:root {
  --bg: #fffff8;
  --fg: #111;
  --fg-muted: #888;
  --border: #ddd;
  --bg-input: #fff;
  --bg-hover: #f5f5f0;
}

@media (prefers-color-scheme: dark) {
  html {
    color-scheme: dark;
  }
  :root {
    --bg: #1a1a1a;
    --fg: #e0e0e0;
    --fg-muted: #999;
    --border: #333;
    --bg-input: #252525;
    --bg-hover: #2a2a2a;
  }
}

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

body {
  font-family: Georgia, 'Times New Roman', serif;
  background: var(--bg);
  color: var(--fg);
  max-width: 1825px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
  line-height: 1.5;
}

/* ─── Menubar ─────────────────────────────────────────── */

.menubar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.5rem;
}

.logo {
  font-size: 1.1rem;
  font-weight: normal;
  letter-spacing: 0.04em;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.pixel-bird {
  display: inline-block;
  width: 32px;
  height: 32px;
  image-rendering: pixelated;
  background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" shape-rendering="crispEdges"><rect x="6" y="2" width="2" height="2" fill="%23f7dc6f"/><rect x="8" y="2" width="2" height="2" fill="%23f7dc6f"/><rect x="4" y="4" width="2" height="2" fill="%23f7dc6f"/><rect x="6" y="4" width="2" height="2" fill="%23f7dc6f"/><rect x="8" y="4" width="2" height="2" fill="%23fff"/><rect x="10" y="4" width="2" height="2" fill="%23f7dc6f"/><rect x="2" y="6" width="2" height="2" fill="%23f7dc6f"/><rect x="4" y="6" width="2" height="2" fill="%23f7dc6f"/><rect x="6" y="6" width="2" height="2" fill="%23f7dc6f"/><rect x="8" y="6" width="2" height="2" fill="%23000"/><rect x="10" y="6" width="2" height="2" fill="%23f7dc6f"/><rect x="12" y="6" width="2" height="2" fill="%23e67e22"/><rect x="4" y="8" width="2" height="2" fill="%23f7dc6f"/><rect x="6" y="8" width="2" height="2" fill="%23f7dc6f"/><rect x="8" y="8" width="2" height="2" fill="%23f7dc6f"/><rect x="10" y="8" width="2" height="2" fill="%23e67e22"/><rect x="12" y="8" width="2" height="2" fill="%23e67e22"/><rect x="6" y="10" width="2" height="2" fill="%23f7dc6f"/><rect x="8" y="10" width="2" height="2" fill="%23f7dc6f"/></svg>');
  background-size: contain;
}

.menubar nav {
  display: flex;
  gap: 0.5rem;
}

.menubar button {
  font-family: inherit;
  font-size: 0.85rem;
  background: none;
  border: 1px solid var(--border);
  color: var(--fg);
  padding: 0.25rem 0.75rem;
  cursor: pointer;
  border-radius: 2px;
}

.menubar button:hover {
  background: var(--bg-hover);
}

.logo-subtitle {
  font-size: 0.85rem;
  color: var(--fg-muted);
  font-style: italic;
  margin-left: 0.3rem;
}

/* ─── Menubar Layout with Tabs ───────────────────────── */

.menubar-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-tabs {
  display: flex;
  gap: 0.25rem;
}

.tab {
  font-family: inherit;
  font-size: 0.8rem;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--fg-muted);
  padding: 0.2rem 0.6rem;
  cursor: pointer;
  border-radius: 2px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}

.tab:hover {
  background: var(--bg-hover);
  color: var(--fg);
}

.page-desc {
  font-size: 0.8rem;
  color: var(--fg-muted);
  font-style: italic;
  margin-left: 0.75rem;
}

.tab.tab-active {
  color: var(--fg);
  background: rgba(247, 220, 111, 0.18);
  border: 1px solid #f7dc6f;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.2);
  transform: translateY(0.5px);
}

/* ─── Model Spec ──────────────────────────────────────── */

.model-spec {
  margin-bottom: 2rem;
}

.model-name-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.model-name-field {
  flex: 1;
}

.model-name-field .tufte-label {
  font-size: 0.7rem;
}

.model-name {
  font-family: inherit;
  font-size: 1.5rem;
  background: none;
  border: none;
  border-bottom: 1px solid var(--border);
  color: #222;
  width: 100%;
  padding: 0.25rem 0;
  outline: none;
}

