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

:root {
  --bg: #0d1117;
  --surface: #161b22;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --accent-hover: #79b8ff;
  --green: #3fb950;
  --red: #f85149;

  /* diff2html dark theme custom properties */
  --d2h-dark-bg-color: #161b22;
  --d2h-dark-border-color: #30363d;
  --d2h-dark-dim-color: #8b949e;
  --d2h-dark-line-border-color: #30363d;
  --d2h-dark-file-header-bg-color: #0d1117;
  --d2h-dark-file-header-border-color: #30363d;
  --d2h-dark-empty-placeholder-bg-color: #0d1117;
  --d2h-dark-empty-placeholder-border-color: #30363d;
  --d2h-dark-selected-color: rgba(88, 166, 255, 0.15);
  --d2h-dark-ins-bg-color: rgba(63, 185, 80, 0.12);
  --d2h-dark-ins-border-color: rgba(63, 185, 80, 0.25);
  --d2h-dark-ins-highlight-bg-color: rgba(63, 185, 80, 0.30);
  --d2h-dark-ins-label-color: #3fb950;
  --d2h-dark-del-bg-color: rgba(248, 81, 73, 0.12);
  --d2h-dark-del-border-color: rgba(248, 81, 73, 0.25);
  --d2h-dark-del-highlight-bg-color: rgba(248, 81, 73, 0.30);
  --d2h-dark-del-label-color: #f85149;
  --d2h-dark-info-bg-color: rgba(88, 166, 255, 0.08);
  --d2h-dark-info-border-color: rgba(88, 166, 255, 0.2);
  --d2h-dark-change-del-color: rgba(248, 81, 73, 0.40);
  --d2h-dark-change-ins-color: rgba(63, 185, 80, 0.40);
  --d2h-dark-change-label-color: #d29922;
  --d2h-dark-moved-label-color: #58a6ff;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Top stack (header + toolbar, single sticky unit) ── */
.top-stack {
  position: sticky;
  top: 0;
  z-index: 10;
}

/* ── Header ── */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.header-left {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

header h1 {
  font-size: 20px;
  font-weight: 600;
}

.tagline {
  color: var(--text-muted);
  font-size: 13px;
}

/* ── Theme select ── */
.theme-select {
  padding: 5px 10px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
  outline: none;
}

.theme-select:hover,
.theme-select:focus {
  border-color: var(--accent);
}

.theme-select option {
  background: var(--surface);
  color: var(--text);
}

/* ── View toggle ── */
.view-toggle {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.toggle-btn {
  padding: 6px 14px;
  background: transparent;
  color: var(--text-muted);
  border: none;
  font-size: 13px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

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

.toggle-btn.active {
  background: var(--accent);
  color: #fff;
}

/* ── Buttons ── */
.btn {
  padding: 8px 18px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}

.btn.primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.btn.primary:hover {
  background: var(--accent-hover);
}

.btn.secondary {
  background: var(--surface);
  color: var(--text);
}

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

.btn-sm {
  padding: 4px 12px;
  font-size: 12px;
}

/* ── Export dropdown ── */
.export-dropdown {
  position: relative;
  display: inline-block;
}

.export-menu {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  z-index: 50;
  min-width: 140px;
  overflow: hidden;
}

.export-menu.hidden {
  display: none;
}

.export-item {
  display: block;
  width: 100%;
  padding: 8px 14px;
  font-size: 12px;
  font-family: inherit;
  color: var(--text);
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
}

.export-item:hover {
  background: var(--bg);
  color: var(--accent);
}

.export-item + .export-item {
  border-top: 1px solid var(--border);
}

kbd {
  display: inline-block;
  padding: 2px 6px;
  font-size: 11px;
  font-family: "SFMono-Regular", Consolas, monospace;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-muted);
}

/* ── Main ── */
main {
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* ── Footer ── */
.site-footer {
  padding: 14px 24px;
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

.site-footer a {
  color: var(--accent);
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* ── Input panel ── */
.input-panel {
  max-width: 860px;
  width: 100%;
  margin: 40px auto;
  padding: 0 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.input-panel h2 {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-muted);
}

.input-hints {
  font-size: 12px;
  color: var(--text-muted);
}

.input-hints code {
  padding: 2px 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 11px;
}

#diffInput {
  width: 100%;
  min-height: 320px;
  padding: 14px;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 13px;
  line-height: 1.5;
  resize: vertical;
  tab-size: 4;
}

#diffInput:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.15);
}

.input-actions {
  display: flex;
  gap: 10px;
  align-items: center;
}

.input-footer {
  font-size: 12px;
  color: var(--text-muted);
}

/* ── Output panel ── */
.output-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.output-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  gap: 12px;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  min-width: 0;
  flex: 1;
}

