/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #ffffff;
  --bg-secondary: #f6f8fa;
  --bg-tertiary: #eef1f5;
  --border: #d1d9e0;
  --text: #1f2328;
  --text-secondary: #656d76;
  --text-tertiary: #8b949e;
  --primary: #0969da;
  --primary-hover: #0550ae;
  --primary-glow: rgba(9, 105, 218, 0.15);
  --danger: #cf222e;
  --danger-bg: #ffebe9;
  --success: #1a7f37;
  --success-bg: #dafbe1;
  --info: #0969da;
  --info-bg: #ddf4ff;
  --radius: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Consolas, monospace;
  --transition: 0.2s ease;
}

[data-theme="dark"] {
  --bg: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --text-secondary: #8b949e;
  --text-tertiary: #656d76;
  --primary: #58a6ff;
  --primary-hover: #79c0ff;
  --primary-glow: rgba(88, 166, 255, 0.15);
  --danger: #f85149;
  --danger-bg: rgba(248, 81, 73, 0.1);
  --success: #3fb950;
  --success-bg: rgba(63, 185, 80, 0.1);
  --info: #58a6ff;
  --info-bg: rgba(88, 166, 255, 0.1);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.4);
}

body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* === Layout === */
.container, .viewer-container {
  max-width: 920px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* === Header === */
.header {
  text-align: center;
  margin-bottom: 2rem;
  position: relative;
}

.header-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.logo {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.03em;
}

a.logo:hover { color: var(--primary); text-decoration: none; }

.tagline {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 1.25rem;
}

/* === Theme Toggle === */
#theme-toggle {
  position: absolute;
  top: 0;
  right: 0;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all var(--transition);
}

#theme-toggle:hover {
  color: var(--primary);
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

/* === Feature Badges === */
.feature-badges {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.75rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.78rem;
  color: var(--text-secondary);
  font-weight: 500;
  transition: all var(--transition);
}

.badge:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.badge svg { width: 14px; height: 14px; }

/* === Tabs === */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
}

.tab {
  padding: 0.6rem 1.25rem;
  border: 1px solid transparent;
  border-bottom: none;
  background: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-family: var(--font-sans);
  color: var(--text-secondary);
  border-radius: var(--radius) var(--radius) 0 0;
  transition: all var(--transition);
}

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

.tab.active {
  color: var(--text);
  background: var(--bg);
  border-color: var(--border);
  border-bottom: 1px solid var(--bg);
  margin-bottom: -1px;
  font-weight: 600;
}

/* === Toolbar === */
#toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  padding: 0.4rem 0.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-bottom: none;
  border-radius: var(--radius) var(--radius) 0 0;
}

#toolbar button {
  padding: 0.3rem 0.5rem;
  background: none;
  border: 1px solid transparent;
  border-radius: 4px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all var(--transition);
  min-width: 28px;
  text-align: center;
}

#toolbar button:hover {
  background: var(--bg-tertiary);
  color: var(--text);
  border-color: var(--border);
}

.toolbar-sep {
  width: 1px;
  background: var(--border);
  margin: 0.2rem 0.3rem;
}

/* === Editor === */
.editor-area {
  border: 1px solid var(--border);
  border-radius: 0 0 var(--radius) var(--radius);
  min-height: 400px;
  position: relative;
  background: var(--bg);
  box-shadow: var(--shadow-sm);
}

.panel { display: none; }
.panel.active { display: block; }

#editor {
  width: 100%;
  min-height: 350px;
  padding: 1rem;
  border: none;
  resize: vertical;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.7;
  outline: none;
  background: var(--bg);
  color: var(--text);
  transition: background var(--transition), color var(--transition);
}

#preview {
  padding: 1.5rem;
  min-height: 350px;
}

/* === Drop Zone === */
.drop-zone {
  padding: 0.75rem;
  text-align: center;
  border-top: 2px dashed var(--border);
  color: var(--text-secondary);
  font-size: 0.85rem;
  transition: all var(--transition);
}

.drop-zone.dragover {
  background: var(--info-bg);
  border-color: var(--primary);
  color: var(--primary);
}

