:root {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --surface-2: #eef4fb;
  --surface-3: #f8fbff;
  --text: #152033;
  --muted: #64748b;
  --line: #d9e2ef;
  --primary: #0b5cab;
  --primary-2: #084a8d;
  --primary-soft: #e8f3ff;
  --danger: #b42318;
  --success: #067647;
  --warning: #b54708;
  --shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
  --radius: 18px;
  --reader-size: 17px;
  --source-pane: 40%;
  --mobile-source-pane: 43%;
  --header-height: 68px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.6;
}
body.dark {
  --bg: #0f172a;
  --surface: #172033;
  --surface-2: #202b42;
  --surface-3: #141d2f;
  --text: #eef4ff;
  --muted: #b6c2d6;
  --line: #33415b;
  --primary: #69aef4;
  --primary-2: #90c8ff;
  --primary-soft: #183552;
  --shadow: none;
}
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
a { color: var(--primary); }
[hidden] { display: none !important; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  min-height: var(--header-height);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}
.header-inner {
  max-width: 1600px;
  min-height: var(--header-height);
  margin: auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  text-decoration: none;
  min-width: 0;
}
.brand-mark {
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, #0b5cab, #5c9fe0);
  color: #fff;
  font-weight: 900;
}
.brand-copy { min-width: 0; }
.brand strong, .brand small { display: block; }
.brand strong { font-size: 1.05rem; line-height: 1.25; }
.brand small { color: var(--muted); font-size: 0.82rem; }
.header-actions { display: flex; gap: 8px; }
.icon-btn, .mobile-menu-btn {
  min-width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 11px;
  background: var(--surface);
  color: var(--text);
  font-weight: 800;
}
.mobile-menu-btn { display: none; }

.page-shell {
  width: min(1600px, 100%);
  margin: auto;
  padding: 14px 18px 52px;
}
.exam-toolbar-card,
.workspace-panel,
.review-section,
.empty-state {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.exam-toolbar-card {
  position: sticky;
  top: calc(var(--header-height) + 6px);
  z-index: 100;
  padding: 12px 14px;
  background: color-mix(in srgb, var(--surface) 96%, transparent);
  backdrop-filter: blur(12px);
}
.exam-toolbar {
  display: grid;
  grid-template-columns: minmax(190px, 1.1fr) minmax(100px, 0.5fr) minmax(120px, 0.65fr) minmax(260px, 1.45fr) auto;
  gap: 10px;
  align-items: end;
}
label, .field-wrap { display: grid; gap: 5px; }
.exam-toolbar label > span,
.field-label,
.utility-content label > span,
.send-card label > span {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
}
.exam-toolbar input,
.exam-toolbar select,
.utility-content input,
.utility-content select,
.answer-card textarea,
.score-line input,
.send-card input,
.select-button {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  outline: none;
}
.exam-toolbar select,
.select-button { min-height: 42px; padding: 9px 11px; }
.select-button { position: relative; text-align: left; padding-right: 34px; }
.select-button::after { content: "⌄"; position: absolute; right: 12px; top: 8px; }
input:focus, select:focus, textarea:focus, .select-button:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 18%, transparent);
}
.province-wrap { position: relative; }
.province-menu {
  position: absolute;
  top: calc(100% + 7px);
  left: 0;
  right: 0;
  z-index: 140;
  max-height: 244px;
  overflow-y: auto;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  box-shadow: 0 18px 42px rgba(15, 23, 42, 0.2);
}
.province-option {
  width: 100%;
  min-height: 44px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--text);
  text-align: left;
  padding: 9px 11px;
}
.province-option:hover,
.province-option.is-selected {
  background: var(--surface-2);
  color: var(--primary);
  font-weight: 800;
}
.data-health {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  max-width: 220px;
  padding: 8px 11px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 800;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.data-status-dot {
  width: 9px;
  height: 9px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: #d97706;
  box-shadow: 0 0 0 4px rgba(217, 119, 6, 0.12);
}
.data-health.is-success .data-status-dot { background: #12b76a; box-shadow: 0 0 0 4px rgba(18, 183, 106, 0.12); }
.data-health.is-error .data-status-dot { background: #f04438; box-shadow: 0 0 0 4px rgba(240, 68, 56, 0.12); }
.data-health.is-error { color: var(--danger); }
.utility-details {
  margin-top: 9px;
  border-top: 1px solid var(--line);
  padding-top: 8px;
}
.utility-details summary {
  cursor: pointer;
  color: var(--text);
  font-size: 0.84rem;
  font-weight: 900;
}
.utility-details summary span { color: var(--muted); font-weight: 500; }
.utility-content { padding-top: 10px; }
.student-grid { display: grid; grid-template-columns: 1.2fr 0.5fr 1.2fr; gap: 10px; }
.utility-content input { min-height: 42px; padding: 9px 11px; }
.api-key-wrap { display: grid; grid-template-columns: 1fr auto; gap: 10px; align-items: end; margin-top: 10px; }
.password-field { display: flex; }
.password-field input { border-radius: 10px 0 0 10px; }
.password-field button {
  border: 1px solid var(--line);
  border-left: 0;
  border-radius: 0 10px 10px 0;
  background: var(--surface-2);
  color: var(--text);
  padding: 0 13px;
}
.api-note, .local-note { margin: 7px 0 0; color: var(--muted); font-size: 0.78rem; }

.status-bar {
  margin: 12px 0 0;
  padding: 10px 13px;
  border-radius: 11px;
  background: var(--surface-2);
  color: var(--muted);
  font-weight: 700;
}
.status-bar.error { color: var(--danger); background: #fff0ed; border: 1px solid #fecdca; }
.dark .status-bar.error { background: #3b1f21; border-color: #713438; }
.empty-state { margin-top: 14px; padding: 46px 20px; text-align: center; }
.empty-icon { font-size: 2.5rem; }

.workspace {
  --source-pane: 40%;
  margin-top: 14px;
  display: grid;
  grid-template-columns: minmax(300px, var(--source-pane)) 12px minmax(420px, 1fr);
  height: min(860px, calc(100dvh - 154px));
  min-height: 640px;
  gap: 0;
  overflow: hidden;
}
.workspace-panel {
  min-width: 0;
  min-height: 0;
  border-radius: 18px;
  overflow: auto;
  scrollbar-gutter: stable;
  overscroll-behavior: contain;
}
.paper-panel { padding: 0 18px 22px; border-radius: 18px 0 0 18px; }
.answer-panel { padding: 0 18px 22px; border-radius: 0 18px 18px 0; border-color: color-mix(in srgb, var(--primary) 35%, var(--line)); }
.workspace-splitter {
  position: relative;
  display: grid;
  place-items: center;
  background: transparent;
  cursor: col-resize;
  touch-action: none;
  outline: none;
}
.workspace-splitter::before {
  content: "";
  position: absolute;
  inset: 0 3px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--line) 72%, transparent);
}
.workspace-splitter span {
  position: relative;
  z-index: 1;
  width: 6px;
  height: 54px;
  border-radius: 999px;
  background: var(--primary);
  opacity: 0.55;
}
.splitter-hint { display: none; }
.workspace-splitter:hover span,
.workspace-splitter:focus-visible span,
.workspace.is-resizing .workspace-splitter span { opacity: 1; }
.workspace.is-resizing { user-select: none; }

.panel-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  padding: 15px 0 12px;
  border-bottom: 1px solid var(--line);
}
.panel-heading-sticky,
.answer-toolbar-sticky {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--surface) 96%, transparent);
  backdrop-filter: blur(10px);
}
.panel-heading h1,
.panel-heading h2 { margin: 2px 0 0; line-height: 1.25; }
.panel-heading h1 { font-size: 1.25rem; }
.panel-kicker { color: var(--primary); font-size: 0.7rem; letter-spacing: 0.1em; font-weight: 900; }
.current-exam-label { margin: 3px 0 0; color: var(--muted); font-size: 0.78rem; }
.source-heading-actions { display: grid; justify-items: end; gap: 8px; }
.exam-meta { display: flex; gap: 6px; flex-wrap: wrap; justify-content: flex-end; }
.exam-meta span {
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
}
.document-content {
  padding-top: 16px;
  font-family: "Noto Serif", "Times New Roman", Georgia, serif;
  font-size: var(--reader-size);
  line-height: 1.82;
  overflow-wrap: anywhere;
  font-kerning: normal;
  font-variant-ligatures: normal;
  text-rendering: optimizeLegibility;
  letter-spacing: normal;
  word-spacing: normal;
}
.document-content img,
.document-content iframe { max-width: 100%; }
.document-content table { width: 100%; border-collapse: collapse; display: block; overflow: auto; }
.document-content th,
.document-content td { border: 1px solid var(--line); padding: 8px; }
.document-content blockquote { margin: 1rem 0; padding: 0.25rem 1rem; border-left: 4px solid var(--primary); background: var(--surface-2); }
.document-content > :first-child { margin-top: 0; }
.workspace,
.review-section { scroll-margin-top: calc(var(--header-height) + 110px); }
.pdf-protected-shell { width: 100%; user-select: none; -webkit-user-select: none; }
.pdf-protected-viewport {
  position: relative;
  width: 100%;
  height: calc(100dvh - 255px);
  min-height: 500px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface-2);
}
.pdf-frame {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
}
.pdf-toolbar-mask {
  position: absolute;
  z-index: 4;
  top: 0;
  left: 0;
  right: 0;
  height: 52px;
  display: flex;
  align-items: center;
  padding: 0 14px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 98%, transparent);
  color: var(--muted);
  font-family: Inter, system-ui, sans-serif;
  font-size: 0.75rem;
  font-weight: 800;
  pointer-events: auto;
  user-select: none;
  -webkit-user-select: none;
}
.pdf-protected-note { margin: 8px 2px 0; color: var(--muted); font-family: Inter, sans-serif; font-size: 0.75rem; font-weight: 700; line-height: 1.45; }

