* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  background: #f2f5fb;
  color: #1f2937;
}

.container {
  max-width: 900px;
  margin: 30px auto;
  padding: 0 16px;
}

.top h1 {
  margin: 0 0 8px;
  font-size: 28px;
}

.welcome {
  margin: 0 0 18px;
  font-size: 32px;
}

.meta {
  display: flex;
  gap: 12px;
  align-items: center;
  color: #4b5563;
}

.tag {
  padding: 3px 10px;
  border-radius: 999px;
  background: #dbeafe;
  color: #1d4ed8;
  font-size: 13px;
}

.card {
  margin-top: 16px;
  background: #fff;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}

.question {
  font-size: 20px;
  line-height: 1.65;
  margin: 0 0 16px;
}

.options {
  display: grid;
  gap: 10px;
}

.option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  border: 1px solid #d1d5db;
  border-radius: 10px;
  padding: 10px 12px;
  cursor: pointer;
}

.option:hover {
  border-color: #93c5fd;
  background: #eff6ff;
}

.option input {
  margin-top: 3px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.btn {
  border: 1px solid #d1d5db;
  background: #fff;
  color: #111827;
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn.primary {
  background: #2563eb;
  border-color: #2563eb;
  color: #fff;
}

.btn.warn {
  border-color: #f59e0b;
  color: #b45309;
}

.result {
  margin-top: 16px;
  border-radius: 10px;
  padding: 12px 14px;
  line-height: 1.7;
}

.result.ok {
  background: #ecfdf5;
  border: 1px solid #86efac;
  color: #166534;
}

.result.bad {
  background: #fef2f2;
  border: 1px solid #fca5a5;
  color: #991b1b;
}

.answer-line {
  color: #dc2626;
  font-weight: 700;
  background: #fef08a;
  display: inline-block;
  padding: 1px 6px;
  border-radius: 4px;
}

.hidden {
  display: none;
}

.settings-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 12px;
}

.settings-row label {
  color: #111827;
  font-weight: 600;
}

.settings-row select,
.settings-row input {
  min-width: 220px;
  padding: 7px 10px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font-size: 14px;
}

.panel {
  position: fixed;
  top: 0;
  right: 0;
  width: min(480px, 100%);
  height: 100vh;
  background: #ffffff;
  border-left: 1px solid #e5e7eb;
  box-shadow: -8px 0 20px rgba(15, 23, 42, 0.12);
  padding: 18px 16px;
  overflow: auto;
  z-index: 50;
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-head h2 {
  margin: 0;
}

.panel-actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
}

.hint {
  color: #4b5563;
  margin-top: 12px;
}

.wrong-list {
  margin-top: 10px;
  display: grid;
  gap: 10px;
}

.wrong-item {
  border: 1px solid #fca5a5;
  background: #fff7ed;
  border-radius: 8px;
  padding: 10px;
}

.wrong-item .meta-line {
  color: #7c2d12;
  font-size: 13px;
  margin-top: 6px;
}