@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');
:root{--font-sans:'Inter',sans-serif;--font-mono:'JetBrains Mono',monospace}
[data-theme="dark"]{--bg:#0f0f14;--bg-surface:#16161d;--bg-card:#1e1e28;--bg-input:#1a1a24;--border:#2a2a3a;--text:#e8e8ef;--text-secondary:#a0a0b8;--text-muted:#6b6b80;--accent:#6366f1;--accent-subtle:rgba(99,102,241,0.12);--glass-bg:rgba(30,30,40,0.7);--glass-border:rgba(255,255,255,0.08)}
[data-theme="light"]{--bg:#f5f5f7;--bg-surface:#fff;--bg-card:#fff;--bg-input:#f8f8fc;--border:#e0e0e8;--text:#1a1a2e;--text-secondary:#4a4a60;--text-muted:#8888a0;--accent:#6366f1;--accent-subtle:rgba(99,102,241,0.08);--glass-bg:rgba(255,255,255,0.75);--glass-border:rgba(0,0,0,0.06)}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
body{font-family:var(--font-sans);background:var(--bg);color:var(--text);min-height:100vh;display:flex;flex-direction:column}
.container{max-width:1400px;margin:0 auto;padding:0 1rem;width:100%}
.navbar{position:sticky;top:0;z-index:200;backdrop-filter:blur(16px);background:var(--glass-bg);border-bottom:1px solid var(--glass-border);padding:.4rem 0}
.nav-inner{display:flex;align-items:center;justify-content:space-between;max-width:1400px;margin:0 auto;padding:0 1rem}
.brand{font-weight:700;font-size:1.1rem;color:var(--text);text-decoration:none}
.nav-links{display:flex;align-items:center;gap:.5rem}
.nav-links select{padding:.3rem .5rem;background:var(--bg-card);color:var(--text);border:1px solid var(--border);border-radius:6px;font-size:.8rem}
.btn{display:inline-flex;align-items:center;padding:.4rem .8rem;border:none;border-radius:6px;font-weight:600;font-size:.8rem;cursor:pointer;transition:all .15s}
.btn-sm{padding:.3rem .6rem;font-size:.75rem}
.btn-secondary{background:var(--bg-card);color:var(--text);border:1px solid var(--border)}
.btn-secondary:hover{border-color:var(--accent);color:var(--accent)}
.theme-btn{background:var(--bg-card);border:1px solid var(--border);border-radius:6px;padding:2px 8px;cursor:pointer;font-size:1rem}
.text-muted{color:var(--text-muted)}
.hidden{display:none!important}

.editor-layout{flex:1;display:flex;flex-direction:column;max-width:1400px;margin:0 auto;width:100%}
.toolbar{display:flex;align-items:center;gap:2px;padding:.4rem .75rem;background:var(--bg-surface);border-bottom:1px solid var(--border);flex-wrap:wrap}
.toolbar button{background:none;border:1px solid transparent;color:var(--text-secondary);padding:4px 8px;border-radius:4px;cursor:pointer;font-size:.8rem;font-family:var(--font-sans);transition:all .15s}
.toolbar button:hover{background:var(--accent-subtle);color:var(--accent);border-color:var(--accent)}
.sep{color:var(--border);margin:0 2px}

.panes{flex:1;display:grid;grid-template-columns:1fr 1fr;min-height:0}
.pane{display:flex;flex-direction:column;overflow:hidden}
.pane-header{display:flex;justify-content:space-between;align-items:center;padding:.4rem .75rem;background:var(--bg-surface);border-bottom:1px solid var(--border);font-size:.8rem;font-weight:600}
.editor-pane{border-right:1px solid var(--border)}
#editor{flex:1;width:100%;resize:none;border:none;outline:none;padding:1rem;font-family:var(--font-mono);font-size:.9rem;line-height:1.7;background:var(--bg);color:var(--text);tab-size:2}

.preview-pane{overflow:hidden}
.preview-content{flex:1;overflow-y:auto;padding:1.5rem;line-height:1.8;font-size:.95rem}
.preview-content h1{font-size:1.8rem;margin:1rem 0 .5rem;padding-bottom:.3rem;border-bottom:2px solid var(--border)}
.preview-content h2{font-size:1.4rem;margin:1rem 0 .4rem;padding-bottom:.2rem;border-bottom:1px solid var(--border)}
.preview-content h3{font-size:1.15rem;margin:.8rem 0 .3rem}
.preview-content p{margin:.5rem 0}
.preview-content code{background:var(--bg-input);padding:2px 6px;border-radius:4px;font-family:var(--font-mono);font-size:.85em;color:var(--accent)}
.preview-content pre{background:var(--bg-input);padding:1rem;border-radius:8px;overflow-x:auto;margin:.75rem 0;border:1px solid var(--border)}
.preview-content pre code{background:none;padding:0;color:var(--text)}
.preview-content blockquote{border-left:4px solid var(--accent);padding:.5rem 1rem;margin:.75rem 0;color:var(--text-secondary);background:var(--accent-subtle);border-radius:0 8px 8px 0}
.preview-content ul,.preview-content ol{padding-left:1.5rem;margin:.5rem 0}
.preview-content li{margin:.2rem 0}
.preview-content table{width:100%;border-collapse:collapse;margin:.75rem 0}
.preview-content th,.preview-content td{border:1px solid var(--border);padding:.5rem .75rem;text-align:left}
.preview-content th{background:var(--bg-surface);font-weight:600}
.preview-content img{max-width:100%;border-radius:8px}
.preview-content hr{border:none;border-top:2px solid var(--border);margin:1.5rem 0}
.preview-content a{color:var(--accent);text-decoration:underline}
.preview-content input[type="checkbox"]{margin-right:.4rem}

.status-bar{display:flex;justify-content:space-between;padding:.3rem .75rem;background:var(--bg-surface);border-top:1px solid var(--border);font-size:.75rem;color:var(--text-muted)}
.outline-toggle{cursor:pointer;color:var(--accent)}
.outline-panel{position:fixed;right:0;top:60px;bottom:30px;width:220px;background:var(--bg-card);border-left:1px solid var(--border);padding:1rem;overflow-y:auto;z-index:100}
.outline-panel h4{margin-bottom:.75rem;font-size:.85rem}
.outline-panel a{display:block;padding:2px 0;font-size:.8rem;color:var(--text-secondary);text-decoration:none;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.outline-panel a:hover{color:var(--accent)}
.outline-panel a.h2{padding-left:.75rem}
.outline-panel a.h3{padding-left:1.5rem}

@media(max-width:768px){.panes{grid-template-columns:1fr}.editor-pane{border-right:none;border-bottom:1px solid var(--border);max-height:50vh}}
@media print{.navbar,.toolbar,.status-bar,.outline-panel{display:none!important}.panes{grid-template-columns:1fr}.editor-pane{display:none!important}.preview-pane{overflow:visible}}