:root{--editor-bg: #1e1e1e;--editor-text: #d4d4d4;--preview-bg: #ffffff;--preview-text: #333333;--header-bg: #2d2d2d;--preview-header-bg: #f6f8fa;--border-color: #444;--primary-color: #4daafc}body{margin:0;padding:env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);font-family:-apple-system,system-ui,sans-serif;height:100dvh;overflow:hidden;background:#000}.app-container{display:flex;flex-direction:column;width:100%;height:100%}@media (min-width: 768px){.app-container{flex-direction:row}}.pane{display:flex;flex-direction:column;flex:1;min-height:0;min-width:0}.editor-pane{background:var(--editor-bg);color:var(--editor-text);border-bottom:2px solid #000}@media (min-width: 768px){.editor-pane{border-bottom:none;border-right:2px solid #000}}.preview-pane{background:var(--preview-bg);color:var(--preview-text)}.pane-header{display:flex;justify-content:space-between;align-items:center;padding:8px 12px;flex-shrink:0}.editor-pane .pane-header{background:var(--header-bg);border-bottom:1px solid var(--border-color)}.preview-pane .pane-header{background:var(--preview-header-bg);border-bottom:1px solid #e1e4e8;color:#24292e;font-weight:700}.tabs{display:flex;gap:15px}.tab-btn{background:none;border:none;color:#888;font-size:.9em;font-weight:600;cursor:pointer;padding:5px 0}.tab-btn.active{color:var(--primary-color);border-bottom:2px solid var(--primary-color)}.actions{display:flex;gap:8px;align-items:center}.action-btn{background:transparent;border:1px solid currentColor;color:inherit;border-radius:4px;padding:4px 10px;font-size:.8em;font-weight:700;cursor:pointer}.editor-pane .action-btn{color:#ccc;border-color:#666}.editor-pane .action-btn:active{background:#444}.preview-pane .action-btn{color:#0366d6;border-color:#0366d6}.preview-pane .action-btn:active{background:#e1e4e8}.icon-btn{background:none;border:none;cursor:pointer;font-size:1.1em;opacity:.7;padding:4px}.icon-btn:active{opacity:1}#sync-scroll-btn.active{opacity:1!important;color:var(--primary-color);background:#4daafc1a;border-radius:4px}.pane-content{flex:1;overflow-y:auto;position:relative;-webkit-overflow-scrolling:touch}textarea{position:absolute;top:0;left:0;width:100%;height:100%;box-sizing:border-box;padding:15px;border:none;background:transparent;color:inherit;font-family:monospace;font-size:14px;resize:none;outline:none}textarea.hidden{display:none}#preview-content{padding:15px;font-size:15px;line-height:1.6}#preview-content pre{background:#f6f8fa;padding:12px;border-radius:6px;overflow-x:auto}#preview-content code{background:#f6f8fa;padding:.2em .4em;border-radius:3px;font-family:monospace;font-size:.9em;color:#d73a49}#preview-content pre code{padding:0;color:#24292e;background:transparent}#preview-content blockquote{border-left:4px solid #dfe2e5;color:#6a737d;padding-left:16px;margin:0}#preview-content table{border-collapse:collapse;width:100%;margin-bottom:16px}#preview-content th,#preview-content td{border:1px solid #dfe2e5;padding:6px 13px}#preview-content th{background-color:#f6f8fa}.pane.maximized{flex:1 1 100%!important;display:flex!important}.app-container.has-maximized .pane:not(.maximized){display:none!important}.modal-overlay{position:absolute;top:0;left:0;right:0;bottom:0;background:#0009;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;justify-content:center;align-items:center;z-index:1000;padding:20px}.modal-overlay.hidden{display:none}.modal-content{background:var(--preview-bg);color:var(--preview-text);width:100%;max-width:600px;max-height:85dvh;border-radius:8px;display:flex;flex-direction:column;overflow:hidden;box-shadow:0 10px 30px #00000080}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:15px 20px;background:var(--preview-header-bg);border-bottom:1px solid #e1e4e8}.modal-header h2{margin:0;font-size:1.1em}.history-toggle{font-size:.85em;margin-right:15px;display:flex;align-items:center;gap:5px;cursor:pointer;color:#24292e;font-weight:700}.history-toggle input{margin:0;cursor:pointer}.history-list{overflow-y:auto;-webkit-overflow-scrolling:touch}.history-item{padding:15px 20px;border-bottom:1px solid #e1e4e8;cursor:pointer;transition:background .2s}.history-item:hover{background:#f6f8fa}.history-item .time{font-size:.8em;color:#666;font-weight:700;margin-bottom:5px}.history-item .snippet{font-size:.9em;color:#444;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}