/* ============================================
   铁鹰式期权学习测试 — 明亮色彩方案
   ============================================ */

:root {
  /* 基础色 */
  --bg: #FAFBFE;
  --bg-card: #FFFFFF;
  --bg-soft: #F1F4FB;
  --bg-code: #F8FAFD;
  --border: #E4E9F4;
  --border-soft: #EEF1F8;

  /* 文字 */
  --text: #1F2A44;
  --text-soft: #5C6788;
  --text-muted: #8A93B0;

  /* 主色（明亮蓝紫） */
  --primary: #6366F1;
  --primary-soft: #E0E2FF;
  --primary-deep: #4F46E5;
  --primary-gradient: linear-gradient(135deg, #6366F1 0%, #8B5CF6 100%);

  /* 强调色（明亮琥珀） */
  --accent: #F59E0B;
  --accent-soft: #FEF3C7;

  /* 反馈 */
  --success: #10B981;
  --success-soft: #D1FAE5;
  --danger: #EF4444;
  --danger-soft: #FEE2E2;
  --warning: #F59E0B;
  --warning-soft: #FEF3C7;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(31, 42, 68, 0.06);
  --shadow-md: 0 4px 12px rgba(31, 42, 68, 0.08);
  --shadow-lg: 0 10px 32px rgba(31, 42, 68, 0.10);
  --shadow-primary: 0 4px 14px rgba(99, 102, 241, 0.30);

  /* 尺寸 */
  --radius-card: 12px;
  --radius-btn: 8px;
  --radius-chip: 999px;
  --header-h: 64px;
  --tabs-h: 56px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Helvetica Neue", sans-serif;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}

/* ============================================
   顶部 Header
   ============================================ */
.quiz-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 16px;
}

.quiz-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
}

.quiz-logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--primary-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 14px;
  box-shadow: var(--shadow-primary);
}

.quiz-logo-title {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.quiz-logo-title small {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 500;
}

.quiz-header-spacer {
  flex: 1;
}

.quiz-header-progress {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 240px;
}

.quiz-header-progress-text {
  font-size: 13px;
  color: var(--text-soft);
  white-space: nowrap;
}
.quiz-header-progress-text strong {
  color: var(--primary-deep);
  font-weight: 700;
}

.quiz-header-progress-bar {
  flex: 1;
  height: 6px;
  background: var(--bg-soft);
  border-radius: var(--radius-chip);
  overflow: hidden;
  min-width: 80px;
}
.quiz-header-progress-fill {
  height: 100%;
  background: var(--primary-gradient);
  border-radius: var(--radius-chip);
  transition: width 300ms ease;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border: 0;
  padding: 9px 18px;
  border-radius: var(--radius-btn);
  font-weight: 600;
  font-size: 14px;
  box-shadow: var(--shadow-primary);
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
}
.btn-primary:hover:not(:disabled) {
  background: var(--primary-deep);
  transform: translateY(-1px);
}
.btn-primary:disabled {
  background: var(--bg-soft);
  color: var(--text-muted);
  box-shadow: none;
  cursor: not-allowed;
}

.btn-ghost {
  background: transparent;
  color: var(--text-soft);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: var(--radius-btn);
  font-weight: 500;
  font-size: 14px;
  transition: all 150ms ease;
}
.btn-ghost:hover {
  background: var(--bg-soft);
  color: var(--text);
  border-color: var(--primary-soft);
}

.btn-success {
  background: var(--success);
  color: #fff;
  border: 0;
  padding: 9px 18px;
  border-radius: var(--radius-btn);
  font-weight: 600;
  font-size: 14px;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.30);
  transition: transform 150ms ease;
}
.btn-success:hover { transform: translateY(-1px); }

/* ============================================
   侧栏（章节导航）
   ============================================ */
.sidebar {
  width: 260px;
  flex-shrink: 0;
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  height: calc(100vh - var(--header-h));
  position: sticky;
  top: var(--header-h);
  display: flex;
  flex-direction: column;
  z-index: 80;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px 12px;
  border-bottom: 1px solid var(--border-soft);
}
.sidebar-header h3 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}
.sidebar-close {
  display: none;  /* 桌面端不显示，仅移动端 */
  background: transparent;
  border: 0;
  color: var(--text-muted);
  font-size: 28px;
  line-height: 1;
  cursor: pointer;
  padding: 0 4px;
  border-radius: 4px;
}
.sidebar-close:hover { color: var(--text); background: var(--bg-soft); }

