/* ===== PID TUNER PAGE ===== */
.pid-page {
  padding-top: 80px;
  padding-bottom: 3rem;
  min-height: 100vh;
}

.pid-header {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem 1.5rem;
}

.pid-subtitle {
  font-size: 0.92rem;
  color: var(--text-muted);
  max-width: 700px;
  line-height: 1.7;
}

/* ===== LAYOUT ===== */
.pid-layout {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1.5rem;
  align-items: start;
}

/* ===== LEFT PANEL ===== */
.pid-controls {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.control-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  transition: var(--transition-theme);
}

.control-heading {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.sub-heading {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.control-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.control-row label {
  font-size: 0.82rem;
  color: var(--text-muted);
  min-width: 50px;
  flex-shrink: 0;
}

.control-row select,
.control-row input[type="text"] {
  flex: 1;
  min-width: 0;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.4rem 0.6rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.85rem;
  transition: border-color 0.2s;
}

.control-row select:focus,
.control-row input[type="text"]:focus {
  outline: none;
  border-color: var(--accent);
}

.control-row input[type="text"].invalid {
  border-color: #c0392b;
}

/* ===== GAIN SLIDERS ===== */
.gain-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.gain-row label {
  font-size: 0.85rem;
  color: var(--text-muted);
  min-width: 30px;
  text-align: right;
  flex-shrink: 0;
}

.gain-row input[type="range"] {
  flex: 1;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 2px;
  outline: none;
}

.gain-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
}

.gain-row input[type="number"] {
  width: 58px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.25rem 0.4rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.82rem;
  text-align: right;
}

.gain-row input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
}

/* ===== BUTTONS ===== */
.btn-small {
  background: var(--tag-bg);
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.3rem 0.7rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-small:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.btn-apply {
  width: 100%;
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 4px;
  padding: 0.5rem 1rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  margin-top: 0.6rem;
}

.btn-apply:hover {
  background: color-mix(in srgb, var(--accent) 25%, transparent);
}

/* ===== METHOD PICKER (pill toggle) ===== */
.method-picker {
  display: flex;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px;
  gap: 3px;
  margin-bottom: 0.75rem;
}

.method-btn {
  flex: 1;
  background: none;
  border: none;
  border-radius: 4px;
  padding: 0.4rem 0.5rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}

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

.method-btn.active {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}

[data-theme="light"] .method-btn.active {
  color: #fff;
}

.method-options {
  margin-bottom: 0.25rem;
}

.method-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 0.5rem;
  opacity: 0.8;
}

/* ===== NOISE ===== */
.noise-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.noise-row label {
  font-size: 0.82rem;
  color: var(--text-muted);
  min-width: 105px;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
}

.noise-row input[type="range"] {
  flex: 1;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 2px;
  outline: none;
}

.noise-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
}

.noise-row input[type="range"]:disabled {
  opacity: 0.3;
}

.noise-val {
  font-size: 0.78rem;
  color: var(--text-muted);
  min-width: 28px;
  text-align: right;
}

/* ===== PIECEWISE ===== */
.pw-segment {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  margin-bottom: 0.4rem;
  font-size: 0.78rem;
  min-width: 0;
}

.pw-segment input[type="text"] {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.3rem 0.5rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.82rem;
}

.pw-segment input[type="text"]:focus {
  outline: none;
  border-color: var(--accent);
}

.pw-segment input[type="text"].invalid {
  border-color: #c0392b;
}

.pw-segment .pw-bound {
  width: 34px;
  min-width: 34px;
  text-align: center;
  padding: 0.25rem 0.2rem;
  font-size: 0.78rem;
}

.pw-segment .pw-expr {
  flex: 1;
  min-width: 0;
  font-size: 0.78rem;
}

.pw-segment .pw-label {
  color: var(--text-muted);
  flex-shrink: 0;
}

.pw-remove {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.85rem;
  padding: 0 0.15rem;
  flex-shrink: 0;
  transition: color 0.2s;
}

.pw-remove:hover { color: #c0392b; }

.error-msg {
  font-size: 0.78rem;
  color: #c0392b;
  margin-top: 0.3rem;
}

.status-msg {
  font-size: 0.78rem;
  color: var(--accent);
  margin-top: 0.4rem;
}

