:root{
  --bg:#0f172a; --card:#111827; --ink:#e2e8f0; --muted:#94a3b8; --border:#1f2937; --accent:#60a5fa;
  --btn:#162036; --btn-hover:#1c2946;
}

[data-theme="light"]{
  --bg:#f8fafc; --card:#ffffff; --ink:#0f172a; --muted:#475569; --border:#e2e8f0; --accent:#2563eb;
  --btn:#e2e8f0; --btn-hover:#cbd5e1;
}
[data-theme="blue"]{
  --bg:#0a1a2b; --card:#0e2236; --ink:#e6f1ff; --muted:#9fb3d1; --border:#15344f; --accent:#60a5fa;
  --btn:#102c4a; --btn-hover:#14385f;
}
[data-theme="green"]{
  --bg:#052e2b; --card:#073b36; --ink:#e7fff7; --muted:#9be7d7; --border:#0b524b; --accent:#34d399;
  --btn:#0f766e; --btn-hover:#0b5f59;
}
[data-theme="pink"]{
  --bg:#2a0f1f; --card:#3a112a; --ink:#ffe6f3; --muted:#f6b7d3; --border:#5b1c42; --accent:#f472b6;
  --btn:#a81558; --btn-hover:#8d114a;
}

*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family:ui-sans-serif,system-ui,Segoe UI,Roboto,Arial;background:var(--bg);color:var(--ink)}

header{
  display:flex;align-items:center;gap:12px;padding:12px 16px;
  border-bottom:1px solid var(--border);background:var(--card);position:sticky;top:0;z-index:10
}
.brand{display:flex;align-items:center;gap:10px;font-weight:700}
nav{margin-left:auto;display:flex;gap:8px}
nav a{color:var(--ink);text-decoration:none;border:1px solid var(--border);padding:6px 10px;border-radius:12px;background:transparent}
nav a:hover{background-color:color-mix(in oklab, var(--card) 70%, var(--accent))}
.theme-select{border:1px solid var(--border);background:var(--card);color:var(--ink);border-radius:10px;padding:6px 10px}
.header-theme{margin-left:8px}

.app{height:calc(100vh - 60px);display:grid;grid-template-columns:260px 1.2fr 1fr;gap:12px;padding:12px}
.panel{background:var(--card);border:1px solid var(--border);border-radius:14px;box-shadow:0 6px 18px rgba(0,0,0,.25)}

.sidebar{display:flex;flex-direction:column;min-height:0}
.side-head{padding:10px 12px;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center}
.files{flex:1;min-height:0;overflow:auto;padding:6px}
.file{display:flex;align-items:center;gap:8px;padding:8px 10px;border:1px solid var(--border);border-radius:10px;margin:6px 0;cursor:pointer}
.file.active{background:color-mix(in oklab, var(--card) 70%, var(--accent))}
.file small{opacity:.8;margin-left:auto}
.side-actions{padding:10px;border-top:1px solid var(--border);display:grid;gap:8px}

.btn{padding:9px 12px;border-radius:10px;border:1px solid var(--border);background:var(--btn);color:var(--ink);cursor:pointer}
.btn:hover{background:var(--btn-hover)}
.danger{border-color:#7f1d1d;background:#3f1010}
.danger:hover{background:#541414}

.editor-wrap{display:flex;flex-direction:column;min-height:0}
.toolbar{display:flex;gap:8px;align-items:center;padding:10px;border-bottom:1px solid var(--border)}
.toolbar .spacer{flex:1}
.hint{font-size:12px;color:var(--muted)}
.editor{flex:1;min-height:0;border-bottom-left-radius:14px;border-bottom-right-radius:14px;overflow:hidden}
.editor > div{width:100%;height:100%}

.preview-wrap{display:flex;flex-direction:column;min-height:0}
.preview-head{display:flex;align-items:center;justify-content:space-between;padding:10px;border-bottom:1px solid var(--border)}
iframe{flex:1;border:0;background:white;border-bottom-left-radius:14px;border-bottom-right-radius:14px}
.meta{border-top:1px solid var(--border);padding:8px 10px;font-size:12px;color:var(--muted)}
.tag{font-size:12px;border:1px solid var(--border);border-radius:10px;padding:4px 8px;background:color-mix(in oklab, var(--card) 75%, var(--accent))}
.switch{display:flex;align-items:center;gap:6px}
.switch input{accent-color:var(--accent)}