/* Mid-section */
.mid-section {
  width: 100%;
  padding: 20px;
  background-color: #ffffff;
  overflow-y: auto;
  box-shadow: inset 0px 4px 10px rgba(0, 0, 0, 0.05); /* Subtle shadow */
}

.mid-section h1 {
  color: rgb(34, 139, 230);
  font-size: 50px;
  text-align: center;
  border-bottom: 2px solid rgb(230, 230, 230);
}

/* Styling for unit line */
.unit-line {
  text-align: center;
  margin: 30px 0;
}

.unit-name {
  display: flex;
  align-items: center;
  font-size: 26px;
  font-weight: bold;
  color: rgb(161, 0, 182);
  margin-top: 100px;
}

.unit-name::before {
  content: "";
  background: linear-gradient(to right, rgb(161, 0, 182), rgba(0, 0, 0, 0));
  width: 10%;
  height: 60px;
}

.unit-levels {
  display: flex;
  flex-direction: column;
  gap: 100px;
  align-items: center;
}

.level {
  display: flex;
  align-items: center;
  flex-direction: column;
}

/* Level button styles */
.level-btn {
  width: 70px;
  height: 70px;
  border-radius: 50%;
  background-size: contain;
  background-position: center;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.level-btn.lock-level::before {
  content: "🔒";
}

.level-btn.unlock-level::before {
  content: "✓";
}

.level-btn.lock-level {
  background-color: rgb(220, 220, 220);
  font-size: 30px;
  text-align: center;
  line-height: 70px;
}

.level-btn.unlock-level {
  background-color: rgb(161, 0, 182);
  color: white;
  font-weight: 700;
  font-size: 30px;
  text-align: center;
  line-height: 70px;
}

.level-btn:hover {
  transform: scale(1.1);
}

.level:nth-child(odd) {
  margin-left: -50px;
}

.level:nth-child(even) {
  margin-left: 50px;
}

/* Intro level */
.intro-level {
  /* position: absolute;
    right: 30%; */
  background-color: #f1f8e9; /* Light green background */
  padding: 20px 25px;
  display: none;
  flex-direction: column;
  align-items: center;
  border-radius: 12px;
  box-shadow: 0px 6px 15px rgba(0, 0, 0, 0.05);
  z-index: 10;
  width: 320px;
  transition: transform 0.3s ease;
}

.intro-level.show {
  transform: translateY(10%) scale(1);
}

/* Start button */
.start-btn {
  background-color: #ffffff;
  color: #388e3c; /* Dark green text */
  width: 80%;
  height: 45px;
  line-height: 45px;
  text-align: center;
  border-radius: 25px;
  font-weight: 600;
  margin-top: 15px;
  border: 1px solid #c8e6c9; /* Light green border */
  transition: background-color 0.3s, color 0.3s;
  text-decoration: none;
}

.start-btn:hover {
  background-color: #c8e6c9; /* Soft green hover effect */
  color: #ffffff; /* White text on hover */
}

/* Additional styling for intro text */
.level-name {
  color: #388e3c; /* Dark green for consistency */
  font-size: 18px;
  font-weight: 500;
}

.right-section {
  display: flex;
  flex-direction: column;
}

.right-section h1 {
  color: rgb(34, 139, 230); /* Xanh dương nhã nhặn */
  font-size: 25px;
  text-align: center;
}

.identity {
  background-color: rgba(52, 152, 219, 0.8); /* Màu xanh biển trong suốt */
  width: 100%;
  height: inherit;
  padding: 15px;
  color: white;
  font-size: 20px;
  font-weight: 500;
  border-radius: 8px; /* Thêm bo góc mềm mại */
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2); /* Hiệu ứng đổ bóng nhẹ */
  margin-top: 30px;
  text-align: center; /* Căn giữa nội dung */
}