.answer-shell { min-height: 100%; }
.answer-toolbar-sticky { margin: 0 -1px; padding-bottom: 9px; }
.answer-heading { padding-bottom: 10px; }
.save-indicator { color: var(--success); font-size: 0.76rem; font-weight: 900; }
.workspace-view-controls {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  padding: 8px 0 7px;
}
.workspace-view-controls > span { color: var(--muted); font-size: 0.74rem; font-weight: 800; }
.split-preset-btn {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  padding: 5px 9px;
  font-size: 0.72rem;
  font-weight: 800;
}
.split-preset-btn:hover,
.split-preset-btn.is-active { border-color: var(--primary); background: var(--primary-soft); color: var(--primary); }
.question-nav {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 2px 0 8px;
  scrollbar-width: thin;
}
.question-nav button {
  flex: 0 0 auto;
  min-width: 42px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--surface);
  color: var(--muted);
  padding: 6px 8px;
  font-size: 0.72rem;
  font-weight: 900;
}
.question-nav button.is-writing { border-style: dashed; }
.question-nav button.is-active,
.question-nav button:hover { border-color: var(--primary); background: var(--primary); color: #fff; }
.progress-compact {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px;
  align-items: end;
}
.progress-wrap { min-width: 0; }
.progress-meta { display: flex; justify-content: space-between; gap: 10px; color: var(--muted); font-size: 0.76rem; }
.progress-track { height: 7px; overflow: hidden; margin-top: 5px; border-radius: 999px; background: var(--surface-2); }
.progress-track span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, #0b5cab, #56a0e5); transition: width 0.25s; }
.score-summary {
  min-width: 128px;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 10px;
  background: var(--surface-2);
  font-size: 0.75rem;
}
.answer-fields { display: grid; gap: 13px; padding-top: 14px; }
.answer-card {
  scroll-margin-top: 210px;
  border: 1px solid var(--line);
  border-radius: 15px;
  padding: 14px;
  background: var(--surface);
  transition: border-color 0.18s, box-shadow 0.18s, transform 0.18s;
}
.answer-card.is-active {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 12%, transparent);
}
.answer-card.is-writing { border-color: color-mix(in srgb, var(--primary) 42%, var(--line)); }
.answer-card.writing-expanded textarea { min-height: 430px; }
.answer-card-head { display: flex; justify-content: space-between; gap: 10px; align-items: flex-start; margin-bottom: 7px; }
.answer-card-head h3 { margin: 0; font-size: 0.98rem; }
.question-meta { color: var(--muted); font-size: 0.74rem; font-weight: 700; }
.question-prompt,
.review-question,
.review-box,
.reference-card,
.answer-card textarea {
  font-family: "Noto Serif", "Times New Roman", Georgia, serif;
  font-kerning: normal;
  font-variant-ligatures: normal;
  text-rendering: optimizeLegibility;
  letter-spacing: normal;
  word-spacing: normal;
}
.question-prompt { margin: 8px 0; padding: 10px 11px; border-radius: 10px; background: var(--surface-2); }
.answer-card textarea {
  min-height: 125px;
  padding: 11px 12px;
  resize: vertical;
  line-height: 1.65;
}
.answer-card.is-writing textarea { min-height: 250px; }
.answer-tools { display: flex; gap: 7px; flex-wrap: wrap; margin-top: 8px; }
.mini-btn {
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--surface);
  color: var(--text);
  padding: 7px 10px;
  font-size: 0.76rem;
  font-weight: 800;
}
.mini-btn:hover { border-color: var(--primary); color: var(--primary); }
.source-jump-btn { border-color: color-mix(in srgb, var(--primary) 35%, var(--line)); color: var(--primary); }
.hint-box, .ai-result {
  margin-top: 8px;
  border: 1px solid color-mix(in srgb, var(--primary) 18%, var(--line));
  border-radius: 12px;
  background: var(--surface-2);
  font-size: 0.86rem;
}
.ai-scroll-box {
  max-height: min(46vh, 430px);
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  scrollbar-gutter: stable;
  scrollbar-width: thin;
  scrollbar-color: color-mix(in srgb, var(--primary) 62%, transparent) transparent;
  touch-action: pan-y;
}
.ai-scroll-box::-webkit-scrollbar { width: 8px; }
.ai-scroll-box::-webkit-scrollbar-track { background: transparent; }
.ai-scroll-box::-webkit-scrollbar-thumb {
  border: 2px solid transparent;
  border-radius: 999px;
  background: color-mix(in srgb, var(--primary) 58%, transparent);
  background-clip: padding-box;
}
.ai-scroll-head {
  position: sticky;
  top: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 9px 11px;
  border-bottom: 1px solid color-mix(in srgb, var(--primary) 14%, var(--line));
  background: color-mix(in srgb, var(--surface-2) 92%, white 8%);
  backdrop-filter: blur(4px);
}
.ai-scroll-head strong { font-size: 0.82rem; }
.ai-scroll-head span { color: var(--muted); font-size: 0.69rem; font-weight: 700; }
.ai-scroll-body {
  padding: 11px 12px 15px;
  line-height: 1.62;
  overflow-wrap: anywhere;
}
.ai-scroll-body > :first-child { margin-top: 0; }
.ai-scroll-body > :last-child { margin-bottom: 0; }
.ai-scroll-box.is-loading .ai-scroll-body { color: var(--muted); font-style: italic; }
.ai-scroll-box.is-error { border-color: color-mix(in srgb, var(--danger) 45%, var(--line)); }
.ai-scroll-box.is-error .ai-scroll-body { color: var(--danger); }

.score-line { display: flex; align-items: center; gap: 8px; margin-top: 9px; color: var(--muted); font-size: 0.78rem; }
.score-line input { width: 82px; padding: 7px 9px; }

.upload-block {
  margin-top: 12px;
  padding: 12px;
  border: 1px dashed color-mix(in srgb, var(--primary) 50%, var(--line));
  border-radius: 12px;
  background: color-mix(in srgb, var(--surface-2) 65%, transparent);
}
.upload-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; }
.upload-head strong { font-size: 0.88rem; }
.file-label {
  display: inline-flex !important;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--primary);
  border-radius: 9px;
  background: var(--surface);
  color: var(--primary) !important;
  padding: 7px 10px;
  font-size: 0.76rem !important;
  font-weight: 900 !important;
  cursor: pointer;
}
.file-label input { display: none; }
.upload-note { margin: 7px 0; color: var(--muted); font-size: 0.75rem; }
.image-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 9px; }
.image-card { overflow: hidden; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); }
.image-thumb { aspect-ratio: 4 / 3; display: grid; place-items: center; overflow: hidden; background: var(--surface-2); cursor: zoom-in; }
.image-thumb img { width: 100%; height: 100%; object-fit: cover; }
.image-caption { padding: 6px 7px; font-size: 0.7rem; font-weight: 800; }
.image-actions { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.image-actions button { border: 0; border-right: 1px solid var(--line); background: var(--surface); color: var(--text); padding: 6px 2px; }
.image-actions button:last-child { border-right: 0; color: var(--danger); }
.image-empty { padding: 6px 0; color: var(--muted); font-size: 0.8rem; }

.secondary-btn, .primary-btn, .danger-text-btn {
  border-radius: 10px;
  padding: 9px 13px;
  font-weight: 900;
}
.secondary-btn { border: 1px solid var(--line); background: var(--surface); color: var(--text); }
.primary-btn { border: 0; background: var(--primary); color: #fff; }
.primary-btn:hover { background: var(--primary-2); }
.primary-btn:disabled { opacity: 0.55; cursor: not-allowed; }
.danger-text-btn { border: 0; background: transparent; color: var(--danger); }
.full-width-btn { width: 100%; margin-top: 12px; }
.action-row { display: flex; justify-content: space-between; gap: 10px; margin-top: 12px; padding-bottom: 2px; }

.floating-source-btn {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 115;
  display: none;
  border: 1px solid rgba(255,255,255,0.7);
  border-radius: 999px;
  background: var(--primary);
  color: #fff;
  padding: 10px 14px;
  font-weight: 900;
  box-shadow: 0 14px 34px rgba(11, 92, 171, 0.35);
}

