body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background: linear-gradient(to right, #eef2f7, #f8fafc);
  display: flex;
  justify-content: center;
  padding-top: 60px;
}

#app {
  text-align: center;
  width: 95%;
  max-width: 650px;
  background: white;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

h2 {
  margin-bottom: 20px;
  color: #222;
}

#login {
  margin-bottom: 20px;
}

#username {
  padding: 10px;
  width: 220px;
  border: 1px solid #ccc;
  border-radius: 6px;
  outline: none;
}

#username:focus {
  border-color: #4a90e2;
}

button {
  padding: 10px 16px;
  margin-left: 10px;
  border: none;
  border-radius: 6px;
  background: #4a90e2;
  color: white;
  cursor: pointer;
  transition: 0.2s;
}

button:hover {
  background: #357abd;
}

/* Badge */
#topbar {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 10px;
}

#userBadge {
  background: #e6f0ff;
  color: #2c5aa0;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 13px;
}

/* Grid */
#grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(18px, 1fr));
  gap: 6px;
  margin-top: 20px;
}

#grid input {
  width: 18px;
  height: 18px;
  cursor: pointer;
  transition: 0.15s;
}

#grid input:hover {
  transform: scale(1.2);
}

/* Loading */
#loading {
  display: none;
  margin-top: 20px;
  color: #666;
}
#toast {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: red;
  color: white;
  padding: 10px 15px;
  display: none;
  font-weight: bold;
}
#toast.show {
  opacity: 1;
  transform: translateY(0);
}