:root {
  /* --- Light Mode Color Palette --- */
  --font-sans: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI",
    Roboto, "Helvetica Neue", Arial;
  --bg: #f8f9fa;
  --panel-bg: #ffffff;
  --text-primary: #111827;
  --text-muted: #6b7280;
  --border-color: #e5e7eb;
  --accent-primary: #1f2937;
  --accent-primary-fg: #ffffff;
  --accent-gradient: linear-gradient(135deg, #4b5563, #1f2937);
  --highlight-bg: #fef9c3;
  --highlight-border: #fde047;
  --scroll-highlight-bg: #fff3cd;
  --selected-row-bg: #f1f5f9;
  --btn-shadow: 0 1px 2px rgba(0, 0, 0, 0.05); /* Softer shadow */
  --btn-shadow-hover: 0 1px 3px rgba(0, 0, 0, 0.1); /* Softer shadow */
  --radius: 10px;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  --max-width: 1400px;
  --left-width: 50%;
}

/* --- Dark Mode Color Palette (CONTRAST IMPROVED) --- */
html.dark-mode {
  --bg: #111827;
  --panel-bg: #1f2937;
  --text-primary: #e5e7eb;
  --text-muted: #a1a1aa; /* Lighter for better contrast */
  --border-color: #4b5563; /* Lighter for better definition */
  --accent-primary: #cbd5e1; /* Softer white for less glare */
  --accent-primary-fg: #111827;
  --accent-gradient: linear-gradient(135deg, #e5e7eb, #9ca3af);
  --highlight-bg: #4d4d1a; /* Brighter yellow background */
  --highlight-border: #b4950b; /* Brighter yellow border */
  --scroll-highlight-bg: #57460c;
  --selected-row-bg: #374151; /* More distinct from panel */
  --btn-shadow: 1px 1px 3px rgba(0, 0, 0, 0.4);
  --btn-shadow-hover: 1px 1px 4px rgba(0, 0, 0, 0.5);
}

* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text-primary);
  font-size: 15px;
  overflow: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* --- CORE LAYOUT --- */
.app {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px;
  height: 100vh;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 16px;
}

header {
  display: flex;
  align-items: center;
  gap: 14px;
}
.mark {
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--accent-primary-fg);
  font-size: 20px;
  box-shadow: 0 4px 8px rgba(31, 41, 55, 0.1);
}
html.dark-mode .mark {
  color: var(--accent-primary-fg);
}
.title {
  font-size: 18px;
  font-weight: 600;
}
.subtitle {
  color: var(--text-muted);
}

.top-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.search {
  position: relative;
  display: flex;
  gap: 8px;
  align-items: center;
  background: var(--panel-bg);
  padding: 10px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  width: 50%;
  transition: background-color 0.3s ease, border-color 0.3s ease;
  color: var(--text-muted);
}
.search input {
  border: 0;
  outline: 0;
  background: transparent;
  font-size: 14px;
  width: 100%;
  color: var(--text-primary);
}
.search-clear-btn {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  font-size: 20px;
  line-height: 1;
  padding: 0 5px;
  cursor: pointer;
  color: var(--text-muted);
  display: none;
}
.search-clear-btn:hover {
  color: var(--text-primary);
}
.search:has(input:not(:placeholder-shown)) .search-clear-btn {
  display: block;
}

.controls {
  display: flex;
  gap: 10px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--panel-bg);
  border: 1px solid var(--border-color);
  padding: 8px 14px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  color: var(--text-primary);
  transition: background-color 0.2s, box-shadow 0.2s, border-color 0.2s,
    color 0.2s;
  box-shadow: var(--btn-shadow);
}
.btn:hover {
  background: var(--bg);
  box-shadow: var(--btn-shadow-hover);
}
.btn.primary {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: var(--accent-primary-fg);
}
.btn.btn-icon {
  padding: 8px;
  line-height: 0;
}
.btn .icon-holder {
  display: inline-flex;
  align-items: center;
}

.theme-toggle {
  padding: 8px;
  line-height: 0;
}
.dark-mode .sun-icon {
  display: block;
}
.dark-mode .moon-icon {
  display: none;
}
.sun-icon {
  display: none;
}
.moon-icon {
  display: block;
}

.workspace {
  display: grid;
  grid-template-columns: var(--left-width) 1fr;
  gap: 16px;
  min-height: 0;
}
.panel {
  background: var(--panel-bg);
  padding: 0;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}
.panel-header {
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
  transition: border-color 0.3s ease;
}

