/* Choice paper（试卷答题页）— 颜色对齐 ChoiceQuestionSystem practice 玻璃主题 */
html.page--choice_paper {
  --cpp-paper: #f4f5f7;
  --cpp-card: #ffffff;
  --cpp-ink: #09090b;
  --cpp-muted: #71717a;
  --cpp-faint: #a1a1aa;
  --cpp-line: rgba(15, 23, 42, 0.08);
  --cpp-accent: #2563eb;
  --cpp-on-accent: #ffffff;
  --cpp-accent-soft: rgba(37, 99, 235, 0.08);
  --cpp-ok: #16a34a;
  --cpp-ok-soft: #f0fdf4;
  --cpp-bad: #dc2626;
  --cpp-bad-soft: #fef2f2;
  --cpp-warn: #d97706;
  --cpp-warn-soft: #fffbeb;
  --cpp-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
  --cpp-shadow-lg: 0 8px 24px rgba(15, 23, 42, 0.08);
  --cpp-radius: 10px;
  --cpp-font: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--cpp-paper);
  color: var(--cpp-ink);
}
/* Hydro 账号主题 class、顶栏 data-theme、body.dark 都可能表示暗色；
   一旦 html[data-theme=light]（顶栏已切亮），这些暗色规则必须让路。 */
html.page--choice_paper[data-theme="dark"],
html.page--choice_paper.theme--dark:not([data-theme="light"]) {
  --cpp-paper: #0d1117;
  --cpp-card: #161b22;
  --cpp-ink: #fafafa;
  --cpp-muted: #a1a1aa;
  --cpp-faint: #71717a;
  --cpp-line: rgba(255, 255, 255, 0.08);
  --cpp-accent: #60a5fa;
  --cpp-accent-soft: rgba(96, 165, 250, 0.14);
  --cpp-ok: #4ade80;
  --cpp-ok-soft: #052e16;
  --cpp-bad: #f87171;
  --cpp-bad-soft: #450a0a;
  --cpp-warn: #fbbf24;
  --cpp-warn-soft: #422006;
  --cpp-shadow: none;
  --cpp-shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.4);
}
html.page--choice_paper:not([data-theme="light"]) body.theme--dark,
html.page--choice_paper:not([data-theme="light"]) body.dark {
  --cpp-paper: #0d1117;
  --cpp-card: #161b22;
  --cpp-ink: #fafafa;
  --cpp-muted: #a1a1aa;
  --cpp-faint: #71717a;
  --cpp-line: rgba(255, 255, 255, 0.08);
  --cpp-accent: #60a5fa;
  --cpp-accent-soft: rgba(96, 165, 250, 0.14);
  --cpp-ok: #4ade80;
  --cpp-ok-soft: #052e16;
  --cpp-bad: #f87171;
  --cpp-bad-soft: #450a0a;
  --cpp-warn: #fbbf24;
  --cpp-warn-soft: #422006;
  --cpp-shadow: none;
  --cpp-shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.4);
}
/* 顶栏切换写的是 data-theme；必须压过残留的 theme--dark */
html.page--choice_paper[data-theme="light"] {
  --cpp-paper: #f4f5f7;
  --cpp-card: #ffffff;
  --cpp-ink: #09090b;
  --cpp-muted: #71717a;
  --cpp-faint: #a1a1aa;
  --cpp-line: rgba(15, 23, 42, 0.08);
  --cpp-accent: #2563eb;
  --cpp-accent-soft: rgba(37, 99, 235, 0.08);
  --cpp-ok: #16a34a;
  --cpp-ok-soft: #f0fdf4;
  --cpp-bad: #dc2626;
  --cpp-bad-soft: #fef2f2;
  --cpp-warn: #d97706;
  --cpp-warn-soft: #fffbeb;
  --cpp-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
  --cpp-shadow-lg: 0 8px 24px rgba(15, 23, 42, 0.08);
}
html.page--choice_paper body,
html.page--choice_paper .main,
html.page--choice_paper .section,
html.page--choice_paper .section__body,
html.page--choice_paper .main-content {
  background: var(--cpp-paper);
  color: var(--cpp-ink);
}
.cpp-theme {
  font-family: var(--cpp-font);
  color: var(--cpp-ink);
  box-sizing: border-box;
}
.cpp-theme *,
.cpp-theme *::before,
.cpp-theme *::after { box-sizing: border-box; }

/* 试卷舱体比 Hydro 默认栏宽 */
body:has(.cpp-shell) .section,
body:has(.cpp-shell) .main-content,
body:has(.cpp-shell) .container {
  max-width: none;
  width: 100%;
}
/* 沉浸式答题：隐藏站点页脚与 omnibar（与 choice_practice 一致） */
html.page--choice_paper .footer,
html.page--choice_paper .omnibar,
html.page--choice_paper .omnibar-toggle { display: none !important; }

.cpp-shell {
  max-width: 1400px;
  width: min(94%, 1400px);
  margin: 0 auto 48px;
  padding: 8px 0 72px;
  min-height: 64vh;
}

