transparent);
}

@media (max-width: 960px) {
  .controls-panel {
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 0.5px solid var(--md-outline);
    padding: 16px 16px 24px;
  }
}

/* ─── MD3 Card (Control Section) ────────────────────────────── */
.ctrl-section {
  background: var(--md-surface-container);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 0.5px solid var(--md-outline);
  transition: box-shadow var(--transition), border-color var(--transition);
}

.ctrl-section:hover {
  border-color: color-mix(in srgb, var(--md-primary) 24%, var(--md-outline-variant));
}

/* Collapsible section header */
.ctrl-section-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 16px;
  cursor: pointer;
  user-select: none;
  list-style: none;
  position: relative;
  overflow: hidden;
  transition: background var(--transition);
}

.ctrl-section-header::-webkit-details-marker { display: none; }

.ctrl-section-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-on-surface);
  opacity: 0;
  transition: opacity var(--transition);
}

.ctrl-section-header:hover::before  { opacity: 0.06; }
.ctrl-section-header:active::before { opacity: 0.1; }

.ctrl-section-icon {
  width: 18px;
  height: 18px;
  color: var(--md-primary);
  flex-shrink: 0;
  display: flex;
  align-items: center;
}

.ctrl-title {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--md-on-surface);
  flex: 1;
}

.ctrl-chevron {
  color: var(--md-on-surface-variant);
  display: flex;
  align-items: center;
  transition: transform var(--md-duration-medium2) var(--md-easing-standard);
  flex-shrink: 0;
}

details.ctrl-section[open] .ctrl-chevron {
  transform: rotate(180deg);
}

.ctrl-section-body {
  padding: 4px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  border-top: 0.5px solid var(--md-outline);
}

/* ─── MD3 Text Field (Outlined) ──────────────────────────────── */
.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field-label {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--md-on-surface-variant);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.field-input,
.field-select {
  background: var(--md-surface-highest);
  border: 0.5px solid var(--md-outline);
  border-radius: var(--radius-sm);
  color: var(--md-on-surface);
  font-size: 15px;
  font-family: var(--font-sans);
  padding: 10px 12px;
  width: 100%;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
  appearance: auto;
  letter-spacing: 0.01em;
}

.field-input::placeholder { color: var(--md-outline); }

.field-input:hover,
.field-select:hover {
  border-color: var(--md-on-surface);
}

.field-input:focus,
.field-select:focus {
  border-color: var(--md-primary);
  border-width: 2px;
  box-shadow: none;
  padding: 9px 11px; /* compensate for extra border width */
}

.field-select { cursor: pointer; }

/* Custom select arrow for dark theme */
[data-theme="dark"] .field-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='%23938F99'%3E%3Cpath d='M7 10l5 5 5-5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: 32px;
  appearance: none;
}

[data-theme="light"] .field-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='%2379747E'%3E%3Cpath d='M7 10l5 5 5-5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: 32px;
  appearance: none;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.select-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

/* ─── Range Value Chip ───────────────────────────────────────── */
.range-val {
  font-size: 11px;
  font-weight: 500;
  color: var(--md-primary);
  background: var(--md-primary-container);
  padding: 2px 8px;
  border-radius: var(--shape-full);
  letter-spacing: 0.02em;
}

/* ─── MD3 Slider ─────────────────────────────────────────────── */
.field-range {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: var(--md-surface-variant);
  border-radius: var(--radius-md);
  outline: none;
  cursor: pointer;
  margin-top: 4px;
  position: relative;
}

.field-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--md-primary);
  border-radius: 50%;
  cursor: pointer;
  border: none;
  box-shadow: 0 1px 3px rgba(0,0,0,0.4);
  transition: transform var(--md-duration-short2) var(--md-easing-standard),
              box-shadow var(--transition);
}

.field-range::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  box-shadow: 0 0 0 10px var(--state-hover);
}

.field-range::-webkit-slider-thumb:active {
  transform: scale(1.1);
  box-shadow: 0 0 0 12px var(--state-pressed);
}

