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

body {
  background: #f0f4f8;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.screen {
  display: none;
  width: 100%;
  max-width: 1000px;
  background: white;
  border-radius: 24px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.15);
  padding: 30px;
  transition: all 0.3s;
}

.screen.active {
  display: block;
}

/* Login */
.login-container {
  text-align: center;
  padding: 30px 20px;
}

.login-container h1 {
  color: #1a3a5c;
  margin-bottom: 10px;
}

.login-container input {
  width: 80%;
  max-width: 320px;
  padding: 14px 20px;
  border: 2px solid #dce4ec;
  border-radius: 40px;
  font-size: 16px;
  margin: 20px 0 12px;
  outline: none;
  transition: 0.2s;
}

.login-container input:focus {
  border-color: #2a6f97;
}

.login-container button {
  background: #1a3a5c;
  color: white;
  border: none;
  padding: 14px 48px;
  border-radius: 40px;
  font-size: 18px;
  font-weight: bold;
  cursor: pointer;
  transition: 0.2s;
}

.login-container button:hover {
  background: #2a6f97;
  transform: scale(1.02);
}

.error {
  color: #c0392b;
  margin-top: 10px;
  min-height: 24px;
}

/* Header */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  border-bottom: 2px solid #ecf0f1;
  padding-bottom: 16px;
  margin-bottom: 20px;
}

.header h2 {
  color: #1a3a5c;
}

.badge {
  background: #2a6f97;
  color: white;
  padding: 6px 18px;
  border-radius: 30px;
  font-size: 14px;
  margin-right: 12px;
}

.logout-btn {
  background: #e74c3c;
  color: white;
  border: none;
  padding: 8px 20px;
  border-radius: 30px;
  cursor: pointer;
  font-weight: bold;
}

.logout-btn:hover {
  background: #c0392b;
}

/* Filters */
.filter-section {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.filter-btn {
  background: #ecf0f1;
  border: none;
  padding: 8px 20px;
  border-radius: 40px;
  font-size: 14px;
  cursor: pointer;
  transition: 0.2s;
  font-weight: 500;
}

.filter-btn:hover {
  background: #d5dbe2;
}

.filter-btn.active {
  background: #1a3a5c;
  color: white;
}

.category-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.cat-btn {
  background: #ecf0f1;
  border: none;
  padding: 6px 16px;
  border-radius: 40px;
  font-size: 13px;
  cursor: pointer;
  transition: 0.2s;
}

.cat-btn:hover {
  background: #d5dbe2;
}

.cat-btn.active {
  background: #e67e22;
  color: white;
}

/* Question List */
.question-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.question-card {
  background: #f8faff;
  border-left: 6px solid #2a6f97;
  padding: 20px 24px;
  border-radius: 16px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  transition: 0.2s;
}

.question-card:hover {
  background: #f0f6fe;
}

.question-card .type {
  font-size: 13px;
  font-weight: bold;
  color: #2a6f97;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
}

.question-card .batch-tag {
  font-size: 12px;
  background: #1a3a5c;
  color: white;
  padding: 2px 14px;
  border-radius: 30px;
  display: inline-block;
  margin-bottom: 8px;
}

.question-card .category-tag {
  font-size: 12px;
  background: #e67e22;
  color: white;
  padding: 2px 14px;
  border-radius: 30px;
  display: inline-block;
  margin-bottom: 8px;
  margin-left: 6px;
}

.question-card .en {
  font-size: 18px;
  font-weight: 600;
  color: #1e2a3a;
}

.question-card .my {
  font-size: 16px;
  color: #2c3e50;
  margin-top: 6px;
  padding: 8px 14px;
  background: #eef3f9;
  border-radius: 12px;
  border-left: 4px solid #2a6f97;
}

.sub-details {
  margin-top: 10px;
  padding-left: 16px;
  color: #34495e;
  font-size: 15px;
}

.sub-details li {
  list-style: disc;
  margin-left: 20px;
  line-height: 1.8;
}

/* Answer Key Styles */
.answer-section {
  margin-top: 14px;
  padding: 16px 18px;
  background: #e8f5e9;
  border-radius: 12px;
  border-left: 5px solid #2e7d32;
}

.answer-section .answer-label {
  font-weight: bold;
  color: #2e7d32;
  font-size: 14px;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.answer-section .answer-label .toggle-btn {
  background: #2e7d32;
  color: white;
  border: none;
  padding: 3px 14px;
  border-radius: 30px;
  font-size: 12px;
  cursor: pointer;
  transition: 0.2s;
}

.answer-section .answer-label .toggle-btn:hover {
  background: #1b5e20;
}

.answer-section .answer-content {
  color: #1e3a2a;
  font-size: 15px;
  line-height: 1.7;
  display: none;
}

.answer-section .answer-content.show {
  display: block;
}

.answer-section .answer-content .en-answer {
  margin-bottom: 8px;
  padding: 8px 12px;
  background: white;
  border-radius: 8px;
}

.answer-section .answer-content .my-answer {
  padding: 8px 12px;
  background: #f1f8e9;
  border-radius: 8px;
  border-left: 3px solid #2e7d32;
}

/* Responsive */
@media (max-width: 600px) {
  .screen {
    padding: 16px;
  }
  .question-card .en {
    font-size: 15px;
  }
  .filter-btn, .cat-btn {
    padding: 5px 12px;
    font-size: 12px;
  }
  .answer-section {
    padding: 12px 14px;
  }
}