/* ===== 顶栏 ===== */
.cpp-top {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
  position: sticky;
  top: 0;
  z-index: 8;
  padding: 10px 0 12px;
  background: color-mix(in srgb, var(--cpp-paper) 88%, transparent);
  backdrop-filter: blur(12px);
}
.cpp-back {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 10px; flex-shrink: 0;
  background: var(--cpp-card); color: var(--cpp-muted); text-decoration: none;
  border: 1px solid var(--cpp-line); cursor: pointer; padding: 0;
  box-shadow: var(--cpp-shadow); transition: transform 0.15s, color 0.15s, border-color 0.15s;
}
.cpp-back:hover { color: var(--cpp-ink); border-color: var(--cpp-line); background: var(--cpp-accent-soft); transform: translateX(-1px); }
.cpp-top-copy { flex: 1; min-width: 0; }
.cpp-page-title-row { display: flex; align-items: baseline; flex-wrap: wrap; gap: 8px 12px; }
.cpp-page-title { font-size: 22px; margin: 0; font-weight: 750; letter-spacing: -0.03em; color: var(--cpp-ink); }
.cpp-page-sub { font-size: 13px; font-weight: 500; color: var(--cpp-muted); line-height: 1.4; }
.cpp-top-badges { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.cpp-total-badge,
.cpp-score-badge {
  font-size: 12px; color: var(--cpp-muted); background: var(--cpp-card);
  border: 1px solid var(--cpp-line); padding: 5px 12px; border-radius: 999px;
  white-space: nowrap; font-variant-numeric: tabular-nums;
}
.cpp-score-badge { font-size: 14px; font-weight: 750; color: var(--cpp-accent); border-color: color-mix(in srgb, var(--cpp-accent) 30%, var(--cpp-line)); }

/* ===== 顶栏信息行（所属场次 / 所属题库） ===== */
.cpp-info-row { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; margin-top: 6px; }
.cpp-info-row[hidden] { display: none !important; }
.cpp-info-chip {
  display: inline-flex; align-items: center; gap: 5px; max-width: 260px;
  padding: 3px 10px; border: 1px solid var(--cpp-line); border-radius: 999px;
  background: var(--cpp-card); color: var(--cpp-muted); cursor: pointer;
  font-size: 12px; line-height: 1.5; white-space: nowrap;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}
.cpp-info-chip svg { width: 13px; height: 13px; fill: currentColor; flex-shrink: 0; }
.cpp-info-chip span { overflow: hidden; text-overflow: ellipsis; }
.cpp-info-chip:hover { color: var(--cpp-accent); border-color: color-mix(in srgb, var(--cpp-accent) 45%, var(--cpp-line)); background: var(--cpp-accent-soft); }
.cpp-info-chip[hidden] { display: none !important; }

/* ===== 场次切换下拉（由顶栏「场次」chip 触发，菜单左对齐 chip） ===== */
.cpp-switcher-menu {
  position: fixed; top: 0; left: 0; z-index: 10050;
  width: min(360px, 72vw); max-height: min(420px, 58vh);
  display: flex; flex-direction: column; overflow: hidden;
  border: 1px solid var(--cpp-line); border-radius: 12px;
  background: var(--cpp-card); color: var(--cpp-ink);
  box-shadow: var(--cpp-shadow-lg);
}
.cpp-switcher-menu[hidden] { display: none !important; }
.cpp-switcher-menu__header {
  flex: 0 0 auto; padding: 10px 12px 8px;
  border-bottom: 1px solid var(--cpp-line);
  font-size: 12px; font-weight: 700; color: var(--cpp-ink);
  background: color-mix(in srgb, var(--cpp-paper) 55%, var(--cpp-card));
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.cpp-switcher-menu__body { flex: 1 1 auto; min-height: 0; overflow-y: auto; padding: 6px; }
.cpp-switcher-item {
  display: grid; grid-template-columns: 20px 52px minmax(0, 1fr) auto;
  align-items: center; gap: 6px; min-height: 38px; padding: 6px 8px;
  border-radius: 8px; color: var(--cpp-ink); text-decoration: none !important;
}
.cpp-switcher-item:hover { background: color-mix(in srgb, var(--cpp-paper) 70%, var(--cpp-card)); }
.cpp-switcher-item--current {
  background: var(--cpp-accent-soft);
  box-shadow: inset 3px 0 0 var(--cpp-accent);
}
.cpp-switcher-item__status {
  width: 18px; height: 18px; display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--cpp-line); border-radius: 999px;
}
.cpp-switcher-item__status svg { width: 13px; height: 13px; fill: var(--cpp-ok); }
.cpp-switcher-item__status--accepted { border-color: transparent; }
.cpp-switcher-item__idx { font-size: 12px; font-weight: 700; font-variant-numeric: tabular-nums; }
.cpp-switcher-item__title { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 12px; font-weight: 600; }
.cpp-switcher-item__diff { min-width: 30px; font-size: 11px; font-weight: 600; text-align: right; }
.cpp-switcher-menu__empty { padding: 18px 12px; text-align: center; font-size: 12px; color: var(--cpp-muted); }
.cpp-switcher-menu__loading { display: flex; align-items: center; justify-content: center; gap: 8px; padding: 18px 12px; font-size: 12px; color: var(--cpp-muted); }
.cpp-spinner-dot {
  width: 12px; height: 12px; border: 2px solid var(--cpp-line);
  border-top-color: var(--cpp-accent); border-radius: 999px;
  animation: cpp-spin 0.8s linear infinite;
}
@keyframes cpp-spin { to { transform: rotate(360deg); } }