.field-range::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--md-primary);
  border-radius: 50%;
  cursor: pointer;
  border: none;
  box-shadow: 0 1px 3px rgba(0,0,0,0.4);
}

/* ─── Color Fields ───────────────────────────────────────────── */
.color-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.color-row {
  display: flex;
  gap: 6px;
  align-items: stretch;
}

.color-text {
  flex: 1;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
}

.color-swatch {
  width: 38px;
  height: 38px;
  border: 0.5px solid var(--md-outline);
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 3px;
  background: var(--md-surface-highest);
  flex-shrink: 0;
  transition: border-color var(--transition);
}

.color-swatch:hover { border-color: var(--md-primary); }

/* Focused color field highlight */
.field[data-color-field].focused .field-label {
  color: var(--md-primary);
}

/* ─── MD3 Color Palette ──────────────────────────────────────── */
.palette-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 4px;
  padding-top: 12px;
  border-top: 0.5px solid var(--md-outline);
}

.palette-hint {
  font-size: 11px;
  letter-spacing: 0.02em;
  color: var(--md-outline);
}

.palette-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.palette-dot {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  cursor: pointer;
  border: 2px solid transparent;
  transition: transform var(--md-duration-short2) var(--md-easing-standard),
              border-color var(--transition),
              box-shadow var(--transition);
  box-shadow: 0 1px 4px rgba(0,0,0,0.3);
}

.palette-dot:hover {
  transform: scale(1.3);
  border-color: var(--md-on-surface);
  box-shadow: 0 2px 8px rgba(0,0,0,0.4);
}

/* ─── MD3 Switch ─────────────────────────────────────────────── */
.toggle-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.toggle-item {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 400;
  color: var(--md-on-surface);
  user-select: none;
  padding: 8px 4px;
  border-radius: var(--shape-sm);
  transition: background var(--transition);
  position: relative;
}

.toggle-item:hover { background: var(--state-hover); }

.toggle-check { display: none; }

/* MD3 Switch Track */
.toggle-indicator {
  width: 52px;
  height: 32px;
  background: var(--md-surface-variant);
  border-radius: var(--shape-full);
  border: 2px solid var(--md-outline);
  position: relative;
  flex-shrink: 0;
  transition: background var(--md-duration-short4) var(--md-easing-standard),
              border-color var(--md-duration-short4) var(--md-easing-standard);
}

/* MD3 Switch Thumb */
.toggle-indicator::after {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  background: var(--md-outline);
  border-radius: 50%;
  top: 50%;
  left: 6px;
  transform: translateY(-50%);
  transition: transform var(--md-duration-short4) var(--md-easing-standard),
              width var(--md-duration-short4) var(--md-easing-standard),
              height var(--md-duration-short4) var(--md-easing-standard),
              background var(--md-duration-short4) var(--md-easing-standard);
  box-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

/* Checked state */
.toggle-check:checked + .toggle-indicator {
  background: var(--md-primary);
  border-color: var(--md-primary);
}

.toggle-check:checked + .toggle-indicator::after {
  background: var(--md-on-primary);
  transform: translateX(20px) translateY(-50%);
  width: 24px;
  height: 24px;
  left: 2px;
}

/* Hover on checked */
.toggle-item:hover .toggle-check:checked + .toggle-indicator::after {
  box-shadow: 0 0 0 8px rgba(208, 188, 255, 0.12);
}

/* ─── MD3 Filter Chips (Icon Picker) ─────────────────────────── */
.icon-picker-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.icon-btn {
  min-width: 40px;
  height: 40px;
  padding: 0 12px;
  border-radius: var(--radius-md);
  border: 0.5px solid var(--md-outline);
  background: transparent;
  cursor: pointer;
  font-size: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition), border-color var(--transition);
  color: var(--md-on-surface-variant);
  position: relative;
  overflow: hidden;
}

.icon-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: currentColor;
  opacity: 0;
  transition: opacity var(--transition);
}

