:root {
  color-scheme: light;
  --bg: #f5f7fb;
  --panel: #ffffff;
  --panel-soft: #eef2f8;
  --text: #172033;
  --muted: #5f6b86;
  --border: #d8e0ee;
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --shadow: 0 18px 50px rgba(18, 28, 45, 0.09);
  --editor-bg: #fbfcff;
  --code-bg: #0f172a;
  --code-text: #e5eefc;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b1020;
  --panel: #11172a;
  --panel-soft: #151d33;
  --text: #e7ecff;
  --muted: #a0accb;
  --border: #24304b;
  --accent: #60a5fa;
  --accent-strong: #3b82f6;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  --editor-bg: #0d1324;
  --code-bg: #020617;
  --code-text: #dbeafe;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top, rgba(37, 99, 235, 0.08), transparent 30%), var(--bg);
  color: var(--text);
}

button,
input,
textarea {
  font: inherit;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 24px;
  gap: 18px;
}

.topbar,
.main-panel {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 20px 22px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.55);
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow);
}

html[data-theme="dark"] .topbar {
  background: rgba(17, 23, 42, 0.72);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.brand-mark {
  width: 48px;
  height: 48px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: white;
  font-weight: 800;
  font-size: 1.5rem;
  flex: 0 0 auto;
  box-shadow: 0 12px 30px rgba(37, 99, 235, 0.3);
}

.brand h1 {
  margin: 0;
  font-size: 1.15rem;
  line-height: 1.2;
}

.brand p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-end;
}

.btn {
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  border-radius: 14px;
  padding: 11px 15px;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease, color 0.15s ease;
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.05);
}

.btn:hover {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: white;
  border-color: transparent;
}

.main-panel {
  display: grid;
  gap: 14px;
}

.status-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.status-message {
  font-weight: 600;
}

.file-info {
  color: var(--muted);
  text-align: right;
}

.workspace {
  border: 1px solid var(--border);
  border-radius: 28px;
  overflow: hidden;
  background: var(--panel);
  box-shadow: var(--shadow);
  min-height: calc(100vh - 220px);
}

.editor,
.preview {
  width: 100%;
  height: min(74vh, 760px);
  min-height: 500px;
}

.editor {
  display: block;
  border: 0;
  resize: none;
  padding: 22px;
  outline: none;
  background: var(--editor-bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 1rem;
}

.preview {
  display: none;
  padding: 28px;
  overflow: auto;
  background: var(--panel);
}

body.mode-view .editor {
  display: none;
}

body.mode-view .preview {
  display: block;
}

.markdown-body {
  line-height: 1.75;
  word-wrap: break-word;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  line-height: 1.25;
  margin: 1.2em 0 0.55em;
}

.markdown-body h1 { font-size: 2rem; }
.markdown-body h2 { font-size: 1.65rem; }
.markdown-body h3 { font-size: 1.3rem; }

.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body pre,
.markdown-body table {
  margin: 0 0 1em;
}

.markdown-body a {
  color: var(--accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.markdown-body code {
  font-family: ui-monospace, SFMono-Regular, SF Mono, Menlo, Consolas, monospace;
  font-size: 0.95em;
  background: color-mix(in srgb, var(--panel-soft) 85%, transparent);
  padding: 0.15em 0.35em;
  border-radius: 8px;
}

.markdown-body pre {
  overflow: auto;
  padding: 16px 18px;
  border-radius: 18px;
  background: var(--code-bg);
  color: var(--code-text);
}

.markdown-body pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}

.markdown-body blockquote {
  padding: 0.2em 1em;
  border-left: 4px solid var(--accent);
  color: var(--muted);
  background: color-mix(in srgb, var(--panel-soft) 70%, transparent);
  border-radius: 0 14px 14px 0;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  display: block;
  overflow-x: auto;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--border);
  padding: 10px 12px;
  text-align: left;
}

.markdown-body th {
  background: var(--panel-soft);
}

.markdown-body img {
  max-width: 100%;
}

.markdown-body hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 1.5em 0;
}

.hidden {
  display: none !important;
}

@media (max-width: 900px) {
  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .toolbar {
    justify-content: stretch;
  }

  .btn {
    flex: 1 1 auto;
  }

  .status-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .file-info {
    text-align: left;
  }

  .workspace {
    min-height: calc(100vh - 300px);
  }

  .editor,
  .preview {
    min-height: 58vh;
  }
}

@media (max-width: 640px) {
  .app-shell {
    padding: 14px;
  }

  .topbar,
  .status-row,
  .workspace {
    border-radius: 20px;
  }

  .topbar {
    padding: 16px;
  }

  .brand h1 {
    font-size: 1.02rem;
  }

  .brand p {
    font-size: 0.88rem;
  }

  .editor,
  .preview {
    padding: 18px;
  }
}