body {
  margin: 0;
  font-family: Arial;
  background: #eef2f3;

  display: flex;
  justify-content: center;   /* horizontal */
  align-items: center;       /* vertical */
  height: 100vh;             /* full layar */
}

.screen { display: none; }
.screen.active { display: block; }

input {
  display: block;
  margin: 10px auto;
  padding: 10px;
}

button {
  padding: 10px 20px;
  margin-top: 10px;
  cursor: pointer;
}

.container {
  display: grid;
  gap: 15px;
  justify-content: center;
  margin-top: 20px;
}

.btn {
  width: 100px;
  height: 100px;
  border-radius: 20px;
  background: white;
  border: 4px solid;
  cursor: pointer;
  transition: all 0.2s ease;
}

/* warna border */
.btn[data-color="red"] { border-color: #e74c3c; }
.btn[data-color="blue"] { border-color: #3498db; }
.btn[data-color="green"] { border-color: #2ecc71; }
.btn[data-color="yellow"] { border-color: #f1c40f; }
.btn[data-color="purple"] { border-color: #9b59b6; }
.btn[data-color="orange"] { border-color: #e67e22; }

/* saat aktif */
.btn.active[data-color="red"] { background: #e74c3c; }
.btn.active[data-color="blue"] { background: #3498db; }
.btn.active[data-color="green"] { background: #2ecc71; }
.btn.active[data-color="yellow"] { background: #f1c40f; }
.btn.active[data-color="purple"] { background: #9b59b6; }
.btn.active[data-color="orange"] { background: #e67e22; }

.btn.active {
  box-shadow: 0 0 15px rgba(0,0,0,0.2);
  transform: scale(1.1);
}

/* efek klik */
.btn.correct {
  background: lightgreen !important;
}

.btn.wrong {
  background: #ff6b6b !important;
}

.timer {
  width: 300px;
  height: 20px;
  background: #ddd;
  margin: 20px auto;
  border-radius: 10px;
  overflow: hidden;
}

#timer-bar {
  height: 100%;
  width: 100%;
  background: linear-gradient(to right, green, orange, red);
}

#menu {
  max-width: 320px;
  margin: auto;
  padding: 20px;
  background: white;
  border-radius: 15px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.form-group {
  margin-bottom: 15px;
  text-align: left;
}

.form-group label {
  display: block;
  margin-bottom: 5px;
  font-size: 14px;
}

.form-group input {
  width: 100%;
  padding: 8px;
  border-radius: 8px;
  border: 1px solid #ccc;
}

.checkbox {
  text-align: center;
}

#startBtn {
  width: 100%;
  margin-top: 15px;
  padding: 10px;
  border-radius: 10px;
  border: none;
  background: #333;
  color: white;
  font-size: 16px;
}

.result-card {
  background: white;
  padding: 25px;
  border-radius: 20px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  width: 300px;
}

.result-card h1 {
  margin-bottom: 20px;
}

.result-item {
  display: flex;
  justify-content: space-between;
  margin: 10px 0;
  font-size: 18px;
}

.result-item strong {
  font-size: 20px;
}

.result-message {
  margin-top: 20px;
  font-size: 20px;
  font-weight: bold;
}

.result-card button {
  margin-top: 20px;
  width: 100%;
  padding: 10px;
  border-radius: 10px;
  border: none;
  background: #333;
  color: white;
  font-size: 16px;
  cursor: pointer;
}