/* ===== 题库列表抽屉（参照 IDE pset drawer） ===== */
.cpp-pset-overlay {
  position: fixed; z-index: 10020; top: 45px; right: 0; bottom: 0; left: 0;
  display: flex; align-items: stretch;
}
.cpp-pset-overlay[hidden] { display: none !important; }
.cpp-pset-mask { position: absolute; inset: 0; background: rgba(9, 9, 11, 0.48); }
.cpp-pset-drawer {
  position: relative; margin-right: auto;
  width: min(560px, 92vw); height: 100%;
  display: flex; flex-direction: column;
  background: var(--cpp-card); color: var(--cpp-ink);
  border-right: 1px solid var(--cpp-line);
  box-shadow: 12px 0 30px rgba(15, 23, 42, 0.18);
  animation: cpp-drawer-in 0.22s ease;
}
@keyframes cpp-drawer-in { from { transform: translateX(-24px); opacity: 0.6; } to { transform: translateX(0); opacity: 1; } }
.cpp-pset-header {
  flex: 0 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 10px;
  padding: 10px 14px; border-bottom: 1px solid var(--cpp-line);
  background-image: var(--cpp-pset-cover, none), linear-gradient(135deg, color-mix(in srgb, var(--cpp-paper) 40%, var(--cpp-card)), var(--cpp-card));
  background-size: cover; background-position: center right;
}
.cpp-pset-header__titles { min-width: 0; flex: 1; }
.cpp-pset-title {
  font-size: 15px; font-weight: 750; letter-spacing: -0.02em;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.cpp-pset-title--clickable { cursor: pointer; }
.cpp-pset-title--clickable:hover { color: var(--cpp-accent); }
.cpp-pset-subtitle { margin-top: 2px; font-size: 12px; color: var(--cpp-muted); }
.cpp-pset-close {
  flex-shrink: 0; width: 28px; height: 28px; border: 1px solid var(--cpp-line); border-radius: 8px;
  background: var(--cpp-card); color: var(--cpp-muted); font-size: 16px; line-height: 1; cursor: pointer;
}
.cpp-pset-close:hover { color: var(--cpp-bad); border-color: var(--cpp-bad); }
.cpp-pset-progress { flex: 0 0 auto; padding: 10px 14px; border-bottom: 1px solid var(--cpp-line); font-size: 12px; color: var(--cpp-muted); }
.cpp-pset-progress__main { display: grid; grid-template-columns: 44px minmax(0, 1fr); align-items: center; gap: 10px; }
.cpp-pset-progress__badge {
  width: 40px; height: 40px; border-radius: 10px;
  background-image: var(--cpp-pset-cover, none), linear-gradient(135deg, color-mix(in srgb, var(--cpp-paper) 60%, var(--cpp-card)), var(--cpp-paper));
  background-size: cover; background-position: center;
  box-shadow: inset 0 0 0 1px var(--cpp-line);
}
.cpp-pset-progress__content { display: flex; flex-direction: column; min-width: 0; }
.cpp-pset-progress__label { margin-bottom: 6px; font-size: 11px; font-weight: 600; color: var(--cpp-muted); }
.cpp-pset-progress__bar-row { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 10px; }
.cpp-pset-progress__bar {
  min-width: 72px; height: 8px; overflow: hidden; border-radius: 999px; background: var(--cpp-line);
}
.cpp-pset-progress__bar span {
  display: block; height: 100%; border-radius: inherit;
  background: var(--cpp-accent);
  transition: width 0.35s ease;
}
.cpp-pset-progress__count { font-size: 12px; font-variant-numeric: tabular-nums; color: var(--cpp-ink); white-space: nowrap; }
.cpp-pset-list { flex: 1 1 auto; min-height: 0; overflow-y: auto; padding: 12px 14px 16px; }
.cpp-pset-section {
  overflow: hidden; margin-bottom: 12px;
  border: 1px solid var(--cpp-line); border-radius: 10px;
  background: var(--cpp-card);
}
.cpp-pset-section__header {
  padding: 7px 12px; font-size: 12px; font-weight: 700; color: var(--cpp-ink);
  background: color-mix(in srgb, var(--cpp-paper) 55%, var(--cpp-card));
  border-left: 3px solid var(--cpp-accent);
}
.cpp-pset-item {
  display: grid; grid-template-columns: 20px 52px minmax(0, 1fr) auto;
  align-items: center; gap: 6px; min-height: 44px; padding: 5px 12px;
  color: var(--cpp-ink); text-decoration: none !important;
  border-top: 1px solid var(--cpp-line);
}
.cpp-pset-section__body .cpp-pset-item:first-child { border-top-color: transparent; }
.cpp-pset-item:hover { background: color-mix(in srgb, var(--cpp-paper) 70%, var(--cpp-card)); }
.cpp-pset-item--current {
  background: var(--cpp-accent-soft);
  box-shadow: inset 3px 0 0 var(--cpp-accent);
}
.cpp-pset-item__status {
  width: 18px; height: 18px; display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--cpp-line); border-radius: 999px;
}
.cpp-pset-item__status svg { width: 13px; height: 13px; fill: var(--cpp-ok); }
.cpp-pset-item__status--accepted { border-color: transparent; }
.cpp-pset-item__idx { font-size: 12px; font-weight: 700; font-variant-numeric: tabular-nums; }
.cpp-pset-item__title { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 12px; font-weight: 600; }
.cpp-pset-item__diff { min-width: 30px; font-size: 11px; font-weight: 600; text-align: right; }
.cpp-diff-easy { color: #14b8a6; }
.cpp-diff-medium { color: #eab308; }
.cpp-diff-hard { color: #ef476f; }
.cpp-pset-footer {
  flex: 0 0 auto; padding: 8px 14px calc(8px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--cpp-line); text-align: center;
  font-size: 11px; color: var(--cpp-faint);
}


