/* CT-02 错题批改与变式：学生端 /study、老师端 /teach、学生拍题页里的三种模式面板共用
   颜色全部取 style.css 的主题变量（浅色 / 暗色自动跟随） */

.ct-page { max-width: 720px; margin: 0 auto; padding: 0 14px calc(84px + env(safe-area-inset-bottom)); }
.ct-top {
  position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 10px;
  padding: 12px 14px; background: var(--header-bg); backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px); border-bottom: 1px solid var(--glass-border);
}
.ct-top h1 { font-size: 16px; font-weight: 700; margin: 0; color: var(--text-primary); flex: 1; min-width: 0;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ct-link { font: inherit; font-size: 13px; color: var(--accent-primary); text-decoration: none; white-space: nowrap;
  background: none; border: none; cursor: pointer; padding: 6px 4px; }

.ct-card {
  background: var(--glass-card); border: 1px solid var(--glass-border); border-radius: var(--radius-md);
  box-shadow: var(--card-shadow); padding: 14px; margin: 12px 0; color: var(--text-primary);
}
.ct-card h2 { font-size: 15px; margin: 0 0 8px; }
.ct-card h3 { font-size: 14px; margin: 10px 0 6px; }
.ct-muted { color: var(--text-secondary); font-size: 12.5px; line-height: 1.6; }
.ct-small { font-size: 12px; color: var(--text-muted); }
.ct-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.ct-row.between { justify-content: space-between; }
.ct-grow { flex: 1; min-width: 0; }
.ct-list-item { display: block; width: 100%; text-align: left; cursor: pointer; font: inherit; }
.ct-list-item:active { transform: scale(0.995); }
.ct-empty { text-align: center; color: var(--text-muted); padding: 32px 10px; font-size: 13.5px; }

.ct-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 40px;
  padding: 8px 16px; border-radius: 999px; border: 1px solid transparent; font-size: 14px; font-weight: 600;
  cursor: pointer; background: var(--accent-primary); color: #fff; text-decoration: none;
}
.ct-btn[disabled] { opacity: .45; cursor: not-allowed; }
.ct-btn.ghost { background: transparent; color: var(--accent-primary); border-color: var(--glass-border-focus); }
.ct-btn.soft { background: var(--chip-bg); color: var(--chip-text); border-color: var(--chip-border); }
.ct-btn.danger { background: var(--accent-rose); }
.ct-btn.ok { background: var(--accent-green); }
.ct-btn.block { width: 100%; }
.ct-btn.small { min-height: 32px; padding: 4px 12px; font-size: 12.5px; }

.ct-input, .ct-select, .ct-textarea {
  width: 100%; box-sizing: border-box; padding: 10px 12px; border-radius: var(--radius-sm);
  border: 1px solid var(--input-border); background: var(--input-bg); color: var(--input-text); font-size: 15px;
}
.ct-textarea { min-height: 64px; resize: vertical; }

.ct-badge { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 11.5px; font-weight: 600;
  background: var(--chip-bg); color: var(--chip-text); white-space: nowrap; }
.ct-badge.right { background: rgba(5, 150, 105, .14); color: var(--accent-green); }
.ct-badge.wrong { background: rgba(225, 29, 72, .12); color: var(--accent-rose); }
.ct-badge.pending { background: rgba(217, 119, 6, .14); color: var(--accent-amber); }
.ct-badge.todo { background: var(--limit-pill-bg); color: var(--limit-pill-text); }
.ct-dot { display: inline-block; min-width: 16px; height: 16px; padding: 0 4px; border-radius: 999px; background: var(--accent-rose);
  color: #fff; font-size: 10.5px; line-height: 16px; text-align: center; font-weight: 700; vertical-align: top; }

/* 底部导航 */
.ct-tabs {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 30; display: flex;
  background: var(--bottom-bar-bg); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-top: 1px solid var(--glass-border); padding-bottom: env(safe-area-inset-bottom);
}
.ct-tabs button {
  flex: 1; background: none; border: none; padding: 8px 0 7px; font-size: 11.5px; color: var(--text-secondary);
  cursor: pointer; position: relative; display: flex; flex-direction: column; align-items: center; gap: 2px;
}
.ct-tabs button .ico { font-size: 19px; line-height: 1; }
.ct-tabs button.active { color: var(--accent-primary); font-weight: 700; }
.ct-tabs button .ct-dot { position: absolute; top: 3px; left: calc(50% + 6px); }

