:root {
  --bg-primary: #0b0d12;
  --bg-secondary: #111318;
  --bg-tertiary: #181b22;
  --bg-card: rgba(24,27,34,.92);
  --bg-input: rgba(30,33,42,.8);
  --text-primary: #eaecf0;
  --text-secondary: #8b8fa4;
  --text-muted: #4e5264;
  --accent: #7c6cf7;
  --accent-dim: rgba(124,108,247,.12);
  --accent-glow: rgba(124,108,247,.25);
  --accent-hover: #8d7eff;
  --green: #34d399;
  --green-dim: rgba(52,211,153,.12);
  --blue: #60a5fa;
  --blue-dim: rgba(96,165,250,.12);
  --orange: #fb923c;
  --orange-dim: rgba(251,146,60,.12);
  --danger: #f87171;
  --border: rgba(255,255,255,.07);
  --border-active: rgba(255,255,255,.14);
  --radius: 14px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', monospace;
}
*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
body { font-family:var(--font); background:var(--bg-primary); color:var(--text-primary); height:100vh; display:flex; overflow:hidden; -webkit-font-smoothing:antialiased; }

/* Login */
.login-overlay { position:fixed; inset:0; background:var(--bg-primary); display:flex; align-items:center; justify-content:center; z-index:9999; }
.login-box { background:var(--bg-secondary); border:1px solid var(--border); padding:48px 40px; border-radius:24px; text-align:center; width:100%; max-width:420px; box-shadow:0 24px 48px rgba(0,0,0,.5); }
.login-logo { width:72px; height:72px; margin:0 auto 20px; background:linear-gradient(135deg, var(--accent), #a78bfa); border-radius:20px; display:flex; align-items:center; justify-content:center; font-size:36px; box-shadow:0 12px 32px var(--accent-glow); animation: float 3s ease-in-out infinite; }
@keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-6px)} }
.login-box h2 { font-size:24px; font-weight:700; margin-bottom:6px; letter-spacing:-.3px; }
.login-sub { color:var(--text-muted); font-size:13px; margin-bottom:28px; letter-spacing:.5px; text-transform:uppercase; }
.login-box input { width:100%; background:var(--bg-input); border:1px solid var(--border); color:#fff; padding:15px 18px; border-radius:var(--radius); margin-bottom:16px; outline:none; font-size:15px; text-align:center; font-family:var(--font); transition:.2s; }
.login-box input:focus { border-color:var(--accent); box-shadow:0 0 0 3px var(--accent-dim); }
.login-box button { width:100%; background:var(--accent); color:#fff; border:none; padding:15px; border-radius:var(--radius); font-size:15px; font-weight:600; cursor:pointer; transition:.2s; font-family:var(--font); }
.login-box button:hover { background:var(--accent-hover); box-shadow:0 0 20px var(--accent-glow); transform:translateY(-1px); }
.login-error { color:var(--danger); font-size:13px; margin-top:14px; min-height:20px; }

/* Sidebar */
.sidebar { width:280px; min-width:280px; background:var(--bg-secondary); border-right:1px solid var(--border); display:flex; flex-direction:column; transition:transform .3s cubic-bezier(.4,0,.2,1); z-index:100; }
.sidebar-header { padding:20px; border-bottom:1px solid var(--border); display:flex; align-items:center; gap:14px; }
.logo-icon { width:38px; height:38px; background:linear-gradient(135deg, var(--accent), #a78bfa); border-radius:11px; display:flex; align-items:center; justify-content:center; font-size:18px; box-shadow:0 6px 16px var(--accent-glow); flex-shrink:0; }
.logo-text h1 { font-size:17px; font-weight:700; letter-spacing:-.3px; }
.logo-text span { font-size:11px; color:var(--text-muted); letter-spacing:.3px; }
.sidebar-toggle { display:none; background:none; border:none; color:var(--text-muted); font-size:16px; cursor:pointer; margin-left:auto; padding:4px 8px; border-radius:6px; }
.sidebar-toggle:hover { color:var(--text-primary); background:rgba(255,255,255,.05); }

.new-chat-btn { margin:16px; padding:11px; background:var(--accent); color:#fff; border:none; border-radius:var(--radius); font-weight:600; font-size:14px; cursor:pointer; display:flex; align-items:center; justify-content:center; gap:8px; transition:.2s; font-family:var(--font); }
.new-chat-btn:hover { background:var(--accent-hover); box-shadow:0 4px 16px var(--accent-glow); transform:translateY(-1px); }
.new-chat-btn span { font-size:18px; font-weight:300; }

