:root{
  --bg:#eef5ff;
  --bg2:#fff8f1;
  --text:#172033;
  --muted:#627089;
  --line:rgba(36,72,129,.10);

  --blue:#2563eb;
  --orange:#ff8a1d;

  --white:rgba(255,255,255,.78);
  --shadow:0 18px 45px rgba(23,63,130,.10);
  --radius-xl:24px;
  --radius-lg:18px;
}

*{
  margin:0;
  padding:0;
  box-sizing:border-box;
}

html, body{
  height:100%;
}

body{
  font-family:Arial, Helvetica, sans-serif;
  color:var(--text);
  background:
    radial-gradient(circle at top left, rgba(37,99,235,.10), transparent 22%),
    radial-gradient(circle at top right, rgba(255,138,29,.10), transparent 20%),
    linear-gradient(180deg, var(--bg) 0%, #f3f8ff 48%, var(--bg2) 100%);
}

a{
  text-decoration:none;
  color:inherit;
}

.container{
  width:min(1280px, calc(100% - 24px));
  margin:0 auto;
}

.app-header{
  position:sticky;
  top:0;
  z-index:50;
  background:rgba(255,255,255,.72);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}

.app-header-inner{
  min-height:70px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}

.brand{
  font-size:28px;
  font-weight:800;
  letter-spacing:-.4px;
}

.brand-blue{
  color:var(--blue);
}

.brand-orange{
  color:var(--orange);
}

.app-nav{
  display:flex;
  align-items:center;
  gap:22px;
}

.app-nav a{
  font-size:15px;
  font-weight:700;
  color:var(--muted);
  transition:.2s ease;
}

.app-nav a:hover{
  color:var(--blue);
}

.app-page{
  padding:10px 12px 12px;
  height:calc(100vh - 70px);
}

.iframe-wrap{
  width:min(1400px, 100%);
  height:100%;
  margin:0 auto;
  background:var(--white);
  border:1px solid rgba(255,255,255,.65);
  border-radius:var(--radius-xl);
  overflow:hidden;
  box-shadow:var(--shadow);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
}

.chat-frame{
  width:100%;
  height:100%;
  border:none;
  display:block;
  background:#fff;
}

@media (max-width: 768px){
  .app-header-inner{
    min-height:64px;
    flex-direction:column;
    justify-content:center;
    padding:10px 0;
  }

  .brand{
    font-size:24px;
  }

  .app-nav{
    gap:14px;
    flex-wrap:wrap;
    justify-content:center;
  }

  .app-nav a{
    font-size:14px;
  }

  .app-page{
    height:calc(100vh - 92px);
    padding:8px;
  }

  .iframe-wrap{
    border-radius:18px;
  }
}