/* ===== 进度条 ===== */
.cpp-cockpit-bar { display: flex; align-items: center; gap: 14px; margin-bottom: 12px; flex-wrap: wrap; }
.cpp-cockpit-tag { font-size: 15px; font-weight: 720; letter-spacing: -0.02em; }
.cpp-chapter-track {
  flex: 1; min-width: 140px; height: 8px; border-radius: 999px;
  background: var(--cpp-line); overflow: hidden;
}
.cpp-chapter-fill { height: 100%; width: 0; background: var(--cpp-accent); border-radius: inherit; transition: width 0.35s ease; }
.cpp-chapter-meta { font-size: 12px; color: var(--cpp-muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
.cpp-mode {
  display: inline-flex; align-items: center; padding: 2px; gap: 2px; flex-shrink: 0;
  border: 1px solid var(--cpp-line); border-radius: 999px; background: var(--cpp-card);
}
.cpp-mode-btn {
  border: none; background: transparent; color: var(--cpp-muted); cursor: pointer;
  font-size: 12px; font-weight: 650; line-height: 1.4; padding: 4px 10px; border-radius: 999px;
}
.cpp-mode-btn.is-active { background: var(--cpp-accent); color: var(--cpp-on-accent, #fff); }
.cpp-mode-btn:hover:not(.is-active):not(:disabled) { color: var(--cpp-ink); }
.cpp-mode-btn:disabled { cursor: default; opacity: 0.55; }
.cpp-paper-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 12px 16px;
  margin: -4px 0 12px; padding: 8px 12px;
  border: 1px solid var(--cpp-line); border-radius: 12px; background: var(--cpp-card);
}
.cpp-paper-bar-copy { min-width: 0; flex: 1; }
.cpp-paper-bar-title { font-size: 13px; font-weight: 720; letter-spacing: -0.02em; }
.cpp-paper-hint { margin: 2px 0 0; font-size: 12px; line-height: 1.5; color: var(--cpp-muted); }
.cpp-paper-bar-actions { display: flex; flex-wrap: wrap; gap: 8px; flex-shrink: 0; }
.cpp-paper-bar-actions .cpp-btn { padding: 6px 14px; font-size: 13px; }
#cpp-paper-hint[hidden],
#cpp-submit-type[hidden] { display: none !important; }

/* ===== 布局 ===== */
.cpp-layout { display: flex; gap: 20px; align-items: flex-start; }
.cpp-main { flex: 1; min-width: 0; }
.cpp-side { width: 300px; flex-shrink: 0; }

/* ===== 题目卡片 ===== */
.cpp-card {
  background: var(--cpp-card); padding: 26px 28px; border-radius: var(--cpp-radius);
  box-shadow: var(--cpp-shadow); border: 1px solid var(--cpp-line); margin-bottom: 16px; min-height: 280px;
}
/* github-markdown 按系统 prefers-color-scheme / 残留 theme--dark 上色，题面卡片必须跟 --cpp-* */
html .cpp-theme .markdown-body {
  background-color: transparent;
  color: inherit;
}
html .cpp-theme .markdown-body h1,
html .cpp-theme .markdown-body h2,
html .cpp-theme .markdown-body h3,
html .cpp-theme .markdown-body h4,
html .cpp-theme .markdown-body h5,
html .cpp-theme .markdown-body h6 {
  color: var(--cpp-ink) !important;
  border-bottom-color: var(--cpp-line);
}
html .cpp-theme .markdown-body img { background-color: transparent; }
html .cpp-theme .markdown-body table tr {
  background-color: var(--cpp-card);
  border-top-color: var(--cpp-line);
}
html .cpp-theme .markdown-body table tr:nth-child(2n) { background-color: var(--cpp-paper); }

.cpp-question-top-bar { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 14px; }
.cpp-question-meta { display: flex; gap: 6px; flex-wrap: wrap; flex: 1; min-width: 0; }
.cpp-tag {
  display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 12px;
  font-weight: 600; line-height: 1.6; background: var(--cpp-paper); color: var(--cpp-muted);
  border: 1px solid var(--cpp-line);
}
.cpp-tag-type { background: var(--cpp-accent-soft); color: var(--cpp-accent); border-color: transparent; }
.cpp-tag-score { background: var(--cpp-ok-soft); color: var(--cpp-ok); border-color: transparent; }
.cpp-question-content { font-size: 16px; line-height: 1.8; margin-bottom: 18px; color: var(--cpp-ink); }

/* ===== 选项 ===== */
.cpp-options { display: flex; flex-direction: column; gap: 8px; margin-bottom: 20px; }
.cpp-option {
  display: flex !important; flex-direction: row !important; align-items: flex-start; gap: 12px;
  padding: 13px 16px; border: 1.5px solid var(--cpp-line); border-radius: 12px; cursor: pointer;
  transition: border-color 0.15s, background 0.15s, transform 0.12s, box-shadow 0.15s;
  font-size: 15px; line-height: 1.6; background: var(--cpp-card);
  font-weight: 400; text-transform: none; margin: 0;
}
.cpp-option:hover { border-color: color-mix(in srgb, var(--cpp-accent) 55%, var(--cpp-line)); background: var(--cpp-accent-soft); }
.cpp-option.selected { border-color: var(--cpp-accent); background: var(--cpp-accent-soft); box-shadow: 0 0 0 3px var(--cpp-accent-soft); }
.cpp-option.correct { border-color: var(--cpp-ok); background: var(--cpp-ok-soft); }
.cpp-option.wrong { border-color: var(--cpp-bad); background: var(--cpp-bad-soft); }
.cpp-option input { flex-shrink: 0; width: 16px; height: 16px; margin-top: 4px; cursor: pointer; accent-color: var(--cpp-accent); }
.cpp-option input:disabled { cursor: default; }
.cpp-option-letter {
  flex-shrink: 0; width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center;
  font-weight: 750; font-size: 13px; color: var(--cpp-muted); background: var(--cpp-paper);
  line-height: 1; user-select: none;
}
.cpp-option.selected .cpp-option-letter { background: var(--cpp-accent); color: var(--cpp-on-accent, #fff); }
.cpp-option.correct .cpp-option-letter { background: var(--cpp-ok); color: var(--cpp-on-accent, #fff); }
.cpp-option.wrong .cpp-option-letter { background: var(--cpp-bad); color: var(--cpp-on-accent, #fff); }
.cpp-option .markdown-body { flex: 1; min-width: 0; font-size: 15px; }

