:root {
  --bg-top: #fff8e7;
  --bg-bottom: #e6f7ff;
  --primary: #ff9aa2;
  --primary-dark: #ff7582;
  --secondary: #a0e7e5;
  --accent: #ffdac1;
  --accent2: #b5ead7;
  --text: #4a4a4a;
  --text-light: #777;
  --success: #7fdb7f;
  --error: #ff9aa2;
  --card: #ffffff;
  --shadow: rgba(74, 74, 74, 0.12);
  --radius: 24px;
  --radius-sm: 14px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 100%);
  background-attachment: fixed;
}

/* Animal decorations */
.animal {
  position: fixed;
  z-index: 0;
  pointer-events: none;
}

.animal-panda {
  width: 90px;
  height: 90px;
  background: #fff;
  border-radius: 50%;
  top: 30px;
  left: 30px;
  box-shadow: inset -6px -6px 0 rgba(0,0,0,0.05), 0 8px 20px var(--shadow);
}
.animal-panda::before, .animal-panda::after {
  content: "";
  position: absolute;
  width: 26px;
  height: 26px;
  background: #333;
  border-radius: 50%;
  top: 14px;
}
.animal-panda::before { left: 10px; }
.animal-panda::after { right: 10px; }
.animal-panda .face {
  position: absolute;
  width: 10px;
  height: 10px;
  background: #333;
  border-radius: 50%;
  top: 42px;
  left: 32px;
  box-shadow: 16px 0 0 #333;
}
.animal-panda .face::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 10px;
  border-radius: 0 0 16px 16px;
  background: #333;
  top: 16px;
  left: 5px;
}

.animal-bunny {
  width: 70px;
  height: 70px;
  background: #fff;
  border-radius: 50%;
  bottom: 40px;
  right: 40px;
  box-shadow: 0 8px 20px var(--shadow);
}
.animal-bunny::before, .animal-bunny::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 42px;
  background: #fff;
  border-radius: 50%;
  top: -24px;
}
.animal-bunny::before { left: 16px; transform: rotate(-10deg); }
.animal-bunny::after { right: 16px; transform: rotate(10deg); }
.animal-bunny .face {
  position: absolute;
  width: 8px;
  height: 8px;
  background: #333;
  border-radius: 50%;
  top: 26px;
  left: 22px;
  box-shadow: 18px 0 0 #333;
}
.animal-bunny .face::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 6px;
  border-radius: 0 0 10px 10px;
  background: #ff9aa2;
  top: 14px;
  left: 8px;
}

.animal-bird {
  width: 60px;
  height: 60px;
  background: #ffdac1;
  border-radius: 50%;
  top: 60px;
  right: 60px;
  box-shadow: 0 6px 16px var(--shadow);
}
.animal-bird::before, .animal-bird::after {
  content: "";
  position: absolute;
  width: 22px;
  height: 14px;
  background: #ffdac1;
  border-radius: 50%;
  top: 10px;
}
.animal-bird::before { left: -8px; transform: rotate(-20deg); }
.animal-bird::after { right: -8px; transform: rotate(20deg); }
.animal-bird .face {
  position: absolute;
  width: 6px;
  height: 6px;
  background: #333;
  border-radius: 50%;
  top: 22px;
  left: 18px;
  box-shadow: 14px 0 0 #333;
}
.animal-bird .beak {
  position: absolute;
  width: 0;
  height: 0;
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
  border-top: 10px solid #ff9aa2;
  top: 32px;
  left: 22px;
}

.animal-cat {
  width: 60px;
  height: 60px;
  background: #b5ead7;
  border-radius: 50%;
  bottom: 80px;
  left: 60px;
  box-shadow: 0 6px 16px var(--shadow);
}
.animal-cat::before, .animal-cat::after {
  content: "";
  position: absolute;
  width: 0;
  height: 0;
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-bottom: 18px solid #b5ead7;
  top: -10px;
}
.animal-cat::before { left: 6px; transform: rotate(-10deg); }
.animal-cat::after { right: 6px; transform: rotate(10deg); }
.animal-cat .face {
  position: absolute;
  width: 7px;
  height: 7px;
  background: #333;
  border-radius: 50%;
  top: 22px;
  left: 16px;
  box-shadow: 20px 0 0 #333;
}
.animal-cat .face::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 7px;
  border-radius: 0 0 10px 10px;
  background: #ff9aa2;
  top: 14px;
  left: 8px;
}

/* Layout */
.container {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 20px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header {
  text-align: center;
  margin-bottom: 30px;
}

header h1 {
  font-size: 2.8rem;
  margin: 0 0 10px;
  color: var(--primary-dark);
  text-shadow: 2px 2px 0 #fff;
}

header p {
  font-size: 1.2rem;
  color: var(--text-light);
  margin: 0;
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: 0 10px 30px var(--shadow);
  width: 100%;
  max-width: 720px;
}

/* Home page */
.level-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
  margin-top: 10px;
}

.level-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 30px 20px;
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  background: var(--accent);
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 6px 0 rgba(0,0,0,0.08);
  cursor: pointer;
}

.level-card:nth-child(2) { background: var(--secondary); }
.level-card:nth-child(3) { background: #ffd6e8; }

.level-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 0 rgba(0,0,0,0.08);
}

