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

:root {
  --bg-app: #f0f2f5;
  --bg-sidebar: #ffffff;
  --bg-plot-section: #fafafa;
  --bg-plot: #ffffff;
  --bg-header: #2c3e50;
  --bg-filter-item: #ffffff;
  --bg-filter-hover: #f8f9fa;
  --bg-input: #ffffff;
  --bg-btn: #ffffff;
  --bg-btn-primary: #3498db;
  --bg-details: #f8f9fa;
  --text-primary: #222222;
  --text-secondary: #666666;
  --text-muted: #888888;
  --text-header: #ecf0f1;
  --text-header-label: #bdc3c7;
  --border: #dddddd;
  --border-light: #eeeeee;
  --border-input: #e0e0e0;
  --border-btn: #cccccc;
  --scrollbar-thumb: #cccccc;
  --scrollbar-hover: #aaaaaa;
}

body.dark {
  --bg-app: #1e1e1e;
  --bg-sidebar: #252526;
  --bg-plot-section: #1e1e1e;
  --bg-plot: #1e1e1e;
  --bg-header: #1a1a2e;
  --bg-filter-item: #2a2a2b;
  --bg-filter-hover: #333334;
  --bg-input: #3e3e3e;
  --bg-btn: #3e3e3e;
  --bg-btn-primary: #2980b9;
  --bg-details: #333333;
  --text-primary: #cccccc;
  --text-secondary: #999999;
  --text-muted: #777777;
  --text-header: #e0e0e0;
  --text-header-label: #999999;
  --border: #3e3e3e;
  --border-light: #333333;
  --border-input: #555555;
  --border-btn: #555555;
  --scrollbar-thumb: #555555;
  --scrollbar-hover: #777777;
}

html, body {
  height: 100%;
  font-family: 'Segoe UI', -apple-system, Arial, sans-serif;
  font-size: 14px;
  color: var(--text-primary);
  background: var(--bg-app);
  transition: background 0.2s, color 0.2s;
}

#app {
  display: grid;
  grid-template-rows: auto 1fr;
  grid-template-columns: var(--sidebar-width, 360px) 5px 1fr;
  grid-template-areas:
    "header header header"
    "sidebar divider plot";
  height: 100vh;
}

#divider {
  grid-area: divider;
  background: var(--border-light);
  cursor: col-resize;
  transition: background 0.15s;
  z-index: 10;
}

#divider:hover,
#divider.active {
  background: #3498db;
}

/* ─── Header ─── */

header {
  grid-area: header;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 20px;
  background: var(--bg-header);
  color: var(--text-header);
  gap: 20px;
  transition: background 0.2s;
}

header h1 {
  font-size: 18px;
  font-weight: 600;
  white-space: nowrap;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 16px;
}

.header-controls label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-header-label);
}

.header-controls input {
  width: 80px;
  padding: 4px 8px;
  border: 1px solid #5d6d7e;
  border-radius: 4px;
  background: #34495e;
  color: #ecf0f1;
  font-size: 13px;
  text-align: right;
  color-scheme: dark;
}

.header-controls input:focus {
  outline: none;
  border-color: #3498db;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-separator {
  color: #5d6d7e;
  font-size: 16px;
  margin: 0 4px;
}

.header-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: #bdc3c7;
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: color 0.15s;
}

.header-link:hover {
  color: #ecf0f1;
  text-decoration: underline;
}

.github-icon {
  flex-shrink: 0;
}

.header-btn {
  padding: 4px 10px;
  border: 1px solid #5d6d7e;
  border-radius: 4px;
  background: #34495e;
  color: #bdc3c7;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  line-height: 1.4;
}

.header-btn:hover {
  background: #3d566e;
  color: #ecf0f1;
}

/* ─── Sidebar ─── */

#filter-panel {
  grid-area: sidebar;
  display: flex;
  flex-direction: column;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  overflow: hidden;
  transition: background 0.2s, border-color 0.2s;
}

.filter-panel-controls {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.filter-panel-controls label {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: var(--text-secondary);
}

.filter-panel-controls input {
  width: 70px;
  padding: 3px 6px;
  border: 1px solid var(--border-input);
  border-radius: 3px;
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 12px;
  text-align: right;
}

