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

:root {
  --panel-bg: #E4DCCB;
  --text: #3B2F1E;
  --text-muted: #8A7B65;
  --accent: #6B4F12;
  --border: #CCC2AC;
  --selected: #8B6914;
  --selected-text: #FFF;
  --wood-mid: #B8864E;
  --wood-dark: #8B6914;
  --radius: 5px;
  --transition: 150ms ease;
  --font: 0.8rem;
}

html { font-size: 16px; }

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  background: #fff;
  color: var(--text);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* --- Header --- */

.app-header {
  padding: 1rem 1.5rem;
  background: var(--panel-bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}

.app-header h1 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
}

.app-header .subtitle {
  font-size: 1rem;
  color: var(--text);
  font-weight: 400;
  opacity: 0.5;
}

/* --- Layout --- */

.app-layout {
  display: flex;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

/* --- Controls Panel --- */

.controls-panel {
  width: 240px;
  min-width: 240px;
  background: var(--panel-bg);
  border-right: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0;
  font-size: var(--font);
}

.control-group {
  padding: 1.25rem 0;
}

.control-group:first-child {
  padding-top: 0.75rem;
}

.control-group + .control-group {
  border-top: 1px solid rgba(0,0,0,0.07);
}

.control-group h2 {
  font-size: var(--font);
  text-transform: none;
  letter-spacing: 0;
  color: var(--text);
  margin-bottom: 0.6rem;
  font-weight: 600;
}

/* --- Radio buttons --- */

.radio-group {
  display: flex;
  gap: 0.75rem;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
  font-size: var(--font);
  font-weight: 400;
  user-select: none;
  color: var(--text);
}

.radio-label input[type="radio"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.radio-custom {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 2px solid var(--text-muted);
  background: transparent;
  transition: border-color var(--transition), background var(--transition);
  position: relative;
  flex-shrink: 0;
}

.radio-label input[type="radio"]:checked + .radio-custom {
  border-color: var(--selected);
  background: var(--selected);
}

.radio-label input[type="radio"]:checked + .radio-custom::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: white;
}

.radio-label input[type="radio"]:focus-visible + .radio-custom {
  outline: 2px solid var(--selected);
  outline-offset: 2px;
}

/* --- Segmented control --- */

.segmented-control {
  display: flex;
  background: rgba(0,0,0,0.08);
  border-radius: var(--radius);
  padding: 2px;
  gap: 2px;
}

.seg-btn {
  flex: 1;
  padding: 0.3rem 0.5rem;
  border: none;
  border-radius: calc(var(--radius) - 2px);
  background: transparent;
  color: var(--text-muted);
  font-size: var(--font);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.seg-btn:hover { color: var(--text); }

.seg-btn.selected {
  background: rgba(255,255,255,0.7);
  color: var(--accent);
  font-weight: 600;
}

.seg-btn:focus-visible {
  outline: 2px solid var(--selected);
  outline-offset: 1px;
}

/* --- Pitch selector --- */

.pitch-selector {
  display: flex;
  gap: 0.25rem;
}

.pitch-btn {
  flex: 1;
  padding: 0.35rem 0.25rem;
  border: none;
  border-radius: var(--radius);
  background: rgba(0,0,0,0.08);
  color: var(--text);
  font-size: var(--font);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.pitch-btn:hover { background: rgba(0,0,0,0.13); }

.pitch-btn.selected {
  background: var(--selected);
  color: var(--selected-text);
  font-weight: 600;
}

.pitch-btn:focus-visible {
  outline: 2px solid var(--selected);
  outline-offset: 2px;
}

/* --- Range sliders --- */

.input-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: var(--font);
  font-weight: 400;
  color: var(--text);
  margin-bottom: 0.3rem;
  margin-top: 1rem;
}

.input-label:first-of-type { margin-top: 0; }

.input-value {
  font-weight: 600;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 3px;
  border-radius: 2px;
  background: rgba(0,0,0,0.12);
  outline: none;
  cursor: pointer;
  touch-action: manipulation;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--wood-mid);
  border: 2px solid var(--wood-dark);
  cursor: grab;
  transition: background var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover { background: var(--wood-dark); }

input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--wood-mid);
  border: 2px solid var(--wood-dark);
  cursor: grab;
}

input[type="range"]:focus-visible {
  outline: 2px solid var(--selected);
  outline-offset: 2px;
}