.model-name:focus {
  border-bottom-color: var(--fg);
}

@media (prefers-color-scheme: dark) {
  .model-name {
    color: #ddd;
  }
}

.btn-save {
  font-family: inherit;
  font-size: 0.8rem;
  background: none;
  border: 1px solid var(--border);
  color: var(--fg-muted);
  padding: 0.2rem 0.6rem;
  cursor: pointer;
  border-radius: 2px;
  white-space: nowrap;
}

.btn-save:hover {
  color: var(--fg);
  background: var(--bg-hover);
}

.kbd-hint {
  font-size: 0.65rem;
  color: var(--fg-muted);
  margin-left: 0.3rem;
  opacity: 0.5;
}

.model-name::placeholder {
  color: var(--fg-muted);
}

.model-name:focus {
  border-bottom-color: var(--fg);
}

.model-name:focus-visible {
  outline: 2px solid var(--fg-muted);
  outline-offset: 2px;
}

.calc-inputs {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 1.25rem;
  margin-bottom: 0.75rem;
}

.tufte-field {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.tufte-label {
  font-size: 0.7rem;
  color: var(--fg-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.calc-type {
  font-family: inherit;
  font-size: 1.2rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--fg);
  padding: 0.4rem 0.65rem;
  border-radius: 2px;
  height: 2.5rem;
}

.calc-inputs input[type="text"] {
  font-family: inherit;
  font-size: 1.2rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--fg);
  padding: 0.4rem 0.65rem;
  border-radius: 2px;
  min-width: 13rem;
  height: 2.5rem;
}

.calc-inputs input::placeholder {
  color: var(--fg-muted);
}

.formula-desc {
  font-size: 1rem;
  color: var(--fg-muted);
  margin-left: 0.5rem;
}

.flop-display {
  font-size: 1.8rem;
  padding: 0.25rem 0;
}

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

.flop-label {
  font-size: 1rem;
  color: var(--fg-muted);
  font-weight: normal;
  margin-left: 0.5rem;
}

.flop-exp {
  font-size: 0.6em;
}

.flop-emoji {
  margin-left: 0.25rem;
}

.flop-eng {
  font-size: 0.85rem;
  color: var(--fg-muted);
  font-variant-numeric: tabular-nums;
  margin-top: -0.1rem;
}

.flop-eng-e {
  font-size: 0.75em;
  margin: 0 0.1em;
}

/* ─── Accelerator Table ───────────────────────────────── */

.accel-table-toolbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}

.accel-toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.75rem;
  font-size: 0.8rem;
  color: var(--fg-muted);
}

.accel-toggle {
  cursor: pointer;
  user-select: none;
}

.accel-toggle input[type="checkbox"] {
  margin-right: 0.15rem;
  vertical-align: -1px;
}

.btn-copy-csv {
  font-family: inherit;
  font-size: 0.75rem;
  background: none;
  border: 1px solid var(--border);
  color: var(--fg-muted);
  padding: 0.2rem 0.5rem;
  cursor: pointer;
  border-radius: 2px;
  white-space: nowrap;
  flex-shrink: 0;
}

.btn-copy-csv:hover {
  color: var(--fg);
  background: var(--bg-hover);
}

.accel-table {
  overflow-x: auto;
}

.accel-table table {
  width: auto;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.accel-table th {
  text-align: left;
  font-weight: normal;
  color: var(--fg-muted);
  padding: 0.4rem 0.4rem;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
  position: relative;
}

.accel-table th[data-formula]:hover::after {
  content: attr(data-formula);
  position: absolute;
  left: 50%;
  top: calc(100% + 4px);
  transform: translateX(-50%);
  background: #333;
  color: #fff;
  font-size: 0.75rem;
  padding: 0.4rem 0.6rem;
  border-radius: 3px;
  white-space: nowrap;
  z-index: 10;
  pointer-events: none;
}

.accel-table th[data-formula]:has(.info-tip:hover)::after {
  display: none;
}

.info-tip {
  display: inline-block;
  font-size: 0.7rem;
  color: var(--fg-muted);
  cursor: help;
  vertical-align: middle;
  margin-left: 0.2rem;
  opacity: 0.6;
  position: relative;
}