@keyframes dash-march {
  to { background-position: 100% 0; }
}

.drop-zone.dragover {
  animation: pulse-border 1s ease infinite;
}

@keyframes pulse-border {
  0%, 100% { border-color: var(--primary); }
  50% { border-color: var(--border); }
}

.file-label {
  color: var(--primary);
  cursor: pointer;
  font-weight: 600;
}

.file-label:hover { text-decoration: underline; }

/* === Options Bar === */
.options-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  flex-wrap: wrap;
}

.option-group {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.option-group label {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-weight: 500;
}

.option-group select {
  padding: 0.3rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  cursor: pointer;
}

.option-group input[type="checkbox"] {
  accent-color: var(--primary);
  cursor: pointer;
}

.option-group input[type="password"] {
  padding: 0.3rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.82rem;
  width: 140px;
}

.password-field { display: none; }
.password-field.visible { display: flex; }

/* === Share Bar === */
.share-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
}

.share-result {
  display: none;
  align-items: center;
  gap: 0.5rem;
  flex: 1;
  animation: slideIn 0.3s ease;
}

.share-result.visible {
  display: flex;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

.share-result input {
  flex: 1;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: var(--bg-secondary);
  color: var(--text);
}

.share-extras {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.share-extras.hidden { display: none; }

.qr-container {
  width: 128px;
  height: 128px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: white;
  padding: 8px;
}

.qr-container canvas, .qr-container img { width: 100%; height: 100%; }

.burn-warning-share {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--danger);
  font-size: 0.82rem;
  font-weight: 500;
}

/* === Buttons === */
.btn {
  padding: 0.55rem 1.25rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 1px 3px rgba(0,0,0,0.12);
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-hover);
  box-shadow: 0 2px 8px var(--primary-glow), 0 1px 3px rgba(0,0,0,0.12);
  transform: translateY(-1px);
}

.btn-primary:active:not(:disabled) { transform: translateY(0); }

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

.btn-secondary:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-tertiary);
}

.btn-sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
}

.btn-icon {
  padding: 0.4rem;
  border-radius: 6px;
}

/* === Viewer === */
.viewer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.5rem;
}

.viewer-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.expiry-badge {
  font-size: 0.78rem;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-weight: 500;
}

.encrypted-badge {
  font-size: 0.78rem;
  color: var(--success);
  background: var(--success-bg);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

/* === Burn Warning Banner === */
.burn-banner {
  background: var(--danger-bg);
  border: 1px solid var(--danger);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--danger);
  font-weight: 600;
  font-size: 0.9rem;
}

.burn-banner svg { flex-shrink: 0; }

/* === Password Prompt Overlay === */
.password-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  backdrop-filter: blur(4px);
}

.password-modal {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  max-width: 400px;
  width: 90%;
  box-shadow: var(--shadow-lg);
  text-align: center;
}

.password-modal h2 {
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
}

.password-modal p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1.25rem;
}

.password-modal input {
  width: 100%;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  background: var(--bg-secondary);
  color: var(--text);
  margin-bottom: 1rem;
  text-align: center;
}

.password-modal input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.password-error {
  color: var(--danger);
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
  display: none;
}

/* === Loading & Error === */
.loading {
  text-align: center;
  color: var(--text-secondary);
  padding: 3rem;
}

.error-message {
  text-align: center;
  padding: 3rem;
  color: var(--text-secondary);
}

.error-message h2 {
  color: var(--text);
  margin-bottom: 0.5rem;
}

/* === Markdown Body (GitHub-style) === */
.markdown-body { color: var(--text); }

.markdown-body h1, .markdown-body h2, .markdown-body h3,
.markdown-body h4, .markdown-body h5, .markdown-body h6 {
  margin-top: 1.5em;
  margin-bottom: 0.5em;
  font-weight: 600;
  line-height: 1.25;
}

.markdown-body h1 { font-size: 2em; padding-bottom: 0.3em; border-bottom: 1px solid var(--border); }
.markdown-body h2 { font-size: 1.5em; padding-bottom: 0.3em; border-bottom: 1px solid var(--border); }
.markdown-body h3 { font-size: 1.25em; }

