:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --text: #182230;
  --muted: #667085;
  --line: #d9e2ec;
  --accent: #0f766e;
  --accent-2: #2563eb;
  --danger: #b42318;
  --ok: #067647;
  --warn: #b54708;
  --shadow: 0 12px 32px rgba(16, 24, 40, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
}

button, input, textarea {
  font: inherit;
}

.app-shell {
  display: grid;
  grid-template-columns: 320px 1fr;
  min-height: 100vh;
}

.sidebar {
  background: #0b1f2a;
  color: #f8fafc;
  padding: 24px;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 28px;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  background: #14b8a6;
  color: #052e2b;
  font-weight: 800;
  border-radius: 8px;
}

.brand h1 {
  font-size: 18px;
  margin: 0 0 4px;
}

.brand p, .eyebrow, .label {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.sidebar .brand p,
.sidebar .label {
  color: #a7b6c2;
}

.tabs {
  display: grid;
  gap: 8px;
  margin-bottom: 24px;
}

.tab {
  text-align: left;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(255, 255, 255, 0.04);
  color: #e6edf3;
  padding: 12px 14px;
  border-radius: 8px;
  cursor: pointer;
}

.tab.active {
  background: #ffffff;
  color: #0b1f2a;
  border-color: #ffffff;
}

.progress-panel {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 18px;
}

.progress-panel h2 {
  font-size: 15px;
  margin: 0 0 12px;
}

.mastery-list {
  display: grid;
  gap: 12px;
}

.mastery-item {
  display: grid;
  gap: 6px;
}

.mastery-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 13px;
}

.bar {
  height: 8px;
  background: rgba(255, 255, 255, 0.14);
  border-radius: 99px;
  overflow: hidden;
}

.bar > span {
  display: block;
  height: 100%;
  background: #2dd4bf;
  width: 0;
}

.main {
  padding: 28px;
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  margin-bottom: 18px;
}

.topbar h2 {
  margin: 4px 0 0;
  font-size: 28px;
}

.top-actions,
.submit-row {
  display: flex;
  gap: 10px;
  align-items: center;
}

.primary-btn,
.secondary-btn,
.icon-btn {
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
  background: #fff;
  color: var(--text);
}

.primary-btn {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  padding: 12px 18px;
  font-weight: 700;
}

.secondary-btn {
  padding: 10px 14px;
}

.icon-btn {
  width: 42px;
  height: 42px;
  font-size: 22px;
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.status-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}

.status-strip > div,
.question,
.result-panel,
.summary-box,
.wrong-empty,
.upload-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.status-strip > div {
  padding: 14px;
}

.status-strip strong {
  display: block;
  margin-top: 4px;
}

.quiz-form {
  display: grid;
  gap: 12px;
  margin-bottom: 16px;
}

.question {
  padding: 16px;
}

.question-header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.question-title {
  font-weight: 700;
}

.question-tag {
  color: var(--muted);
  font-size: 13px;
}

.prompt {
  line-height: 1.7;
  margin: 8px 0 12px;
  white-space: pre-wrap;
}

.answer-input {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid #bdc8d6;
  border-radius: 8px;
  outline: none;
}

.answer-input:focus {
  border-color: var(--accent-2);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.result-panel {
  padding: 16px;
  margin-top: 18px;
}

.hidden {
  display: none;
}

.score-card {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
  margin-bottom: 14px;
}

.score-card h3 {
  margin: 4px 0 0;
  font-size: 30px;
}

.score-card p:last-child {
  margin: 0;
  max-width: 620px;
  line-height: 1.7;
}

.feedback-list,
.wrong-book {
  display: grid;
  gap: 10px;
}

.feedback {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fbfdff;
}

.feedback.ok {
  border-color: rgba(6, 118, 71, 0.35);
}

.feedback.bad {
  border-color: rgba(180, 35, 24, 0.35);
}

.feedback strong.ok {
  color: var(--ok);
}

.feedback strong.bad {
  color: var(--danger);
}

.feedback code {
  background: #eef4ff;
  padding: 2px 6px;
  border-radius: 6px;
}

.summary-box {
  width: 100%;
  min-height: 620px;
  padding: 18px;
  line-height: 1.75;
  resize: vertical;
}

.upload-panel {
  padding: 18px;
  margin-bottom: 16px;
}

.upload-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.upload-panel label {
  display: grid;
  gap: 6px;
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 13px;
}

.upload-note {
  min-height: 92px;
  resize: vertical;
}

.upload-status {
  color: var(--muted);
}

.upload-list {
  display: grid;
  gap: 10px;
}

.analysis-result {
  min-height: 260px;
  max-height: 640px;
  overflow: auto;
  white-space: pre-wrap;
  background: #f8fbff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  line-height: 1.75;
  margin: 0;
}

.upload-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fbfdff;
}

.upload-item strong {
  display: block;
  margin-bottom: 6px;
}

.compact {
  margin-bottom: 12px;
}

.wrong-empty {
  padding: 18px;
  color: var(--muted);
}

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

  .sidebar {
    padding: 18px;
  }

  .status-strip {
    grid-template-columns: 1fr;
  }

  .upload-grid {
    grid-template-columns: 1fr;
  }

  .topbar,
  .score-card {
    align-items: stretch;
    flex-direction: column;
  }
}