/* ==========================================================================
   xieanyu.com Note Web App Design System
   ========================================================================== */

:root {
  /* Light Theme */
  --bg-app: #fbfcfd;
  --bg-header: #ffffff;
  --bg-pane: #ffffff;
  --bg-input: #ffffff;
  --bg-toolbar: #f8fafc;
  --bg-card: #f1f5f9;
  --bg-hover: #f1f5f9;
  --bg-active: #e2e8f0;

  --border-subtle: #f1f5f9;
  --border-color: #e2e8f0;
  --border-focus: #2563eb;

  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-subtle: #94a3b8;
  --text-on-accent: #ffffff;

  --accent-primary: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #eff6ff;

  --status-success: #10b981;
  --status-saving: #f59e0b;
  --status-error: #ef4444;

  --danger-color: #ef4444;
  --danger-hover: #dc2626;
  --danger-soft: #fef2f2;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08);

  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

[data-theme="dark"] {
  /* Dark Theme */
  --bg-app: #0c0d12;
  --bg-header: #13151c;
  --bg-pane: #13151c;
  --bg-input: #13151c;
  --bg-toolbar: #181b24;
  --bg-card: #1d212c;
  --bg-hover: #1d212c;
  --bg-active: #262b3a;

  --border-subtle: #1a1d28;
  --border-color: #242938;
  --border-focus: #3b82f6;

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --text-on-accent: #ffffff;

  --accent-primary: #3b82f6;
  --accent-hover: #60a5fa;
  --accent-soft: #1e293b;

  --status-success: #34d399;
  --status-saving: #fbbf24;
  --status-error: #f87171;

  --danger-color: #f87171;
  --danger-hover: #ef4444;
  --danger-soft: #2c1618;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.6);
}

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

html, body {
  height: 100%;
  width: 100%;
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-main);
  background-color: var(--bg-app);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.app-layout {
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100vw;
  background-color: var(--bg-app);
}

/* ==========================================================================
   Header Navigation
   ========================================================================== */

.app-header {
  height: 56px;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background-color: var(--bg-header);
  border-bottom: 1px solid var(--border-color);
  z-index: 20;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: inherit;
}

.brand-logo {
  width: 32px;
  height: 32px;
  background-color: var(--accent-soft);
  color: var(--accent-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s ease;
}

.brand-link:hover .brand-logo {
  transform: scale(1.05);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
  color: var(--text-main);
}

.brand-tag {
  font-size: 10.5px;
  color: var(--text-subtle);
  line-height: 1;
}

.sync-status {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background-color: var(--bg-card);
  border-radius: var(--radius-full);
  font-size: 11.5px;
  color: var(--text-muted);
  transition: all 0.2s ease;
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--status-success);
  transition: background-color 0.2s ease;
}

.sync-status.saving .status-dot {
  background-color: var(--status-saving);
  animation: pulse 1s infinite ease-in-out;
}

.sync-status.error .status-dot {
  background-color: var(--status-error);
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

/* Tabs */
.header-center {
  display: flex;
  align-items: center;
}

.view-mode-tabs {
  display: flex;
  background-color: var(--bg-card);
  padding: 3px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.tab-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
}

.tab-btn.active {
  background-color: var(--bg-pane);
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
}

.tab-btn:hover:not(.active) {
  color: var(--text-main);
}

/* Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.action-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background-color: var(--bg-card);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
}

.action-btn:hover {
  background-color: var(--bg-hover);
  color: var(--text-main);
}

.action-btn.danger:hover {
  background-color: var(--danger-soft);
  color: var(--danger-color);
}

.divider {
  width: 1px;
  height: 20px;
  background-color: var(--border-color);
  margin: 0 4px;
}

.icon-toggle-btn {
  width: 32px;
  height: 32px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.icon-toggle-btn:hover {
  background-color: var(--bg-hover);
  color: var(--text-main);
}

.sun-icon { display: none; }
.moon-icon { display: block; }
[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }

/* ==========================================================================
   Formatting Bar
   ========================================================================== */

.formatting-bar {
  background-color: var(--bg-toolbar);
  border-bottom: 1px solid var(--border-subtle);
  padding: 6px 24px;
}

.formatting-bar-inner {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 4px;
  overflow-x: auto;
}

.tool-btn {
  padding: 4px 8px;
  font-size: 12px;
  font-weight: 500;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.12s ease;
  white-space: nowrap;
}

.tool-btn:hover {
  background-color: var(--bg-active);
  color: var(--text-main);
}

.tool-divider {
  width: 1px;
  height: 16px;
  background-color: var(--border-color);
  margin: 0 4px;
}

