:root{
    --bg:#0f1724;
    --card:#0b1220;
    --muted:#94a3b8;
    --accent:#7c3aed;
    --accent-2:#06b6d4;
    --glass: rgba(255,255,255,0.03);
    --radius:10px;
    --gap:14px;
    --text:#e6eef8;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
    margin:0;
    font-family: Inter, "Segoe UI", Roboto, Arial, sans-serif;
    background: linear-gradient(180deg, #071029 0%, #081225 50%, #071022 100%);
    color:var(--text);
    padding:28px;
}

/* Layout */
.app {
    max-width:1100px;
    margin:0 auto;
    display:flex;
    gap:var(--gap);
    align-items:flex-start;
}

.sidebar{
    width:280px;
    background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
    border-radius:var(--radius);
    padding:18px;
    box-shadow: 0 8px 24px rgba(2,6,23,0.6);
    border:1px solid rgba(255,255,255,0.03);
    display:flex;
    flex-direction:column;
    gap:12px;
}

.brand{display:flex;align-items:center;gap:12px}
.logo{width:40px;height:40px;border-radius:8px;background:linear-gradient(135deg,var(--accent),var(--accent-2))}

.channel-list{display:flex;flex-direction:column;gap:8px;overflow:auto;padding-right:6px}
.channel{padding:10px 12px;border-radius:8px;cursor:pointer;color:var(--text);display:flex;align-items:center;justify-content:space-between;background:transparent;border:1px solid transparent}
.channel:hover{background:var(--glass);border-color:rgba(255,255,255,0.03)}
.channel.active{background: linear-gradient(90deg, rgba(124,58,237,0.12), rgba(6,182,212,0.06));border:1px solid rgba(124,58,237,0.18)}

.main{flex:1;display:flex;flex-direction:column;gap:12px}
.topbar{display:flex;justify-content:space-between;align-items:center}
.topbar .title{font-size:18px;font-weight:700}
.topbar .sub{color:var(--muted);font-size:13px}

/* Card / editor */
.card{background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));border-radius:var(--radius);padding:14px;box-shadow:0 10px 30px rgba(2,6,23,0.6);border:1px solid rgba(255,255,255,0.03);display:flex;flex-direction:column;gap:12px;min-height:320px}
.editor{flex:1;display:flex;flex-direction:column;gap:8px}
textarea#sharedText{width:100%;height:100%;resize:vertical;min-height:220px;background:transparent;border-radius:8px;border:1px solid rgba(255,255,255,0.04);padding:14px;color:var(--text);font-family:ui-monospace, SFMono-Regular, Menlo, Monaco, "Roboto Mono", monospace;font-size:14px;line-height:1.5;outline:none}

.controls{display:flex;gap:10px;align-items:center;justify-content:flex-end}

/* Buttons */
.btn{padding:8px 12px;border-radius:8px;border:1px solid rgba(255,255,255,0.04);background:rgba(255,255,255,0.02);color:var(--text);cursor:pointer;font-weight:600;font-size:13px;transition:all .12s ease}
.btn:hover{transform:translateY(-2px)}
.btn.primary{background: linear-gradient(90deg,var(--accent),var(--accent-2));border:none}
.btn.ghost{background:transparent;border:1px solid rgba(255,255,255,0.04)}

.small{font-size:13px;color:var(--muted)}
.footer{color:var(--muted);font-size:12px;text-align:center;margin-top:6px}

@media (max-width:900px){
    .app{flex-direction:column;padding:18px}
    .sidebar{width:100%}
    .main{width:100%}
}