/* 题目 */
.ct-q { border-top: 1px dashed var(--glass-border); padding-top: 12px; margin-top: 12px; }
.ct-q:first-child { border-top: none; margin-top: 0; padding-top: 0; }
.ct-q-head { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; flex-wrap: wrap; }
.ct-q-no { font-weight: 800; color: var(--accent-primary); }
.ct-stem { font-size: 14.5px; line-height: 1.75; }   /* 不再整块横向滑动：长公式由 math-fit 处理 */
.ct-stem p { margin: 0 0 4px; }
.ct-opts { display: grid; gap: 8px; margin-top: 8px; }
.ct-opt {
  display: flex; gap: 8px; align-items: flex-start; padding: 10px 12px; border-radius: var(--radius-sm);
  border: 1px solid var(--input-border); background: var(--input-bg); color: var(--text-primary);
  cursor: pointer; text-align: left; font-size: 14px; line-height: 1.6;
}
.ct-opt.on { border-color: var(--accent-primary); box-shadow: 0 0 0 2px var(--glass-border-focus); }
.ct-opt b { color: var(--accent-primary); }
.ct-photos { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 8px; }
.ct-thumb { position: relative; width: 72px; height: 72px; border-radius: 8px; overflow: hidden;
  border: 1px solid var(--glass-border); background: var(--chip-bg); }
.ct-thumb img { width: 100%; height: 100%; object-fit: cover; }
.ct-thumb .del { position: absolute; top: 2px; right: 2px; width: 22px; height: 22px; border-radius: 50%; border: none;
  background: rgba(15, 23, 42, .65); color: #fff; font-size: 13px; cursor: pointer; }
.ct-add-photo { width: 72px; height: 72px; border-radius: 8px; border: 1.5px dashed var(--upload-border);
  background: var(--upload-bg); color: var(--text-secondary); font-size: 12px; cursor: pointer; }

/* 三种模式面板 */
.ct-solve { margin-top: 10px; border-radius: var(--radius-md); border: 1px solid var(--report-card-border);
  background: var(--report-card-bg); padding: 12px; }
.ct-seg { display: flex; background: var(--type-tab-bg); border-radius: 999px; padding: 3px; gap: 3px; }
.ct-seg button { flex: 1; border: none; background: transparent; border-radius: 999px; padding: 8px 4px; font-size: 13px;
  color: var(--text-secondary); cursor: pointer; font-weight: 600; }
.ct-seg button.on { background: var(--type-tab-active); color: var(--type-tab-active-text); box-shadow: var(--type-tab-active-shadow); }
.ct-seg button[disabled] { opacity: .4; cursor: not-allowed; }
.ct-lock-note { font-size: 12px; color: var(--accent-amber); margin-top: 6px; }
.ct-step { margin-top: 10px; }
.ct-step-prog { font-size: 12px; color: var(--text-muted); }
.ct-step-title { font-weight: 700; font-size: 14.5px; margin: 4px 0; }
.ct-step-hint { background: var(--input-bg); border-left: 3px solid var(--accent-primary); padding: 8px 10px;
  border-radius: 6px; font-size: 14px; line-height: 1.7; }
.ct-step-hint p, .ct-step-explain p, .ct-gcard dd p { margin: 0; }
.ct-step-explain { margin-top: 8px; background: var(--user-msg-bg); border: 1px solid var(--user-msg-border);
  padding: 8px 10px; border-radius: 6px; font-size: 14px; line-height: 1.7; color: var(--text-primary); }
.ct-step-done { color: var(--text-secondary); font-size: 13px; margin-top: 6px; }
.ct-step-done details { margin-top: 4px; }
.ct-solve-body { margin-top: 10px; font-size: 14px; line-height: 1.75; }   /* 同上：只让放不下的那一行公式自己滑 */

/* 批改卡片 */
.ct-gcard { margin-top: 10px; border-radius: var(--radius-md); border: 1px solid var(--glass-border);
  background: var(--input-bg); padding: 12px; }
.ct-gcard .score { font-size: 15px; font-weight: 800; }
.ct-gcard .score small { font-weight: 500; color: var(--text-muted); font-size: 11.5px; margin-left: 6px; }
.ct-gcard dl { margin: 8px 0 0; }
.ct-gcard dt { font-size: 12px; color: var(--text-muted); margin-top: 8px; }
.ct-gcard dd { margin: 2px 0 0; font-size: 14px; line-height: 1.7; }
.ct-gcard .cheer { margin-top: 10px; padding: 8px 10px; border-radius: 8px; background: rgba(5, 150, 105, .1);
  color: var(--accent-green); font-size: 13.5px; }
.ct-photo-mark { position: relative; display: inline-block; max-width: 100%; margin-top: 8px; }
.ct-photo-mark img { display: block; max-width: 100%; border-radius: 8px; }
.ct-photo-mark .box { position: absolute; border: 2.5px solid var(--accent-rose); border-radius: 40%;
  box-shadow: 0 0 0 2px rgba(255, 255, 255, .6); pointer-events: none; }
.ct-photo-mark .box.missing { border-style: dashed; border-color: var(--accent-amber); }