.review-section { margin-top: 16px; padding: 20px; }
.review-heading { display: flex; justify-content: space-between; gap: 14px; align-items: flex-start; padding-bottom: 14px; border-bottom: 1px solid var(--line); }
.review-heading h2 { margin: 2px 0 0; }
.review-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin: 16px 0; }
.review-tab { border: 1px solid var(--line); border-radius: 999px; background: var(--surface); color: var(--text); padding: 9px 13px; font-weight: 900; }
.review-tab.is-active { border-color: var(--primary); background: var(--primary); color: #fff; }
.review-panel { display: none; }
.review-panel.is-active { display: block; }
.review-question { margin: 12px 0; padding: 14px; border: 1px solid var(--line); border-radius: 14px; }
.review-question h3 { margin: 0 0 8px; }
.review-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.review-box { padding: 11px; border-radius: 11px; background: var(--surface-2); }
.review-box h4 { margin: 0 0 7px; font-family: Inter, sans-serif; font-size: 0.82rem; }
.reference-card { margin: 12px 0; padding: 15px; border: 1px solid var(--line); border-radius: 14px; }
.reference-card h3 { margin: 0 0 10px; }
.reference-note { padding: 10px; border-left: 4px solid var(--warning); background: #fff7ed; color: #7c2d12; font-family: Inter, sans-serif; font-size: 0.84rem; }
.dark .reference-note { background: #3a281d; color: #ffd7b0; }
.send-card { max-width: 900px; }
.send-card h3 { margin-bottom: 0.35rem; font-size: 1.2rem; }
.send-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 14px 0; }
.send-card input { min-height: 43px; padding: 10px 12px; }
.confirm-line { display: flex; align-items: flex-start; gap: 8px; }
.confirm-line input { width: auto; margin-top: 5px; }
.send-summary { margin: 12px 0; padding: 11px; border-radius: 11px; background: var(--surface-2); font-size: 0.86rem; }
.upload-progress { margin-top: 14px; }
.send-result { margin-top: 14px; padding: 12px; border-radius: 11px; }
.send-result.success { background: #ecfdf3; color: var(--success); }
.send-result.error { background: #fff0ed; color: var(--danger); }

/* AI chấm toàn bài trong phần kết quả */
.ai-score-card {
  padding: 16px;
  border: 1px solid color-mix(in srgb, var(--primary) 32%, var(--line));
  border-radius: 15px;
  background: linear-gradient(145deg, color-mix(in srgb, var(--primary-soft) 48%, var(--surface)), var(--surface));
}
.ai-score-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
}
.ai-score-head h3 { margin: 3px 0 5px; font-size: 1.18rem; }
.ai-score-head p { max-width: 820px; margin: 0; color: var(--muted); font-size: 0.86rem; }
.ai-score-head .primary-btn { flex: 0 0 auto; }
.ai-score-status {
  display: grid;
  gap: 3px;
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: 11px;
  background: var(--surface-2);
  color: var(--muted);
  font-size: 0.85rem;
}
.ai-score-status strong { color: var(--text); }
.ai-score-status.is-loading { border-left: 4px solid var(--primary); }
.ai-score-status.is-error { border-left: 4px solid var(--danger); background: #fff0ed; color: var(--danger); }
.dark .ai-score-status.is-error { background: #3b1f21; }
.ai-score-content { margin-top: 15px; }
.ai-score-summary-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 18px;
  align-items: center;
  padding: 16px;
  border-radius: 14px;
  background: var(--surface);
  border: 1px solid var(--line);
}
.ai-score-number {
  min-width: 148px;
  display: grid;
  justify-items: center;
  padding: 14px 18px;
  border-radius: 13px;
  background: var(--primary);
  color: #fff;
}
.ai-score-number strong { font-size: clamp(2rem, 5vw, 3.25rem); line-height: 1; }
.ai-score-number span { margin-top: 5px; font-size: 0.8rem; font-weight: 800; }
.ai-score-summary-copy p { margin: 9px 0 0; }
.ai-confidence {
  display: inline-flex;
  padding: 5px 9px;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 900;
}
.ai-confidence.is-high { background: #ecfdf3; color: #067647; }
.ai-confidence.is-medium { background: #fff7ed; color: #b54708; }
.ai-confidence.is-low { background: #fff0ed; color: #b42318; }
.dark .ai-confidence.is-high { background: #173b2c; color: #9be7be; }
.dark .ai-confidence.is-medium { background: #3a281d; color: #ffd7b0; }
.dark .ai-confidence.is-low { background: #3b1f21; color: #ffb4ab; }
.ai-overview-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
}
.ai-overview-grid section {
  padding: 13px 15px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface);
}
.ai-overview-grid h4 { margin: 0 0 7px; }
.ai-overview-grid ul { margin: 0; padding-left: 1.25rem; }
.ai-question-list { display: grid; gap: 10px; margin-top: 12px; }
.ai-question-score {
  padding: 13px 15px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface);
}
.ai-question-score-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: flex-start;
}
.ai-question-score-head > div { display: grid; gap: 2px; }
.ai-question-score-head small { color: var(--muted); }
.ai-question-score-head > span {
  flex: 0 0 auto;
  padding: 5px 9px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  font-weight: 900;
}
.ai-question-score p { margin: 8px 0; }
.ai-question-score > div:not(.ai-question-score-head) { margin-top: 5px; color: var(--muted); font-size: 0.84rem; }
.ai-disclaimer {
  margin-top: 13px;
  padding: 10px 12px;
  border-left: 4px solid var(--warning);
  background: #fff7ed;
  color: #7c2d12;
  font-size: 0.82rem;
}
.dark .ai-disclaimer { background: #3a281d; color: #ffd7b0; }

.toast {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 220;
  max-width: min(420px, calc(100vw - 40px));
  padding: 12px 15px;
  border-radius: 11px;
  background: #172033;
  color: #fff;
  box-shadow: 0 18px 42px rgba(0,0,0,0.25);
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: 0.2s;
}
.toast.show { opacity: 1; transform: none; }
.lightbox { position: fixed; inset: 0; z-index: 300; display: grid; place-items: center; padding: 24px; background: rgba(0,0,0,0.88); }
.lightbox img { max-width: 95vw; max-height: 90vh; object-fit: contain; }
.lightbox button { position: absolute; right: 22px; top: 18px; width: 44px; height: 44px; border: 0; border-radius: 50%; background: #fff; color: #111; font-size: 1.8rem; }
footer { padding: 22px; text-align: center; color: var(--muted); }

@media (max-width: 1180px) {
  .exam-toolbar { grid-template-columns: 1fr 0.55fr 0.65fr 1.2fr; }
  .data-health { grid-column: 1 / -1; justify-self: start; min-height: 30px; padding: 4px 8px; }
  .workspace { grid-template-columns: minmax(280px, var(--source-pane)) 10px minmax(370px, 1fr); }
}

@media (max-width: 820px) {
  :root { --header-height: 64px; }
  .header-inner { min-height: var(--header-height); padding: 0 12px; }
  .mobile-menu-btn { display: inline-grid; place-items: center; }
  .header-actions {
    display: none;
    position: absolute;
    right: 12px;
    top: 58px;
    padding: 8px;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: var(--shadow);
  }
  .header-actions.open { display: flex; }
  .page-shell { padding: 10px 8px 42px; }
  .exam-toolbar-card { top: calc(var(--header-height) + 3px); padding: 9px; border-radius: 14px; }
  .exam-toolbar { grid-template-columns: 1fr 0.72fr; gap: 8px; }
  .exam-select-field { grid-column: 1 / -1; }
  .data-health { grid-column: 1 / -1; max-width: 100%; justify-self: stretch; justify-content: flex-start; }
  .student-grid, .api-key-wrap, .send-grid, .review-grid { grid-template-columns: 1fr; }
  .utility-details summary span { display: none; }