.markdown-body p { margin-bottom: 1em; }

.markdown-body a { color: var(--primary); }
.markdown-body a:hover { text-decoration: underline; }

.markdown-body code {
  padding: 0.2em 0.4em;
  background: var(--bg-secondary);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.85em;
}

.markdown-body pre {
  padding: 1rem;
  background: var(--bg-secondary);
  border-radius: var(--radius);
  overflow-x: auto;
  margin-bottom: 1em;
  border: 1px solid var(--border);
}

.markdown-body pre code { padding: 0; background: none; border: none; }

.markdown-body blockquote {
  padding: 0.5rem 1rem;
  border-left: 3px solid var(--primary);
  color: var(--text-secondary);
  margin-bottom: 1em;
  background: var(--bg-secondary);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.markdown-body ul, .markdown-body ol { padding-left: 2em; margin-bottom: 1em; }
.markdown-body li { margin-bottom: 0.25em; }
.markdown-body img { max-width: 100%; border-radius: var(--radius); }

.markdown-body table { width: 100%; border-collapse: collapse; margin-bottom: 1em; }
.markdown-body th, .markdown-body td { padding: 0.5rem 1rem; border: 1px solid var(--border); }
.markdown-body th { background: var(--bg-secondary); font-weight: 600; }

.markdown-body hr { border: none; border-top: 1px solid var(--border); margin: 1.5em 0; }

/* Mermaid diagrams */
.markdown-body .mermaid {
  display: flex;
  justify-content: center;
  margin: 1em 0;
  padding: 1rem;
  background: var(--bg-secondary);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

/* === "Why md-share?" Feature Grid === */
.features-section {
  margin-top: 4rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--border);
}

.features-section h2 {
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.features-section .section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-size: 1rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  padding: 1.25rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: all var(--transition);
}

.feature-card:hover {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
  transform: translateY(-2px);
}

.feature-card .feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.75rem;
  font-size: 1.25rem;
}

.feature-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.feature-card p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* === Toast Notifications === */
#toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  pointer-events: none;
}

.toast {
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-md);
  pointer-events: auto;
  opacity: 0;
  transform: translateX(100%);
  transition: all 0.3s ease;
  max-width: 340px;
}

.toast-visible {
  opacity: 1;
  transform: translateX(0);
}

.toast-success { background: var(--success-bg); color: var(--success); border: 1px solid var(--success); }
.toast-error { background: var(--danger-bg); color: var(--danger); border: 1px solid var(--danger); }
.toast-info { background: var(--info-bg); color: var(--info); border: 1px solid var(--info); }

/* === Footer === */
.footer {
  text-align: center;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.82rem;
}

.footer a { color: var(--primary); }
.footer p + p { margin-top: 0.25rem; }

/* === Responsive === */
@media (max-width: 768px) {
  .feature-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .container, .viewer-container { padding: 1rem; }
  .header { margin-bottom: 1.5rem; }
  .logo { font-size: 1.5rem; }
  .tagline { font-size: 0.95rem; }
  #editor { min-height: 250px; font-size: 0.82rem; }
  .share-bar { flex-direction: column; align-items: stretch; }
  .options-bar { flex-direction: column; align-items: stretch; gap: 0.75rem; }
  .viewer-header { flex-direction: column; gap: 0.75rem; align-items: flex-start; }
  #toolbar { gap: 1px; padding: 0.3rem; }
  #toolbar button { padding: 0.25rem 0.4rem; font-size: 0.7rem; }
  .feature-badges { gap: 0.5rem; }
  .badge { font-size: 0.72rem; padding: 0.25rem 0.6rem; }
}

/* === Focus Styles (Accessibility) === */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

button:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  box-shadow: 0 0 0 3px var(--primary-glow);
}

/* === highlight.js dark mode override === */
[data-theme="dark"] .hljs {
  background: var(--bg-secondary) !important;
  color: var(--text) !important;
}