:root {
  color-scheme: dark;
  --bg: #0f1115;
  --panel: #171a21;
  --border: #2a2e37;
  --text: #e6e8ec;
  --muted: #9aa1ac;
  --accent: #6ea8fe;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", "Hiragino Kaku Gothic ProN", sans-serif;
}

.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.topbar h1 {
  font-size: 1.1rem;
  margin: 0;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.slide-count {
  color: var(--muted);
  font-size: 0.85rem;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 8px 16px;
  font-size: 0.9rem;
  cursor: pointer;
  font-weight: 600;
}

.btn-primary {
  background: var(--accent);
  color: #0f1115;
}

.btn-primary:hover {
  opacity: 0.9;
}

.editor-layout {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 0;
}

@media (max-width: 800px) {
  .editor-layout {
    grid-template-columns: 1fr;
    grid-template-rows: 1fr 1fr;
  }
}

.pane {
  min-height: 0;
  overflow: auto;
}

.pane-editor {
  border-right: 1px solid var(--border);
}

#md-input {
  width: 100%;
  height: 100%;
  border: none;
  resize: none;
  background: var(--bg);
  color: var(--text);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.95rem;
  line-height: 1.6;
  padding: 20px;
  outline: none;
}

.preview-scroll {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.slide-preview {
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: var(--panel);
}

.slide-preview-label {
  font-size: 0.7rem;
  color: var(--muted);
  padding: 6px 14px;
  border-bottom: 1px solid var(--border);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.slide-content {
  padding: 24px;
  aspect-ratio: 16 / 9;
  overflow: auto;
}

.slide-content h1,
.slide-content h2,
.slide-content h3 {
  margin-top: 0;
  background: linear-gradient(135deg, #ffffff, #9aa1ac);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.slide-content p {
  line-height: 1.7;
}

.slide-content code {
  background: rgba(255, 255, 255, 0.08);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.9em;
}

.slide-content pre {
  background: #05060a;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  overflow-x: auto;
}

.slide-content pre code {
  background: none;
  padding: 0;
}

.slide-content blockquote {
  border-left: 3px solid var(--accent);
  margin: 0;
  padding: 4px 16px;
  color: var(--muted);
}

.slide-content img {
  max-width: 100%;
  border-radius: 6px;
}

.slide-content a {
  color: var(--accent);
}

.present-overlay {
  position: fixed;
  inset: 0;
  background: #05060a;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.present-overlay.hidden {
  display: none;
}

.present-slide {
  width: min(90vw, 1200px);
  aspect-ratio: 16 / 9;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 60px;
}

.present-slide .slide-content {
  padding: 0;
  aspect-ratio: auto;
  overflow: visible;
}

.present-slide h1 {
  font-size: 3rem;
}

.present-slide h2 {
  font-size: 2.2rem;
}

.present-slide p,
.present-slide li {
  font-size: 1.4rem;
}

.present-exit,
.present-nav {
  position: fixed;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
  border-radius: 50%;
}

.present-exit {
  top: 20px;
  right: 20px;
  width: 40px;
  height: 40px;
  font-size: 1.1rem;
}

.present-nav {
  top: 50%;
  transform: translateY(-50%);
  width: 56px;
  height: 56px;
  font-size: 1.8rem;
}

.present-nav:disabled {
  opacity: 0.2;
  cursor: default;
}

.present-nav-prev {
  left: 20px;
}

.present-nav-next {
  right: 20px;
}

.present-counter {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--muted);
  font-size: 0.9rem;
}