.subtitle-list {
  flex-grow: 1;
  overflow-y: auto;
  padding: 16px;
  min-height: 0;
}
.sub-row {
  display: flex;
  gap: 12px;
  padding: 8px;
  border-radius: 8px;
  margin-bottom: 4px;
  border: 1px solid transparent;
  transition: background-color 0.4s ease, border-color 0.4s ease;
}
.sub-row.is-selected {
  background: var(--selected-row-bg);
  border-color: var(--border-color);
}
.sub-row.is-scrolled-to {
  background-color: var(--scroll-highlight-bg);
}
.sub-meta {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}
.sub-checkbox {
  accent-color: var(--accent-primary);
}
.timestamp {
  min-width: 75px;
  color: var(--text-muted);
  font-size: 13px;
  font-family: monospace;
}
.sub-text {
  flex: 1;
  line-height: 1.5;
}
.sub-word {
  padding: 1px 3px;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.2s;
}
.sub-word:hover {
  background: rgba(127, 127, 127, 0.15);
}
.sub-word.is-saved {
  background-color: var(--highlight-bg);
  border-radius: 4px;
  box-shadow: 0 0 0 1px var(--highlight-border);
}

.editor-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--text-muted);
  padding: 40px 20px;
  margin: auto;
}
.editor.is-blank .editor-form {
  display: none;
}
.editor:not(.is-blank) .editor-placeholder {
  display: none;
}
.editor-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  flex-grow: 1;
  overflow-y: auto;
  padding: 16px;
  min-height: 0;
}
.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.field label {
  font-weight: 600;
  font-size: 14px;
}
input[type="text"],
textarea {
  padding: 10px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 14px;
  font-family: var(--font-sans);
  width: 100%;
  background-color: var(--panel-bg);
  color: var(--text-primary);
  transition: background-color 0.3s, border-color 0.3s;
}
textarea {
  min-height: 42px;
  resize: vertical;
}
textarea#wordInput {
  padding-top: 10px;
  height: 42px;
  overflow-y: auto;
}
.save-row {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-top: auto;
  padding-top: 16px;
}

.bottom-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.bottom-bar > div {
  display: flex;
  align-items: center;
  gap: 10px;
}

.toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translate(-50%, 20px);
  background: var(--accent-primary);
  color: var(--accent-primary-fg);
  padding: 12px 24px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  font-weight: 500;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
  z-index: 200;
}
.toast.is-error {
  background: #dc2626;
  color: #ffffff;
} /* Error style */
.toast.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, 0);
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(6, 8, 15, 0.4);
  z-index: 100;
}
.modal {
  width: 760px;
  max-width: 90%;
  background: var(--panel-bg);
  padding: 20px;
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  transition: background-color 0.3s, color 0.3s;
}
.modal.modal-small {
  width: 400px;
}
/* NEW: Styles for modal structure */
.modal-body {
  padding: 16px 0;
}
.modal-body p {
  margin: 0;
  line-height: 1.5;
}
.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  transition: border-color 0.3s;
}
/* NEW: Style for the destructive button */
.btn.btn-danger {
  background-color: #dc2626;
  border-color: #dc2626;
  color: #ffffff;
}
.dark-mode .btn.btn-danger {
  background-color: #ef4444;
  border-color: #ef4444;
}
.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
  transition: border-color 0.3s;
}
.modal-title-group {
  display: flex;
  align-items: center;
  gap: 24px;
}
.sort-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}
.btn.btn-sort {
  padding: 4px 10px;
  font-size: 13px;
  box-shadow: var(--btn-shadow);
}
.btn.btn-sort.is-active {
  background: var(--accent-primary);
  color: var(--accent-primary-fg);
  border-color: var(--accent-primary);
}
.modal .list {
  max-height: 400px;
  overflow: auto;
  margin-top: 16px;
}
.modal .list .row {
  padding: 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  margin-bottom: 8px;
  transition: border-color 0.3s;
}
.modal .row .meta {
  color: var(--text-muted);
  font-size: 13px;
  line-height: 1.4;
  margin: 4px 0 0 0;
}
.help-content h4 {
  margin-top: 20px;
}
.help-content ol,
.help-content ul {
  padding-left: 20px;
}
.help-content code {
  background: var(--border-color);
  color: var(--text-primary);
  padding: 2px 6px;
  border-radius: 4px;
  transition: background-color 0.3s, color 0.3s;
}

@media (max-width: 980px) {
  html,
  body {
    overflow: auto;
  }
  .app {
    height: auto;
    display: block;
  }
  .workspace {
    display: block;
    height: auto;
    min-height: 400px;
  }
  .panel {
    height: auto;
    min-height: 400px;
    margin-bottom: 16px;
  }
}