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 8px 8px 16px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.sidebar-nav::-webkit-scrollbar { width: 4px; }
.sidebar-nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: 0;
  background: transparent;
  border-radius: 8px;
  color: var(--text-soft);
  font-size: 13px;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
  transition: all 120ms ease;
  width: 100%;
}
.sidebar-item:hover {
  background: var(--bg-soft);
  color: var(--text);
}
.sidebar-item.active {
  background: var(--primary-soft);
  color: var(--primary-deep);
  font-weight: 600;
}
.sidebar-item-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--border);
  flex-shrink: 0;
}
.sidebar-item-dot.green { background: var(--success); }
.sidebar-item-dot.red   { background: var(--danger); }
.sidebar-item-dot.amber { background: var(--warning); }
.sidebar-item-title {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sidebar-item-count {
  flex-shrink: 0;
  font-size: 11px;
  background: var(--bg-soft);
  color: var(--text-soft);
  padding: 2px 7px;
  border-radius: var(--radius-chip);
  font-weight: 600;
}
.sidebar-item.active .sidebar-item-count {
  background: var(--primary);
  color: #fff;
}

.sidebar-footer {
  padding: 12px 18px;
  border-top: 1px solid var(--border-soft);
}
.sidebar-tip {
  font-size: 11px;
  color: var(--text-muted);
}

/* 移动端遮罩 */
.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(31, 42, 68, 0.45);
  z-index: 79;
  animation: fade-in 200ms ease;
}
@keyframes fade-in { from { opacity: 0; } to { opacity: 1; } }

/* 汉堡按钮（仅移动端） */
.hamburger {
  display: none;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: transparent;
  border: 0;
  border-radius: 8px;
  color: var(--text);
  cursor: pointer;
  flex-shrink: 0;
  transition: background 150ms ease;
}
.hamburger:hover { background: var(--bg-soft); }

/* ============================================
   两列布局
   ============================================ */
.layout {
  display: flex;
  flex: 1;
  align-items: stretch;
  min-height: 0;
}
.layout-content {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* ============================================
   主内容
   ============================================ */
.quiz-main {
  flex: 1;
  max-width: 880px;
  width: 100%;
  margin: 0 auto;
  padding: 32px 24px 80px;
}

.section-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin: 0 0 8px;
}
.section-heading h2 {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
}
.section-heading .section-progress {
  font-size: 13px;
  color: var(--text-muted);
  white-space: nowrap;
  font-weight: 500;
}
.section-heading .section-progress strong {
  color: var(--primary-deep);
}

.section-intro {
  color: var(--text-soft);
  font-size: 14px;
  margin: 0 0 24px;
  padding: 14px 18px;
  background: var(--bg-soft);
  border-left: 3px solid var(--primary);
  border-radius: 6px;
}

.section-intro p { margin: 6px 0; }
.section-intro p:first-child { margin-top: 0; }
.section-intro p:last-child { margin-bottom: 0; }

/* ============================================
   题目卡
   ============================================ */
.question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 24px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 200ms ease, transform 200ms ease;
}
.question-card:hover {
  box-shadow: var(--shadow-md);
}

.question-card.correct {
  border-color: var(--success);
  background: linear-gradient(180deg, var(--success-soft) 0%, var(--bg-card) 30%);
}
.question-card.wrong {
  border-color: var(--danger);
  background: linear-gradient(180deg, var(--danger-soft) 0%, var(--bg-card) 30%);
}
.question-card.partial {
  border-color: var(--warning);
  background: linear-gradient(180deg, var(--warning-soft) 0%, var(--bg-card) 30%);
}

.question-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 500;
}
.question-number {
  background: var(--primary-soft);
  color: var(--primary-deep);
  padding: 3px 8px;
  border-radius: var(--radius-chip);
  font-weight: 700;
  font-size: 11px;
  letter-spacing: 0.02em;
}
.question-type {
  background: var(--bg-soft);
  color: var(--text-soft);
  padding: 3px 8px;
  border-radius: var(--radius-chip);
  font-weight: 600;
  font-size: 11px;
}
.question-type.multiple { background: var(--accent-soft); color: #B45309; }
.question-difficulty {
  margin-left: auto;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.question-difficulty.easy { color: var(--success); }
.question-difficulty.medium { color: var(--accent); }
.question-difficulty.hard { color: var(--danger); }

.question-body {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  margin: 0 0 16px;
}
.question-body p { margin: 6px 0; }
.question-body p:first-child { margin-top: 0; }
.question-body p:last-child { margin-bottom: 0; }
.question-body code {
  background: var(--bg-code);
  padding: 1px 6px;
  border-radius: 4px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 14px;
  border: 1px solid var(--border-soft);
}