/* ===== 操作按钮 ===== */
.cpp-actions { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.cpp-btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 9px 22px; border-radius: 999px;
  font-size: 14px; font-weight: 650; border: none; cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, opacity 0.15s; text-decoration: none;
}
.cpp-btn-primary {
  background: var(--cpp-accent); color: var(--cpp-on-accent, #fff);
}
.cpp-btn-primary:hover { transform: translateY(-1px); }
.cpp-btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }
.cpp-btn-outline { background: var(--cpp-card); color: var(--cpp-ink); border: 1.5px solid var(--cpp-line); }
.cpp-btn-outline:hover { border-color: var(--cpp-accent); color: var(--cpp-accent); }
.cpp-btn-outline:disabled { opacity: 0.4; cursor: not-allowed; }
.cpp-btn-warn { background: var(--cpp-warn); color: #fff; }
.cpp-btn-warn:hover { transform: translateY(-1px); }
.cpp-reset:hover:not(:disabled) { border-color: var(--cpp-warn); color: var(--cpp-warn); }

/* ===== 判题结果 / 题解 / AI ===== */
.cpp-result { padding: 14px 18px; border-radius: 12px; margin-bottom: 16px; font-size: 15px; font-weight: 650; animation: cpp-fade-in 0.28s ease; }
.cpp-submit-loading {
  display: flex; align-items: center; gap: 8px;
  margin-bottom: 16px; padding: 12px 16px; border-radius: 12px;
  background: var(--cpp-paper); color: var(--cpp-muted);
  font-size: 14px; font-weight: 650; animation: cpp-fade-in 0.2s ease;
}
.cpp-card.is-submitting .cpp-option { pointer-events: none; }
.cpp-result-correct { background: var(--cpp-ok-soft); color: var(--cpp-ok); }
.cpp-result-wrong { background: var(--cpp-bad-soft); color: var(--cpp-bad); }
.cpp-answer-lock {
  margin-bottom: 16px; padding: 12px 16px; border-radius: 12px;
  background: var(--cpp-warn-soft); color: var(--cpp-warn);
  font-size: 14px; font-weight: 650; line-height: 1.6;
}
.cpp-answer-lock a { color: var(--cpp-warn); font-weight: 750; margin-left: 6px; }
.cpp-solution { background: var(--cpp-paper); border: 1px solid var(--cpp-line); border-radius: 12px; padding: 16px 20px; margin-top: 16px; }
.cpp-solution.cpp-reveal { animation: cpp-fade-in 0.28s ease; }
.cpp-solution-title { font-size: 12px; font-weight: 700; color: var(--cpp-muted); margin-bottom: 10px; letter-spacing: 0.08em; text-transform: uppercase; }
.cpp-ai-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 12px; }
.cpp-ai-analyze-btn {
  padding: 8px 22px; border-radius: 999px; border: none;
  background: linear-gradient(135deg, #fb923c, #ea580c); color: #fff;
  font-size: 13px; font-weight: 650; cursor: pointer;
  transition: opacity 0.15s;
}
.cpp-ai-analyze-btn:hover { opacity: 0.9; }
.cpp-ai-analyze-btn:disabled { opacity: 0.45; cursor: not-allowed; pointer-events: none; }
.cpp-ai-result { border: 1px solid var(--cpp-line); border-radius: 10px; padding: 14px 16px; background: var(--cpp-paper); margin-top: 12px; }
.cpp-ai-result:empty { display: none; }

