:root {
  --bg-base: #1e1e1e;
  --bg-panel: #2d2d2d;
  --bg-panel-alt: #252526;
  --bg-elevated: #34363b;
  --border-subtle: #3c3c3c;
  --border-strong: #555;
  --text-main: #d4d4d4;
  --text-muted: #8f98a3;
  --accent: #8cb4ff;
  --accent-soft: rgba(140, 180, 255, 0.18);
  --scrollbar-thumb: #4a4f57;
  --scrollbar-thumb-hover: #5b616b;
}

body {
  margin: 0;
  font-family: sans-serif;
  display: flex;
  height: 100vh;
  overflow: hidden;
  background-color: var(--bg-base);
  color: var(--text-main);
}

#sidebar {
  width: 290px;
  display: flex;
  flex-direction: column;
  min-height: 0;
  background-color: var(--bg-panel);
  padding: 1rem;
  box-sizing: border-box;
  border-right: 1px solid var(--border-subtle);
  overflow: hidden;
}

#sidebar-controls {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.sidebar-field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.sidebar-label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

#note-list {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding-right: 0.35rem;
  margin-right: -0.35rem;
  scrollbar-width: thin;
  scrollbar-color: var(--scrollbar-thumb) transparent;
}

#content {
  flex-grow: 1;
  min-width: 0;
  padding: 1rem;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

input, textarea, button, select {
  width: 100%;
  padding: 0.5rem;
  background-color: var(--bg-base);
  color: var(--text-main);
  border: 1px solid var(--border-strong);
  box-sizing: border-box;
}

input,
textarea,
select {
  border-radius: 10px;
}

textarea {
  flex: 1;
  min-height: 0;
  resize: none;
  scrollbar-width: thin;
  scrollbar-color: var(--scrollbar-thumb) transparent;
}

button {
  cursor: pointer;
  border-radius: 10px;
  transition: background-color 140ms ease, border-color 140ms ease, color 140ms ease;
}

button:hover,
select:hover,
input:hover,
textarea:hover {
  border-color: #6a6a6a;
}

#content-toolbar {
  display: flex;
  justify-content: flex-start;
}

#mode-switcher {
  display: inline-flex;
  padding: 0.25rem;
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  background-color: var(--bg-panel-alt);
  gap: 0.25rem;
}

.mode-btn {
  width: auto;
  border: none;
  padding: 0.55rem 1rem;
  background: transparent;
  color: var(--text-muted);
}

.mode-btn.active {
  background-color: var(--accent-soft);
  color: var(--accent);
}

#editor-panel,
#preview-panel {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

#editor-panel[hidden],
#preview-panel[hidden] {
  display: none !important;
}

.preview-card {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 1.5rem;
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.03), rgba(255, 255, 255, 0)),
    var(--bg-panel-alt);
  scrollbar-width: thin;
  scrollbar-color: var(--scrollbar-thumb) transparent;
}

.preview-card-header {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

#preview-title {
  margin: 0;
  font-size: 2rem;
  line-height: 1.2;
}

#preview-meta {
  margin: 0.5rem 0 0;
  color: var(--text-muted);
  font-size: 0.92rem;
}

#preview-empty {
  color: var(--text-muted);
  padding: 1rem 0;
}

#preview-body {
  line-height: 1.7;
}

.note-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.25rem 0;
}

.note-item.selected .note-item-button {
  border-color: var(--accent);
  background-color: var(--accent-soft);
}

.note-item-button {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.22rem;
  padding: 0.7rem 0.8rem;
  text-align: left;
  border: 1px solid transparent;
  background-color: transparent;
}

.note-item-button:hover {
  background-color: rgba(255, 255, 255, 0.04);
}

.note-title {
  flex-grow: 1;
  cursor: pointer;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 600;
}

.note-meta {
  font-size: 0.76rem;
  color: var(--text-muted);
}

.delete-btn {
  visibility: hidden;
  background: none;
  color: #ff6b6b;
  border: none;
  font-weight: bold;
  font-size: 1.2rem;
  cursor: pointer;
  width: 1.5rem;
  text-align: center;
  padding: 0.2rem;
}

.note-item:hover .delete-btn {
  visibility: visible;
}

#note-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

#refresh-btn {
  width: 1.5rem;
  height: 1.5rem;
  background: none;
  border: 1px solid #555;
  color: #d4d4d4;
  cursor: pointer;
  padding: 0;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

#new-note-btn,
#upload-btn {
  background-color: var(--bg-elevated);
}

.empty-note-list {
  padding: 1rem 0.35rem;
  color: var(--text-muted);
  text-align: center;
}

#preview-body h1,
#preview-body h2,
#preview-body h3,
#preview-body h4,
#preview-body h5,
#preview-body h6 {
  margin: 1.5rem 0 0.75rem;
  line-height: 1.3;
}

#preview-body p,
#preview-body ul,
#preview-body ol,
#preview-body blockquote,
#preview-body pre {
  margin: 0.85rem 0;
}

#preview-body ul,
#preview-body ol {
  padding-left: 1.4rem;
}

#preview-body a {
  color: var(--accent);
}

#preview-body blockquote {
  margin-left: 0;
  padding: 0.85rem 1rem;
  border-left: 3px solid var(--accent);
  background-color: rgba(255, 255, 255, 0.03);
  color: #c6d6f7;
}

#preview-body code {
  padding: 0.15rem 0.35rem;
  border-radius: 6px;
  background-color: rgba(255, 255, 255, 0.08);
  font-family: "SFMono-Regular", Consolas, monospace;
}

#preview-body pre {
  overflow-x: auto;
  padding: 1rem;
  border-radius: 12px;
  background-color: #161719;
}

#preview-body pre code {
  padding: 0;
  background: transparent;
}

#preview-body hr {
  border: none;
  border-top: 1px solid var(--border-subtle);
}

#note-list::-webkit-scrollbar,
textarea::-webkit-scrollbar,
.preview-card::-webkit-scrollbar {
  width: 10px;
}

#note-list::-webkit-scrollbar-track,
textarea::-webkit-scrollbar-track,
.preview-card::-webkit-scrollbar-track {
  background: transparent;
}

#note-list::-webkit-scrollbar-thumb,
textarea::-webkit-scrollbar-thumb,
.preview-card::-webkit-scrollbar-thumb {
  background-color: var(--scrollbar-thumb);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

#note-list::-webkit-scrollbar-thumb:hover,
textarea::-webkit-scrollbar-thumb:hover,
.preview-card::-webkit-scrollbar-thumb:hover {
  background-color: var(--scrollbar-thumb-hover);
}

@media (max-width: 900px) {
  body {
    flex-direction: column;
  }

  #sidebar {
    width: 100%;
    max-height: 45vh;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
  }

  #content {
    min-height: 0;
  }
}