:root {
  --bg: #0f1115;
  --bg-elev: #161922;
  --bg-elev-2: #1d2230;
  --border: #2a2f3d;
  --border-strong: #3b4256;
  --text: #e6e9ef;
  --text-muted: #8a92a6;
  --accent: #7c9cff;
  --accent-strong: #5d80ff;
  --danger: #ff6b6b;
  --success: #6bcf8a;
  --warning: #f0b95b;
  --radius: 8px;
  --radius-lg: 12px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f8fa;
    --bg-elev: #ffffff;
    --bg-elev-2: #f0f2f7;
    --border: #e3e6ec;
    --border-strong: #c9cfdb;
    --text: #1c2030;
    --text-muted: #6a7280;
    --accent: #4663d8;
    --accent-strong: #3450c5;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Helvetica, Arial,
    sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
}

button {
  font: inherit;
  cursor: pointer;
  border: 1px solid var(--border-strong);
  background: var(--bg-elev-2);
  color: var(--text);
  padding: 6px 12px;
  border-radius: var(--radius);
  transition: background 120ms, border-color 120ms, opacity 120ms;
}
button:hover:not(:disabled) {
  background: var(--bg-elev);
  border-color: var(--accent);
}
button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}
button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}
button.primary:hover:not(:disabled) {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
}
button.ghost {
  background: transparent;
  border-color: var(--border);
}
button.ghost:hover:not(:disabled) {
  background: var(--bg-elev-2);
}
button.danger {
  color: var(--danger);
  border-color: var(--border);
}
button.danger:hover:not(:disabled) {
  background: rgba(255,107,107,.1);
  border-color: var(--danger);
}
button.small { padding: 3px 8px; font-size: 12px; }
button.block { display: block; width: 100%; }

input, textarea, select {
  font: inherit;
  color: var(--text);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 10px;
  outline: none;
  transition: border-color 120ms;
}
input:focus, textarea:focus, select:focus {
  border-color: var(--accent);
}

.muted { color: var(--text-muted); }
.small { font-size: 12px; }
.spacer { flex: 1; }

/* ---------- 登录页 ---------- */
.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 24px;
}
.login-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  max-width: 360px;
  width: 100%;
}
.login-card h1 { margin: 0 0 4px; font-size: 24px; }
.login-card p { margin: 0 0 24px; }
.login-card form { display: flex; flex-direction: column; gap: 12px; }
.login-card label { display: flex; flex-direction: column; gap: 6px; }
.login-card label span { font-size: 13px; color: var(--text-muted); }
.login-card button[type="submit"] {
  margin-top: 8px;
  padding: 10px;
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}
.login-card .error {
  margin: 8px 0 0;
  color: var(--danger);
  font-size: 13px;
}

/* ---------- 应用布局 ---------- */
#app {
  display: grid;
  grid-template-columns: 300px 1fr;
  height: 100vh;
  overflow: hidden;
}

.sidebar {
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}
.sidebar-header h1 {
  margin: 0;
  font-size: 16px;
  letter-spacing: 0.3px;
}
.sidebar-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px;
  border-bottom: 1px solid var(--border);
}

.note-list {
  list-style: none;
  margin: 0;
  padding: 6px;
  overflow-y: auto;
  flex: 1;
  min-height: 0;
}
.note-list li {
  padding: 10px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  margin-bottom: 2px;
  border: 1px solid transparent;
}
.note-list li:hover { background: var(--bg-elev-2); }
.note-list li.active {
  background: var(--bg-elev-2);
  border-color: var(--border-strong);
}
.note-list .item-title {
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.note-list .item-meta {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 2px;
  display: flex;
  gap: 8px;
}
.note-list .item-tags {
  margin-top: 4px;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}
.note-list .item-tags .tag-pill {
  font-size: 10px;
  padding: 1px 6px;
}

.sidebar-footer {
  padding: 8px 16px;
  border-top: 1px solid var(--border);
}

/* ---------- 编辑器 ---------- */
.editor {
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.empty-state {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1;
  color: var(--text-muted);
  font-size: 15px;
}
.editor-pane {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 20px 28px;
  gap: 12px;
  min-height: 0;
}

.title-input {
  font-size: 22px;
  font-weight: 600;
  padding: 8px 0;
  background: transparent;
  border: none;
  border-bottom: 1px solid transparent;
}
.title-input:focus { border-bottom-color: var(--border); }

.tags-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}
.tags { display: contents; }
.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 12px;
  color: var(--text);
}
.tag-pill button {
  all: unset;
  cursor: pointer;
  font-size: 11px;
  color: var(--text-muted);
  padding: 0 2px;
}
.tag-pill button:hover { color: var(--danger); }
.tag-input {
  width: 160px;
  padding: 3px 8px;
  font-size: 12px;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  padding: 6px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.translate-group {
  display: flex;
  align-items: stretch;
}
.translate-group select {
  padding: 4px 8px;
  border-radius: var(--radius) 0 0 var(--radius);
  border-right: none;
  font-size: 13px;
}
.translate-group button {
  border-radius: 0 var(--radius) var(--radius) 0;
}

.content-input {
  flex: 1;
  resize: none;
  padding: 14px;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
  font-size: 14px;
  line-height: 1.65;
  background: var(--bg-elev);
  min-height: 200px;
}

/* ---------- 模态框 ---------- */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  z-index: 100;
}
.modal-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: min(900px, 100%);
  max-height: 85vh;
  display: flex;
  flex-direction: column;
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
}
.modal-header h2 { margin: 0; font-size: 15px; }
.modal-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  padding: 16px 18px;
  flex: 1;
  min-height: 0;
}
.diff-col {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 0;
}
.diff-label {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.diff-col textarea {
  flex: 1;
  resize: none;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  min-height: 280px;
}
.modal-footer {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 18px;
  border-top: 1px solid var(--border);
}

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  padding: 10px 16px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  z-index: 200;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
  max-width: 80vw;
}
.toast.error { border-color: var(--danger); color: var(--danger); }
.toast.success { border-color: var(--success); color: var(--success); }

/* ---------- 响应式 ---------- */
@media (max-width: 720px) {
  #app { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  #app.show-sidebar .sidebar { display: flex; }
  #app.show-sidebar .editor { display: none; }
  .modal-body { grid-template-columns: 1fr; }
}