* { margin: 0; padding: 0; box-sizing: border-box; user-select: none; }
body { background: #000; font-family: Arial, sans-serif; overflow: hidden; }

/* partículas */
#particles {
  position: fixed; top:0; left:0; width:100%; height:100%; z-index: -1;
}

#panel {
  position: absolute; top:50%; left:50%; transform: translate(-50%, -50%);
  width: 90%; max-width: 850px; height: 520px;
  border: 2px solid #ff002b; box-shadow: 0 0 20px #ff002b;
  background: rgba(0,0,0,0.85); border-radius: 10px;
  display: flex; flex-direction: column; justify-content: flex-start;
}

#login {
  text-align: center; padding: 40px;
}
#login h1 { color: #fff; text-shadow: 0 0 10px #ff002b; }
#login hr { border: none; border-top: 1px solid #ff002b; margin: 15px 0; }
#login input {
  width: 80%; padding: 10px; margin-top: 10px;
  border: 1px solid #ff002b; border-radius: 5px;
  background: #111; color: #fff; outline: none;
}
#login button {
  margin-top: 15px; padding: 10px 25px; background: #ff002b;
  border: none; border-radius: 5px; color: #fff;
  cursor: pointer; box-shadow: 0 0 10px #ff002b;
}
#loginError { color: red; margin-top: 10px; }

.hidden { display: none; }

header {
  text-align: center; padding: 10px;
  border-bottom: 1px solid #ff002b; color: #fff;
  text-shadow: 0 0 10px #ff002b;
}

.panel-body {
  display: flex; height: 100%;
}
nav {
  width: 150px; display: flex; flex-direction: column; border-right: 1px solid #ff002b;
}
nav button {
  background: transparent; border: none; color: #fff; padding: 15px;
  text-align: left; cursor: pointer; font-size: 16px;
}
nav button.active { background: #ff002b44; text-shadow: 0 0 5px #ff002b; }

.divider { width: 1px; background: #ff002b; }

.tab-content {
  flex: 1; padding: 20px; color: #fff; display: none;
  overflow-y: auto;
}
.tab-content.active { display: block; }

label {
  display: flex; align-items: center; margin: 10px 0;
  font-size: 16px;
}
input[type=checkbox] { margin-right: 10px; transform: scale(1.2); }

.fov { margin: 20px 0; }
#fovRange { width: 100%; }
button {
  display: block; margin: 15px 0; padding: 10px;
  width: 100%; background: #ff002b; border: none;
  border-radius: 5px; color: #fff; cursor: pointer;
  box-shadow: 0 0 10px #ff002b;
}
button:disabled { background: #444; box-shadow: none; cursor: not-allowed; }

@media(max-width:600px){
  #panel { height: 500px; }
  nav { width: 120px; }
}