.icon-btn:hover::before { opacity: 0.08; }
.icon-btn:active::before { opacity: 0.12; }
.icon-btn:hover { border-color: var(--md-on-surface); color: var(--md-on-surface); }

.icon-btn.active {
  background: var(--md-secondary-container);
  border-color: transparent;
  color: var(--md-on-secondary-container);
}

.icon-btn.active::before { display: none; }
.icon-btn.active:hover { filter: brightness(1.05); }

.icon-btn[data-icon="none"] { font-size: 11px; font-weight: 500; letter-spacing: 0.02em; }

.icon-upload-area {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 4px;
  padding-top: 12px;
  border-top: 0.5px solid var(--md-outline);
}

.icon-upload-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* MD3 Outlined Button style for upload */
.upload-btn {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--md-primary);
  background: transparent;
  border: 0.5px solid var(--md-outline);
  border-radius: var(--radius-md);
  padding: 8px 20px;
  transition: border-color var(--transition), background var(--transition);
  position: relative;
  overflow: hidden;
}

.upload-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

.upload-btn:hover::before { opacity: 0.08; }
.upload-btn:hover { border-color: var(--md-primary); }

.upload-btn input[type="file"] {
  position: absolute;
  width: 0; height: 0;
  opacity: 0;
  pointer-events: none;
}

.icon-preview-img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  border: 0.5px solid var(--md-outline);
  object-fit: contain;
  background: var(--md-surface-highest);
}

/* MD3 Text Button with danger color */
.icon-clear-btn {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--md-error);
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  padding: 8px 12px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: background var(--transition);
}

.icon-clear-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-error);
  opacity: 0;
  transition: opacity var(--transition);
  border-radius: inherit;
}

.icon-clear-btn:hover::before { opacity: 0.08; }

/* ─── MD3 Input Chips (Preset Grid) ──────────────────────────── */
.preset-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.preset-btn {
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 0.5px solid var(--md-outline);
  background: transparent;
  color: var(--md-on-surface-variant);
  font-size: 13px;
  font-weight: 500;
  font-family: var(--font-sans);
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition), color var(--transition);
  position: relative;
  overflow: hidden;
}

.preset-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

.preset-btn:hover::before { opacity: 0.08; }
.preset-btn:hover {
  border-color: var(--md-on-surface);
  color: var(--md-on-surface);
}

.preset-btn.active {
  background: var(--md-secondary-container);
  border-color: transparent;
  color: var(--md-on-secondary-container);
}

.preset-btn.active::before { display: none; }

/* ─── Output Panel ───────────────────────────────────────────── */
.output-panel {
  padding: 24px 24px 72px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  background: var(--md-background);
}

@media (max-width: 960px) {
  .output-panel { padding: 16px 16px 40px; }
}

/* ─── Preview Card (MD3 Elevated Card) ───────────────────────── */
.preview-card {
  background: var(--md-surface-container);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 0.5px solid var(--md-outline);
  box-shadow: 0 4px 24px rgba(0,0,0,0.5);
  transition: box-shadow var(--transition);
}

.preview-card:hover {
  box-shadow: 0 4px 24px rgba(0,0,0,0.5);
}

.preview-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--md-surface-high);
  gap: 12px;
  flex-wrap: wrap;
}

.preview-label {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--md-on-surface-variant);
}

/* Background switcher — MD3 Segmented Button */
.preview-bg-switcher {
  display: flex;
  border: 0.5px solid var(--md-outline);
  border-radius: var(--radius-md);
  overflow: hidden;
  gap: 0;
}

.bg-btn {
  font-size: 12px;
  font-weight: 500;
  padding: 6px 14px;
  border: none;
  border-right: 0.5px solid var(--md-outline);
  background: transparent;
  color: var(--md-on-surface-variant);
  cursor: pointer;
  letter-spacing: 0.01em;
  transition: background var(--transition), color var(--transition);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.bg-btn:last-child { border-right: none; }

.bg-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

.bg-btn:hover::before { opacity: 0.08; }

.bg-btn.active {
  background: var(--md-secondary-container);
  color: var(--md-on-secondary-container);
}