.filter-panel-controls input:focus {
  outline: none;
  border-color: #3498db;
}

body.dark .filter-panel-controls input {
  color-scheme: dark;
}

.filter-panel-header {
  padding: 12px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  gap: 6px;
}

.filter-panel-header select {
  flex: 1;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 13px;
  background: var(--bg-input);
  color: var(--text-primary);
}

#filter-list {
  flex: 1;
  overflow-y: auto;
  list-style: none;
}

.filter-item {
  border-bottom: 1px solid var(--border-light);
  padding: 8px 12px;
  background: var(--bg-filter-item);
  transition: background 0.2s;
}

.filter-item:hover {
  background: var(--bg-filter-hover);
}

.filter-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.filter-number {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 12px;
  min-width: 22px;
}

.filter-type-select {
  flex: 1;
  padding: 4px 6px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 13px;
  background: var(--bg-input);
  color: var(--text-primary);
  cursor: pointer;
}

.filter-type-select:focus {
  border-color: #3498db;
  outline: none;
}

.filter-actions {
  display: flex;
  gap: 2px;
}

.filter-params {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 8px;
  padding-left: 30px;
}

.param-label {
  display: flex;
  align-items: center;
  gap: 3px;
  font-size: 11px;
  color: var(--text-secondary);
  white-space: nowrap;
}

.param-label input {
  width: 65px;
  padding: 2px 4px;
  border: 1px solid var(--border-input);
  border-radius: 3px;
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 11px;
  text-align: right;
}

.param-label input:focus {
  border-color: #3498db;
  outline: none;
}

body.dark .param-label input,
body.dark .filter-type-select,
body.dark .filter-panel-header select,
body.dark .header-controls input {
  color-scheme: dark;
}

.coeffs-details {
  margin-top: 4px;
  padding-left: 30px;
  font-size: 11px;
  color: var(--text-secondary);
}

.coeffs-details summary {
  cursor: pointer;
  color: var(--text-muted);
  font-size: 10px;
  user-select: none;
}

.coeffs-details summary:hover {
  color: var(--text-secondary);
}

.coeffs-details code {
  display: block;
  font-family: 'Consolas', 'Courier New', monospace;
  font-size: 11px;
  color: var(--text-secondary);
  padding: 1px 0;
}

.filter-panel-actions {
  padding: 10px 12px;
  border-top: 1px solid var(--border-light);
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

/* ─── Plot section ─── */

#plot-section {
  grid-area: plot;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-plot-section);
  transition: background 0.2s;
}

#plot-tabs {
  display: flex;
  align-items: center;
  background: var(--bg-sidebar);
  border-bottom: 1px solid var(--border);
  padding: 0 8px;
  flex-shrink: 0;
  transition: background 0.2s, border-color 0.2s;
}

#plot-tabs .spacer {
  flex: 1;
}

.tab {
  padding: 8px 16px;
  border: none;
  background: transparent;
  font-size: 13px;
  cursor: pointer;
  color: var(--text-muted);
  border-bottom: 2px solid transparent;
  transition: color 0.15s, background 0.15s;
}

.tab:hover {
  color: var(--text-primary);
  background: var(--bg-filter-hover);
}

.tab.active {
  color: var(--text-primary);
  border-bottom-color: #3498db;
  font-weight: 600;
}

.tab-btn {
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-btn);
  color: var(--text-secondary);
  font-size: 12px;
  cursor: pointer;
  margin-left: 6px;
  transition: background 0.15s, color 0.15s;
}

.tab-btn:hover {
  background: var(--bg-filter-hover);
  color: var(--text-primary);
}

#plot {
  flex: 1;
  min-height: 0;
}

.empty-plot {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  font-size: 16px;
}

/* ─── Buttons ─── */

.btn {
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-btn);
  color: var(--text-primary);
  font-size: 12px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s;
}

.btn:hover {
  background: var(--bg-filter-hover);
}

.btn-icon {
  width: 24px;
  height: 24px;
  padding: 0;
  border: 1px solid transparent;
  border-radius: 3px;
  background: transparent;
  font-size: 14px;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all 0.15s;
}

.btn-icon:hover:not(:disabled) {
  background: var(--bg-filter-hover);
  color: var(--text-primary);
}

