/* Core Palette & Design Tokens */
:root {
    --bg-base: #0f0f11;
    --bg-surface: #16161a;
    --bg-input: #111113;
    --border-color: #24242b;
    
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #4b5563;
    
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    
    --font-sans: 'Inter', sans-serif;
    --font-mono: 'Fira Code', monospace;
}

/* Base Rules & Resets */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

/* Header */
.app-header {
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
    z-index: 10;
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.05em;
}

.logo span {
    color: var(--accent-color);
}

.toolbar {
    display: flex;
    gap: 0.75rem;
}

/* Controls */
.btn {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 500;
    padding: 0.5rem 0.85rem;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: background-color 0.2s, transform 0.1s;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
}

.btn-secondary {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
}

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

.btn:active {
    transform: scale(0.98);
}

/* Workspace Panels */
.workspace {
    display: flex;
    flex: 1;
    overflow: hidden;
    height: calc(100vh - 60px);
}

.pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pane:first-of-type {
    border-right: 1px solid var(--border-color);
}

.pane-header {
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    padding: 0.5rem 1.25rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

/* Editor Styling */
#markdown-input {
    flex: 1;
    width: 100%;
    background-color: var(--bg-input);
    color: var(--text-primary);
    border: none;
    resize: none;
    padding: 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    line-height: 1.6;
    outline: none;
}

#markdown-input::placeholder {
    color: #4b5563;
    opacity: 0.8;
}

/* Preview Workspace Styling */
#preview-output {
    flex: 1;
    padding: 1.5rem 2rem;
    overflow-y: auto;
    background-color: var(--bg-base);
}

/* Generated Markdown Typography Style */
.markdown-body {
    font-size: 1rem;
    line-height: 1.6;
    color: #e5e7eb;
}

.markdown-body h1, 
.markdown-body h2, 
.markdown-body h3 {
    margin-top: 1.5rem;
    margin-bottom: 1rem;
    font-weight: 600;
    color: #ffffff;
}

.markdown-body h1 { font-size: 1.75rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.3rem;}
.markdown-body h2 { font-size: 1.35rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.3rem;}
.markdown-body h3 { font-size: 1.15rem; }

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

.markdown-body ul, 
.markdown-body ol {
    margin-bottom: 1rem;
    padding-left: 2rem;
}

.markdown-body li {
    margin-bottom: 0.25rem;
}

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

.markdown-body pre {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 1rem;
    overflow-x: auto;
    margin-bottom: 1rem;
}

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

.markdown-body blockquote {
    border-left: 4px solid var(--accent-color);
    padding-left: 1rem;
    color: var(--text-secondary);
    margin: 1rem 0;
    font-style: italic;
}

/* Print Overrides for Document Exports */
.pdf-export-mode {
    background-color: #ffffff !important;
    color: #000000 !important;
}

.pdf-export-mode .markdown-body {
    color: #111111 !important;
}

.pdf-export-mode .markdown-body h1,
.pdf-export-mode .markdown-body h2,
.pdf-export-mode .markdown-body h3 {
    color: #000000 !important;
    border-bottom: 1px solid #e5e7eb !important;
}

.pdf-export-mode .markdown-body code {
    background-color: #f3f4f6 !important;
    color: #c2410c !important;
    border: 1px solid #e5e7eb !important;
}

.pdf-export-mode .markdown-body pre {
    background-color: #f9fafb !important;
    border: 1px solid #e5e7eb !important;
}

.pdf-export-mode .markdown-body pre code {
    color: #111111 !important;
}

/* Mobile Responsiveness (Vertical Stack Layout) */
@media (max-width: 768px) {
    body {
        overflow: auto;
    }

    .app-header {
        padding: 0.75rem 1rem;
        flex-direction: column;
        height: auto;
        gap: 0.75rem;
    }

    .workspace {
        flex-direction: column;
        height: auto;
        overflow: visible;
    }

    .pane {
        flex: none;
        height: 450px; /* Uniform panel heights on stacked layouts */
        overflow: hidden;
    }

    .pane:first-of-type {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
    }

    #preview-output {
        overflow-y: auto;
    }
}