.bg-btn.active::before { display: none; }

.preview-stage {
  min-height: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 24px;
  transition: background var(--md-duration-medium2) var(--md-easing-standard);
}

.preview-stage.checker {
  background-color: var(--md-surface-highest);
  background-image:
    linear-gradient(45deg, rgba(128,128,128,0.12) 25%, transparent 25%),
    linear-gradient(-45deg, rgba(128,128,128,0.12) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, rgba(128,128,128,0.12) 75%),
    linear-gradient(-45deg, transparent 75%, rgba(128,128,128,0.12) 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

.preview-stage.dark  { background: var(--preview-dark); }
.preview-stage.light { background: var(--preview-light); }

.preview-svg-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--md-duration-short2) var(--md-easing-standard);
}

.preview-svg-wrap.pop { transform: scale(1.05); }

.preview-meta {
  padding: 8px 20px 10px;
  border-top: 0.5px solid var(--md-outline);
  background: var(--md-surface-high);
}

.badge-dims {
  font-size: 11px;
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  color: var(--md-outline);
}

/* ─── MD3 Buttons (Action Bar) ───────────────────────────────── */
.action-bar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
  background: color-mix(in srgb, var(--md-surface-container) 88%, transparent);
  border: 0.5px solid var(--md-outline);
  border-radius: var(--radius-lg);
  padding: 12px;
  position: sticky;
  top: 80px;
  z-index: 40;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
}

/* Base button */
.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  border: 0.5px solid var(--md-outline);
  background: transparent;
  color: var(--md-on-surface-variant);
  font-size: 15px;
  font-weight: 500;
  font-family: var(--font-sans);
  letter-spacing: 0.01em;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: background var(--transition), color var(--transition),
              border-color var(--transition), box-shadow var(--transition);
}

.action-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: currentColor;
  opacity: 0;
  transition: opacity var(--transition);
}

.action-btn:hover::before  { opacity: 0.08; }
.action-btn:active::before { opacity: 0.12; }

.action-btn:hover {
  border-color: var(--md-on-surface);
  color: var(--md-on-surface);
}

.action-btn:active { transform: scale(0.97); }

/* MD3 Filled Button (primary action) */
.action-btn--primary {
  background: var(--md-primary);
  border-color: transparent;
  color: var(--md-on-primary);
  box-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

.action-btn--primary::before {
  background: var(--md-on-primary);
}

.action-btn--primary:hover {
  background: var(--md-primary);
  border-color: transparent;
  color: var(--md-on-primary);
  box-shadow: 0 2px 6px rgba(0,0,0,0.3), 0 4px 8px rgba(0,0,0,0.15);
}

/* MD3 Tonal Button (secondary action) */
.action-btn--tonal {
  background: var(--md-secondary-container);
  border-color: transparent;
  color: var(--md-on-secondary-container);
}

.action-btn--tonal::before {
  background: var(--md-on-secondary-container);
}

.action-btn--tonal:hover {
  background: var(--md-secondary-container);
  border-color: transparent;
  color: var(--md-on-secondary-container);
  filter: brightness(1.07);
}

/* Danger (text button style) */
.action-btn--danger {
  color: var(--md-error);
  border-color: transparent;
}

.action-btn--danger::before { background: var(--md-error); }

.action-btn--danger:hover {
  border-color: transparent;
  color: var(--md-error);
}

.btn-icon {
  font-size: 16px;
  line-height: 1;
  display: inline-flex;
  align-items: center;
}

/* ─── Output Groups (MD3 Outlined card-like) ─────────────────── */
.output-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.output-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

@media (max-width: 1140px) {
  .output-grid {
    grid-template-columns: 1fr;
  }
}

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2px;
}

.output-label {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--md-on-surface-variant);
}

/* MD3 Text Button for copy */
.output-copy-btn {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.01em;
  padding: 6px 14px;
  border-radius: var(--radius-md);
  border: none;
  background: transparent;
  color: var(--md-primary);
  cursor: pointer;
  transition: background var(--transition);
  position: relative;
  overflow: hidden;
}