.chat-list { flex:1; overflow-y:auto; padding:0 10px; }
.chat-item { padding:10px 12px; border-radius:10px; cursor:pointer; font-size:13px; color:var(--text-secondary); display:flex; align-items:center; gap:8px; margin-bottom:2px; transition:.15s; }
.chat-item-title { overflow:hidden; text-overflow:ellipsis; white-space:nowrap; flex:1; }
.chat-item:hover { background:rgba(255,255,255,.04); }
.chat-item.active { background:var(--accent-dim); color:var(--text-primary); font-weight:500; }
.delete-chat { background:transparent; border:none; color:var(--text-muted); cursor:pointer; padding:4px 6px; border-radius:6px; font-size:12px; opacity:0; transition:.15s; }
.chat-item:hover .delete-chat { opacity:1; }
.delete-chat:hover { color:var(--danger); background:rgba(248,113,113,.1); }

/* Sidebar Footer */
.sidebar-footer { border-top:1px solid var(--border); padding:0; }
.metrics-mini { display:grid; grid-template-columns:1fr 1fr 1fr; gap:1px; padding:12px 16px; border-bottom:1px solid var(--border); }
.metric { text-align:center; }
.metric-label { display:block; font-size:10px; color:var(--text-muted); text-transform:uppercase; letter-spacing:.5px; margin-bottom:2px; }
.metric-val { display:block; font-size:14px; font-weight:700; font-family:var(--mono); color:var(--text-primary); }
.sidebar-actions { display:flex; gap:6px; padding:10px 16px; border-bottom:1px solid var(--border); }
.action-btn { flex:1; padding:8px; background:var(--bg-tertiary); color:var(--text-secondary); border:1px solid var(--border); border-radius:8px; cursor:pointer; font-size:14px; transition:.15s; }
.action-btn:hover { background:rgba(255,255,255,.06); color:var(--text-primary); border-color:var(--border-active); }
.action-btn.danger:hover { background:rgba(248,113,113,.08); color:var(--danger); border-color:rgba(248,113,113,.3); }
.sidebar-status { padding:12px 16px; font-size:12px; color:var(--text-muted); display:flex; align-items:center; gap:8px; }
.status-dot { width:7px; height:7px; border-radius:50%; background:var(--text-muted); flex-shrink:0; transition:.3s; }
.status-dot.online { background:var(--green); box-shadow:0 0 8px var(--green); }

/* Main Area */
.main { flex:1; display:flex; flex-direction:column; background:var(--bg-primary); min-width:0; }
.topbar { padding:12px 24px; border-bottom:1px solid var(--border); display:flex; align-items:center; gap:12px; background:rgba(17,19,24,.85); backdrop-filter:blur(12px); -webkit-backdrop-filter:blur(12px); }
.hamburger { display:none; background:none; border:none; color:var(--text-secondary); font-size:20px; cursor:pointer; padding:4px 8px; border-radius:6px; }
.hamburger:hover { color:var(--text-primary); background:rgba(255,255,255,.05); }
.model-selector { background:var(--bg-input); border:1px solid var(--border); border-radius:10px; color:var(--text-primary); padding:8px 14px; outline:none; font-weight:500; font-size:13px; font-family:var(--font); max-width:280px; }
.model-selector:focus { border-color:var(--accent); }
.topbar-metrics { display:flex; gap:6px; margin-left:auto; flex-wrap:wrap; }
.badge { padding:5px 10px; border-radius:8px; font-size:11px; font-weight:600; font-family:var(--mono); letter-spacing:.2px; transition:.3s; white-space:nowrap; }
.badge.in { background:var(--blue-dim); color:var(--blue); }
.badge.out { background:var(--green-dim); color:var(--green); }
.badge.total { background:var(--accent-dim); color:var(--accent); }
.badge.time { background:var(--orange-dim); color:var(--orange); }
.badge.pulse { animation: badgePulse .4s ease; }
@keyframes badgePulse { 0%{transform:scale(1)} 50%{transform:scale(1.12)} 100%{transform:scale(1)} }

/* Messages */
.messages { flex:1; overflow-y:auto; padding:28px 24px; scroll-behavior:smooth; }
.message { max-width:780px; margin:0 auto 28px; display:flex; gap:14px; animation:msgIn .3s ease; }
@keyframes msgIn { from{opacity:0;transform:translateY(8px)} to{opacity:1;transform:translateY(0)} }
.message-avatar { width:34px; height:34px; border-radius:10px; display:flex; align-items:center; justify-content:center; font-size:16px; flex-shrink:0; }
.message.user .message-avatar { background:linear-gradient(135deg, #3b82f6, #2563eb); }
.message.assistant .message-avatar { background:linear-gradient(135deg, var(--accent), #a78bfa); }
.message-content { flex:1; min-width:0; }
.role { font-size:12px; font-weight:600; color:var(--text-muted); margin-bottom:6px; text-transform:uppercase; letter-spacing:.4px; }
.text { font-size:14.5px; line-height:1.7; color:var(--text-primary); }
.text pre { background:var(--bg-tertiary); padding:16px; border-radius:12px; border:1px solid var(--border); overflow-x:auto; margin:12px 0; font-family:var(--mono); font-size:13px; line-height:1.6; }
.text code { background:var(--accent-dim); padding:2px 6px; border-radius:5px; font-family:var(--mono); font-size:.88em; color:#c4b5fd; }
.text pre code { background:transparent; padding:0; color:var(--text-primary); }
.msg-usage { display:flex; gap:10px; margin-top:8px; padding-top:8px; border-top:1px solid var(--border); }
.msg-usage span { font-size:11px; color:var(--text-muted); font-family:var(--mono); }