  .workspace {
    --mobile-source-pane: 43%;
    grid-template-columns: 1fr;
    grid-template-rows: minmax(0, var(--mobile-source-pane)) 24px minmax(0, 1fr);
    height: calc(100dvh - var(--header-height) - 12px);
    min-height: 560px;
    margin-top: 10px;
  }
  .paper-panel {
    grid-row: 1;
    min-height: 0;
    border-radius: 16px 16px 0 0;
    padding: 0 12px 14px;
    transition: opacity 0.16s ease, visibility 0.16s ease;
  }
  .workspace-splitter {
    grid-row: 2;
    min-height: 24px;
    cursor: row-resize;
    touch-action: none;
    -webkit-tap-highlight-color: transparent;
    background: color-mix(in srgb, var(--surface-2) 72%, transparent);
  }
  .workspace-splitter::before { inset: 8px 0; }
  .workspace-splitter span { width: 58px; height: 6px; }
  .splitter-hint {
    position: absolute;
    left: 50%;
    top: 50%;
    z-index: 2;
    display: block;
    max-width: calc(100% - 90px);
    padding: 2px 7px;
    border-radius: 999px;
    background: var(--surface);
    color: var(--muted);
    font-size: 0.62rem;
    font-weight: 800;
    line-height: 1.2;
    white-space: nowrap;
    transform: translate(38px, -50%);
    pointer-events: none;
  }
  .answer-panel {
    grid-row: 3;
    min-height: 0;
    border-radius: 0 0 16px 16px;
    padding: 0 12px 16px;
    transition: border-radius 0.16s ease;
  }
  .workspace.is-source-collapsed {
    --mobile-source-pane: 0%;
    grid-template-rows: 0 24px minmax(0, 1fr);
  }
  .workspace.is-source-collapsed .paper-panel {
    visibility: hidden;
    opacity: 0;
    overflow: hidden;
    padding: 0;
    border-width: 0;
    pointer-events: none;
  }
  .workspace.is-source-collapsed .answer-panel {
    border-radius: 16px;
  }
  .workspace.is-source-collapsed .workspace-view-controls {
    display: none;
  }
  .workspace.is-source-collapsed .workspace-splitter {
    border-radius: 12px 12px 0 0;
    background: color-mix(in srgb, var(--primary-soft) 76%, var(--surface));
  }
  .workspace.is-source-collapsed .workspace-splitter span { opacity: 0.95; }
  .workspace.is-source-compact .source-heading h1,
  .workspace.is-source-compact .current-exam-label,
  .workspace.is-source-compact .source-heading-actions { display: none; }
  .panel-heading { padding-top: 11px; }
  .source-heading { align-items: center; }
  .source-heading-actions { display: flex; align-items: center; }
  .source-heading-actions .exam-meta { display: none; }
  .document-content { padding-top: 11px; }
  .pdf-protected-viewport { height: calc(100% - 74px); min-height: 150px; }
  .workspace.is-source-compact .pdf-protected-viewport { height: 100%; min-height: 0; }
  .workspace.is-source-compact .panel-heading-sticky { min-height: 42px; }
  .workspace-view-controls { padding-top: 7px; }
  .workspace-view-controls > span { display: none; }
  .split-preset-btn { flex: 1 1 auto; text-align: center; }
  .progress-compact { grid-template-columns: 1fr; gap: 7px; }
  .score-summary { min-width: 0; }
  .answer-card { scroll-margin-top: 230px; }
  .answer-card.is-writing textarea { min-height: 230px; }
  .answer-card.writing-expanded textarea { min-height: 55vh; }
  .ai-scroll-box { max-height: min(40vh, 360px); }
  .ai-scroll-head { align-items: flex-start; padding: 8px 10px; }
  .ai-scroll-head span { max-width: 48%; text-align: right; line-height: 1.25; }
  .ai-scroll-body { padding: 10px 11px 14px; }
  .floating-source-btn:not([hidden]) { display: block; }
  .review-section { padding: 14px; }
  .review-heading { display: block; }
  .review-heading button { margin-top: 10px; }
  .review-tabs { display: grid; grid-template-columns: 1fr; }
  .review-tab { border-radius: 10px; }
  .ai-score-head { display: grid; }
  .ai-score-head .primary-btn { width: 100%; }
  .ai-score-summary-card { grid-template-columns: 1fr; }
  .ai-score-number { min-width: 0; }
  .ai-overview-grid { grid-template-columns: 1fr; }
  .pdf-toolbar-mask { height: 48px; padding-inline: 10px; }
  .action-row { flex-direction: column-reverse; }
  .action-row button { width: 100%; }
  .image-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 520px) {
  .brand strong { font-size: 0.98rem; }
  .brand small { font-size: 0.78rem; }
  .brand-mark { width: 40px; height: 40px; }
  .exam-toolbar { grid-template-columns: 1fr 1fr; }
  .province-wrap, .exam-select-field, .data-health { grid-column: 1 / -1; }
  .exam-toolbar select, .select-button { min-height: 40px; }
  .panel-heading h1 { font-size: 1.05rem; }
  .panel-heading h2 { font-size: 1.05rem; }
  .current-exam-label { display: none; }
  .source-heading-actions .mini-btn { padding: 6px 8px; font-size: 0.7rem; }
  .answer-card { padding: 12px; }
  .question-prompt { padding: 9px 10px; }
}

@media print {
  .site-header,
  .exam-toolbar-card,
  .answer-panel,
  .workspace-splitter,
  .review-tabs,
  .review-heading button,
  .floating-source-btn,
  footer,
  .toast { display: none !important; }
  .page-shell { max-width: none; padding: 0; }
  .workspace { display: block; height: auto; min-height: 0; }
  .paper-panel, .review-section { border: 0; box-shadow: none; }
}

/* Trên điện thoại chỉ giữ một chấm trạng thái nhỏ, không tạo thêm một khối thông báo. */
@media (max-width: 820px) {
  .exam-toolbar-card { position: sticky; }
  .data-health {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 24px;
    min-width: 24px;
    max-width: 24px;
    height: 24px;
    min-height: 24px;
    padding: 0;
    border: 0;
    background: transparent;
    grid-column: auto;
    justify-self: auto;
    overflow: visible;
  }
  .data-health #dataStatusText { display: none; }
  .data-status-dot { width: 10px; height: 10px; }
}

.mobile-exam-summary { display: none; }

@media (max-width: 820px) {
  .exam-toolbar-card.is-collapsed {
    padding: 7px 9px;
  }
  .exam-toolbar-card.is-collapsed .exam-toolbar,
  .exam-toolbar-card.is-collapsed .utility-details {
    display: none;
  }
  .exam-toolbar-card.is-collapsed .mobile-exam-summary {
    display: flex !important;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
  }
  .mobile-exam-summary > div {
    min-width: 0;
    display: grid;
    gap: 1px;
  }
  .mobile-exam-summary span {
    color: var(--muted);
    font-size: 0.68rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.06em;
  }
  .mobile-exam-summary strong {
    overflow: hidden;
    color: var(--text);
    font-size: 0.86rem;
    white-space: nowrap;
    text-overflow: ellipsis;
  }
  .mobile-exam-summary button {
    flex: 0 0 auto;
    padding: 7px 10px;
    font-size: 0.76rem;
  }
  .exam-toolbar-card.is-collapsed .data-health {
    display: none;
  }
  .floating-source-btn {
    right: 12px;
    bottom: 12px;
    padding: 8px 11px;
    font-size: 0.8rem;
  }
}

@media (max-width: 820px) {
  .floating-source-btn {
    width: 44px;
    height: 44px;
    padding: 0;
    display: grid;
    place-items: center;
    font-size: 0;
  }
  .floating-source-btn::before {
    content: "📖";
    font-size: 1.08rem;
    line-height: 1;
  }
}

/* =====================================================================
   V11.0 — KHÔNG GIAN LÀM BÀI NGỮ VĂN
   Thiết kế “giấy – mực – điểm nhấn”: toàn màn hình, ít lớp giao diện,
   ngữ liệu và bài làm luôn chia sẻ đúng toàn bộ không gian khả dụng.
   ===================================================================== */
:root {
  --bg: #f3f0e9;
  --surface: #fffefb;
  --surface-2: #edf3f2;
  --surface-3: #f7f4ed;
  --text: #253541;
  --muted: #6b7880;
  --line: #d8ddd9;
  --primary: #315e73;
  --primary-2: #244a5c;
  --primary-soft: #e4eff1;
  --accent: #b97836;
  --accent-soft: #f7eadc;
  --success: #39735f;
  --danger: #aa463f;
  --warning: #b97836;
  --shadow: 0 18px 55px rgba(38, 52, 60, 0.10);
  --radius: 16px;
  --reader-size: 17px;
  --source-pane: 42%;
  --mobile-source-pane: 46%;
  --header-height: 58px;
  --dock-height: 56px;
}

body.v11-app {
  height: 100dvh;
  overflow: hidden;
  background:
    radial-gradient(circle at 10% 0%, rgba(185,120,54,.08), transparent 32%),
    radial-gradient(circle at 100% 100%, rgba(49,94,115,.08), transparent 35%),
    var(--bg);
}
body.v11-app.dark {
  --bg: #182127;
  --surface: #222e34;
  --surface-2: #2b3a40;
  --surface-3: #202a2f;
  --text: #eef1ed;
  --muted: #b5c0c2;
  --line: #3b4b50;
  --primary: #86b7c2;
  --primary-2: #a8d4dc;
  --primary-soft: #29424a;
  --accent: #dfaa70;
  --accent-soft: #4b3828;
  --success: #80c4a8;
  --shadow: none;
}

body.v11-app .site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 180;
  height: var(--header-height);
  min-height: var(--header-height);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 82%, transparent);
  box-shadow: 0 5px 24px rgba(38, 52, 60, .06);
  backdrop-filter: blur(16px);
}
body.v11-app .header-progress {
  position: absolute;
  inset: auto 0 0 0;
  height: 3px;
  overflow: hidden;
  background: color-mix(in srgb, var(--primary) 10%, transparent);
}
body.v11-app .header-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width .24s ease;
}
body.v11-app .header-inner {
  width: min(1700px, 100%);
  height: var(--header-height);
  min-height: var(--header-height);
  padding: 0 14px;
  gap: 12px;
}
body.v11-app .brand { gap: 9px; flex: 0 0 auto; }
body.v11-app .brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: linear-gradient(145deg, var(--primary), #648b91);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.18);
  font-size: .86rem;
}
body.v11-app .brand strong { font-size: .92rem; letter-spacing: -.02em; }
body.v11-app .brand small { font-size: .68rem; line-height: 1.1; }
body.v11-app .current-exam-trigger {
  min-width: 0;
  flex: 1 1 auto;
  max-width: 660px;
  height: 42px;
  display: grid;
  grid-template-columns: auto minmax(0,1fr) auto;
  align-items: center;
  column-gap: 8px;
  padding: 5px 11px;
  border: 1px solid color-mix(in srgb, var(--primary) 20%, var(--line));
  border-radius: 12px;
  background: color-mix(in srgb, var(--primary-soft) 50%, var(--surface));
  color: var(--text);
  text-align: left;
}
body.v11-app .current-exam-trigger:hover { border-color: var(--primary); }
body.v11-app .current-exam-overline {
  color: var(--primary);
  font-size: .62rem;
  font-weight: 900;
  letter-spacing: .08em;
  text-transform: uppercase;
}
body.v11-app .current-exam-trigger strong {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  font-size: .84rem;
}
body.v11-app .header-live-status {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 0 4px;
  font-size: .75rem;
}
body.v11-app .save-indicator { color: var(--success); }
body.v11-app .header-live-status strong {
  min-width: 42px;
  padding: 5px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: color-mix(in srgb, var(--accent) 82%, var(--text));
  text-align: center;
}
body.v11-app .mobile-menu-btn {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 42px;
  min-width: 42px;
  height: 42px;
  border-color: color-mix(in srgb, var(--primary) 22%, var(--line));
  background: var(--surface);
}