.info-tip:hover {
  opacity: 1;
}

.info-tip:hover::after {
  content: attr(data-tip);
  position: absolute;
  left: 50%;
  top: calc(100% + 6px);
  transform: translateX(-50%);
  background: #333;
  color: #fff;
  font-size: 0.75rem;
  padding: 0.4rem 0.6rem;
  border-radius: 3px;
  white-space: normal;
  max-width: 1980px;
  line-height: 1.4;
  z-index: 10;
  pointer-events: none;
}

.accel-table td {
  padding: 0.4rem 0.4rem;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.accel-table tr:last-child td {
  border-bottom: none;
}

.super-header-row th {
  border-bottom: none;
  padding-bottom: 0;
}

.accel-table th.super-header {
  text-align: center;
  font-size: 0.8rem;
  font-style: italic;
  color: var(--fg-muted);
}

.accel-table .col-sep {
  border-left: 2px solid var(--border);
}

.accel-table .result-cell,
.accel-table th.result-header {
  text-align: right;
}

.accel-table .chip-count {
  display: block;
  font-variant-numeric: tabular-nums;
}

.accel-table .pod-count {
  display: block;
  font-size: 0.75rem;
  color: var(--fg-muted);
}

.penalty-hint {
  cursor: help;
  border-bottom: 1px dotted var(--fg-muted);
}

/* ─── Editable Cells (Phase 4) ───────────────────────── */

.cell-prefix {
  font-size: 0.85rem;
  color: var(--fg-muted);
  margin-right: 0.1rem;
}

.editable-cell {
  position: relative;
  white-space: nowrap;
  min-width: 4rem;
}

.cell-editable {
  font-family: inherit;
  font-size: 0.85rem;
  background: none;
  border: 1px solid transparent;
  padding: 0.15rem 0.3rem;
  border-radius: 2px;
  width: 3.8rem;
  color: var(--fg);
  -moz-appearance: textfield;
}

.cell-editable::-webkit-inner-spin-button,
.cell-editable::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.cell-editable:hover,
.cell-editable:focus {
  border-color: var(--border);
  background: var(--bg-input);
  outline: none;
}

.cell-editable:focus-visible {
  outline: 2px solid var(--fg-muted);
  outline-offset: 1px;
}

.cell-default {
  color: var(--fg-muted);
}

.cell-edited {
  color: var(--fg);
}

.btn-reset {
  font-size: 0.7rem;
  background: none;
  border: none;
  color: var(--fg-muted);
  cursor: pointer;
  padding: 0;
  margin-left: 0.25rem;
  line-height: 1;
  vertical-align: middle;
}

.btn-reset:hover {
  color: var(--fg);
}

.cell-error {
  border-color: #c44 !important;
  background: rgba(204, 68, 68, 0.1);
}

.cell-error-msg {
  position: absolute;
  left: 0;
  top: 100%;
  background: #c44;
  color: #fff;
  font-size: 0.7rem;
  padding: 0.2rem 0.4rem;
  border-radius: 2px;
  white-space: nowrap;
  z-index: 10;
  margin-top: 2px;
  animation: fadeIn 0.15s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ─── Saved Calcs Modal (Phase 7) ────────────────────── */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

.saved-calcs-modal {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  width: 90%;
  max-width: 480px;
  max-height: 70vh;
  display: flex;
  flex-direction: column;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 1rem;
  font-weight: normal;
  margin: 0;
}

.modal-kbd-hints {
  font-size: 0.7rem;
  color: var(--fg-muted);
  margin-left: auto;
  margin-right: 1rem;
}

.modal-kbd-hints .kbd-hint {
  background: var(--bg-hover);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 0.1rem 0.3rem;
  margin-right: 0.2rem;
  font-family: monospace;
  opacity: 0.8;
}

.btn-modal-close {
  font-family: inherit;
  font-size: 1.2rem;
  background: none;
  border: none;
  color: var(--fg-muted);
  cursor: pointer;
  padding: 0 0.25rem;
  line-height: 1;
}

.btn-modal-close:hover {
  color: var(--fg);
}

.modal-body {
  overflow-y: auto;
  padding: 0.5rem 0;
}

.modal-empty {
  text-align: center;
  color: var(--fg-muted);
  padding: 2rem 1rem;
  font-size: 0.9rem;
}