.question-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 16px 0;
}

.option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: var(--bg-card);
  cursor: pointer;
  transition: all 150ms ease;
  user-select: none;
}
.option:hover:not(.disabled) {
  border-color: var(--primary-soft);
  background: var(--bg-soft);
  transform: translateX(2px);
}
.option.selected {
  border-color: var(--primary);
  background: var(--primary-soft);
}
.option.disabled {
  cursor: not-allowed;
  opacity: 0.95;
}
.option.correct-answer {
  border-color: var(--success);
  background: var(--success-soft);
}
.option.wrong-answer {
  border-color: var(--danger);
  background: var(--danger-soft);
}
.option.partial-answer {
  border-color: var(--warning);
  background: var(--warning-soft);
}

.option-marker {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--bg-soft);
  border: 1.5px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 700;
  color: var(--text-soft);
  flex-shrink: 0;
  margin-top: 1px;
  transition: all 150ms ease;
}
.option.selected .option-marker {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}
.option.correct-answer .option-marker {
  background: var(--success);
  color: #fff;
  border-color: var(--success);
}
.option.wrong-answer .option-marker {
  background: var(--danger);
  color: #fff;
  border-color: var(--danger);
}
.option-marker.checkbox {
  border-radius: 5px;
}
.option.selected .option-marker.checkbox::after {
  content: "✓";
  color: #fff;
  font-size: 14px;
}

.option-text {
  flex: 1;
  font-size: 14.5px;
  line-height: 1.55;
  color: var(--text);
}
.option-text p { margin: 4px 0; }
.option-text p:first-child { margin-top: 0; }
.option-text p:last-child { margin-bottom: 0; }

.option-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
  flex-shrink: 0;
  align-self: center;
}
.option-badge.is-correct { background: var(--success); color: #fff; }
.option-badge.is-wrong { background: var(--danger); color: #fff; }

/* 答案解析折叠 */
.question-explanation {
  margin-top: 12px;
  border-top: 1px dashed var(--border);
  padding-top: 14px;
}
.question-explanation summary {
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary-deep);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
  user-select: none;
}
.question-explanation summary::-webkit-details-marker { display: none; }
.question-explanation summary::before {
  content: "💡";
  font-size: 14px;
}
.question-explanation summary::after {
  content: "展开";
  margin-left: auto;
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 500;
  background: var(--bg-soft);
  padding: 2px 8px;
  border-radius: var(--radius-chip);
}
.question-explanation[open] summary::after { content: "收起"; }

.question-explanation-body {
  margin-top: 12px;
  padding: 14px 16px;
  background: var(--bg-soft);
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-soft);
}
.question-explanation-body p { margin: 6px 0; }
.question-explanation-body p:first-child { margin-top: 0; }
.question-explanation-body p:last-child { margin-bottom: 0; }
.question-explanation-body strong { color: var(--text); }
.question-explanation-body code {
  background: var(--bg-card);
  padding: 1px 6px;
  border-radius: 4px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 13px;
  border: 1px solid var(--border-soft);
}

/* ============================================
   章节间导航按钮
   ============================================ */
.section-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border-soft);
}

/* ============================================
   提交按钮区
   ============================================ */
.submit-bar {
  position: sticky;
  bottom: 16px;
  margin: 24px auto 0;
  display: flex;
  justify-content: center;
  gap: 12px;
  z-index: 50;
}
.submit-bar-inner {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-chip);
  padding: 8px;
  display: flex;
  gap: 8px;
  box-shadow: var(--shadow-lg);
}

/* ============================================
   结果页 — 总分卡
   ============================================ */
.results-page {
  max-width: 880px;
  margin: 0 auto;
  padding: 32px 24px 80px;
}

.score-card {
  background: var(--primary-gradient);
  color: #fff;
  border-radius: 18px;
  padding: 36px;
  text-align: center;
  box-shadow: 0 12px 40px rgba(99, 102, 241, 0.30);
  margin-bottom: 32px;
  position: relative;
  overflow: hidden;
}
.score-card::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255,255,255,0.18) 0%, transparent 70%);
  border-radius: 50%;
}
.score-card-label {
  font-size: 14px;
  opacity: 0.85;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-weight: 600;
}
.score-card-value {
  font-size: 72px;
  font-weight: 800;
  line-height: 1.1;
  margin: 6px 0;
  letter-spacing: -0.02em;
}
.score-card-value sup {
  font-size: 36px;
  opacity: 0.8;
  margin-left: 2px;
}
.score-card-meta {
  font-size: 15px;
  opacity: 0.92;
  font-weight: 500;
}
.score-card-meta strong {
  font-weight: 700;
}

.results-section-list {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 20px 24px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
}
.results-section-list h3 {
  margin: 0 0 16px;
  font-size: 16px;
  font-weight: 700;
}