/* Drawer: đề, học sinh và tùy chọn chỉ hiện khi cần. */
body.v11-app .drawer-backdrop,
body.v11-app .ai-backdrop {
  position: fixed;
  inset: 0;
  z-index: 240;
  background: rgba(20, 31, 36, .42);
  backdrop-filter: blur(2px);
}
body.v11-app .settings-drawer {
  position: fixed;
  z-index: 250;
  top: 0;
  right: 0;
  width: min(430px, 94vw);
  height: 100dvh;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 18px;
  background: var(--surface);
  border-left: 1px solid var(--line);
  box-shadow: -24px 0 70px rgba(18, 31, 37, .18);
  transform: translateX(104%);
  transition: transform .24s ease;
}
body.v11-app .settings-drawer.is-open { transform: translateX(0); }
body.v11-app .drawer-head {
  position: sticky;
  top: -18px;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: -18px -18px 12px;
  padding: 17px 18px 12px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 96%, transparent);
  backdrop-filter: blur(12px);
}
body.v11-app .drawer-head h2 { margin: 1px 0 0; font-size: 1.15rem; }
body.v11-app .drawer-close {
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface-3);
  color: var(--text);
  font-size: 1.4rem;
}
body.v11-app .exam-toolbar-card {
  position: static;
  padding: 0;
  border: 0;
  border-radius: 0;
  box-shadow: none;
  background: transparent;
  backdrop-filter: none;
}
body.v11-app .drawer-section-title {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 18px 0 9px;
  color: var(--text);
  font-size: .82rem;
}
body.v11-app .drawer-section-title span {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 9px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: .68rem;
  font-weight: 900;
}
body.v11-app .exam-toolbar,
body.v11-app .student-grid,
body.v11-app .api-key-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
body.v11-app .province-wrap,
body.v11-app .exam-select-field,
body.v11-app .api-key-wrap > label { grid-column: 1 / -1; }
body.v11-app .data-health {
  grid-column: 1 / -1;
  max-width: none;
  justify-content: flex-start;
  min-height: 36px;
}
body.v11-app .student-grid label:first-child,
body.v11-app .student-grid label:last-child { grid-column: 1 / -1; }
body.v11-app .api-key-wrap { margin-top: 10px; }
body.v11-app .utility-details {
  margin: 0;
  padding: 0;
  border: 0;
}
body.v11-app .utility-details summary { display: none; }
body.v11-app .drawer-layout-controls { display: grid; gap: 10px; }
body.v11-app .workspace-view-controls { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; padding: 0; }
body.v11-app .split-preset-btn {
  min-height: 40px;
  border-radius: 11px;
  padding: 7px;
}
body.v11-app .header-actions { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; position: static; padding: 0; border: 0; box-shadow: none; background: transparent; }
body.v11-app .icon-btn { width: 100%; background: var(--surface-3); }
body.v11-app .drawer-score {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 12px;
  background: var(--accent-soft);
  font-size: .82rem;
}
body.v11-app .drawer-score strong { color: var(--accent); font-size: 1.05rem; }

/* Workspace toàn màn hình. */
body.v11-app .page-shell {
  width: 100%;
  max-width: none;
  height: 100dvh;
  margin: 0;
  padding: var(--header-height) 0 0;
  overflow: hidden;
}
body.v11-app .status-bar {
  position: fixed;
  z-index: 175;
  top: calc(var(--header-height) + 7px);
  left: 50%;
  width: min(760px, calc(100vw - 24px));
  margin: 0;
  transform: translateX(-50%);
  box-shadow: var(--shadow);
}
body.v11-app .empty-state {
  width: min(720px, calc(100% - 28px));
  margin: 24px auto;
  box-shadow: var(--shadow);
}
body.v11-app .workspace {
  --source-pane: 42%;
  width: 100%;
  height: calc(100dvh - var(--header-height));
  min-height: 0;
  margin: 0;
  display: grid;
  grid-template-columns: minmax(300px, var(--source-pane)) 10px minmax(400px, 1fr);
  grid-template-rows: minmax(0, 1fr) var(--dock-height);
  grid-template-areas:
    "source splitter answer"
    "dock dock dock";
  gap: 0;
  overflow: hidden;
  background: var(--surface);
}
body.v11-app .sourcePanel { grid-area: source; }
body.v11-app #sourcePanel { grid-area: source; }
body.v11-app #workspaceSplitter { grid-area: splitter; }
body.v11-app #answerPanel { grid-area: answer; }
body.v11-app .work-dock { grid-area: dock; }
body.v11-app .workspace-panel {
  min-width: 0;
  min-height: 0;
  border: 0;
  border-radius: 0;
  box-shadow: none;
  background: var(--surface);
}
body.v11-app .paper-panel {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 0;
  border-right: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 96%, var(--surface-3));
}
body.v11-app .answer-panel {
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0;
  scrollbar-gutter: stable;
  overscroll-behavior: contain;
  background: var(--surface);
}
body.v11-app .workspace-splitter {
  cursor: col-resize;
  background: color-mix(in srgb, var(--surface-3) 82%, var(--line));
}
body.v11-app .workspace-splitter::before { inset: 0 4px; background: color-mix(in srgb, var(--primary) 18%, var(--line)); }
body.v11-app .workspace-splitter span { width: 4px; height: 58px; background: var(--primary); }
body.v11-app .splitter-hint { display: none; }
body.v11-app .panel-heading {
  min-height: 50px;
  padding: 8px 13px;
  align-items: center;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 96%, transparent);
}
body.v11-app .panel-heading-sticky,
body.v11-app .answer-toolbar-sticky {
  position: sticky;
  top: 0;
  z-index: 22;
  background: color-mix(in srgb, var(--surface) 96%, transparent);
  backdrop-filter: blur(10px);
}
body.v11-app .panel-heading h1,
body.v11-app .panel-heading h2 { margin: 0; font-size: 1rem; line-height: 1.2; }
body.v11-app .panel-kicker { font-size: .61rem; color: var(--primary); }
body.v11-app .current-exam-label { display: none; }
body.v11-app .source-heading-actions { display: flex; align-items: center; gap: 7px; }
body.v11-app .exam-meta span { padding: 3px 7px; font-size: .65rem; }
body.v11-app .source-heading .mini-btn,
body.v11-app .compact-tools-btn { padding: 5px 8px; font-size: .68rem; }
body.v11-app #examContent {
  flex: 1 1 auto;
  min-height: 0;
  overflow: auto;
  padding: 14px 16px 20px;
  scrollbar-gutter: stable;
  overscroll-behavior: contain;
}
body.v11-app .document-content { padding-top: 0; }
body.v11-app .pdf-protected-shell,
body.v11-app .pdf-protected-viewport {
  width: 100%;
  height: 100%;
  min-height: 0;
}
body.v11-app .pdf-protected-viewport { border-radius: 8px; }
body.v11-app .pdf-protected-note { display: none; }

/* Phiếu trả lời: giảm thẻ, giảm tiêu đề, tăng vùng nhập. */
body.v11-app .answer-shell { min-height: 100%; padding-bottom: 28px; }
body.v11-app .answer-toolbar-sticky { padding: 0; }
body.v11-app .answer-heading { min-height: 48px; }
body.v11-app .answer-fields {
  display: block;
  padding: 0 18px;
}
body.v11-app .answer-card {
  scroll-margin-top: 58px;
  margin: 0;
  padding: 20px 0 22px;
  border: 0;
  border-bottom: 1px solid var(--line);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  transform: none;
}
body.v11-app .answer-card.is-active {
  border-color: var(--line);
  box-shadow: none;
}
body.v11-app .answer-card.is-active::before {
  content: "";
  display: block;
  width: 34px;
  height: 3px;
  margin: -20px 0 13px;
  border-radius: 99px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}
body.v11-app .answer-card.is-writing { border-color: var(--line); }
body.v11-app .answer-card-head { margin: 0 0 8px; }
body.v11-app .answer-card-head h3 { font-size: 1rem; color: var(--text); }
body.v11-app .question-meta { font-size: .7rem; }
body.v11-app .question-prompt {
  margin: 8px 0 10px;
  padding: 11px 13px;
  border-left: 3px solid var(--accent);
  border-radius: 4px 10px 10px 4px;
  background: color-mix(in srgb, var(--accent-soft) 60%, var(--surface));
}
body.v11-app .answer-card textarea {
  min-height: 150px;
  padding: 13px 14px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--surface) 90%, var(--surface-3));
  line-height: 1.72;
}
body.v11-app .answer-card.is-writing textarea { min-height: 340px; }
body.v11-app .answer-tools { margin-top: 9px; gap: 6px; }
body.v11-app .mini-btn { background: var(--surface-3); }
body.v11-app .score-line {
  justify-content: flex-end;
  margin-top: 8px;
  font-family: Inter, sans-serif;
}
body.v11-app .upload-block { background: var(--surface-3); }
body.v11-app .answer-tail-tools {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 16px 18px 0;
}
body.v11-app .local-note { padding: 0 18px; }

