:root{
  --bg:#0b1020; --bg2:#121a33; --card:#161f3d; --line:#24304f;
  --txt:#eaf0ff; --mut:#93a0c4; --acc:#4f8cff; --acc2:#22d3a6; --danger:#ff5d6c;
  --radius:16px; --shadow:0 12px 40px rgba(0,0,0,.45);
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{
  font-family:'Inter',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  background:radial-gradient(1200px 600px at 80% -10%,#1b2a55 0%,transparent 60%),
             radial-gradient(900px 500px at -10% 110%,#123b34 0%,transparent 55%),var(--bg);
  color:var(--txt);min-height:100%;
}
a{color:var(--acc);text-decoration:none}
.wrap{max-width:1080px;margin:0 auto;padding:22px 20px 60px}
header{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:26px}
.brand{display:flex;align-items:center;gap:12px;font-weight:800;font-size:20px;letter-spacing:.2px}
.logo{width:38px;height:38px;border-radius:11px;background:linear-gradient(135deg,var(--acc),var(--acc2));
  display:grid;place-items:center;box-shadow:0 6px 18px rgba(79,140,255,.4)}
.logo svg{width:22px;height:22px}
.lang{display:flex;gap:6px}
.lang button{background:transparent;border:1px solid var(--line);color:var(--mut);border-radius:9px;
  padding:6px 11px;cursor:pointer;font-weight:600;font-size:13px}
.lang button.on{background:var(--acc);border-color:var(--acc);color:#fff}
.hero{text-align:center;margin:8px 0 30px}
.hero h1{font-size:clamp(26px,4vw,40px);margin:0 0 10px;line-height:1.1}
.hero p{color:var(--mut);font-size:17px;max-width:620px;margin:0 auto}
.cards{display:grid;grid-template-columns:1fr 1fr;gap:20px}
@media(max-width:780px){.cards{grid-template-columns:1fr}}
.card{background:linear-gradient(180deg,var(--card),var(--bg2));border:1px solid var(--line);
  border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}
.card h2{margin:0 0 6px;font-size:20px;display:flex;align-items:center;gap:10px}
.card .sub{color:var(--mut);font-size:14px;margin:0 0 20px}
.pill{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;flex:none}
.pill.a{background:rgba(79,140,255,.15);color:var(--acc)}
.pill.b{background:rgba(34,211,166,.15);color:var(--acc2)}
.pill svg{width:19px;height:19px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;width:100%;
  border:none;border-radius:12px;padding:14px 18px;font-size:15px;font-weight:700;cursor:pointer;
  background:var(--acc);color:#fff;transition:transform .05s,filter .15s}
.btn:hover{filter:brightness(1.08)}
.btn:active{transform:translateY(1px)}
.btn.green{background:var(--acc2);color:#04241b}
.btn.ghost{background:transparent;border:1px solid var(--line);color:var(--txt)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn svg{width:18px;height:18px}
.field{display:flex;gap:10px;margin-top:6px}
.field input{flex:1;background:#0d1428;border:1px solid var(--line);color:var(--txt);
  border-radius:12px;padding:14px 16px;font-size:20px;letter-spacing:3px;text-align:center;font-weight:700}
.field input::placeholder{letter-spacing:2px;color:#4a5678;font-weight:600}
.codebox{margin:6px 0 16px;text-align:center;background:#0d1428;border:1px dashed var(--line);
  border-radius:14px;padding:20px}
.codebox .lbl{color:var(--mut);font-size:13px;margin-bottom:8px}
.codebox .code{font-size:40px;font-weight:800;letter-spacing:6px;font-variant-numeric:tabular-nums;
  background:linear-gradient(135deg,var(--acc),var(--acc2));-webkit-background-clip:text;background-clip:text;color:transparent}
.codebox .code.wait{background:none;color:var(--mut);font-size:22px;letter-spacing:2px}
.copy{margin-top:10px;font-size:13px;color:var(--acc);cursor:pointer;background:none;border:none}
.hint{color:var(--mut);font-size:13px;margin-top:14px;line-height:1.5}
.sep{display:flex;align-items:center;gap:12px;color:var(--mut);font-size:12px;margin:18px 0}
.sep::before,.sep::after{content:"";height:1px;background:var(--line);flex:1}
.foot{margin-top:34px;text-align:center;color:var(--mut);font-size:13px}
.badge{display:inline-flex;align-items:center;gap:6px;background:rgba(34,211,166,.12);color:var(--acc2);
  border:1px solid rgba(34,211,166,.3);border-radius:999px;padding:4px 12px;font-size:12px;font-weight:700;margin-bottom:14px}
.dot{width:8px;height:8px;border-radius:50%;background:var(--acc2);animation:pulse 1.6s infinite}
@keyframes pulse{0%,100%{opacity:.4}50%{opacity:1}}

/* ── session (viewer / host share) ── */
.session{display:none;position:fixed;inset:0;background:#05070f;flex-direction:column;z-index:50}
.session.on{display:flex}
.bar{display:flex;align-items:center;gap:14px;padding:10px 16px;background:#0b1122;border-bottom:1px solid var(--line)}
.bar .status{display:flex;align-items:center;gap:8px;font-weight:600;font-size:14px}
.bar .status .dot{background:var(--danger)}
.bar .status.live .dot{background:var(--acc2)}
.bar .grow{flex:1}
.bar .tag{color:var(--mut);font-size:13px}
.bar button{border:1px solid var(--line);background:#111a30;color:var(--txt);border-radius:9px;
  padding:8px 13px;font-size:13px;font-weight:600;cursor:pointer}
.bar button.leave{background:var(--danger);border-color:var(--danger);color:#fff}
.bar button.on{background:var(--acc);border-color:var(--acc);color:#fff}
.stage{flex:1;display:grid;place-items:center;overflow:hidden;position:relative;background:#05070f}
#screen{max-width:100%;max-height:100%;cursor:crosshair;background:#000;image-rendering:auto}
.overlay{position:absolute;inset:0;display:grid;place-items:center;text-align:center;color:var(--mut);
  pointer-events:none;padding:20px}
.overlay .card2{background:rgba(11,17,34,.85);border:1px solid var(--line);border-radius:14px;padding:28px 34px;max-width:420px}
.spin{width:34px;height:34px;border:3px solid var(--line);border-top-color:var(--acc);border-radius:50%;
  animation:spin 1s linear infinite;margin:0 auto 14px}
@keyframes spin{to{transform:rotate(360deg)}}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:#111a30;border:1px solid var(--line);
  color:var(--txt);padding:12px 18px;border-radius:12px;box-shadow:var(--shadow);z-index:99;font-size:14px;display:none}
.toast.on{display:block}
.dlrow{display:flex;gap:10px;margin-top:10px}
.dlrow .btn{flex:1}
code.k{background:#0d1428;border:1px solid var(--line);padding:2px 7px;border-radius:6px;font-size:13px}