:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --secondary: #e2e8f0;
  --text: #1e293b;
  --text-light: #64748b;
  --success: #10b981;
  --radius: 14px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px;
}

.header {
  text-align: center;
  padding: 28px 0 20px;
}

.logo {
  margin: 0;
  font-size: 32px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 2px;
}

.slogan {
  margin: 8px 0 0;
  color: var(--text-light);
  font-size: 15px;
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
  margin-bottom: 16px;
}

.section-title {
  margin: 0 0 12px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

.input-area {
  width: 100%;
  border: 1px solid #cbd5e1;
  border-radius: 10px;
  padding: 12px;
  font-size: 16px;
  line-height: 1.5;
  resize: vertical;
  outline: none;
  transition: border-color 0.2s;
}

.input-area:focus {
  border-color: var(--primary);
}

.input-actions {
  display: flex;
  gap: 10px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.btn {
  border: none;
  border-radius: 10px;
  padding: 10px 18px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s, opacity 0.2s;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn:active {
  transform: scale(0.98);
}

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

.btn-primary:hover {
  background: var(--primary-dark);
}

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

.btn-ghost {
  background: transparent;
  color: var(--primary);
  border: 1px solid #c7d2fe;
}

.btn-small {
  padding: 6px 12px;
  font-size: 13px;
}

.option-row {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.option-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--text-light);
  cursor: pointer;
}

.option-label input {
  width: 16px;
  height: 16px;
  accent-color: var(--primary);
}

.result-header {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.result-header .section-title {
  margin: 0;
  margin-right: auto;
}

.cards-container {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.learn-card {
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 14px;
  background: #fafafa;
}

.card-line {
  margin: 6px 0;
  line-height: 1.6;
}

.card-label {
  display: inline-block;
  min-width: 44px;
  color: var(--text-light);
  font-size: 13px;
  margin-right: 6px;
}

.card-english {
  color: var(--text);
  font-size: 17px;
  font-weight: 600;
}

.card-ipa {
  color: var(--primary);
  font-size: 15px;
  font-family: "Segoe UI", "Arial", sans-serif;
}

.card-yiyin {
  color: #059669;
  font-size: 15px;
  background: #ecfdf5;
  padding: 2px 6px;
  border-radius: 6px;
}

.card-chinese {
  color: #334155;
  font-size: 15px;
  border-bottom: 1px dashed #cbd5e1;
  padding-bottom: 2px;
  cursor: text;
}

.card-chinese:focus {
  outline: none;
  border-bottom-color: var(--primary);
}

.word-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed #e2e8f0;
}

.word-chip {
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 20px;
  padding: 4px 10px;
  font-size: 13px;
}

.word-chip .w {
  color: var(--primary);
  font-weight: 600;
}

.word-chip .y {
  color: #059669;
  margin-left: 4px;
}

.result-actions {
  display: flex;
  gap: 10px;
  margin-top: 16px;
  flex-wrap: wrap;
}

.tips-list {
  margin: 0;
  padding-left: 18px;
  color: var(--text-light);
  font-size: 14px;
  line-height: 1.8;
}

.footer {
  text-align: center;
  padding: 16px 0 24px;
  color: var(--text-light);
  font-size: 13px;
}

.hidden {
  display: none !important;
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
}

.modal-content {
  background: #fff;
  border-radius: var(--radius);
  padding: 24px;
  max-width: 360px;
  width: 100%;
  text-align: center;
}

.modal-content h3 {
  margin: 0 0 10px;
}

.modal-content p {
  color: var(--text-light);
  font-size: 14px;
  margin: 0 0 18px;
}

.modal-content .btn {
  width: 100%;
  margin-bottom: 10px;
}

@media (max-width: 480px) {
  .app {
    padding: 10px;
  }

  .logo {
    font-size: 26px;
  }

  .card {
    padding: 14px;
  }

  .input-actions {
    flex-direction: column;
  }

  .input-actions .btn {
    width: 100%;
  }

  .result-actions .btn {
    width: 100%;
  }
}