.calc-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.calc-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 1rem;
  cursor: pointer;
  font-size: 0.9rem;
}

.calc-item:hover,
.calc-item.active {
  background: var(--bg-hover);
}

.calc-item-name {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.pin-indicator {
  font-size: 0.8rem;
}

.calc-item-actions {
  display: flex;
  gap: 0.25rem;
  flex-shrink: 0;
  margin-left: 0.5rem;
}

.btn-pin,
.btn-delete {
  font-family: inherit;
  font-size: 0.75rem;
  background: none;
  border: 1px solid var(--border);
  color: var(--fg-muted);
  cursor: pointer;
  padding: 0.1rem 0.4rem;
  border-radius: 2px;
}

.btn-pin:hover,
.btn-delete:hover {
  color: var(--fg);
  background: var(--bg-hover);
}

/* ─── Focus Indicators (Phase 8 Accessibility) ──────── */

button:focus-visible,
select:focus-visible,
input:focus-visible {
  outline: 2px solid var(--fg-muted);
  outline-offset: 2px;
}

/* ─── Mobile Responsiveness (Phase 8) ────────────────── */

@media (max-width: 600px) {
  body {
    padding: 1rem 0.5rem;
  }

  .menubar {
    gap: 0.25rem;
  }

  .menubar button {
    font-size: 0.75rem;
    padding: 0.2rem 0.5rem;
  }

  .model-name {
    font-size: 1rem;
  }

  .calc-inputs input[type="text"] {
    min-width: 7rem;
    flex: 1;
  }

  .accel-table-toolbar {
    flex-wrap: wrap;
    gap: 0.5rem;
  }

  .accel-table {
    -webkit-overflow-scrolling: touch;
  }

  .accel-table table {
    font-size: 0.8rem;
  }

  .accel-table th,
  .accel-table td {
    padding: 0.3rem 0.5rem;
  }

  .editable-cell {
    min-width: 4.5rem;
  }

  .cell-editable {
    width: 3rem;
    font-size: 0.8rem;
  }
}

.accel-table th.chips-train-header {
  white-space: normal;
  max-width: 6rem;
  vertical-align: middle;
  text-align: right;
  border-bottom: 1px solid var(--border);
}

.custom-days-input,
.custom-chips-input {
  font-family: inherit;
  font-size: 0.8rem;
  width: 3.5rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--fg);
  padding: 0.15rem 0.3rem;
  border-radius: 2px;
  -moz-appearance: textfield;
}

.custom-days-input::-webkit-inner-spin-button,
.custom-days-input::-webkit-outer-spin-button,
.custom-chips-input::-webkit-inner-spin-button,
.custom-chips-input::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.time-value {
  display: block;
  font-variant-numeric: tabular-nums;
}

/* ─── Reverse Page ───────────────────────────────────── */

.reverse-table th,
.reverse-table td {
  padding-left: 1rem;
  padding-right: 1rem;
}

.reverse-info-line {
  font-size: 0.85rem;
  color: var(--fg-muted);
  font-style: italic;
  margin-bottom: 0.25rem;
}

.reverse-selected-row {
  background: rgba(247, 220, 111, 0.15);
}

.reverse-selected-row td {
  font-weight: 600;
}

.accel-table td[data-formula]:hover,
.accel-table td[title] {
  position: relative;
}

.accel-table td[data-formula]:hover::after {
  content: attr(data-formula);
  position: absolute;
  left: 50%;
  top: calc(100% + 4px);
  transform: translateX(-50%);
  background: #333;
  color: #fff;
  font-size: 0.75rem;
  padding: 0.4rem 0.6rem;
  border-radius: 3px;
  white-space: nowrap;
  z-index: 10;
  pointer-events: none;
}

/* ─── Toast ──────────────────────────────────────────── */

.toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--fg);
  color: var(--bg);
  padding: 0.6rem 1rem;
  border-radius: 4px;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  z-index: 200;
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.toast-undo {
  font-family: inherit;
  font-size: 0.8rem;
  background: transparent;
  border: 1px solid var(--bg);
  color: var(--bg);
  padding: 0.2rem 0.5rem;
  cursor: pointer;
  border-radius: 2px;
}

.toast-undo:hover {
  background: var(--bg);
  color: var(--fg);
}

.toast-undo .kbd-hint {
  opacity: 0.7;
}