/* AI theo ngữ cảnh mở thành panel riêng, không làm câu hỏi dài ra. */
body.v11-app .ai-backdrop { z-index: 280; }
body.v11-app .ai-scroll-box:not([hidden]) {
  position: fixed;
  z-index: 290;
  top: var(--header-height);
  right: 0;
  bottom: 0;
  width: min(460px, 92vw);
  max-height: none;
  margin: 0;
  overflow-y: auto;
  border: 0;
  border-left: 1px solid var(--line);
  border-radius: 0;
  background: var(--surface);
  box-shadow: -20px 0 55px rgba(18,31,37,.2);
}
body.v11-app .ai-scroll-head {
  min-height: 56px;
  padding: 11px 14px;
  background: color-mix(in srgb, var(--primary-soft) 60%, var(--surface));
}
body.v11-app .ai-scroll-head span { margin-left: auto; }
body.v11-app .ai-close-btn {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  font-size: 1.1rem;
}
body.v11-app .ai-scroll-body { padding: 18px; font-size: .94rem; }

/* Thanh điều hướng dưới cùng. */
body.v11-app .work-dock {
  min-width: 0;
  height: var(--dock-height);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 9px;
  padding: 7px 12px max(7px, env(safe-area-inset-bottom));
  border-top: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 96%, transparent);
  box-shadow: 0 -8px 25px rgba(38,52,60,.06);
  backdrop-filter: blur(12px);
}
body.v11-app .dock-source-btn,
body.v11-app .finish-dock-btn {
  height: 40px;
  border-radius: 11px;
  font-weight: 900;
}
body.v11-app .dock-source-btn {
  min-width: 68px;
  border: 1px solid color-mix(in srgb, var(--primary) 28%, var(--line));
  background: var(--primary-soft);
  color: var(--primary);
}
body.v11-app .finish-dock-btn {
  min-width: 118px;
  padding: 8px 14px;
  background: linear-gradient(135deg, var(--primary), #4f7e84);
}
body.v11-app .question-nav {
  min-width: 0;
  padding: 0;
  gap: 5px;
  scrollbar-width: none;
}
body.v11-app .question-nav::-webkit-scrollbar { display: none; }
body.v11-app .question-nav button {
  min-width: 38px;
  height: 38px;
  padding: 4px 7px;
  border-radius: 10px;
  background: var(--surface-3);
}
body.v11-app .question-nav button.is-active {
  border-color: var(--primary);
  background: var(--primary);
  color: #fff;
  box-shadow: 0 6px 16px rgba(49,94,115,.2);
}
body.v11-app .floating-source-btn { display: none !important; }

body.v11-app .review-section {
  height: calc(100dvh - var(--header-height));
  margin: 0;
  padding: 18px clamp(14px, 3vw, 34px) 40px;
  overflow-y: auto;
  border: 0;
  border-radius: 0;
  box-shadow: none;
  background: var(--bg);
}
body.v11-app .review-heading,
body.v11-app .review-tabs,
body.v11-app .review-panel { max-width: 1280px; margin-left: auto; margin-right: auto; }
body.v11-app footer { display: none; }

/* Máy tính nhỏ. */
@media (max-width: 1050px) and (min-width: 821px) {
  body.v11-app .workspace { grid-template-columns: minmax(270px, var(--source-pane)) 9px minmax(340px, 1fr); }
  body.v11-app .brand-copy small { display: none; }
}

/* Điện thoại: hai vùng chia dọc, luôn lấp đầy chiều cao, không còn khoảng trống chết. */
@media (max-width: 820px) {
  :root {
    --header-height: 54px;
    --dock-height: 56px;
    --mobile-source-pane: 46%;
  }
  body.v11-app .header-inner { padding: 0 8px; gap: 7px; }
  body.v11-app .brand-copy { display: none; }
  body.v11-app .brand-mark { width: 38px; height: 38px; }
  body.v11-app .current-exam-trigger {
    height: 40px;
    grid-template-columns: minmax(0,1fr) auto;
    padding: 5px 9px;
  }
  body.v11-app .current-exam-overline { display: none; }
  body.v11-app .current-exam-trigger strong { font-size: .78rem; }
  body.v11-app .header-live-status { gap: 5px; }
  body.v11-app .header-live-status .save-indicator { display: none; }
  body.v11-app .header-live-status strong { min-width: 38px; padding: 4px 6px; font-size: .7rem; }
  body.v11-app .mobile-menu-btn { width: 40px; min-width: 40px; height: 40px; }

  body.v11-app .workspace {
    --mobile-source-pane: 46%;
    height: calc(100dvh - var(--header-height));
    grid-template-columns: 1fr;
    grid-template-rows: minmax(120px, var(--mobile-source-pane)) 12px minmax(0, 1fr) var(--dock-height);
    grid-template-areas:
      "source"
      "splitter"
      "answer"
      "dock";
  }
  body.v11-app .paper-panel {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  body.v11-app .workspace-splitter {
    min-height: 12px;
    cursor: row-resize;
    background: color-mix(in srgb, var(--surface-3) 75%, var(--line));
  }
  body.v11-app .workspace-splitter::before { inset: 4px 0; }
  body.v11-app .workspace-splitter span { width: 58px; height: 4px; }
  body.v11-app .splitter-hint { display: none; }
  body.v11-app .panel-heading { min-height: 42px; padding: 6px 10px; }
  body.v11-app .panel-heading h1,
  body.v11-app .panel-heading h2 { font-size: .9rem; }
  body.v11-app .panel-kicker { display: none; }
  body.v11-app .source-heading .exam-meta { display: none; }
  body.v11-app #examContent { padding: 8px 10px 12px; }
  body.v11-app .pdf-toolbar-mask { height: 42px; font-size: .65rem; }
  body.v11-app .answer-fields { padding: 0 12px; }
  body.v11-app .answer-card { padding: 15px 0 18px; scroll-margin-top: 48px; }
  body.v11-app .answer-card.is-active::before { margin-top: -15px; }
  body.v11-app .answer-card textarea { min-height: 130px; }
  body.v11-app .answer-card.is-writing textarea { min-height: 250px; }
  body.v11-app .question-prompt { font-size: calc(var(--reader-size) * .96); }
  body.v11-app .answer-tools { overflow-x: auto; flex-wrap: nowrap; scrollbar-width: none; }
  body.v11-app .answer-tools::-webkit-scrollbar { display: none; }
  body.v11-app .answer-tools button { flex: 0 0 auto; }
  body.v11-app .answer-tail-tools { padding-inline: 12px; }
  body.v11-app .local-note { padding-inline: 12px; }

  body.v11-app .work-dock { gap: 6px; padding-inline: 7px; }
  body.v11-app .dock-source-btn { min-width: 44px; width: 44px; padding: 0; font-size: 1rem; }
  body.v11-app .dock-source-btn span { display: none; }
  body.v11-app .finish-dock-btn { min-width: 92px; padding-inline: 9px; font-size: .78rem; }
  body.v11-app .question-nav button { min-width: 36px; width: 36px; height: 38px; }

  body.v11-app .ai-scroll-box:not([hidden]) {
    top: auto;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    height: min(82dvh, 720px);
    border-left: 0;
    border-top: 1px solid var(--line);
    border-radius: 18px 18px 0 0;
    box-shadow: 0 -24px 60px rgba(18,31,37,.22);
  }
  body.v11-app .ai-scroll-head::before {
    content: "";
    position: absolute;
    top: 6px;
    left: 50%;
    width: 44px;
    height: 4px;
    border-radius: 999px;
    background: color-mix(in srgb, var(--muted) 35%, transparent);
    transform: translateX(-50%);
  }
  body.v11-app .ai-scroll-head { position: sticky; padding-top: 17px; }

  body.v11-app .review-section { padding: 12px 10px 34px; }
  body.v11-app .review-heading h2 { font-size: 1.1rem; }
  body.v11-app .review-tabs {
    position: sticky;
    top: 0;
    z-index: 8;
    display: flex;
    flex-wrap: nowrap;
    overflow-x: auto;
    padding: 8px 0;
    background: var(--bg);
  }
  body.v11-app .review-tab { flex: 0 0 auto; border-radius: 10px; }
}

@media (max-width: 440px) {
  body.v11-app .current-exam-trigger strong { font-size: .73rem; }
  body.v11-app .header-live-status strong { display: none; }
  body.v11-app .finish-dock-btn { min-width: 86px; }
  body.v11-app .answer-card-head h3 { font-size: .94rem; }
}

@media print {
  body.v11-app { overflow: visible; height: auto; }
  body.v11-app .site-header,
  body.v11-app .settings-drawer,
  body.v11-app .drawer-backdrop,
  body.v11-app .work-dock,
  body.v11-app .answer-panel,
  body.v11-app .workspace-splitter { display: none !important; }
  body.v11-app .page-shell,
  body.v11-app .workspace { height: auto; padding: 0; display: block; }
  body.v11-app .paper-panel { display: block; overflow: visible; }
}

