:root {
  color-scheme: light;
  --bg: #f6f8f7;
  --surface: #ffffff;
  --surface-soft: #eef6f3;
  --ink: #14211f;
  --muted: #66736f;
  --line: #dce6e2;
  --teal: #0f8b75;
  --teal-dark: #086959;
  --amber: #d8891c;
  --red: #c8493d;
  --green: #198754;
  --shadow: 0 18px 50px rgba(20, 33, 31, 0.08);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
  letter-spacing: 0;
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 22px 0 38px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 0 16px;
}

.app-label {
  margin: 0 0 6px;
  color: var(--teal-dark);
  font-size: 14px;
  font-weight: 700;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(26px, 4vw, 42px);
  line-height: 1.08;
}

h2 {
  font-size: 24px;
  line-height: 1.25;
}

h3 {
  font-size: 18px;
  line-height: 1.35;
}

.primary-action,
.ghost-action,
.danger-action,
.nav-tab,
.option,
.chip,
.small-action {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  min-height: 42px;
  padding: 10px 14px;
  font-weight: 700;
}

.primary-action {
  background: var(--teal);
  border-color: var(--teal);
  color: white;
  box-shadow: 0 12px 26px rgba(15, 139, 117, 0.2);
}

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

.danger-action {
  color: var(--red);
  border-color: rgba(200, 73, 61, 0.35);
}

.small-action {
  min-height: 34px;
  padding: 7px 10px;
  font-size: 13px;
}

.nav-tabs {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 10px 0 14px;
  background: linear-gradient(var(--bg) 72%, rgba(246, 248, 247, 0));
}

.nav-tab {
  white-space: nowrap;
  color: var(--muted);
}

.nav-tab.is-active {
  background: var(--ink);
  border-color: var(--ink);
  color: white;
}

.main-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 18px;
  align-items: start;
}

.panel,
.question-panel,
.side-panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.panel,
.question-panel {
  padding: 22px;
}

.side-panel {
  padding: 18px;
}

.full-width {
  grid-column: 1 / -1;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}

.metric {
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.metric strong {
  display: block;
  margin-top: 6px;
  font-size: 28px;
}

.metric span,
.muted {
  color: var(--muted);
}

.toolbar,
.actions,
.filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.toolbar {
  justify-content: space-between;
  margin-bottom: 16px;
}

.filter-row {
  margin: 14px 0;
}

.select,
.input,
.textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
  padding: 11px 12px;
}

.select {
  min-width: 158px;
  width: auto;
}

.textarea {
  min-height: 120px;
  resize: vertical;
  line-height: 1.7;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.chip {
  min-height: 28px;
  padding: 5px 9px;
  background: var(--surface-soft);
  color: var(--teal-dark);
  font-size: 12px;
}

.question-text {
  white-space: pre-wrap;
  font-size: 19px;
  line-height: 1.75;
}

.options {
  display: grid;
  gap: 10px;
  margin: 18px 0;
}

.option {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  width: 100%;
  text-align: left;
  line-height: 1.55;
  background: #fff;
}

.option.is-selected {
  border-color: var(--teal);
  background: #e9f7f3;
}

.option.is-correct {
  border-color: rgba(25, 135, 84, 0.45);
  background: #ebf7ef;
}

.option.is-wrong {
  border-color: rgba(200, 73, 61, 0.45);
  background: #fff0ee;
}

.option-key {
  display: inline-grid;
  place-items: center;
  flex: 0 0 28px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--surface-soft);
  color: var(--teal-dark);
  font-weight: 800;
}

.answer-box {
  margin-top: 16px;
  padding: 16px;
  border-left: 4px solid var(--teal);
  background: #f4fbf8;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.answer-box.is-wrong {
  border-left-color: var(--red);
  background: #fff5f4;
}

.answer-box pre,
.reference-answer {
  white-space: pre-wrap;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

.reference-answer ol {
  margin: 8px 0 0;
  padding-left: 24px;
  white-space: normal;
}

.reference-answer li {
  margin: 8px 0;
}

.subjective-summary {
  margin: 10px 0 16px;
  padding: 12px 14px;
  border: 1px solid rgba(15, 139, 117, 0.22);
  border-radius: var(--radius);
  background: #e9f7f3;
}

.subjective-summary p {
  margin: 6px 0 0;
  line-height: 1.7;
}

.answer-code {
  margin: 12px 0;
  padding: 14px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #101817;
  color: #eef8f5;
  font-family: Consolas, "Cascadia Code", "Courier New", monospace;
  font-size: 14px;
  line-height: 1.65;
  white-space: pre;
}

.progress-list,
.wrong-list,
.exam-review {
  display: grid;
  gap: 10px;
}

.wrong-section {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.wrong-section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.wrong-section-title h3 {
  margin: 0;
}

.list-row {
  display: grid;
  gap: 8px;
  padding: 13px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.type-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.type-card {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.bar {
  height: 9px;
  overflow: hidden;
  background: #e7ecea;
  border-radius: 999px;
}

.bar span {
  display: block;
  height: 100%;
  background: var(--teal);
}

.exam-header {
  position: sticky;
  top: 60px;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(10px);
}

.status-good {
  color: var(--green);
}

.status-bad {
  color: var(--red);
}

.status-warn {
  color: var(--amber);
}

.empty {
  padding: 28px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: #fff;
}

@media (max-width: 920px) {
  .app-shell {
    width: min(100% - 20px, 720px);
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .main-grid,
  .metrics,
  .type-grid {
    grid-template-columns: 1fr;
  }

  .side-panel {
    order: initial;
  }
}

@media (max-width: 560px) {
  .app-shell {
    width: 100%;
    padding: 12px 10px 28px;
  }

  .panel,
  .question-panel,
  .side-panel {
    padding: 16px;
  }

  h1 {
    font-size: 28px;
  }

  .question-text {
    font-size: 17px;
  }

  .primary-action,
  .ghost-action,
  .danger-action {
    width: 100%;
  }

  .toolbar,
  .actions {
    align-items: stretch;
    flex-direction: column;
  }

  .select {
    width: 100%;
  }
}