:root {
  --color-text: #333;
  --color-text-light: #666;
  --color-primary: #6e8efb;
  --color-secondary: #a777e3;
  --color-code-bg: #f8f8f8;
  --space-unit: 1rem;
  --space-sm: calc(0.5 * var(--space-unit));
  --space-md: var(--space-unit);
  --space-lg: calc(2 * var(--space-unit));
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, monospace;
  --line-height: 1.6;
}

body {
  margin: 0;
  padding: var(--space-md);
  min-height: 100vh;
  font-family: var(--font-sans);
}

h1 {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 2.5rem;
  text-align: center;
  margin-bottom: var(--space-lg);
  color: #222;
  animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

.container {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  width: 100%;
  max-width: 1600px;
  margin: 0 auto;
  height: auto;
  min-height: calc(100vh - 10rem);
  padding-bottom: 2rem;
}

@media (min-width: 992px) {
  .container {
    flex-direction: row;
    height: calc(100vh - 8rem);
  }
}

.editor-panel, .preview-panel {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  min-height: 500px;
}

.editor-panel {
  margin-bottom: 2rem;
}

.preview-panel {
  margin-bottom: 2rem;
}

.panel-content {
  flex: 1;
  display: flex;
  min-height: 300px;
}

#markdown-input, #preview {
  flex: 1;
  width: 100%;
  padding: var(--space-md);
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 0.9em;
  line-height: var(--line-height);
  background: white !important;
  color: #333 !important;
  overflow-y: auto;
}

#markdown-input {
  resize: vertical;
  font-family: var(--font-mono);
  min-height: 400px;
  padding-bottom: 1.5rem;
}

#preview {
  font-family: var(--font-sans);
  min-height: 400px;
}

#preview * {
  color: inherit !important;
}

#preview pre, #preview code {
  background-color: #f8f8f8 !important;
}

.controls {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
  flex-wrap: wrap;
}

button {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  cursor: pointer;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.9rem;
  text-transform: uppercase;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

.markdown-body {
  width: 100%;
  color: var(--color-text);
  line-height: var(--line-height);
}

.markdown-body pre {
  background: var(--color-code-bg);
  padding: var(--space-md);
  border-radius: 6px;
  overflow-x: auto;
}

@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  .container { height: auto; }
}

@media print {
  .markdown-body { color: black !important; }
  #markdown-input, #preview { color: #000 !important; }
}

@media print {
  body, .markdown-body, #preview {
    background-color: white !important;
    color: #333 !important;
  }
  pre, code {
    background-color: #f8f8f8 !important;
    page-break-inside: avoid;
  }
}

@media print {
  body > * {
    display: none;
  }
  body::after {
    content: "";
    display: block;
    height: 0;
    overflow: hidden;
  }
  #preview, #preview * {
    display: block !important;
    visibility: visible !important;
    color: #000 !important;
    background: white !important;
  }
}

@media (prefers-color-scheme: dark) {
  :root { --color-text: #e0e0e0; }
  .markdown-body { background: #121212; }
  #markdown-input, #preview {
    background: white !important;
    color: #333 !important;
  }
}