:root {
  /* Brand */
  --color-primary: #282c34;
  --color-primary-dim: rgba(0, 0, 0, 0.6);
  --color-surface: #2f343d;
  --color-text: #abb2bf;
  --color-text-strong: #c0c7d1;
  --color-text-muted: #98a0ac;

  /* Buttons & footer */
  --color-footer: #1f232b;

  /* Syntax highlighting */
  --color-variable: #e87884;
  --color-number: #d19a66;
  --color-operator: #56b6c2;
  --color-currency: #98c379;
  --color-title: #9aa4b0;

  /* Feedback */

  /* Links */
  --color-link: #61afef;
  --color-link-visited: #c678dd;

  /* Inline ghost results */
  --color-ghost: rgba(255, 255, 255, 0.5);
  --color-ghost-error: #ef8181;

  /* Editor line-number gutter */
  --line-gutter: 3.5em;

  /* Safe-area insets for standalone PWA (notch / home indicator) */
  --safe-top: env(safe-area-inset-top);
  --safe-left: env(safe-area-inset-left);
  --safe-right: env(safe-area-inset-right);
  --safe-bottom: env(safe-area-inset-bottom);

  /* Borders */
  --border-light: rgba(255, 255, 255, 0.2);
  --border-faint: rgba(255, 255, 255, 0.15);
  --border-strong: #3e4451;
  --border-soft: rgba(255, 255, 255, 0.12);
  --border-table: rgba(255, 255, 255, 0.1);

  /* Modal surfaces */
  --surface-nav: #1f232b;
  --surface-chip: #2f343d;
  --surface-chip-hover: #353b45;
  --surface-link-hover: #353b45;
  --surface-code: #1f232b;
  --border-chip: rgba(255, 255, 255, 0.14);
  --shadow-modal: rgba(0, 0, 0, 0.5);
  --text-over-primary: rgba(255, 255, 255, 0.8);
}

/* Dracula */
html[data-theme='dracula'] {
  --color-primary: #282a36;
  --color-surface: #2f3141;
  --color-text: #f8f8f2;
  --color-text-strong: #e3e3e6;
  --color-text-muted: #9aa0b8;
  --color-footer: #1e1f29;
  --color-variable: #ff79c6;
  --color-number: #bd93f9;
  --color-operator: #8be9fd;
  --color-currency: #50fa7b;
  --color-title: #9aa0b8;
  --color-ghost-error: #ff8a8a;
  --color-link: #8be9fd;
  --color-link-visited: #bd93f9;
  --border-strong: #44475a;
  --surface-nav: #21222c;
  --surface-chip: #2f3141;
  --surface-chip-hover: #353b52;
  --surface-link-hover: #353b52;
  --surface-code: #21222c;
}

/* Solarized Dark */
html[data-theme='solarized-dark'] {
  --color-primary: #002b36;
  --color-surface: #073642;
  --color-text: #93a1a1;
  --color-text-strong: #a4b1b4;
  --color-text-muted: #8fa1a8;
  --color-footer: #001f27;
  --color-variable: #2f98d6;
  --color-number: #b58900;
  --color-operator: #2aa198;
  --color-currency: #859900;
  --color-title: #a4b1b4;
  --color-ghost-error: #e56757;
  --color-link: #2f98d6;
  --color-link-visited: #8b92e0;
  --border-strong: #586e75;
  --surface-nav: #00232c;
  --surface-chip: #073642;
  --surface-chip-hover: #0a4150;
  --surface-link-hover: #0a4150;
  --surface-code: #00232c;
}

/* Monokai */
html[data-theme='monokai'] {
  --color-primary: #272822;
  --color-surface: #2d2d26;
  --color-text: #f8f8f2;
  --color-text-strong: #e6e6df;
  --color-text-muted: #9a958a;
  --color-footer: #1d1e19;
  --color-variable: #ff4f8f;
  --color-number: #ae81ff;
  --color-operator: #e6db74;
  --color-currency: #a6e22e;
  --color-title: #9a958a;
  --color-ghost-error: #ff8a8a;
  --color-link: #66d9ef;
  --color-link-visited: #ae81ff;
  --border-strong: #49483e;
  --surface-nav: #1d1e19;
  --surface-chip: #2d2d26;
  --surface-chip-hover: #34342c;
  --surface-link-hover: #34342c;
  --surface-code: #1d1e19;
}

* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  background: var(--color-footer);
  color: var(--color-text);
  font-size: var(--app-font-size, 16px);
  font-family: monospace;
  line-height: 1.65em;
}
.layout {
  display: grid;
  grid-template-rows: auto 1fr auto;
  height: 100%;
}
.tabs-bar {
  display: flex;
  align-items: stretch;
  min-height: 2.2em;
  padding: var(--safe-top) var(--safe-right) 0 var(--safe-left);
  background: var(--color-footer);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  overflow-x: auto;
  scrollbar-width: thin;
}
.tab {
  display: flex;
  align-items: center;
  padding-left: 0.6em;
  cursor: pointer;
  user-select: none;
  color: var(--color-text);
  border-right: 1px solid var(--border-faint);
  white-space: nowrap;
  touch-action: none;
}
.tab.dragging {
  opacity: 0.5;
  outline: 1px dashed var(--color-operator);
  outline-offset: -1px;
}
.tab.active {
  background: var(--color-primary);
  color: var(--color-text);
}
.tab-name {
  font: inherit;
}
.tab:focus-visible {
  outline: 2px solid var(--color-variable);
  outline-offset: -2px;
}
.tab-close {
  margin-left: 0.5em;
}
.tab-close,
.modal-close,
.find-close {
  background: transparent;
  color: inherit;
}
.tab-new {
  margin-left: auto;
  align-self: stretch;
  padding: 0 0.9em;
  border: 0;
  background: transparent;
  color: var(--color-text);
  font-size: 1.5em;
  line-height: 1;
  cursor: pointer;
}
.tab-new:hover {
  color: var(--color-operator);
}
.tab-rename {
  font: inherit;
  color: inherit;
  background: var(--color-surface);
  border: 0;
  outline: 1px solid var(--color-variable);
  padding: 0.1em 0.3em;
  min-width: 6em;
}
.calculator {
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr auto;
  min-height: 0;
  overflow: hidden;
}
.input {
  position: relative;
  min-height: 0;
  cursor: text;
  background: var(--color-primary);
}
/*
 * The editor is a transparent textarea overlaid by a highlighted .view layer
 * (a pre) that renders the same text, so the caret lives in the real input
 * while the styled copy is what the user sees. Both layers are content-sized
 * grid cells inside .editor-scroll, which is the scroll container — the view
 * may be wider than the textarea (its ghost results are scrollable content),
 * and both layers move together, so no scroll mirroring is needed. They must
 * share identical metrics (font, line-height, padding, white-space) or the
 * ghost text drifts from the caret. white-space: pre keeps every expression
 * on one line.
 */
.editor-scroll {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  overflow: auto;
  scrollbar-gutter: stable;
}
.editor-content {
  display: grid;
  grid-template-columns: minmax(max-content, 1fr);
  grid-template-rows: minmax(max-content, 1fr);
  width: max-content;
  height: max-content;
  min-width: 100%;
  min-height: 100%;
}
.content-editable,
.view {
  grid-area: 1 / 1;
  width: auto;
  height: auto;
  margin: 0;
  padding: 1em calc(1em + var(--safe-right)) 1em calc(1em + var(--line-gutter) + var(--safe-left));
  font: inherit;
  line-height: var(--editor-line-height, 1.65em);
  white-space: pre;
}
.content-editable {
  z-index: 1;
  border: 0;
  background: transparent;
  color: transparent;
  caret-color: var(--color-text);
  outline: none;
  resize: none;
  overflow: hidden;
}
.content-editable::placeholder {
  color: var(--color-text);
  opacity: 0.55;
}
input::placeholder {
  color: var(--color-text);
  opacity: 0.55;
}
.view {
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
  color: var(--color-text);
}
.line-row {
  /* The row spans the line plus its result, so the view (and the scroll
     container) is wide enough to reveal the result by scrolling. The height is
     the integer pixel line height measured from the textarea, so rows can never
     drift from the input, no matter how the browser renders form controls. */
  width: max-content;
  height: var(--editor-line-height, 1.65em);
  line-height: var(--editor-line-height, 1.65em);
}
.ghost-result {
  margin-left: 1.5em;
  color: var(--color-ghost);
  /* A subtle chip separates results/errors from the user's input. */
  background: var(--color-footer);
