* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #0f1221;
  color: #f4f6fb;
}

.topbar {
  padding: 1.2rem 1rem;
  background: #171b31;
  border-bottom: 1px solid #2a3158;
  text-align: center;
}

.topbar h1 {
  margin: 0;
}

.container {
  max-width: 900px;
  margin: 1rem auto 2rem;
  padding: 0 1rem;
}

.stats {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.chip {
  background: #1f2748;
  border: 1px solid #33407a;
  padding: 0.45rem 0.65rem;
  border-radius: 999px;
  font-size: 0.9rem;
}

.panel {
  background: #181d36;
  border: 1px solid #2b3463;
  border-radius: 14px;
  padding: 1rem;
  margin-bottom: 1rem;
}

.panel select,
.panel textarea {
  width: 100%;
  margin-top: 0.5rem;
  margin-bottom: 0.8rem;
  background: #0f1638;
  color: #f4f6fb;
  border: 1px solid #374a86;
  border-radius: 8px;
  padding: 0.65rem;
}

.nav-panel {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tab {
  background: #283469;
  border: 0;
  color: #fff;
  padding: 0.6rem 0.8rem;
  border-radius: 8px;
  cursor: pointer;
}

.tab.active {
  background: #5172ff;
}

.flashcard {
  background: #0f1638;
  border: 1px solid #2f438b;
  border-radius: 12px;
  padding: 1.2rem;
  min-height: 180px;
  margin-bottom: 0.9rem;
}

.controls {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

button {
  background: #3f57c2;
  border: 0;
  color: #fff;
  padding: 0.6rem 0.8rem;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  background: #4f67db;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.choices {
  display: grid;
  gap: 0.6rem;
  margin: 0.8rem 0;
}

.choice-btn {
  width: 100%;
  text-align: left;
  background: #243056;
  border: 1px solid #374a86;
}

.choice-btn.correct {
  background: #1f7a45;
}

.choice-btn.wrong {
  background: #982e3b;
}

.feedback {
  min-height: 1.2rem;
  color: #b9c8ff;
}

.note {
  color: #b8c3ef;
}

.awa-topic-box {
  border: 1px solid #2f438b;
  border-radius: 10px;
  background: #0f1638;
  padding: 0.8rem;
  line-height: 1.4;
  margin-bottom: 0.8rem;
}

.awa-result {
  background: #0f1638;
  border: 1px solid #2f438b;
  border-radius: 10px;
  padding: 0.8rem;
  margin-top: 0.5rem;
}

.word-list {
  max-height: 300px;
  overflow: auto;
  padding-left: 1.2rem;
  margin: 0.4rem 0 0;
}

.word-list li {
  margin-bottom: 0.4rem;
}

.hidden {
  display: none;
}

footer {
  text-align: center;
  color: #95a0d3;
  padding-bottom: 1rem;
}