.output-copy-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-primary);
  opacity: 0;
  transition: opacity var(--transition);
  border-radius: inherit;
}

.output-copy-btn:hover::before { opacity: 0.08; }

.output-textarea {
  background: var(--md-surface-highest);
  border: 0.5px solid var(--md-outline);
  border-radius: var(--shape-sm);
  color: var(--md-on-surface);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  padding: 12px 14px;
  resize: vertical;
  width: 100%;
  min-height: 52px;
  outline: none;
  letter-spacing: 0.03em;
  transition: border-color var(--transition);
}

.output-textarea:hover  { border-color: var(--md-outline); }
.output-textarea:focus  { border-color: var(--md-primary); border-width: 2px; }

.output-hint {
  margin: 4px 0 0;
  font-size: 0.75rem;
  color: var(--md-on-surface-variant, #888);
  line-height: 1.3;
}

/* ─── Gallery (MD3 Cards) ────────────────────────────────────── */
.gallery-section {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 10px 14px 14px;
  border: 0.5px solid var(--md-outline);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--md-surface-low) 82%, transparent);
}

.gallery-title {
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.005em;
  color: var(--md-on-surface);
  padding-bottom: 10px;
  border-bottom: 0.5px solid var(--md-outline);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
}

.gallery-item {
  background: var(--md-surface-container);
  border-radius: var(--radius-lg);
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--md-duration-short2) var(--md-easing-standard);
  box-shadow: 0 1px 2px rgba(0,0,0,0.2);
  text-align: center;
}

.gallery-item::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--md-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

.gallery-item:hover {
  box-shadow: 0 2px 6px rgba(0,0,0,0.3), 0 4px 12px rgba(0,0,0,0.15);
  transform: translateY(-2px);
}

.gallery-item:hover::before { opacity: 0.06; }
.gallery-item:active { transform: translateY(0); }
.gallery-item:active::before { opacity: 0.1; }

.gallery-item-label {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--md-on-surface-variant);
  text-transform: capitalize;
  position: relative; /* above ::before overlay */
}

.gallery-item svg {
  max-width: 100%;
  height: auto;
  position: relative;
  filter: drop-shadow(0 1px 2px rgba(0,0,0,0.2));
}

/* ─── Footer ─────────────────────────────────────────────────── */
.app-footer {
  border-top: 0.5px solid var(--md-outline);
  padding: 18px 24px;
  text-align: center;
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--md-outline);
  background: color-mix(in srgb, var(--md-surface-low) 82%, transparent);
}

.controls-intro {
  padding: 4px 6px 12px;
}

.controls-kicker,
.workspace-kicker {
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--md-primary);
  font-weight: 500;
}

.controls-heading {
  font-size: 24px;
  line-height: 1.2;
  margin: 4px 0 8px;
  font-weight: 500;
}

.controls-note {
  color: var(--md-on-surface-variant);
  line-height: 1.45;
  font-size: 13px;
}

.workspace-summary {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.workspace-title {
  font-size: 24px;
  line-height: 1.2;
  font-weight: 500;
}

@media (max-width: 960px) {
  .controls-heading,
  .workspace-title {
    font-size: 20px;
  }

  .action-bar {
    position: static;
    backdrop-filter: none;
  }
}

/* ─── Scrollbar ──────────────────────────────────────────────── */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--md-outline-variant);
  border-radius: var(--radius-md);
  border: 2px solid transparent;
  background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--md-outline); background-clip: padding-box; }

/* ─── Focus Visible (MD3 Focus Ring) ────────────────────────── */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ─── Selection ──────────────────────────────────────────────── */
::selection {
  background: var(--md-primary-container);
  color: var(--md-on-primary-container);
}

/* ─── Divider utility ────────────────────────────────────────── */
.divider {
  height: 1px;
  background: var(--md-outline-variant);
  margin: 4px 0;
}

/* ─── Reduced Motion ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }
}