.section-result {
  display: grid;
  grid-template-columns: minmax(160px, 1.5fr) 2fr auto;
  gap: 16px;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px dashed var(--border-soft);
}
.section-result:last-child { border-bottom: 0; }
.section-result-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}
.section-result-bar {
  height: 8px;
  background: var(--bg-soft);
  border-radius: var(--radius-chip);
  overflow: hidden;
}
.section-result-bar-fill {
  height: 100%;
  border-radius: var(--radius-chip);
  background: var(--primary-gradient);
  transition: width 600ms ease;
}
.section-result-bar-fill.perfect { background: var(--success); }
.section-result-bar-fill.partial { background: var(--accent); }
.section-result-bar-fill.low     { background: var(--danger); }
.section-result-stat {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-soft);
  white-space: nowrap;
}
.section-result-stat .pct {
  color: var(--primary-deep);
  font-size: 14px;
  margin-left: 4px;
}
.section-result-stat .pct.low { color: var(--danger); }
.section-result-stat .pct.high { color: var(--success); }

.wrong-list-title {
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.wrong-list-title .count {
  background: var(--danger-soft);
  color: var(--danger);
  padding: 2px 10px;
  border-radius: var(--radius-chip);
  font-size: 13px;
  font-weight: 700;
}

.wrong-section-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-soft);
  margin: 24px 0 12px;
  padding: 8px 14px;
  background: var(--bg-soft);
  border-left: 3px solid var(--primary);
  border-radius: 0 6px 6px 0;
}

/* ============================================
   Loading / Error
   ============================================ */
.center-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  gap: 16px;
  text-align: center;
  padding: 24px;
}
.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--primary-soft);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 800ms linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.error-card {
  background: var(--danger-soft);
  border: 1px solid var(--danger);
  color: #991B1B;
  padding: 20px;
  border-radius: var(--radius-card);
  max-width: 480px;
}
.error-card h3 { margin: 0 0 8px; }
.error-card code {
  background: rgba(0,0,0,0.05);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 13px;
}

.empty-state {
  text-align: center;
  padding: 60px 24px;
  color: var(--text-muted);
}

/* ============================================
   回到顶部
   ============================================ */
.fab-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: 0;
  box-shadow: var(--shadow-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  z-index: 80;
  transition: transform 150ms ease;
}
.fab-top:hover { transform: translateY(-2px); }

/* ============================================
   响应式
   ============================================ */
@media (max-width: 860px) {
  /* 移动端：侧栏变抽屉 */
  .sidebar {
    position: fixed;
    top: var(--header-h);
    left: 0;
    height: calc(100vh - var(--header-h));
    width: 280px;
    max-width: 85vw;
    transform: translateX(-100%);
    transition: transform 240ms cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 4px 0 20px rgba(31, 42, 68, 0.10);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .sidebar-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
  }
  .hamburger {
    display: flex;
  }
}

@media (max-width: 720px) {
  :root { --header-h: 56px; }
  .quiz-header { padding: 0 12px; gap: 8px; }
  .quiz-logo { gap: 8px; }
  .quiz-logo-icon { width: 28px; height: 28px; font-size: 12px; }
  .quiz-logo-title { font-size: 14px; }
  .quiz-logo-title small { display: none; }
  .quiz-header-progress { min-width: 0; flex: 1; max-width: 120px; }
  .quiz-header-progress-bar { min-width: 40px; }
  .quiz-header-progress-text { display: none; }
  .btn-primary, .btn-success { padding: 7px 12px; font-size: 13px; }
  .btn-ghost { padding: 6px 10px; font-size: 12px; }
  .quiz-main { padding: 20px 12px 80px; }
  .results-page { padding: 20px 12px 80px; }
  .question-card { padding: 16px; }
  .question-body { font-size: 15px; }
  .option { padding: 10px 12px; }
  .option-text { font-size: 13.5px; }
  .score-card { padding: 24px 16px; }
  .score-card-value { font-size: 52px; }
  .score-card-value sup { font-size: 26px; }
  .score-card-meta { font-size: 13px; }
  .results-section-list { padding: 16px; }
  .section-result {
    grid-template-columns: 1fr;
    gap: 6px;
  }
  .section-result-name { font-size: 13px; }
  .section-result-stat { text-align: right; }
  .section-heading { flex-direction: column; gap: 4px; align-items: flex-start; }
  .section-heading h2 { font-size: 19px; }
  .section-intro { padding: 12px 14px; font-size: 13px; }
  .fab-top { right: 16px; bottom: 16px; width: 40px; height: 40px; }
}