/* 弹层 */
.ct-sheet-mask { position: fixed; inset: 0; background: rgba(15, 23, 42, .45); z-index: 50; display: flex;
  align-items: flex-end; justify-content: center; }
.ct-sheet { width: 100%; max-width: 720px; max-height: 88vh; overflow-y: auto; background: var(--modal-bg);
  color: var(--text-primary); border-radius: 18px 18px 0 0; padding: 16px 16px calc(16px + env(safe-area-inset-bottom));
  box-shadow: var(--modal-shadow); }
.ct-check { display: flex; gap: 10px; align-items: flex-start; padding: 10px 0; border-bottom: 1px solid var(--glass-border); }
.ct-check input { width: 20px; height: 20px; margin-top: 2px; flex: none; }

.ct-toast { position: fixed; left: 50%; bottom: calc(96px + env(safe-area-inset-bottom)); transform: translateX(-50%);
  background: rgba(15, 23, 42, .88); color: #fff; padding: 10px 16px; border-radius: 999px; font-size: 13px; z-index: 60;
  max-width: 86vw; text-align: center; }
.ct-stat { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.ct-stat div { background: var(--input-bg); border-radius: 10px; padding: 10px 6px; text-align: center; }
.ct-stat b { display: block; font-size: 20px; color: var(--accent-primary); }
.ct-stat span { font-size: 11.5px; color: var(--text-muted); }
.ct-bar { height: 8px; border-radius: 99px; background: var(--chip-bg); overflow: hidden; margin-top: 4px; }
.ct-bar i { display: block; height: 100%; background: var(--accent-rose); border-radius: 99px; }

/* 学生拍题页里的提示与面板 */
.ct-visible-hint { font-size: 12px; color: var(--text-secondary); margin: 0 0 10px; display: flex; gap: 6px; align-items: center; }

.ct-entry-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 10px; margin: 12px 0 0;
  padding: 11px 16px; border-radius: var(--radius-md); background: var(--glass-card); border: 1px solid var(--glass-border);
  box-shadow: var(--card-shadow); color: var(--text-primary); text-decoration: none; font-size: 14px; font-weight: 600;
}
.ct-entry-right { display: inline-flex; align-items: center; gap: 8px; }
.ct-entry-arrow { color: var(--text-muted); font-size: 18px; line-height: 1; }
.ct-qimg { max-width: 100%; height: auto; vertical-align: middle; }
.ct-qimg.auth-img-failed { display: inline-block; min-width: 72px; min-height: 22px; border: 1px dashed var(--glass-border);
  border-radius: 6px; font-size: 12px; color: var(--text-muted); }

/* CT-FX01A：一页一题、题号圆点、多空填空 */
.ct-dots { display: flex; gap: 6px; flex-wrap: wrap; }
.ct-dotnav { width: 30px; height: 30px; border-radius: 50%; border: 2px solid transparent; font-size: 12.5px; font-weight: 700;
  cursor: pointer; background: var(--chip-bg); color: var(--text-secondary); padding: 0; }
.ct-dotnav.right { background: var(--accent-green); color: #fff; }
.ct-dotnav.wrong { background: var(--accent-rose); color: #fff; }
.ct-dotnav.pending { background: var(--accent-amber); color: #fff; }
.ct-dotnav.done { background: rgba(37, 99, 235, .16); color: var(--accent-primary); }
.ct-dotnav.cur { border-color: var(--text-primary); box-shadow: 0 0 0 2px var(--glass-border-focus); }
.ct-dots-legend { font-size: 11.5px; color: var(--text-muted); margin-top: 6px; }
.ct-pager { display: flex; align-items: center; gap: 10px; margin: 12px 0; }
.ct-pager .ct-btn { flex: 1; }
.ct-one .ct-stem { font-size: 16.5px; line-height: 1.85; }
.ct-one .ct-opt { font-size: 15.5px; }
.ct-one .ct-qimg { max-width: 100%; }
.ct-blanks { display: grid; gap: 8px; margin-top: 8px; }
.ct-blank { display: flex; align-items: center; gap: 8px; }
.ct-blank span { font-size: 12.5px; color: var(--text-secondary); white-space: nowrap; min-width: 3.4em; }

/* CT-FX01A 第四节：拍题讲解上方的科目条 */
.subject-bar { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin: 2px 0 8px; }
.subject-chip { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 12px; font-weight: 600;
  background: var(--chip-bg); color: var(--chip-text); border: 1px solid var(--chip-border); }
.subject-change { border: none; background: none; padding: 0; font-size: 12px; color: var(--accent-primary); cursor: pointer;
  text-decoration: underline; text-underline-offset: 2px; }
.subject-pick { width: 100%; display: flex; align-items: center; gap: 6px; flex-wrap: wrap; font-size: 12px; color: var(--text-secondary); }
.subject-pick button { border: 1px solid var(--chip-border); background: var(--chip-bg); color: var(--chip-text); border-radius: 999px;
  padding: 4px 12px; font-size: 12.5px; cursor: pointer; }
.subject-pick button[disabled], .subject-change[disabled] { opacity: .5; cursor: default; }
.history-type-tag.subject-tag { margin-left: 6px; background: rgba(217, 119, 6, .14); color: var(--accent-amber); }