/* =========================================================
   V11.1.0 - Tìm tỉnh/thành và thanh tab tổng kết gọn
   ========================================================= */
body.v11-app .province-search-field {
  display: grid;
  gap: 6px;
  margin-bottom: 10px;
}
body.v11-app .province-search-field > span {
  color: var(--muted);
  font-size: .78rem;
  font-weight: 800;
}
body.v11-app .province-search-control {
  position: relative;
  display: flex;
  align-items: center;
}
body.v11-app .province-search-control input {
  width: 100%;
  min-height: 44px;
  padding: 10px 42px 10px 38px;
  border: 1px solid color-mix(in srgb, var(--primary) 28%, var(--line));
  border-radius: 12px;
  background: color-mix(in srgb, var(--primary-soft) 34%, var(--surface));
  color: var(--text);
  outline: none;
}
body.v11-app .province-search-control input:focus {
  border-color: var(--primary);
  background: var(--surface);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 16%, transparent);
}
body.v11-app .province-search-icon {
  position: absolute;
  left: 13px;
  z-index: 1;
  color: var(--primary);
  font-size: 1.2rem;
  line-height: 1;
  pointer-events: none;
}
body.v11-app .province-search-clear {
  position: absolute;
  right: 7px;
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 9px;
  background: color-mix(in srgb, var(--muted) 10%, transparent);
  color: var(--muted);
  font-size: 1.15rem;
  line-height: 1;
}
body.v11-app .province-search-clear:hover {
  background: var(--surface-2);
  color: var(--text);
}
body.v11-app .province-search-hint {
  color: var(--muted);
  font-size: .7rem;
  line-height: 1.45;
}
body.v11-app .province-menu {
  max-height: min(320px, 42dvh);
}
body.v11-app .province-option {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}
body.v11-app .province-check {
  flex: 0 0 auto;
  color: var(--success);
  font-weight: 900;
}
body.v11-app .province-empty {
  padding: 14px 12px;
  color: var(--muted);
  font-size: .8rem;
  line-height: 1.5;
  text-align: center;
}

body.v11-app .review-heading {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 18px;
  padding-bottom: 14px;
}
body.v11-app .review-heading-main { min-width: 0; }
body.v11-app .review-heading-main > .panel-kicker { display: block; }
body.v11-app .review-heading .review-tabs {
  max-width: none;
  margin: 7px 0 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(120px, 1fr));
  gap: 7px;
}
body.v11-app .review-heading .review-tab {
  width: 100%;
  min-height: 42px;
  display: grid;
  place-items: center;
  padding: 8px 10px;
  border-radius: 11px;
  line-height: 1.2;
  text-align: center;
  white-space: normal;
}
body.v11-app .review-back-btn {
  align-self: center;
  white-space: nowrap;
}

@media (max-width: 820px) {
  body.v11-app .province-search-control input {
    min-height: 46px;
    font-size: .92rem;
  }

  body.v11-app .review-heading {
    position: sticky;
    top: 0;
    z-index: 12;
    display: block;
    margin: -12px -10px 12px;
    padding: 10px 10px 11px;
    border-bottom: 1px solid var(--line);
    background: color-mix(in srgb, var(--bg) 94%, transparent);
    backdrop-filter: blur(12px);
  }
  body.v11-app .review-heading-main { width: 100%; }
  body.v11-app .review-heading-main > .panel-kicker {
    display: block;
    min-height: 28px;
    padding-right: 112px;
  }
  body.v11-app .review-back-btn {
    position: absolute;
    top: 7px;
    right: 10px;
    min-height: 32px;
    padding: 5px 8px;
    border-radius: 9px;
    font-size: .68rem;
  }
  body.v11-app .review-heading .review-tabs {
    position: static;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px;
    margin: 5px 0 0;
    padding: 0;
    overflow: visible;
    background: transparent;
  }
  body.v11-app .review-heading .review-tab {
    min-width: 0;
    min-height: 43px;
    padding: 7px 5px;
    border-radius: 10px;
    font-size: .76rem;
    line-height: 1.15;
  }
}

@media (max-width: 360px) {
  body.v11-app .review-heading .review-tab {
    font-size: .7rem;
    padding-inline: 3px;
  }
}


/* V11.2.0: Nâng cấp nguyên tắc AI bám sát yêu cầu và hướng dẫn chấm. */

/* =====================================================================
   V11.2.1 — BẢNG MÀU TÍM · XANH CYAN
   Lấy cảm hứng từ giao diện tham chiếu: header gradient, nền lavender,
   card trắng, nút gradient và các vùng chức năng có màu pastel rõ ràng.
   Chỉ thay đổi hệ màu và độ nổi khối; không làm thay đổi logic bố cục V11.
   ===================================================================== */
body.v11-app {
  --bg: #f3f1ff;
  --surface: #ffffff;
  --surface-2: #f0edff;
  --surface-3: #f8f7ff;
  --text: #302d4d;
  --muted: #74718f;
  --line: #ded9f3;
  --primary: #6427d8;
  --primary-2: #4d3bd4;
  --primary-soft: #eee7ff;
  --accent: #159fc9;
  --accent-soft: #e2f7fb;
  --success: #16845f;
  --danger: #c84f70;
  --warning: #e19a27;
  --shadow: 0 18px 48px rgba(79, 55, 163, 0.12);
  background:
    radial-gradient(circle at 0% 0%, rgba(111, 42, 222, .12), transparent 31%),
    radial-gradient(circle at 100% 100%, rgba(21, 159, 201, .11), transparent 35%),
    linear-gradient(180deg, #f7f5ff 0%, #f0effb 100%);
}

body.v11-app.dark {
  --bg: #17142b;
  --surface: #241f3e;
  --surface-2: #312a53;
  --surface-3: #1e1a35;
  --text: #f7f4ff;
  --muted: #c4bedb;
  --line: #4a416f;
  --primary: #b28cff;
  --primary-2: #9476ff;
  --primary-soft: #3b2c63;
  --accent: #55d3e5;
  --accent-soft: #234655;
  --success: #6ed9ad;
  --danger: #ff8ca7;
  --warning: #ffc56b;
  --shadow: 0 20px 55px rgba(0, 0, 0, .28);
  background:
    radial-gradient(circle at 0% 0%, rgba(128, 73, 236, .18), transparent 34%),
    radial-gradient(circle at 100% 100%, rgba(33, 166, 201, .15), transparent 38%),
    var(--bg);
}

/* Header tím → xanh, chữ trắng như giao diện tham chiếu. */
body.v11-app .site-header {
  background: linear-gradient(112deg, #382f91 0%, #6824d8 48%, #159fc9 100%);
  border-bottom: 0;
  box-shadow: 0 8px 28px rgba(58, 47, 146, .24);
}
body.v11-app .header-progress {
  background: rgba(255, 255, 255, .16);
}
body.v11-app .header-progress span {
  background: linear-gradient(90deg, #ffd36c, #72e9ef);
}
body.v11-app .brand,
body.v11-app .brand strong,
body.v11-app .brand small {
  color: #fff;
}
body.v11-app .brand small { opacity: .82; }
body.v11-app .brand-mark {
  background: linear-gradient(145deg, #f7a51d, #ffbe45);
  box-shadow:
    inset 0 0 0 1px rgba(255,255,255,.38),
    0 8px 18px rgba(50, 30, 120, .2);
}
body.v11-app .current-exam-trigger {
  border-color: rgba(255,255,255,.25);
  background: rgba(255,255,255,.14);
  color: #fff;
  backdrop-filter: blur(9px);
}
body.v11-app .current-exam-trigger:hover {
  border-color: rgba(255,255,255,.55);
  background: rgba(255,255,255,.20);
}
body.v11-app .current-exam-overline,
body.v11-app .save-indicator,
body.v11-app .header-live-status strong {
  color: #fff;
}
body.v11-app .header-live-status strong {
  background: rgba(255,255,255,.16);
}
body.v11-app .mobile-menu-btn {
  border-color: rgba(255,255,255,.25);
  background: rgba(255,255,255,.13);
  color: #fff;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.04);
}
body.v11-app .mobile-menu-btn:hover { background: rgba(255,255,255,.22); }

/* Ngăn thiết lập: đầu ngăn gradient, nội dung card trắng/lavender. */
body.v11-app .settings-drawer {
  background: linear-gradient(180deg, #fbfaff 0%, #f3f1ff 100%);
  border-left-color: #d8d1f3;
  box-shadow: -24px 0 70px rgba(58, 47, 146, .23);
}
body.v11-app.dark .settings-drawer { background: var(--surface); }
body.v11-app .drawer-head {
  color: #fff;
  background: linear-gradient(112deg, #4b2aa8 0%, #7229dc 55%, #159fc9 100%);
  border-bottom: 0;
  box-shadow: 0 9px 24px rgba(83, 44, 178, .20);
}
body.v11-app .drawer-head .panel-kicker,
body.v11-app .drawer-head h2 { color: #fff; }
body.v11-app .drawer-close {
  border-color: rgba(255,255,255,.28);
  background: rgba(255,255,255,.14);
  color: #fff;
}
body.v11-app .drawer-section-title strong { color: #5525a9; }
body.v11-app.dark .drawer-section-title strong { color: var(--primary); }
body.v11-app .drawer-section-title span {
  background: linear-gradient(145deg, #eee5ff, #ddf7fc);
  color: #6427d8;
}
body.v11-app.dark .drawer-section-title span { background: var(--primary-soft); color: var(--primary); }
body.v11-app .drawer-score {
  background: linear-gradient(135deg, #f2eaff, #e3f8fc);
  border: 1px solid #ded4f6;
}
body.v11-app.dark .drawer-score { background: var(--surface-2); border-color: var(--line); }

/* Trường nhập và menu chọn. */
body.v11-app input,
body.v11-app select,
body.v11-app textarea,
body.v11-app .select-button {
  border-color: #dcd6f1;
}
body.v11-app input:focus,
body.v11-app select:focus,
body.v11-app textarea:focus,
body.v11-app .select-button:focus {
  border-color: #6a2de2;
  box-shadow: 0 0 0 3px rgba(106,45,226,.14);
}
body.v11-app .province-search-control input {
  background: linear-gradient(135deg, #f5f0ff, #eefbfe);
}
body.v11-app .province-menu {
  border-color: #d9d1f2;
  box-shadow: 0 18px 42px rgba(66, 43, 143, .18);
}
body.v11-app .province-option:hover,
body.v11-app .province-option.is-selected {
  background: linear-gradient(135deg, #efe6ff, #e6f8fc);
  color: #5a26c4;
}
body.v11-app .api-note a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: #5c28c7;
  font-weight: 800;
  text-decoration: none;
}
body.v11-app .api-note a::before { content: "⚡"; }
body.v11-app .api-note a:hover { text-decoration: underline; }
body.v11-app.dark .api-note a { color: var(--primary); }