/* Welcome */
.welcome { display:flex; flex-direction:column; align-items:center; justify-content:center; padding:60px 20px; text-align:center; height:100%; }
.welcome-icon { width:72px; height:72px; background:linear-gradient(135deg, var(--accent), #a78bfa); border-radius:20px; display:flex; align-items:center; justify-content:center; font-size:32px; margin-bottom:24px; box-shadow:0 12px 32px var(--accent-glow); animation: float 3s ease-in-out infinite; }
.welcome h2 { font-size:26px; font-weight:700; margin-bottom:10px; letter-spacing:-.3px; }
.welcome p { color:var(--text-secondary); font-size:15px; max-width:400px; }
.shortcuts { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin-top:36px; width:100%; max-width:520px; }
.shortcut { background:var(--bg-card); border:1px solid var(--border); padding:18px 16px; border-radius:var(--radius); cursor:pointer; transition:.2s; text-align:left; display:flex; flex-direction:column; gap:4px; }
.shortcut:hover { border-color:var(--accent); transform:translateY(-2px); background:rgba(124,108,247,.04); box-shadow:0 8px 20px rgba(0,0,0,.3); }
.sc-icon { font-size:20px; margin-bottom:4px; }
.shortcut strong { font-size:13px; font-weight:600; }
.shortcut small { font-size:11px; color:var(--text-muted); }

/* Input */
.input-area { padding:16px 24px 12px; background:linear-gradient(to top, var(--bg-primary) 60%, transparent); }
.input-wrapper { max-width:780px; margin:0 auto; position:relative; }
.input-wrapper textarea { width:100%; background:var(--bg-secondary); border:1px solid var(--border); border-radius:var(--radius); color:var(--text-primary); padding:16px 56px 16px 18px; resize:none; outline:none; font-size:14.5px; line-height:1.5; font-family:var(--font); transition:.2s; }
.input-wrapper textarea:focus { border-color:var(--accent); box-shadow:0 0 0 3px var(--accent-dim); }
.send-btn { position:absolute; right:10px; bottom:10px; width:36px; height:36px; background:var(--accent); border:none; border-radius:10px; color:#fff; cursor:pointer; display:flex; align-items:center; justify-content:center; transition:.2s; }
.send-btn:hover { background:var(--accent-hover); transform:scale(1.06); box-shadow:0 4px 12px var(--accent-glow); }
.send-btn:disabled { background:var(--text-muted); cursor:not-allowed; transform:none; box-shadow:none; }
.input-footer { text-align:center; font-size:11px; color:var(--text-muted); margin-top:8px; }

/* Typing */
.typing-indicator { display:flex; gap:5px; padding:8px 0; }
.typing-indicator span { width:6px; height:6px; border-radius:50%; background:var(--accent); animation:bounce 1.4s infinite; }
.typing-indicator span:nth-child(2) { animation-delay:.2s; }
.typing-indicator span:nth-child(3) { animation-delay:.4s; }
@keyframes bounce { 0%,100%{opacity:.3;transform:translateY(0)} 50%{opacity:1;transform:translateY(-4px)} }

/* Scrollbar */
::-webkit-scrollbar { width:6px; height:6px; }
::-webkit-scrollbar-track { background:transparent; }
::-webkit-scrollbar-thumb { background:rgba(255,255,255,.08); border-radius:3px; }
::-webkit-scrollbar-thumb:hover { background:rgba(255,255,255,.16); }

/* Mobile */
@media (max-width: 768px) {
  .sidebar { position:fixed; left:0; top:0; bottom:0; transform:translateX(-100%); box-shadow:4px 0 24px rgba(0,0,0,.5); }
  .sidebar.open { transform:translateX(0); }
  .sidebar-toggle { display:block; }
  .hamburger { display:block; }
  .topbar-metrics .badge.in, .topbar-metrics .badge.out { display:none; }
  .shortcuts { grid-template-columns:1fr; }
  .messages { padding:20px 16px; }
  .input-area { padding:12px 16px 8px; }
  .topbar { padding:10px 16px; }
}