/* ===== 笔记 / AI 卡片（结构与练习页一致，数据走同一套 choice API） ===== */
.cpp-note-wrap { margin-top: 0; }
.cpp-note-card {
  background: var(--cpp-card); padding: 0; border-radius: var(--cpp-radius);
  box-shadow: var(--cpp-shadow); border: 1px solid var(--cpp-line); margin-bottom: 16px;
  overflow: hidden; position: relative;
}
.cpp-note-tabs { display: flex; border-bottom: 1px solid var(--cpp-line); }
.cpp-note-tab {
  padding: 10px 18px; font-size: 13px; font-weight: 650; color: var(--cpp-muted);
  cursor: pointer; border: none; background: none; border-bottom: 2px solid transparent;
  display: inline-flex; align-items: center; gap: 6px;
}
.cpp-note-tab svg { flex-shrink: 0; width: 16px; height: 16px; }
.cpp-note-tab:hover, .cpp-note-tab.active { color: var(--cpp-accent); }
.cpp-note-tab.active { border-bottom-color: var(--cpp-accent); }
.cpp-note-body { padding: 18px 22px; min-height: 120px; position: relative; }
.cpp-note-skeleton { display: none; }
.cpp-note-body.is-loading .cpp-note-stack,
.cpp-note-body.is-loading .cpp-ai-pane { visibility: hidden; }
.cpp-note-body.is-loading .cpp-note-skeleton {
  display: flex; flex-direction: column; gap: 10px; justify-content: center;
  position: absolute; inset: 0; z-index: 2; padding: 18px 22px; background: var(--cpp-card);
}
.cpp-skeleton-line {
  height: 14px; border-radius: 6px;
  background: linear-gradient(90deg, var(--cpp-line) 25%, var(--cpp-paper) 37%, var(--cpp-line) 63%);
  background-size: 800px 100%; animation: cpp-shimmer 1.6s ease-in-out infinite;
}
.cpp-skeleton-line.cpp-sk-text { width: 100%; }
.cpp-skeleton-line.cpp-sk-text-short { width: 60%; }
@keyframes cpp-shimmer { 0% { background-position: -400px 0; } 100% { background-position: 400px 0; } }
.cpp-note-view { min-height: 60px; }
.cpp-note-view .markdown-body { font-size: 14px; line-height: 1.7; }
.cpp-note-view-empty { color: var(--cpp-faint); font-size: 13px; text-align: center; padding: 20px 0; }
.cpp-note-editor {
  width: 100%; min-height: 140px; max-height: 400px; border: 1px solid var(--cpp-line);
  border-radius: 8px; padding: 12px; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px; line-height: 1.6; resize: vertical; outline: none;
  background: var(--cpp-paper); color: var(--cpp-ink);
}
.cpp-note-editor:focus { border-color: var(--cpp-accent); background: var(--cpp-card); }
.cpp-note-footer { display: flex; align-items: center; justify-content: space-between; margin-top: 10px; }
.cpp-note-char-count { font-size: 11px; color: var(--cpp-faint); }
.cpp-note-save-btn {
  padding: 6px 16px; border-radius: 8px; border: none; background: var(--cpp-accent);
  color: var(--cpp-on-accent, #fff); font-size: 13px; font-weight: 600; cursor: pointer;
}
.cpp-note-save-btn:disabled { opacity: 0.5; cursor: not-allowed; }
.cpp-note-stack { position: relative; min-height: 120px; }
/* hidden 必须压过后续 display，避免预览和编辑同时排进文档流 */
#cpp-note-view-pane[hidden],
#cpp-note-edit-pane[hidden] { display: none !important; }
.cpp-note-card .cpp-ai-actions { margin: 0 0 12px; }
.cpp-ai-meta { font-size: 12px; color: var(--cpp-muted); line-height: 1.55; flex: 1; min-width: 120px; }
.cpp-ai-meta .cpp-ai-meta-vip-link { color: var(--cpp-warn); font-weight: 650; text-decoration: underline; }
.cpp-ai-meta .ai-quota-link { display: inline-flex; align-items: center; gap: 4px; color: var(--cpp-muted); text-decoration: none; font-size: 12px; }
.cpp-ai-meta .ai-quota-link:hover { color: var(--cpp-accent); }
.cpp-ai-meta .ai-quota-link__value--low, .cpp-ai-meta--low .ai-quota-link__value { color: var(--cpp-bad); font-weight: 650; }
.cpp-ai-meta .ai-quota-link__cool { color: var(--cpp-warn); }
.cpp-note-card .cpp-ai-result { margin-top: 0; }
.cpp-ai-pane { display: flex; flex-direction: column; }
.cpp-ai-inner { display: flex; flex-direction: column; min-height: 220px; flex: 1; }
.cpp-ai-placeholder { color: var(--cpp-faint); font-size: 13px; text-align: center; padding: 16px 8px; }
.cpp-ai-disclaimer { margin-top: auto; align-self: flex-end; text-align: right; font-size: 12px; line-height: 1.55; color: var(--cpp-faint); padding: 12px 0 2px; }
.cpp-ai-cache-tip { font-size: 12px; color: var(--cpp-faint); margin-top: 10px; }
.cpp-ai-stream-live { color: var(--cpp-ink); min-height: 4em; line-height: 1.55; }
.cpp-note-mask-overlay { position: absolute; inset: 0; z-index: 5; display: flex; align-items: center; justify-content: center; }
.cpp-note-mask-overlay--static { position: relative; min-height: 100px; }
.cpp-note-mask-blur {
  position: absolute; left: 0; right: 0; bottom: 0; top: 40%;
  background: linear-gradient(to bottom, transparent, var(--cpp-card));
}
.cpp-note-mask-btn {
  position: relative; z-index: 6; padding: 10px 24px; border-radius: 999px;
  border: none; background: var(--cpp-warn); color: #fff; font-size: 14px; font-weight: 700;
  cursor: pointer; display: inline-flex; align-items: center; gap: 4px;
}
.cpp-note-toggle {
  display: none; width: 100%; align-items: center; justify-content: space-between;
  gap: 8px; padding: 8px 12px; margin-top: 8px; border: 1px solid var(--cpp-line);
  border-radius: 10px; background: var(--cpp-card); color: var(--cpp-ink);
  font-size: 13px; font-weight: 650; cursor: pointer;
}
.cpp-note-toggle-label { display: inline-flex; align-items: center; gap: 6px; }
.cpp-note-toggle::after { content: "展开"; font-size: 12px; font-weight: 500; color: var(--cpp-muted); }
.cpp-note-wrap:not(.is-collapsed) .cpp-note-toggle::after { content: "收起"; }
.cpp-theme [hidden] { display: none !important; }
.cpp-dialog-overlay {
  position: fixed; inset: 0; background: rgba(9, 9, 11, 0.48); z-index: 10000;
  display: flex; align-items: center; justify-content: center; padding: 16px;
}
.cpp-dialog {
  background: var(--cpp-card); color: var(--cpp-ink); border-radius: 18px; padding: 24px 26px;
  max-width: 420px; width: 100%; box-shadow: var(--cpp-shadow-lg); border: 1px solid var(--cpp-line);
}
.cpp-dialog-title { font-size: 17px; font-weight: 750; margin-bottom: 10px; letter-spacing: -0.02em; }
.cpp-dialog-body { font-size: 14px; color: var(--cpp-muted); line-height: 1.65; margin-bottom: 20px; }
.cpp-dialog-actions { display: flex; flex-wrap: wrap; gap: 10px; justify-content: flex-end; }
.cpp-dialog-actions .cpp-btn { text-decoration: none; }

