/* Reset defaults */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: #f0f0f5;
  line-height: 1.6;
}

/* Header */
header {
  text-align: center;
  padding: 15px 0;
  background: linear-gradient(90deg, #4CAF50, #2E8B57);
  color: white;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

header h1 {
  font-size: 20px;
  font-weight: 500;
  letter-spacing: 1px;
}

/* Navbar */
nav {
  background-color: #333;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

nav ul.menu {
  display: flex;
  justify-content: center;
  list-style: none;
  flex-wrap: wrap;
}

nav ul.menu li {
  margin: 8px 12px;
}

nav ul.menu li a {
  text-decoration: none;
  color: white;
  padding: 10px 18px;
  display: block;
  border-radius: 8px;
  transition: all 0.3s ease;
  font-size: 14px;
}

nav ul.menu li a:hover {
  background-color: #4CAF50;
  transform: scale(1.05);
}

/* Hero section */
.hero {
  text-align: center;
  padding: 40px 20px;
  background-color: #e6f2ff;
  margin-top: 20px;
  border-radius: 10px;
  width: 90%;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.hero h2 {
  font-size: 24px;
  color: #333;
  margin-bottom: 15px;
}

.hero p {
  font-size: 16px;
  color: #555;
}

/* Exam Controls */
.exam-controls {
  margin: 20px auto;
  padding: 20px;
  background: #fff;
  border-radius: 10px;
  width: 90%;
  max-width: 600px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.control-row {
  display: flex;
  align-items: center;
  margin-bottom: 15px;
  gap: 10px;
}

.control-row label {
  flex: 1;
  font-size: 14px;
  font-weight: 500;
  color: #333;
}

.control-row input {
  flex: 2;
  padding: 8px;
  border: 1px solid #bbb;
  border-radius: 6px;
  font-size: 14px;
}

.warning {
  color: #f44336;
  font-size: 14px;
  margin-top: 10px;
  text-align: center;
}

/* Selected words box */
.selected-box {
  margin: 30px auto;
  padding: 20px;
  background: #fff;
  border-radius: 10px;
  width: 90%;
  max-width: 600px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  text-align: center;
}

.selected-box h3 {
  font-size: 18px;
  margin-bottom: 10px;
  color: #333;
}

#selected-list {
  font-size: 14px;
  color: #555;
  margin-bottom: 15px;
}

/* Exam Question List */
.exam-container {
  margin: 30px auto;
  padding: 20px;
  background: #fff;
  border-radius: 10px;
  width: 90%;
  max-width: 800px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.exam-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 15px;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 8px;
  background: #fafafa;
}

.exam-item .word {
  font-weight: 600;
  color: #333;
  flex: 1;
  margin-right: 15px;
}

.exam-item .answer-input {
  flex: 2;
  padding: 8px;
  border: 1px solid #bbb;
  border-radius: 6px;
  font-size: 14px;
}

.exam-item .translation {
  flex: 1;
  margin-left: 15px;
  font-style: italic;
  color: #666;
}

.hidden {
  display: none;
}

/* Buttons */
.button-container {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 30px;
  flex-wrap: wrap;
}

.btn {
  text-decoration: none;
  padding: 12px 25px;
  background-color: #4CAF50;
  color: white;
  font-weight: 500;
  border-radius: 8px;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background-color: #45a049;
  transform: scale(1.05);
}

/* Answer feedback */
.correct {
  border-color: #4CAF50;
  background-color: #e6ffe6;
}

.wrong {
  border-color: #f44336;
  background-color: #ffe6e6;
}

/* Responsive */
@media (max-width: 600px) {
  nav ul.menu {
    flex-direction: column;
    align-items: center;
  }

  nav ul.menu li {
    margin: 5px 0;
  }

  .hero h2 {
    font-size: 20px;
  }

  .hero p {
    font-size: 14px;
  }

  .exam-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .exam-item .answer-input {
    width: 100%;
    margin-top: 8px;
  }

  .exam-item .translation {
    margin-left: 0;
    margin-top: 6px;
  }
}