  border-radius: 3px;
  padding: 0 0.35em;
}
.ghost-result.error {
  color: var(--color-ghost-error);
}
.line-numbers {
  position: absolute;
  top: 0;
  left: var(--safe-left);
  z-index: 0;
  width: var(--line-gutter);
  height: 100%;
  margin: 0;
  padding: 1em 0.5em 1em 0;
  overflow: hidden;
  font: inherit;
  line-height: var(--editor-line-height, 1.65em);
  color: var(--color-text);
  text-align: right;
  white-space: pre;
  background: var(--color-surface);
  border-right: 1px solid var(--border-strong);
  user-select: none;
  pointer-events: none;
}
.line-numbers span {
  opacity: 0.55;
}
.line-numbers span.active {
  opacity: 1;
}
.total-row {
  display: flex;
  align-items: center;
  padding: 0.5em 1em 0.5em calc(1em + var(--line-gutter) + var(--safe-left));
  background: var(--color-surface);
  border-top: 1px solid var(--border-strong);
}
.total-label {
  margin-right: 0.75em;
}
.total {
  font-weight: 700;
  color: var(--color-text);
}
.variable {
  color: var(--color-variable);
}
.number {
  color: var(--color-number);
}
.currency {
  color: var(--color-currency);
}
.operator {
  color: var(--color-operator);
}
.comment {
  opacity: 0.5;
}
.title {
  color: var(--color-title);
}
.footer {
  display: flex;
  align-items: center;
  padding: 0.5em calc(1em + var(--safe-right)) calc(0.5em + var(--safe-bottom))
    calc(1em + var(--safe-left));
  background: var(--color-footer);
  color: var(--color-text);
  border-top: 1px solid var(--border-strong);
}
button {
  font-size: 1em;
  font-family: inherit;
  background: var(--color-primary);
  color: var(--color-text);
  border: 0;
  border-radius: 0;
  padding: 0.5em 0.8em;
  cursor: pointer;
}
button:hover {
  filter: brightness(1.15);
}
.button-wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  column-gap: 0.75em;
  row-gap: 0.4em;
}
.size-controls {
  white-space: nowrap;
}
.actions {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  column-gap: 0.5em;
  row-gap: 0.4em;
  white-space: nowrap;
}
.currency-status {
  display: none;
  font-size: 0.85em;
  color: var(--text-over-primary);
}
.currency-status.visible {
  display: inline;
  animation: status-fade 0.3s ease;
}
@keyframes status-fade {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
.size-controls button + button {
  margin-left: 0.5em;
}
.find-bar {
  position: absolute;
  top: 0.5em;
  right: calc(1em + var(--safe-right));
  z-index: 2;
  display: none;
  flex-direction: column;
  gap: 0.35em;
  max-width: calc(100% - 1em);
  padding: 0.5em;
  background: var(--color-footer);
}
.find-bar.open {
  display: flex;
}
.find-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.3em;
}
.find-field {
  font: inherit;
  color: var(--color-text);
  background: var(--color-primary);
  border: 1px solid var(--border-strong);
  border-radius: 0.2em;
  padding: 0.25em 0.4em;
  outline: none;
  width: 14em;
  min-width: 8em;
}
.find-field:focus {
  outline: 1px solid var(--color-operator);
}
.find-count {
  font-size: 0.85em;
  color: var(--color-text-muted);
  min-width: 3.5em;
  text-align: right;
}
.find-prev {
  margin-right: -0.3em;
}
.find-next {
  border-left: 1px solid var(--border-strong);
}
.find-input-wrap {
  position: relative;
}
.find-input-wrap .find-field {
  padding-right: 2em;
}
.find-input-wrap .find-case {
  position: absolute;
  right: 0.25em;
  top: 50%;
  transform: translateY(-50%);
  padding: 0.15em 0.35em;
  font-size: 0.85em;
  line-height: 1;
  border: 0;
  background: transparent;
  color: var(--color-text-muted);
}
.find-input-wrap .find-case:hover {
  filter: none;
  color: var(--color-text);
}
.find-input-wrap .find-case.active {
  color: var(--color-operator);
  outline: none;
}
.find-match {
  background: rgba(255, 213, 79, 0.35);
  outline: 1px solid rgba(255, 213, 79, 0.5);
  border-radius: 0.15em;
  color: inherit;
}
.find-match.active {
  background: rgba(255, 213, 79, 0.6);
  outline: 2px solid rgba(255, 213, 79, 0.9);
}
/* Modal component (generic, reusable) */
.modal {
  width: min(50rem, 100%);
  max-height: calc(100% - 3em);
  margin: auto;
  padding: 0;
  border: 0;
  box-shadow: 0 10px 40px var(--shadow-modal);