/* ===== 空态 ===== */
.cpp-empty { text-align: center; padding: 50px 20px; color: var(--cpp-muted); font-size: 15px; }
.cpp-empty svg { margin-bottom: 14px; opacity: 0.4; }
.cpp-error-card { color: var(--cpp-bad); min-height: 0; }

/* ===== 侧栏卡片 ===== */
.cpp-sb-card {
  background: var(--cpp-card); border-radius: var(--cpp-radius); padding: 16px;
  box-shadow: var(--cpp-shadow); border: 1px solid var(--cpp-line); margin-bottom: 14px;
}
.cpp-sb-title { font-size: 11px; font-weight: 700; color: var(--cpp-muted); margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.08em; }
.cpp-sb-title-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.cpp-sb-title-row .cpp-sb-title { margin-bottom: 0; }
.cpp-sb-stats { display: flex; gap: 6px; }
.cpp-sb-stats-item { flex: 1; text-align: center; padding: 8px 4px; background: var(--cpp-paper); border-radius: 8px; }
.cpp-sb-stats-val { font-size: 16px; font-weight: 750; color: var(--cpp-ink); font-variant-numeric: tabular-nums; }
.cpp-sb-stats-lbl { font-size: 10px; color: var(--cpp-muted); margin-top: 2px; }

/* ===== 题号面板 ===== */
.cpp-qgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(34px, 1fr)); gap: 5px; margin-bottom: 4px; }
.cpp-qcell {
  aspect-ratio: 1; display: flex; align-items: center; justify-content: center;
  border-radius: 7px; font-size: 11px; font-weight: 700; cursor: pointer;
  border: 2px solid transparent; background: var(--cpp-paper); color: var(--cpp-muted);
  transition: 0.12s; user-select: none; position: relative; font-variant-numeric: tabular-nums;
}
.cpp-qcell:hover { transform: scale(1.08); border-color: var(--cpp-accent); }
.cpp-qcell.picked { background: var(--cpp-accent-soft); color: var(--cpp-accent); }
.cpp-qcell.correct { background: var(--cpp-ok-soft); color: var(--cpp-ok); }
/* 对错状态不能只靠红绿色相区分（红绿色弱不可辨）：错题加虚线边框，两态右下角加 ✓/✗ 角标 */
.cpp-qcell.wrong { background: var(--cpp-bad-soft); color: var(--cpp-bad); border-style: dashed; border-color: var(--cpp-bad); }
.cpp-qcell.correct::after,
.cpp-qcell.wrong::after {
  content: ''; position: absolute; right: 3px; bottom: 2px;
  font-size: 8px; font-weight: 900; line-height: 1; pointer-events: none;
}
.cpp-qcell.correct::after { content: '✓'; }
.cpp-qcell.wrong::after { content: '✗'; }
.cpp-qcell.current { border-color: var(--cpp-accent); box-shadow: 0 0 0 3px var(--cpp-accent-soft); animation: cpp-pulse 1.8s ease-in-out infinite; }
@keyframes cpp-pulse {
  0%, 100% { box-shadow: 0 0 0 2px var(--cpp-accent-soft); }
  50% { box-shadow: 0 0 0 4px var(--cpp-accent-soft); }
}
.cpp-qgrid-legend { display: flex; gap: 10px; margin-top: 8px; font-size: 10px; color: var(--cpp-muted); flex-wrap: wrap; }
.cpp-qgrid-legend-item { display: flex; align-items: center; gap: 3px; }
.cpp-qgrid-legend-dot { width: 8px; height: 8px; border-radius: 3px; }
.cpp-legend-current { background: var(--cpp-paper); border: 1px solid var(--cpp-accent); }
/* 图例升级为迷你格子并带 ✓/✗，与格子的实际呈现一致（色弱下仅靠圆点颜色不可辨） */
.cpp-legend-correct, .cpp-legend-wrong {
  width: 15px; height: 15px; border-radius: 5px;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 9px; font-weight: 900; line-height: 1;
}
.cpp-legend-correct { background: var(--cpp-ok-soft); border: 1px solid var(--cpp-ok); }
.cpp-legend-correct::after { content: '✓'; }
.cpp-legend-wrong { background: var(--cpp-bad-soft); border: 1px dashed var(--cpp-bad); }
.cpp-legend-wrong::after { content: '✗'; }
.cpp-legend-picked { background: var(--cpp-accent-soft); border: 1px solid var(--cpp-accent); }
.cpp-legend-unattempted { background: var(--cpp-paper); border: 1px solid var(--cpp-line); }
.cpp-grid-count { font-size: 11px; color: var(--cpp-muted); }

/* ===== 动效 ===== */
@keyframes cpp-fade-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }
.cpp-card.cpp-fade-enter { animation: cpp-fade-in 0.42s ease-out both; }