/* ==========================================================================
   Main Content Area & Modes
   ========================================================================== */

.main-content {
  flex: 1;
  display: flex;
  overflow: hidden;
  position: relative;
  background-color: var(--bg-pane);
}

.pane {
  height: 100%;
  overflow-y: auto;
}

.pane-content-wrapper {
  max-width: 860px;
  margin: 0 auto;
  padding: 32px 32px 60px;
  height: 100%;
  display: flex;
  flex-direction: column;
}

/* Mode Layouts */
.main-content.mode-edit .edit-pane {
  display: block;
  flex: 1;
  width: 100%;
}
.main-content.mode-edit .preview-pane {
  display: none;
}

.main-content.mode-preview .edit-pane {
  display: none;
}
.main-content.mode-preview .preview-pane {
  display: block;
  flex: 1;
  width: 100%;
}

.main-content.mode-split .edit-pane {
  display: block;
  flex: 1;
  width: 50%;
  border-right: 1px solid var(--border-color);
}
.main-content.mode-split .preview-pane {
  display: block;
  flex: 1;
  width: 50%;
}

.main-content.mode-split .pane-content-wrapper {
  padding: 24px 24px 60px;
}

/* Edit Inputs */
.title-input {
  width: 100%;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-main);
  background: transparent;
  border: none;
  outline: none;
  padding: 0 0 16px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 20px;
}

.title-input::placeholder {
  color: var(--text-subtle);
}

.body-textarea {
  flex: 1;
  width: 100%;
  min-height: 400px;
  font-family: var(--font-mono);
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-main);
  background: transparent;
  border: none;
  outline: none;
  resize: none;
}

.body-textarea::placeholder {
  color: var(--text-subtle);
  font-family: var(--font-sans);
}

/* Preview Styles */
.preview-title {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-main);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 20px;
}

.markdown-body {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-main);
}

.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 {
  color: var(--text-main);
  font-weight: 600;
  margin-top: 28px;
  margin-bottom: 14px;
  line-height: 1.3;
}

.markdown-body h1 { font-size: 22px; border-bottom: 1px solid var(--border-subtle); padding-bottom: 6px; }
.markdown-body h2 { font-size: 18px; }
.markdown-body h3 { font-size: 16px; }

.markdown-body p {
  margin-bottom: 16px;
}

.markdown-body ul, .markdown-body ol {
  padding-left: 24px;
  margin-bottom: 16px;
}

.markdown-body li {
  margin-bottom: 4px;
}

.markdown-body blockquote {
  padding: 10px 18px;
  margin: 16px 0;
  border-left: 3px solid var(--accent-primary);
  background-color: var(--bg-card);
  color: var(--text-muted);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.markdown-body code {
  font-family: var(--font-mono);
  font-size: 13px;
  background-color: var(--bg-card);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--accent-primary);
}

.markdown-body pre {
  background-color: var(--bg-card);
  padding: 14px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  overflow-x: auto;
  margin: 18px 0;
}

.markdown-body pre code {
  background: transparent;
  padding: 0;
  color: var(--text-main);
  font-size: 13px;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
}

.markdown-body th, .markdown-body td {
  border: 1px solid var(--border-color);
  padding: 8px 12px;
  text-align: left;
}

.markdown-body th {
  background-color: var(--bg-card);
  font-weight: 600;
}

.markdown-body hr {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 28px 0;
}

.markdown-body a {
  color: var(--accent-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.app-footer {
  height: 38px;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background-color: var(--bg-header);
  border-top: 1px solid var(--border-color);
  font-size: 12px;
  color: var(--text-subtle);
  z-index: 10;
}

.footer-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.tip-badge {
  font-size: 11px;
  color: var(--text-subtle);
}

/* Toast */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 1000;
  pointer-events: none;
}

.toast {
  padding: 10px 16px;
  background-color: var(--text-main);
  color: var(--bg-header);
  border-radius: var(--radius-md);
  font-size: 13px;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 8px;
  animation: toastSlide 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: auto;
}

@keyframes toastSlide {
  from { transform: translateY(12px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* Responsive */
@media (max-width: 768px) {
  .app-header {
    padding: 0 16px;
  }
  .brand-tag, .btn-text, .footer-center {
    display: none;
  }
  .pane-content-wrapper {
    padding: 20px 16px 40px;
  }
  .main-content.mode-split {
    flex-direction: column;
  }
  .main-content.mode-split .edit-pane,
  .main-content.mode-split .preview-pane {
    width: 100%;
  }
  .main-content.mode-split .edit-pane {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }
}