.math-hint {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  line-height: 1.5;
  opacity: 0.7;
}

.math-hint code {
  background: var(--tag-bg);
  padding: 0.1rem 0.3rem;
  border-radius: 2px;
  font-size: 0.7rem;
}

.t-range-input {
  width: 52px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.3rem 0.4rem;
  font-family: 'Karla', sans-serif;
  font-size: 0.82rem;
  text-align: center;
}

.t-range-input:focus {
  outline: none;
  border-color: var(--accent);
}

.t-range-unit {
  font-size: 0.78rem;
  color: var(--text-muted);
  flex-shrink: 0;
}

.plant-eq {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 0.5rem;
  padding: 0.4rem;
  background: var(--bg);
  border-radius: 4px;
}

.hidden { display: none !important; }

/* ===== ADVANCED (collapsible) ===== */
.advanced-section {
  padding: 0;
}

.advanced-toggle {
  cursor: pointer;
  padding: 0.85rem 1.25rem;
  margin-bottom: 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.advanced-toggle::-webkit-details-marker { display: none; }

.advanced-toggle::after {
  content: '+';
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
  transition: transform 0.2s;
}

details.advanced-section[open] .advanced-toggle::after {
  content: '\2212';
}

.advanced-group {
  padding: 0.75rem 1.25rem;
  border-top: 1px solid var(--border);
  overflow: hidden;
}

.advanced-group select {
  width: 100%;
  min-width: 0;
  text-overflow: ellipsis;
}

.advanced-group:last-child {
  padding-bottom: 1rem;
}

/* ===== RIGHT PANEL ===== */
.pid-plots {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.plot-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  transition: var(--transition-theme);
}

.plot-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.4rem;
}

.plot-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
}

.plot-legend {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.plot-legend .legend-item {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.plot-legend .legend-line {
  width: 16px;
  height: 2px;
  border-radius: 1px;
}

.plot-legend .legend-line.dashed {
  background: repeating-linear-gradient(
    90deg, var(--color) 0, var(--color) 4px, transparent 4px, transparent 7px
  );
  height: 2px;
}

.plot-container canvas {
  width: 100%;
  height: 180px;
  display: block;
  border-radius: 4px;
}

/* ===== TIMELINE ===== */
.timeline {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.6rem 1rem;
}

.btn-play {
  background: none;
  border: 1px solid var(--border);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: all 0.2s;
  padding: 0;
}

.btn-play:hover {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
}

/* Play triangle via CSS border trick */
.btn-play .play-icon {
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 5px 0 5px 9px;
  border-color: transparent transparent transparent var(--accent);
  margin-left: 2px;
}

/* Reset: square stop */
.btn-play .reset-icon {
  width: 9px;
  height: 9px;
  background: var(--accent);
  border-radius: 1.5px;
}

/* Pause: two bars */
.btn-play .pause-icon {
  display: flex;
  align-items: center;
  gap: 2.5px;
}

.btn-play .pause-icon span {
  display: block;
  width: 3px;
  height: 10px;
  background: var(--accent);
  border-radius: 1px;
}

.timeline-track {
  flex: 1;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  position: relative;
  cursor: pointer;
}

.timeline-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  width: 0%;
  pointer-events: none;
}

.timeline-head {
  position: absolute;
  top: 50%;
  left: 0%;
  transform: translate(-50%, -50%);
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  cursor: grab;
  box-shadow: 0 1px 4px rgba(0,0,0,0.3);
}

.timeline-head:active { cursor: grabbing; }

.time-display {
  font-size: 0.78rem;
  color: var(--text-muted);
  min-width: 100px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

/* ===== METRICS ===== */
.metrics-panel {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.metric {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.5rem 0.85rem;
  flex: 1;
  min-width: 120px;
  transition: var(--transition-theme);
}

.metric-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  display: block;
  margin-bottom: 0.15rem;
}

.metric-value {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
  .pid-layout {
    grid-template-columns: 1fr;
  }
  .plot-container canvas {
    height: 150px;
  }
}

@media (max-width: 500px) {
  .pid-header { padding: 0 1rem 1rem; }
  .pid-layout { padding: 0 1rem; }
  .metrics-panel { flex-direction: column; }
  .method-picker { flex-direction: column; }
}