/* Reset and Base Theme Variables */
:root {
    --bg-header: #24292e;
    --text-header: #ffffff;
    --bg-app: #f6f8fa;
    --border-color: #d1d5db;
    --border-subtle: #e1e4e8;
    --accent-blue: #0366d6;
    --accent-blue-hover: #0056b3;
    --btn-sec-bg: #f3f4f6;
    --btn-sec-hover: #e5e7eb;
    --text-main: #24292e;
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    --font-mono: ui-monospace, SFMono-Regular, SF Mono, Menlo, Consolas, Liberation Mono, monospace;
}

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

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

/* Header & Toolbar styling */
.app-header {
    background-color: var(--bg-header);
    color: var(--text-header);
    height: 60px;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-shrink: 0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12);
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.brand-icon {
    color: #fff;
}

.brand h1 {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.toolbar-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.toolbar-group {
    display: flex;
    align-items: center;
    gap: 6px;
    background: rgba(255, 255, 255, 0.08);
    padding: 4px 8px;
    border-radius: 6px;
    border: 1px solid rgba(255, 255, 255, 0.15);
}

.toolbar-label {
    font-size: 0.8rem;
    color: #c9d1d9;
    font-weight: 500;
}

.font-size-control-wrapper {
    display: flex;
    align-items: center;
    background: #24292e;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    padding: 1px 4px;
}

.font-size-control-wrapper:hover {
    border-color: rgba(255, 255, 255, 0.4);
}

.number-control {
    background: transparent;
    color: #ffffff;
    border: none;
    outline: none;
    width: 38px;
    font-family: var(--font-stack);
    font-size: 0.8rem;
    text-align: right;
}

/* Hide default browser up/down spinners for clean look, optional */
.number-control::-webkit-inner-spin-button,
.number-control::-webkit-outer-spin-button {
    opacity: 0.6;
}

.unit-label {
    font-size: 0.75rem;
    color: #8b949e;
    margin-left: 2px;
}

/* Buttons */
.btn {
    font-family: var(--font-stack);
    font-size: 0.85rem;
    font-weight: 500;
    padding: 6px 14px;
    border-radius: 6px;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background-color 0.2s ease, border-color 0.2s ease;
    white-space: nowrap;
}

.btn-primary {
    background-color: var(--accent-blue);
    color: #ffffff;
    border-color: rgba(27, 31, 35, 0.1);
}

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

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.1);
    color: #ffffff;
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

/* Main Workspace layout (Split-pane) */
.app-workspace {
    display: flex;
    flex: 1;
    overflow: hidden;
    position: relative;
}

.pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100%;
    background-color: #ffffff;
    min-width: 0;
}

.pane-header {
    background-color: #fafbfc;
    padding: 10px 16px;
    border-bottom: 1px solid var(--border-subtle);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-shrink: 0;
}

.pane-header h2 {
    font-size: 0.85rem;
    font-weight: 600;
    color: #586069;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.meta-info {
    font-size: 0.75rem;
    color: #6a737d;
}

/* Textarea Editor */
#markdown-input {
    flex: 1;
    border: none;
    outline: none;
    padding: 20px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
    resize: none;
    background-color: #ffffff;
    color: #24292e;
}

/* Resizer handle between panes */
.pane-resizer {
    width: 6px;
    background-color: var(--border-subtle);
    cursor: col-resize;
    flex-shrink: 0;
    transition: background-color 0.2s;
}

.pane-resizer:hover, .pane-resizer.active {
    background-color: var(--accent-blue);
}

/* Preview Output Container */
#preview-output {
    flex: 1;
    padding: 24px;
    overflow-y: auto;
    background-color: #ffffff;
}

/* Footer Section */
.app-footer {
    background-color: #ffffff;
    border-top: 1px solid var(--border-subtle);
    padding: 10px 20px;
    flex-shrink: 0;
    font-size: 0.8rem;
    color: #586069;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 100%;
}

.footer-content .credits {
    letter-spacing: 0.4px;
    color: #24292e;
}

/* Custom enhancements for GitHub Markdown Body */
.markdown-body {
    box-sizing: border-box;
    min-width: 200px;
    max-width: 100%;
    margin: 0 auto;
}

/* Code Block Container & Copy Button Styling */
.code-block-wrapper {
    position: relative;
    margin-bottom: 16px;
}

.code-block-wrapper pre {
    margin-top: 0;
    margin-bottom: 0;
    border-radius: 6px;
}

.copy-code-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(27, 31, 35, 0.15);
    color: #24292e;
    font-size: 11px;
    font-weight: 500;
    padding: 3px 8px;
    border-radius: 4px;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.15s ease-in-out, background-color 0.15s;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.code-block-wrapper:hover .copy-code-btn {
    opacity: 1;
}

.copy-code-btn:hover {
    background-color: #f3f4f6;
    border-color: rgba(27, 31, 35, 0.3);
}

.copy-code-btn.copied {
    background-color: #28a745;
    color: #ffffff;
    border-color: #28a745;
    opacity: 1;
}

/* Empty State Styling */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: #6a737d;
    text-align: center;
    padding: 40px;
}

.empty-state svg {
    margin-bottom: 12px;
    color: #a3afbb;
}

.empty-state p {
    font-size: 0.95rem;
}

/* Responsive layout for mobile devices */
@media (max-width: 768px) {
    .app-workspace {
        flex-direction: column;
    }
    .pane-resizer {
        height: 6px;
        width: 100%;
        cursor: row-resize;
    }
    .app-header {
        height: auto;
        padding: 12px 16px;
        flex-direction: column;
        gap: 10px;
    }
    .toolbar-actions {
        width: 100%;
        overflow-x: auto;
        padding-bottom: 4px;
        flex-wrap: wrap;
    }
    .footer-content {
        flex-direction: column;
        gap: 4px;
        text-align: center;
    }
}

/* Strict Print & PDF Export Styles */
@media print {
    @page {
        size: A4;
        margin: 20mm 15mm 20mm 15mm;
    }

    body {
        height: auto !important;
        width: 100% !important;
        overflow: visible !important;
        background: #ffffff !important;
        display: block !important;
        position: static !important;
        margin: 0 !important;
        padding: 0 !important;
    }

    .app-header, 
    .pane-header, 
    .pane-resizer, 
    .editor-pane, 
    .app-footer {
        display: none !important;
    }

    .app-workspace, 
    .pane, 
    #preview-output {
        display: block !important;
        height: auto !important;
        width: 100% !important;
        max-width: 100% !important;
        overflow: visible !important;
        padding: 0 !important;
        margin: 0 !important;
        background: transparent !important;
        position: static !important;
    }

    .markdown-body {
        box-sizing: border-box !important;
        width: 100% !important;
        max-width: 100% !important;
        padding: 0 !important;
        margin: 0 !important;
        line-height: 1.5 !important;
    }

    .copy-code-btn {
        display: none !important;
    }

    pre, blockquote, table, tr, img {
        page-break-inside: avoid;
        break-inside: avoid;
    }

    h1, h2, h3, h4 {
        page-break-after: avoid;
        break-after: avoid;
    }
}