.toolbar-right {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-shrink: 0;
}

/* ── Share URL ── */
.share-url {
  display: flex;
  align-items: center;
  gap: 6px;
  min-width: 0;
  flex: 1;
  max-width: 420px;
}

.share-url input {
  flex: 1;
  min-width: 0;
  padding: 3px 8px;
  background: var(--bg);
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  outline: none;
  cursor: text;
}

.share-url input:focus {
  border-color: var(--accent);
}

/* ── Diff stats ── */
.diff-stats {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
}

.diff-stats .stat-files {
  color: var(--text);
  font-weight: 500;
}

.diff-stats .stat-add {
  color: var(--green);
}

.diff-stats .stat-del {
  color: var(--red);
}

/* ── Output body (sidebar + diff) ── */
.output-body {
  flex: 1;
  display: flex;
  min-height: 0;
}

/* ── Sidebar ── */
.sidebar {
  width: 260px;
  min-width: 260px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: width 0.2s, min-width 0.2s, opacity 0.2s;
}

.sidebar.collapsed {
  width: 0;
  min-width: 0;
  opacity: 0;
  border-right: none;
  pointer-events: none;
}

.sidebar-header {
  padding: 10px 14px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-filter {
  padding: 6px 10px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-filter input {
  width: 100%;
  padding: 4px 8px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  outline: none;
}

.sidebar-filter input:focus {
  border-color: var(--accent);
}

.sidebar-filter input::placeholder {
  color: var(--text-muted);
}

.sidebar-tree {
  flex: 1;
  overflow-y: auto;
  padding: 6px 0;
}

/* Tree items */
.tree-dir {
  display: block;
}

.tree-file {
  display: flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.tree-dir > .tree-label {
  display: flex;
  align-items: center;
  width: 100%;
  padding: 3px 10px;
  font-size: 12px;
  color: var(--text-muted);
  gap: 5px;
  cursor: pointer;
  user-select: none;
}

.tree-dir > .tree-label:hover {
  background: rgba(255, 255, 255, 0.04);
}

.tree-dir > .tree-label .tree-arrow {
  font-size: 10px;
  width: 12px;
  text-align: center;
  transition: transform 0.15s;
  flex-shrink: 0;
}

.tree-dir.closed > .tree-label .tree-arrow {
  transform: rotate(-90deg);
}

.tree-dir.closed > .tree-children {
  display: none;
}

.tree-dir.filter-open > .tree-children {
  display: block;
}

.tree-dir > .tree-label .tree-dirname {
  font-weight: 500;
  color: var(--text);
}

.tree-children {
  /* indent via padding-left on children */
}

.tree-file {
  padding: 3px 10px;
  font-size: 12px;
  font-family: "SFMono-Regular", Consolas, monospace;
  color: var(--text-muted);
  gap: 6px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tree-file:hover {
  background: rgba(255, 255, 255, 0.04);
}

.tree-file.active {
  color: var(--accent);
  background: rgba(88, 166, 255, 0.08);
}

.tree-file .tree-filename {
  overflow: hidden;
  text-overflow: ellipsis;
}

.tree-file .tree-stats {
  margin-left: auto;
  font-size: 10px;
  flex-shrink: 0;
  display: flex;
  gap: 4px;
}

.tree-stats .ts-add { color: var(--green); }
.tree-stats .ts-del { color: var(--red); }

/* Active toggle button state */
.btn.btn-active {
  border-color: var(--accent);
  color: var(--accent);
}

/* ── Diff container ── */
.diff-container {
  flex: 1;
  padding: 16px 24px;
  overflow: auto;
  min-width: 0;
}

/* ── Shortcut hint toast ── */
.shortcut-hint {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  padding: 8px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 12px;
  color: var(--text-muted);
  z-index: 50;
  opacity: 1;
  transition: opacity 0.4s;
  pointer-events: none;
}

.shortcut-hint.fade-out {
  opacity: 0;
}

.hidden {
  display: none !important;
}

/* ── diff2html overrides (minimal — lean on CSS custom properties above) ── */

/* Force dark scheme class since we always use dark theme */
.d2h-wrapper {
  background: transparent;
}

.d2h-file-wrapper {
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 16px;
  overflow: hidden;
}

.d2h-diff-table {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 12px;
}

/* Sticky file headers — top is set by JS to match top-stack height */
.d2h-file-header {
  position: sticky;
  top: 0;
  z-index: 5;
}

/* Ensure file collapse button is visible in dark mode */
.d2h-file-collapse {
  color: var(--text-muted);
  cursor: pointer;
}