.btn-icon:disabled {
  opacity: 0.3;
  cursor: default;
}

.filter-bypass {
  font-size: 16px;
  color: #27ae60;
}

.filter-bypass:hover {
  color: #2ecc71;
}

.filter-item.bypassed {
  opacity: 0.45;
}

.filter-item.bypassed .filter-bypass {
  color: #95a5a6;
}

.filter-item.bypassed .filter-bypass:hover {
  color: #bdc3c7;
}

.filter-delete:hover:not(:disabled) {
  background: #fde8e8;
  color: #e74c3c;
}

body.dark .filter-delete:hover:not(:disabled) {
  background: #4a2020;
  color: #e74c3c;
}

/* ─── Responsive ─── */

@media (max-width: 768px) {
  #app {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto 1fr;
    grid-template-areas:
      "header"
      "sidebar"
      "plot";
  }

  #divider {
    display: none;
  }

  #filter-panel {
    border-right: none;
    border-bottom: 1px solid var(--border);
    max-height: 40vh;
  }

  header {
    flex-wrap: wrap;
  }
}

/* ─── Modal ─── */

.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-overlay.open {
  display: flex;
}

.modal {
  background: var(--bg-sidebar);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

.modal h2 {
  font-size: 16px;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.modal-body {
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 16px;
  white-space: pre-wrap;
}

.modal .btn {
  display: block;
  margin-left: auto;
}

/* ─── Optimization Panel ─── */

#optimize-mode {
  flex: 1;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.optimize-panel {
  padding: 8px 12px;
  font-size: 12px;
  display: flex;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
}

.optimize-section {
  margin-bottom: 10px;
}

.optimize-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  display: block;
  margin-bottom: 4px;
}

.optimize-range {
  display: flex;
  align-items: center;
  gap: 6px;
}

.optimize-range input {
  width: 65px;
  padding: 2px 4px;
  border: 1px solid var(--border-input);
  border-radius: 3px;
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 11px;
  text-align: right;
}

body.dark .optimize-range input {
  color-scheme: dark;
}

.optimize-range span {
  color: var(--text-muted);
  font-size: 11px;
}

.optimize-checkbox {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-secondary);
  cursor: pointer;
}

.optimize-checkbox input {
  accent-color: #3498db;
}

.optimize-target-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.optimize-filename {
  font-size: 11px;
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.optimize-radio-row {
  display: flex;
  gap: 12px;
  font-size: 12px;
  color: var(--text-secondary);
}

.optimize-radio-row input {
  accent-color: #3498db;
}

#opt-params-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#opt-param-list {
  flex: 1;
  overflow-y: auto;
  border: 1px solid var(--border-light);
  border-radius: 4px;
  padding: 4px 6px;
  background: var(--bg-filter-item);
  min-height: 60px;
}

.opt-filter-group {
  margin-bottom: 4px;
}

.opt-filter-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 4px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  border-radius: 3px;
  background: var(--bg-filter-hover);
}

.opt-filter-header:hover {
  background: var(--bg-filter-item);
}

.opt-filter-header input {
  accent-color: #3498db;
}

.opt-param-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 2px 4px 2px 24px;
  font-size: 12px;
  color: var(--text-primary);
  cursor: pointer;
  border-radius: 3px;
}

.opt-param-item:hover {
  background: var(--bg-filter-hover);
}

.opt-param-item input {
  accent-color: #3498db;
}

.opt-param-item .opt-param-key {
  color: var(--text-secondary);
}

.opt-param-item .opt-param-val {
  color: var(--text-muted);
  font-size: 11px;
  margin-left: auto;
  font-variant-numeric: tabular-nums;
}

.optimize-progress {
  font-size: 12px;
  color: var(--text-primary);
  margin-top: 6px;
  min-height: 1.2em;
  font-variant-numeric: tabular-nums;
}

.btn-primary {
  background: #3498db;
  color: #fff;
  border: 1px solid #2980b9;
}

.btn-primary:hover {
  background: #2980b9;
}

#normal-mode {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#normal-mode ul {
  flex: 1;
  overflow-y: auto;
}

/* ─── Scrollbar ─── */

#filter-list::-webkit-scrollbar {
  width: 6px;
}

#filter-list::-webkit-scrollbar-track {
  background: transparent;
}

#filter-list::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 3px;
}

#filter-list::-webkit-scrollbar-thumb:hover {
  background: var(--scrollbar-hover);
}