:root {
    /* Light Theme (Default) */
    --bg-color: #f7f9fb;
    --header-bg: #ffffff;
    --pane-bg: #ffffff;
    --border-color: #e1e4e8;
    --text-primary: #2d3748;
    --text-secondary: #718096;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --accent-bg: #eff6ff;
    --hover-bg: #f7f9fb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --font-ui: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --code-bg: #f6f8fa;
    /* For unstyled code blocks if any */
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #0d1117;
        --header-bg: #161b22;
        --pane-bg: #0d1117;
        --border-color: #30363d;
        --text-primary: #c9d1d9;
        --text-secondary: #8b949e;
        --accent-color: #58a6ff;
        --accent-hover: #79c0ff;
        --accent-bg: rgba(56, 139, 253, 0.15);
        --hover-bg: #21262d;
        --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
        --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.8);
        --code-bg: #161b22;
    }
}

[data-theme="dark"] {
    --bg-color: #0d1117;
    --header-bg: #161b22;
    --pane-bg: #0d1117;
    --border-color: #30363d;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent-color: #58a6ff;
    --accent-hover: #79c0ff;
    --accent-bg: rgba(56, 139, 253, 0.15);
    --hover-bg: #21262d;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.8);
    --code-bg: #161b22;
}

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

body {
    font-family: var(--font-ui);
    background-color: var(--bg-color);
    color: var(--text-primary);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header */
.app-header {
    height: 60px;
    background-color: var(--header-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    box-shadow: var(--shadow-sm);
    z-index: 10;
}

.logo {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-primary);
}

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

button {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    color: var(--text-secondary);
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

button:hover {
    background-color: var(--hover-bg);
    color: var(--text-primary);
}

button.active {
    background-color: var(--accent-bg);
    color: var(--accent-color);
}

.divider {
    width: 1px;
    height: 24px;
    background-color: var(--border-color);
    margin: 0 8px;
}

/* Main Area */
.app-main {
    flex: 1;
    display: flex;
    height: calc(100vh - 60px);
}

.editor-pane,
.preview-pane {
    flex: 1;
    padding: 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

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

.preview-pane {
    background-color: var(--pane-bg);
    padding: 24px 40px;
    overflow-y: auto;
}

/* View Modes */
.app-main.split-view .editor-pane,
.app-main.split-view .preview-pane {
    display: flex;
}

.app-main.editor-only .editor-pane {
    flex: 1;
    border-right: none;
}

.app-main.editor-only .preview-pane {
    display: none;
}

.app-main.preview-only .editor-pane {
    display: none;
}

.app-main.preview-only .preview-pane {
    flex: 1;
    max-width: 800px;
    margin: 0 auto;
    border-left: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

/* Editor */
textarea {
    width: 100%;
    height: 100%;
    border: none;
    outline: none;
    resize: none;
    padding: 24px;
    font-family: var(--font-mono);
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: transparent;
    /* Changed to transparent to inherit from pane */
}

/* Preview Typography */
/* 
   Note: The markdown-body class handles its own dark mode via ghmd-dark.css
   Ensure it doesn't conflict or look out of place.
*/
.markdown-body {
    line-height: 1.6;
    font-size: 16px;
    /* Color managed by ghmd-*.css or fallbacks here */
}

@media print {
    :root {
        --bg-color: #ffffff;
        --header-bg: #ffffff;
        --pane-bg: #ffffff;
        --border-color: #e1e4e8;
        --text-primary: #000000;
        --text-secondary: #586069;
        --accent-color: #3b82f6;
        --code-bg: #f6f8fa;
    }

    header {
        display: none !important;
    }

    .editor-pane {
        display: none !important;
    }

    .preview-pane {
        display: block !important;
        overflow: visible;
        padding: 0;
        margin: 0;
        border: none !important;
        box-shadow: none !important;
        max-width: none !important;
    }

    .app-main.preview-only .preview-pane {
        margin: 0 !important;
        border: none !important;
        box-shadow: none !important;
        max-width: none !important;
    }

    .app-main {
        height: auto;
        display: block;
    }

    body {
        height: auto;
        overflow: visible;
        background-color: white;
        color: black;
    }

    .markdown-body {
        font-size: 12pt;
        color: #24292e !important;
        background-color: #ffffff !important;
    }

    /* Ensure code blocks look like light theme */
    .markdown-body pre {
        background-color: #f6f8fa !important;
        border: 1px solid #e1e4e8;
    }

    .markdown-body code {
        background-color: rgba(27, 31, 35, .05) !important;
    }

    /* Reset links for print */
    .markdown-body a {
        color: #24292e !important;
        text-decoration: underline;
    }
}