/* ===== GitHub-style Markdown Editor ===== */
.md-editor {
    border: 1px solid #d0d7de;
    border-radius: 6px;
    background: #fff;
}
.md-editor:focus-within {
    border-color: #3C6F9A;
    box-shadow: 0 0 0 3px rgba(60, 111, 154, 0.12);
}
.md-editor-header {
    display: flex;
    align-items: center;
    border-bottom: 1px solid #d0d7de;
    background: #f6f8fa;
    border-radius: 6px 6px 0 0;
    padding: 0 8px;
}
.md-editor-tabs {
    display: flex;
}
.md-tab {
    background: none;
    border: none;
    padding: 8px 16px;
    font-size: 0.875rem;
    color: #656d76;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    transition: color 0.15s;
}
.md-tab:hover { color: #1f2328; }
.md-tab.active {
    color: #1f2328;
    font-weight: 600;
    border-bottom-color: #3C6F9A;
    background: #fff;
}
.md-toolbar {
    display: flex;
    align-items: center;
    padding: 4px 8px;
    border-bottom: 1px solid #d0d7de;
    background: #f6f8fa;
    flex-wrap: wrap;
    gap: 1px;
}
.md-btn {
    background: none;
    border: none;
    padding: 4px 8px;
    border-radius: 4px;
    color: #656d76;
    cursor: pointer;
    font-size: 0.85rem;
    line-height: 1;
    transition: all 0.15s;
}
.md-btn:hover {
    background: #dfe2e5;
    color: #1f2328;
}
.md-separator {
    width: 1px;
    height: 16px;
    background: #d0d7de;
    margin: 0 4px;
    display: inline-block;
    vertical-align: middle;
}
.md-textarea {
    width: 100%;
    border: none;
    padding: 12px;
    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
    font-size: 16px;
    line-height: 1.6;
    resize: vertical;
    min-height: 150px;
    outline: none;
    color: #1f2328;
    box-sizing: border-box;
}
.md-textarea::placeholder { color: #a0a8b0; }
.md-preview-panel {
    padding: 12px;
    min-height: 150px;
}
.md-preview-content {
    line-height: 1.8;
    word-break: break-word;
    font-size: 16px;
    color: #1f2328;
}
.md-preview-content img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
    margin: 8px 0;
}
.md-preview-content pre {
    background: #f6f8fa;
    border: 1px solid #e1e4e8;
    border-radius: 6px;
    padding: 16px;
    overflow-x: auto;
    margin: 12px 0;
    font-size: 0.875rem;
    line-height: 1.5;
}
.md-preview-content pre code {
    background: transparent;
    padding: 0;
    border: none;
    font-size: inherit;
    color: inherit;
}
.md-preview-content code {
    background: #f0f2f5;
    padding: 2px 6px;
    border-radius: 3px;
    font-size: 0.875rem;
    color: #d63384;
}
.md-preview-content table {
    border-collapse: collapse;
    width: 100%;
    margin: 12px 0;
}
.md-preview-content th,
.md-preview-content td {
    border: 1px solid #d0d7de;
    padding: 6px 13px;
    text-align: left;
}
.md-preview-content th {
    background: #f6f8fa;
    font-weight: 600;
}
.md-preview-content blockquote {
    border-left: 4px solid #d0d7de;
    padding: 0 16px;
    margin: 12px 0;
    color: #656d76;
}
/* Task list (GFM) */
.md-preview-content ul li input[type="checkbox"] {
    margin-right: 6px;
}
.md-footer {
    padding: 6px 12px;
    border-top: 1px solid #d0d7de;
    background: #f6f8fa;
    border-radius: 0 0 6px 6px;
}
/* Drag overlay */
.md-editor.drag-over {
    border-color: #3C6F9A;
    background: rgba(60, 111, 154, 0.04);
}
.md-editor.drag-over .md-textarea {
    opacity: 0.5;
}