* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #222;
  color: #123456;
}

.page {
  max-width: 1280px;
  margin: 24px auto;
  padding: 0 16px 24px;
}

.header {
  text-align: center;
  margin-bottom: 16px;
}

.header h1 {
  margin: 0;
  font-size: 32px;
  letter-spacing: 0.08em;
}

.subtitle {
  margin-top: 4px;
  color: #35506b;
  font-size: 14px;
}

.main {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 16px;
}

@media (max-width: 900px) {
  .main {
    grid-template-columns: 1fr;
  }
}

.game-panel {
  background: rgba(255, 255, 255, 0.9);
  border-radius: 10px;
  padding: 16px 16px 20px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

.side-panel {
  background: rgba(255, 255, 255, 0.85);
  border-radius: 10px;
  padding: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
  font-size: 14px;
}

.side-panel h2 {
  margin-top: 0;
}

.side-panel ol {
  padding-left: 20px;
}

.sky {
  position: relative;
  height: 360px;
  border-radius: 10px;
  background-image: url("imgs/background.png");
  background-size: auto 100%;
  background-position: 0 0;
  background-repeat: repeat-x;
  overflow: hidden;
  z-index: 0; /* 建立层叠上下文 */
}

.ground {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 40px;
  background: #e1d8a7;
  box-shadow: 0 -2px 0 rgba(0, 0, 0, 0.1) inset;
  display: none; /* 去掉底部黄色条 */
}

.bird {
  position: absolute;
  width: 110px;
  height: 80px;
  background-image: url("imgs/dragon1.png");
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 10; /* 提高层级，确保在背景和障碍物之上 */
}

.obstacle {
  position: absolute;
  width: 72px;
  height: 100px;
  background-image: url("imgs/rock.png");
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  z-index: 5; /* 障碍物在背景之上，但在飞机之下 */
}

.word {
  font-size: 22px;
  letter-spacing: 0.1em;
  font-weight: 600;
  min-height: 32px;
  text-align: center;
}

.word-over-bird {
  position: absolute;
  top: 18%;
  left: 50%;
  transform: translateX(-50%);
  font-size: 28px;
  color: #ffffff;
  background: rgba(0, 0, 0, 0.6);
  padding: 6px 12px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
  text-shadow: none;
  z-index: 15; /* 确保单词位于所有元素上方 */
}

.input-panel {
  margin-top: 10px;
}

#typingInput {
  width: 100%;
  padding: 10px 12px;
  font-size: 18px;
  border-radius: 6px;
  border: 1px solid #c3d1e6;
  outline: none;
  font-family: "Consolas", "Courier New", monospace;
}

#typingInput:focus {
  border-color: #4a7bff;
  box-shadow: 0 0 0 1px rgba(74, 123, 255, 0.25);
}

.hud {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
  font-size: 13px;
}

.hud-left {
  display: flex;
  gap: 8px;
}

.hud-right {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 260px;
}

.stat {
  background: #f7f9fc;
  border-radius: 6px;
  padding: 6px 8px;
  min-width: 90px;
}

.stat-label {
  display: block;
  color: #666;
  font-size: 12px;
}

.stat-value {
  display: block;
  margin-top: 2px;
  font-weight: 600;
}

.pill {
  padding: 3px 10px;
  border-radius: 999px;
  background: #e1ebff;
  color: #234f9b;
  font-size: 12px;
}

.progress-bar {
  margin-top: 0;
  width: 100%;
  height: 8px;
  border-radius: 999px;
  background: #dde6f3;
  overflow: hidden;
}

.progress-inner {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #4caf50, #8bc34a);
  transition: width 0.15s ease-out;
}

.message {
  min-height: 22px;
  margin-top: 8px;
  font-size: 13px;
  color: #333;
}

.message.ok {
  color: #2e7d32;
}

.message.error {
  color: #c62828;
}

.buttons {
  margin-top: 12px;
  display: flex;
  gap: 8px;
}

.letter {
  display: inline-block;
  padding: 0 1px;
  border-bottom: 2px solid transparent;
}

.letter.correct {
  color: #2e7d32;
  border-bottom-color: #2e7d32;
}

.letter.wrong {
  color: #c62828;
  border-bottom-color: #c62828;
}

button {
  padding: 8px 16px;
  border-radius: 999px;
  border: none;
  background: #3f68ff;
  color: white;
  font-size: 14px;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(63, 104, 255, 0.3);
  transition: transform 0.1s ease, box-shadow 0.1s ease, background 0.1s ease;
}

button.secondary {
  background: #eef2ff;
  color: #334155;
  box-shadow: none;
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  box-shadow: none;
}

button:not(:disabled):hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 12px rgba(63, 104, 255, 0.35);
}

.tip {
  margin-top: 12px;
  font-size: 13px;
  color: #526072;
  line-height: 1.5;
}