  overflow: hidden;
  color: var(--color-text-strong);
  background: var(--color-surface);
}
.modal[open] {
  display: flex;
  flex-direction: column;
}
.modal::backdrop {
  background: var(--color-primary-dim);
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7em 0.7em 0.7em 1.25em;
  background: var(--color-primary);
  color: var(--color-text);
}
.modal-title {
  margin: 0;
  font-size: 1.15em;
}
.modal-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25em;
  padding: 0.6em 1.25em;
  border-bottom: 1px solid var(--border-soft);
  background: var(--surface-nav);
}
.modal-nav-link,
.modal-nav-link:visited {
  color: var(--color-text);
  text-decoration: none;
  padding: 0.2em 0.6em;
  border-radius: 4px;
  font-size: 0.9em;
}
.modal-nav-link:hover {
  background: var(--surface-link-hover);
}
.modal-nav-link.active {
  background: var(--color-primary);
  color: var(--color-text);
}
.modal-body {
  flex: 1 1 auto;
  min-height: 0;
  padding: 0.25em 1.25em 1.25em;
  overflow-y: auto;
}
.help-section h2 {
  margin: 1.2em 0 0.4em;
  font-size: 1.05em;
  color: var(--color-text);
  border-bottom: 1px solid var(--border-soft);
  padding-bottom: 0.25em;
}
.help-section:first-child h2 {
  margin-top: 1em;
}
.help-section ul {
  margin: 0.4em 0;
  padding-left: 1.2em;
}
.help-section li {
  margin: 0.2em 0;
}
.help-example {
  display: inline-flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.25em;
  margin: 0.35em 0.5em 0.35em 0;
  padding: 0.45em 0.8em;
  border: 1px solid var(--border-chip);
  border-radius: 6px;
  background: var(--surface-chip);
  cursor: pointer;
  user-select: none;
  vertical-align: top;
}
.help-example:hover,
.help-example:focus-visible {
  border-color: var(--color-operator);
  background: var(--surface-chip-hover);
  outline: none;
}
.help-example code {
  background: transparent;
  padding: 0;
  color: var(--color-text);
  white-space: pre-wrap;
  min-width: 0;
  font-family: inherit;
  line-height: 1.4;
}
.help-returns {
  font-size: 0.82em;
  color: var(--color-text-muted);
}
code {
  background: var(--surface-code);
  color: var(--color-text);
  border-radius: 4px;
  padding: 0.1em 0.35em;
}
.help-section table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.6em 0 1em;
  font-size: 0.92em;
}
.help-section th,
.help-section td {
  text-align: left;
  padding: 0.35em 0.6em;
  border-bottom: 1px solid var(--border-table);
  vertical-align: top;
}
.help-section th {
  color: var(--color-text);
}
.help-section td:first-child {
  white-space: nowrap;
  font-weight: 600;
}
.operator-table th:first-child,
.operator-table td:first-child {
  width: 1%;
  white-space: nowrap;
}
.operator-table tbody tr td:first-child {
  text-align: right;
}
/* Theme picker */
.theme-card {
  display: flex;
  align-items: center;
  gap: 0.6em;
  width: 100%;
  margin: 0.3em 0;
  padding: 0.5em 0.8em;
  background: var(--surface-chip);
  color: var(--color-text);
  border: 1px solid var(--border-chip);
  border-radius: 4px;
  cursor: pointer;
  text-align: left;
}
.theme-card:hover {
  background: var(--surface-chip-hover);
  filter: none;
}
.theme-card.active {
  border-color: var(--color-operator);
  box-shadow: inset 0 0 0 1px var(--color-operator);
}
.theme-swatch {
  display: inline-flex;
  gap: 2px;
}
.theme-swatch span {
  width: 1.2em;
  height: 1.2em;
  border-radius: 2px;
}
.settings-files {
  display: flex;
  gap: 0.5em;
}
.snapshot-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75em;
  padding: 0.4em 0.7em;
  background: var(--surface-chip);
  border: 1px solid var(--border-chip);
}
.snapshot-row:first-child {
  border-top-left-radius: 6px;
  border-top-right-radius: 6px;
}
.snapshot-row:last-child {
  border-bottom-left-radius: 6px;
  border-bottom-right-radius: 6px;
}
.snapshot-row + .snapshot-row {
  margin-top: -1px;
}
.snapshot-row span {
  font-size: 0.9em;
  color: var(--color-text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
#snapshot-history {
  margin-top: 0.5em;
}
a {
  color: var(--color-link);
  text-decoration: underline;
}
a:visited {
  color: var(--color-link-visited);
}
a:hover {
  text-decoration: underline;
  filter: brightness(1.2);
}