/* --- Computed readout --- */

.computed-value {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-top: 0.5rem;
  font-size: var(--font);
}

.computed-label {
  color: var(--text);
  font-weight: 400;
}

.computed-result {
  font-weight: 600;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* --- Checkboxes --- */

.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
  font-size: var(--font);
  font-weight: 400;
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.checkbox-custom {
  width: 13px;
  height: 13px;
  border-radius: 3px;
  border: 2px solid var(--text-muted);
  background: transparent;
  transition: border-color var(--transition), background var(--transition);
  position: relative;
  flex-shrink: 0;
}

.checkbox-label input[type="checkbox"]:checked + .checkbox-custom {
  border-color: var(--selected);
  background: var(--selected);
}

.checkbox-label input[type="checkbox"]:checked + .checkbox-custom::after {
  content: '';
  position: absolute;
  top: 1px;
  left: 3px;
  width: 4px;
  height: 7px;
  border: solid white;
  border-width: 0 1.5px 1.5px 0;
  transform: rotate(45deg);
}

.checkbox-label input[type="checkbox"]:focus-visible + .checkbox-custom {
  outline: 2px solid var(--selected);
  outline-offset: 2px;
}

/* --- Preview Panel --- */

.preview-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 0;
  min-width: 0;
  min-height: 0;
}

.svg-container {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 0;
  background:
    repeating-linear-gradient(0deg, transparent, transparent 19px, rgba(0,0,0,0.04) 19px, rgba(0,0,0,0.04) 20px),
    repeating-linear-gradient(90deg, transparent, transparent 19px, rgba(0,0,0,0.04) 19px, rgba(0,0,0,0.04) 20px);
  background-color: #fff;
}

#dovetailSvg {
  width: 100%;
  height: 100%;
  display: block;
}

.dimensions-readout {
  font-size: var(--font);
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  padding: 0.4rem 0.75rem;
  background: var(--panel-bg);
  border-top: 1px solid var(--border);
}

.dimensions-readout .dim-item {
  padding: 0.15rem 0.4rem;
  font-variant-numeric: tabular-nums;
}

.dimensions-readout .dim-item strong {
  color: var(--text);
  font-weight: 600;
}

/* --- Responsive --- */

@media (max-width: 768px) {
  .app-layout { flex-direction: column; }

  .controls-panel {
    width: 100%;
    min-width: 0;
    border-right: none;
    border-bottom: none;
    max-height: 40vh;
    position: relative;
  }

  .controls-panel::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 28px;
    background: linear-gradient(to bottom, transparent, var(--panel-bg) 60%);
    border-bottom: 1px solid var(--border);
    pointer-events: none;
    z-index: 1;
    opacity: 1;
    transition: opacity 0.3s ease;
  }

  .controls-panel::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 16px;
    height: 28px;
    margin-left: -8px;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='8' viewBox='0 0 16 8'%3E%3Cpath d='M1 1l7 6 7-6' fill='none' stroke='%238A7B65' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center bottom 6px / 16px 8px no-repeat;
    pointer-events: none;
    z-index: 2;
    animation: nudge 3s ease-in-out infinite;
    opacity: 1;
    transition: opacity 0.3s ease;
  }

  .controls-panel.scrolled-bottom::before,
  .controls-panel.scrolled-bottom::after {
    opacity: 0;
  }

  @keyframes nudge {
    0%, 20% { transform: translateY(0); }
    25% { transform: translateY(4px); }
    30% { transform: translateY(-2px); }
    35% { transform: translateY(4px); }
    40% { transform: translateY(-1px); }
    45% { transform: translateY(2px); }
    50%, 100% { transform: translateY(0); }
  }

  .preview-panel {
    flex: 1;
    min-height: 0;
  }

  input[type="range"] {
    height: 6px;
  }

  input[type="range"]::-webkit-slider-thumb {
    width: 24px;
    height: 24px;
  }

  input[type="range"]::-moz-range-thumb {
    width: 24px;
    height: 24px;
  }

  .dimensions-readout {
    padding-bottom: calc(24px + env(safe-area-inset-bottom, 0px));
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }
}