.d2h-file-collapse:hover {
  color: var(--text);
}

/* File stats badges */
.d2h-file-stats {
  font-size: 12px;
}

/* Info line (hunk headers) */
.d2h-info {
  border-bottom: 1px solid var(--border);
}

/* Hide the built-in file list — we use our own pill bar */
.d2h-file-list-wrapper {
  display: none;
}

/* Side-by-side panes get proper widths */
.d2h-file-side-diff {
  overflow-x: auto;
}

/* ── Tutorial view ── */
.tutorial-view {
  padding: 16px;
  max-width: 900px;
}

.tutorial-commit {
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 20px;
  padding: 16px;
  background: var(--surface);
}

.tutorial-commit-subject {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.3;
}

.tutorial-commit-meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.tutorial-commit-author {
  color: var(--accent);
}

.tutorial-commit-body {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  line-height: 1.5;
  color: var(--text);
  white-space: pre-wrap;
}

.tutorial-index {
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 20px;
  overflow: hidden;
}

.tutorial-index-header {
  background: var(--surface);
  padding: 10px 14px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}

.tutorial-index ul {
  list-style: none;
  margin: 0;
  padding: 6px 0;
}

.tutorial-index li {
  padding: 4px 14px;
  font-family: monospace;
  font-size: 13px;
}

.tutorial-index a {
  color: var(--accent);
  text-decoration: none;
}

.tutorial-index a:hover {
  text-decoration: underline;
}

.tutorial-stats {
  margin-left: 8px;
  font-size: 12px;
}

.tutorial-stat-add {
  color: var(--green);
}

.tutorial-stat-del {
  color: var(--red);
  margin-left: 4px;
}

.tutorial-file {
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 20px;
  overflow: hidden;
}

.tutorial-file-header {
  background: var(--surface);
  padding: 10px 14px;
  font-family: monospace;
  font-size: 13px;
  font-weight: 600;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}

.tutorial-file-path {
  color: var(--accent);
}

.tutorial-action-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 2px 6px;
  border-radius: 3px;
  vertical-align: middle;
}

.tutorial-badge-new {
  background: var(--green);
  color: #000;
}

.tutorial-badge-delete {
  background: var(--red);
  color: #fff;
}

.tutorial-step {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
}

.tutorial-step:last-child {
  border-bottom: none;
}

.tutorial-step + .tutorial-step {
  border-top: 1px dashed var(--border);
}

.tutorial-instruction {
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-muted);
}

.tutorial-instruction-find {
  color: var(--yellow, var(--text-muted));
}

.tutorial-instruction-replace {
  color: var(--accent);
  margin-top: 10px;
}

.tutorial-instruction-add {
  color: var(--green);
  margin-top: 10px;
}

.tutorial-instruction-remove {
  color: var(--red);
}

.tutorial-code-wrap {
  position: relative;
}

.tutorial-code {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 10px 12px;
  font-family: monospace;
  font-size: 12px;
  line-height: 1.5;
  overflow-x: auto;
  white-space: pre;
  color: var(--text);
  margin: 0;
}

.tutorial-copy {
  position: absolute;
  top: 6px;
  right: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 3px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s;
}

.tutorial-code-wrap:hover .tutorial-copy {
  opacity: 1;
}

.tutorial-copy:hover {
  color: var(--text);
  border-color: var(--accent);
}

/* ── Drag-over indicator ── */
body.drag-over::after {
  content: "Drop .diff / .patch file here";
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: var(--accent);
  background: rgba(13, 17, 23, 0.85);
  border: 3px dashed var(--accent);
  pointer-events: none;
  z-index: 999;
}

/* ── URL loading state ── */
.url-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  gap: 16px;
  color: var(--text-muted);
  font-size: 14px;
}

.url-loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.url-loading-url {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  color: var(--text-muted);
  word-break: break-all;
  max-width: 600px;
  text-align: center;
}

/* ── URL error state ── */
.url-error {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  gap: 12px;
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

.url-error h3 {
  color: var(--red);
  font-size: 18px;
  font-weight: 600;
}

.url-error p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.5;
}

.url-error-url {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  word-break: break-all;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    gap: 8px;
    align-items: flex-start;
  }

  .output-toolbar {
    flex-direction: column;
    align-items: flex-start;
  }

  .toolbar-right {
    width: 100%;
    justify-content: flex-end;
    flex-wrap: wrap;
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: min(280px, 80vw);
    min-width: 0;
    z-index: 100;
    box-shadow: 4px 0 12px rgba(0, 0, 0, 0.4);
  }

  .sidebar.collapsed {
    box-shadow: none;
    display: none;
  }

  .sidebar-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
  }

  .sidebar-backdrop.hidden {
    display: none;
  }

  .diff-container {
    padding: 8px;
  }
}