.level-card .icon {
  font-size: 3rem;
  margin-bottom: 12px;
}

.level-card h2 {
  margin: 0 0 8px;
  font-size: 1.5rem;
}

.level-card p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-light);
  text-align: center;
}

.nav-bar {
  margin-top: 24px;
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border: none;
  border-radius: 50px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 5px 0 rgba(0,0,0,0.1);
}

.btn:active {
  transform: translateY(3px);
  box-shadow: 0 2px 0 rgba(0,0,0,0.1);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-secondary {
  background: var(--accent2);
  color: var(--text);
}

.btn-danger {
  background: #ffb3b3;
  color: #fff;
}

/* Practice page */
.practice-header {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  font-size: 1.1rem;
  color: var(--text-light);
}

.progress-bar {
  flex: 1;
  height: 14px;
  background: #eee;
  border-radius: 10px;
  margin: 0 16px;
  overflow: hidden;
}

#timer-display {
  font-variant-numeric: tabular-nums;
  margin-right: 12px;
  color: var(--primary-dark);
  font-weight: 600;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--secondary), var(--accent2));
  border-radius: 10px;
  transition: width 0.3s ease;
}

.hanzi-display {
  font-size: 6rem;
  text-align: center;
  margin: 10px 0 20px;
  color: var(--text);
  min-height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  letter-spacing: 0.15em;
}

.pinyin-input {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.pinyin-letter {
  width: 44px;
  height: 54px;
  border: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text);
  background: #fff;
  text-transform: lowercase;
  transition: all 0.15s;
}

.pinyin-letter.filled {
  border-color: var(--accent2);
  background: #f0fffb;
  color: var(--primary-dark);
}

.pinyin-letter.current {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(255,154,162,0.25);
  animation: pulse 1.2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.hint-box {
  text-align: center;
  min-height: 56px;
  margin-bottom: 20px;
}

.hint-text {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 50px;
  font-size: 1.1rem;
  background: var(--error);
  color: #fff;
  opacity: 0;
  transform: translateY(-10px);
  transition: all 0.3s;
}

.hint-text.show {
  opacity: 1;
  transform: translateY(0);
}

.hint-help {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-top: 8px;
}

/* Virtual keyboard */
.keyboard {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
  margin-top: 10px;
}

.keyboard-row {
  display: flex;
  gap: 6px;
  justify-content: center;
  flex-wrap: wrap;
}

.key {
  width: 38px;
  height: 44px;
  background: #fff;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  box-shadow: 0 3px 0 #e0e0e0;
  transition: all 0.1s;
  text-transform: lowercase;
}

.key.target {
  background: var(--primary);
  border-color: var(--primary-dark);
  color: #fff;
  box-shadow: 0 3px 0 var(--primary-dark);
}

.key.pressed {
  transform: translateY(3px);
  box-shadow: 0 0 0 #e0e0e0;
}

.key.wide {
  width: 70px;
}

/* Feedback */
.feedback-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s;
}

.feedback-overlay.show {
  opacity: 1;
}

.feedback-circle {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  font-weight: 800;
  color: #fff;
  transform: scale(0.5);
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.feedback-overlay.show .feedback-circle {
  transform: scale(1);
}

.feedback-circle.success {
  background: var(--success);
  box-shadow: 0 0 40px rgba(127,219,127,0.6);
}

.feedback-circle.error {
  background: var(--error);
  box-shadow: 0 0 40px rgba(255,154,162,0.6);
}

.shake {
  animation: shake 0.4s ease-in-out;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}

/* Result page */
.result-card {
  text-align: center;
}

.result-score {
  font-size: 4rem;
  font-weight: 800;
  color: var(--primary-dark);
  margin: 10px 0;
}

.result-stats {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.result-stat-box {
  background: #f8f9fa;
  border-radius: var(--radius-sm);
  padding: 18px 28px;
  min-width: 120px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.result-stat-label {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-bottom: 6px;
}

.result-stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary-dark);
}

.result-message {
  font-size: 1.3rem;
  color: var(--text-light);
  margin-bottom: 24px;
}

.star-row {
  font-size: 2.5rem;
  margin-bottom: 24px;
  letter-spacing: 0.2em;
}

/* Stats page */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-box {
  background: #f8f9fa;
  border-radius: var(--radius-sm);
  padding: 20px;
  text-align: center;
}

.stat-box h3 {
  margin: 0 0 8px;
  font-size: 0.95rem;
  color: var(--text-light);
}

.stat-box .value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary-dark);
}

.stats-section {
  margin-bottom: 24px;
}

.stats-section h2 {
  font-size: 1.2rem;
  margin: 0 0 12px;
  color: var(--text);
}

.word-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.word-tag {
  background: var(--accent);
  padding: 8px 14px;
  border-radius: 50px;
  font-size: 0.95rem;
}

.word-tag.weak {
  background: var(--error);
  color: #fff;
}

.word-tag.strong {
  background: var(--accent2);
}

.empty-state {
  color: var(--text-light);
  font-style: italic;
}

/* Utilities */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mt-20 {
  margin-top: 20px;
}

/* Responsive */
@media (max-width: 640px) {
  header h1 { font-size: 2.2rem; }
  .hanzi-display { font-size: 4rem; min-height: 100px; }
  .pinyin-letter { width: 36px; height: 46px; font-size: 1.3rem; }
  .key { width: 32px; height: 40px; font-size: 0.85rem; }
  .animal { transform: scale(0.75); }
}