/* ===== Toast ===== */
.cpp-toast {
  position: fixed; left: 50%; bottom: 88px; transform: translateX(-50%) translateY(8px);
  background: var(--cpp-ink); color: var(--cpp-card); padding: 10px 16px; border-radius: 999px;
  font-size: 13px; font-weight: 600; z-index: 10001; opacity: 0; pointer-events: none;
  transition: opacity 0.2s, transform 0.2s;
}
.cpp-toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===== 移动端 ===== */
.cpp-mobile-dock {
  display: none; position: fixed; left: 0; right: 0; bottom: 0; z-index: 30;
  background: color-mix(in srgb, var(--cpp-card) 92%, transparent); backdrop-filter: blur(12px);
  border-top: 1px solid var(--cpp-line); padding: 6px 8px calc(6px + env(safe-area-inset-bottom));
  gap: 6px; justify-content: space-between;
}
.cpp-mobile-dock .cpp-btn { flex: 1; justify-content: center; padding: 8px 6px; font-size: 13px; white-space: nowrap; }
.cpp-mobile-dock #cpp-dock-submit { font-size: 12px; padding-left: 2px; padding-right: 2px; }
.cpp-sheet-backdrop { display: none; position: fixed; inset: 0; background: rgba(9, 9, 11, 0.4); z-index: 35; }
.cpp-sheet-backdrop.is-open { display: block; }
.cpp-mobile-dock[hidden], .cpp-sheet-backdrop[hidden] { display: none !important; }

@media (min-width: 961px) {
  .cpp-mobile-dock, .cpp-sheet-backdrop, .cpp-note-toggle { display: none !important; }
  .cpp-note-wrap.is-collapsed .cpp-note-card { display: block; }
}
@media (max-width: 960px) {
  .cpp-shell { width: 100%; max-width: none; margin: 0; padding: 0 10px calc(64px + env(safe-area-inset-bottom)); }
  .cpp-top { position: static; gap: 8px; padding: 8px 0; }
  .cpp-page-title { font-size: 16px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .cpp-page-sub { display: none; }
  /* chips 是章节/题库列表的唯一入口，移动端保留紧凑展示 */
  .cpp-info-row { margin-top: 4px; }
  .cpp-info-chip { max-width: 140px; font-size: 11px; padding: 2px 8px; }
  .cpp-top-actions { gap: 4px; }
  .cpp-nav-btn { height: 28px; padding: 0 6px; }
  .cpp-total-badge { padding: 3px 8px; font-size: 11px; }
  .cpp-score-badge { padding: 3px 8px; font-size: 12px; }
  .cpp-back { width: 32px; height: 32px; border-radius: 8px; }
  .cpp-cockpit-tag { font-size: 13px; }
  .cpp-chapter-track { min-width: 80px; height: 6px; }
  .cpp-chapter-meta { font-size: 11px; }
  .cpp-layout { flex-direction: column; gap: 0; }
  .cpp-main { width: 100%; }
  .cpp-card { padding: 14px 14px 12px; border-radius: 12px; min-height: 0; }
  .cpp-question-content { font-size: 15px; line-height: 1.6; margin-bottom: 10px; }
  .cpp-options { gap: 6px; margin-bottom: 12px; }
  .cpp-option { padding: 10px 12px; gap: 8px; border-radius: 10px; font-size: 14px; }
  .cpp-actions { display: none; }
  .cpp-mode-btn { padding: 3px 8px; font-size: 11px; }
  .cpp-paper-bar { flex-direction: column; align-items: stretch; margin: 0 0 10px; padding: 8px 10px; }
  .cpp-paper-bar-actions .cpp-btn { flex: 1; justify-content: center; padding: 7px 10px; font-size: 13px; }
  .cpp-result { padding: 10px 12px; margin-bottom: 10px; font-size: 14px; }
  .cpp-solution { padding: 12px 14px; }
  .cpp-empty { padding: 28px 12px; }
  .cpp-note-wrap { flex-shrink: 0; }
  .cpp-note-toggle { display: flex; }
  .cpp-note-wrap.is-collapsed .cpp-note-card { display: none; }
  .cpp-note-wrap:not(.is-collapsed) .cpp-note-toggle {
    border-radius: 10px 10px 0 0; border-bottom: none; margin-top: 8px;
  }
  .cpp-note-wrap:not(.is-collapsed) .cpp-note-card {
    max-height: min(38vh, 280px); overflow: auto; margin-bottom: 0;
    border-radius: 0 0 10px 10px;
  }
  .cpp-note-body, .cpp-note-stack { min-height: 0; padding: 12px; }
  .cpp-note-editor { min-height: 72px; }
  .cpp-ai-inner { min-height: 96px; }
  .cpp-note-view-empty { padding: 12px 0; }
  /* 侧栏收起为底部抽屉，由 dock「题号」呼出 */
  .cpp-side {
    display: none; position: fixed; left: 0; right: 0; bottom: 0; width: 100%;
    max-height: 70vh; overflow: auto; z-index: 40;
    padding: 12px 12px calc(64px + env(safe-area-inset-bottom));
    background: var(--cpp-paper); border-radius: 18px 18px 0 0; box-shadow: var(--cpp-shadow-lg);
  }
  .cpp-side.is-open { display: block; }
  .cpp-mobile-dock:not([hidden]) { display: flex; }
  .cpp-pset-drawer { width: 100vw; border-right: none; }
  .cpp-switcher-menu { width: min(360px, 92vw); }
  .cpp-toast { bottom: calc(64px + env(safe-area-inset-bottom)); }
}