/* Hai vùng làm việc rõ nét nhưng vẫn thoáng. */
body.v11-app .workspace {
  background: #f8f6ff;
}
body.v11-app.dark .workspace { background: var(--surface); }
body.v11-app .paper-panel {
  background: linear-gradient(180deg, #fbfaff 0%, #f6f4ff 100%);
  border-color: #ddd7f1;
}
body.v11-app.dark .paper-panel { background: var(--surface-3); border-color: var(--line); }
body.v11-app .answer-panel {
  background: #fff;
}
body.v11-app.dark .answer-panel { background: var(--surface); }
body.v11-app .panel-heading-sticky,
body.v11-app .answer-toolbar-sticky {
  background: color-mix(in srgb, var(--surface) 93%, transparent);
  border-color: #e0daf3;
  backdrop-filter: blur(13px);
}
body.v11-app .panel-kicker { color: #6128cc; }
body.v11-app.dark .panel-kicker { color: var(--primary); }
body.v11-app .workspace-splitter {
  background: linear-gradient(180deg, #ede8fa, #e5f4fa);
}
body.v11-app .workspace-splitter::before {
  background: linear-gradient(180deg, #6a2de2, #15a4ca) !important;
  opacity: .35;
}
body.v11-app .workspace-splitter:hover::before,
body.v11-app .workspace-splitter:focus::before { opacity: .8; }

/* Câu hỏi, bài làm và các công cụ. */
body.v11-app .answer-card.is-active::before {
  background: linear-gradient(90deg, #6a2de2, #169fc9);
}
body.v11-app .question-prompt {
  border-left-color: #7a39e8;
  background: linear-gradient(135deg, #f0e9ff 0%, #eaf8fb 100%);
  color: #34304f;
}
body.v11-app.dark .question-prompt { background: var(--surface-2); color: var(--text); }
body.v11-app .answer-card textarea {
  background: #fdfcff;
  border-color: #ded8f2;
}
body.v11-app.dark .answer-card textarea { background: var(--surface-3); border-color: var(--line); }
body.v11-app .upload-block {
  border-color: #bca8ee;
  background: linear-gradient(135deg, #f6f0ff, #effafd);
}
body.v11-app.dark .upload-block { border-color: var(--primary); background: var(--surface-2); }
body.v11-app .mini-btn,
body.v11-app .secondary-btn,
body.v11-app .icon-btn,
body.v11-app .split-preset-btn {
  border-color: #d9d2ef;
  background: #faf8ff;
  color: #493e75;
}
body.v11-app.dark .mini-btn,
body.v11-app.dark .secondary-btn,
body.v11-app.dark .icon-btn,
body.v11-app.dark .split-preset-btn { border-color: var(--line); background: var(--surface-3); color: var(--text); }
body.v11-app .mini-btn:hover,
body.v11-app .secondary-btn:hover,
body.v11-app .split-preset-btn:hover {
  border-color: #7b43e6;
  color: #5c26c6;
  background: #f0e9ff;
}
body.v11-app .split-preset-btn.is-active {
  border-color: #7136dc;
  background: linear-gradient(135deg, #eee5ff, #e4f7fb);
  color: #5d27c9;
}
body.v11-app .primary-btn,
body.v11-app .finish-dock-btn {
  background: linear-gradient(115deg, #6b26dc 0%, #4d49e1 52%, #15a4ca 100%);
  box-shadow: 0 10px 23px rgba(89, 48, 205, .22);
}
body.v11-app .primary-btn:hover,
body.v11-app .finish-dock-btn:hover {
  filter: brightness(1.06);
  transform: translateY(-1px);
}

/* Dock dưới: nền trắng và các nút pastel. */
body.v11-app .work-dock {
  border-top-color: #ded8ef;
  background: rgba(255,255,255,.94);
  box-shadow: 0 -10px 28px rgba(78, 55, 154, .10);
}
body.v11-app.dark .work-dock { background: color-mix(in srgb, var(--surface) 94%, transparent); border-color: var(--line); }
body.v11-app .dock-source-btn {
  border-color: #cbbbf0;
  background: #eee7ff;
  color: #5e28c9;
}
body.v11-app .question-nav button {
  border-color: #dfdaf1;
  background: #f8f5ff;
  color: #70698f;
}
body.v11-app .question-nav button:nth-child(3n+2) { background: #fff7dc; }
body.v11-app .question-nav button:nth-child(3n+3) { background: #e6f8f8; }
body.v11-app .question-nav button.is-active {
  border-color: transparent;
  background: linear-gradient(145deg, #6827d9, #4c4fe3);
  color: #fff;
  box-shadow: 0 7px 18px rgba(91, 49, 207, .25);
}

/* AI panel. */
body.v11-app .ai-scroll-box:not([hidden]) {
  border-color: #dcd5f1;
  box-shadow: -20px 0 58px rgba(70, 46, 148, .24);
}
body.v11-app .ai-scroll-head {
  background: linear-gradient(115deg, #f0e8ff, #e4f8fc);
  border-bottom-color: #d9d1ee;
}
body.v11-app.dark .ai-scroll-head { background: var(--surface-2); border-color: var(--line); }
body.v11-app .ai-scroll-head strong { color: #4d267f; }
body.v11-app.dark .ai-scroll-head strong { color: var(--text); }
body.v11-app .ai-close-btn { background: #fff; border-color: #d8d1ec; }
body.v11-app.dark .ai-close-btn { background: var(--surface-3); border-color: var(--line); }

/* Tổng kết và bốn tab có màu pastel riêng. */
body.v11-app .review-section {
  background:
    radial-gradient(circle at 0 0, rgba(107,38,220,.08), transparent 30%),
    radial-gradient(circle at 100% 100%, rgba(21,164,202,.08), transparent 34%),
    #f4f2ff;
}
body.v11-app.dark .review-section { background: var(--bg); }
body.v11-app .review-heading .review-tab {
  border-color: #ded8f0;
  color: #4b416e;
  box-shadow: 0 5px 14px rgba(73, 54, 139, .06);
}
body.v11-app .review-heading .review-tab:nth-child(1) { background: #efe8ff; }
body.v11-app .review-heading .review-tab:nth-child(2) { background: #e3f7fb; }
body.v11-app .review-heading .review-tab:nth-child(3) { background: #fff5d8; }
body.v11-app .review-heading .review-tab:nth-child(4) { background: #eaf7f0; }
body.v11-app .review-heading .review-tab.is-active {
  border-color: transparent;
  background: linear-gradient(115deg, #6b26dc, #4d49e1 52%, #15a4ca);
  color: #fff;
  box-shadow: 0 10px 22px rgba(83, 45, 190, .20);
}
body.v11-app.dark .review-heading .review-tab:not(.is-active) { background: var(--surface-2); color: var(--text); border-color: var(--line); }
body.v11-app .review-question,
body.v11-app .reference-card,
body.v11-app .ai-question-score,
body.v11-app .ai-overview-grid section,
body.v11-app .ai-score-summary-card,
body.v11-app .send-card {
  border-color: #dfd9f0;
  background: rgba(255,255,255,.94);
  box-shadow: 0 12px 28px rgba(71, 52, 144, .07);
}
body.v11-app.dark .review-question,
body.v11-app.dark .reference-card,
body.v11-app.dark .ai-question-score,
body.v11-app.dark .ai-overview-grid section,
body.v11-app.dark .ai-score-summary-card,
body.v11-app.dark .send-card { background: var(--surface); border-color: var(--line); box-shadow: none; }
body.v11-app .review-box,
body.v11-app .send-summary,
body.v11-app .ai-score-status {
  background: linear-gradient(135deg, #f2edff, #edfafd);
}
body.v11-app.dark .review-box,
body.v11-app.dark .send-summary,
body.v11-app.dark .ai-score-status { background: var(--surface-2); }
body.v11-app .ai-score-card {
  border-color: #cbb9ef;
  background: linear-gradient(145deg, #f1e9ff, #eefbfd 58%, #fff);
}
body.v11-app.dark .ai-score-card { border-color: var(--line); background: var(--surface-2); }
body.v11-app .ai-score-number {
  background: linear-gradient(145deg, #6928da, #4d49df 55%, #17a5c8);
  box-shadow: 0 12px 26px rgba(82, 45, 190, .20);
}

/* Scrollbar đồng bộ tím – xanh. */
body.v11-app * {
  scrollbar-color: rgba(101, 47, 207, .58) transparent;
}
body.v11-app *::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, rgba(105,45,218,.62), rgba(21,159,201,.58));
  border-radius: 999px;
}

@media (max-width: 820px) {
  body.v11-app .site-header {
    background: linear-gradient(112deg, #382f91 0%, #6925d7 55%, #159fc9 100%);
  }
  body.v11-app .workspace {
    background: #f7f5ff;
  }
  body.v11-app.dark .workspace { background: var(--surface); }
  body.v11-app .workspace-splitter {
    background: linear-gradient(90deg, #ede8fa, #dff5fa);
  }
  body.v11-app .ai-scroll-box:not([hidden]) {
    box-shadow: 0 -24px 60px rgba(67, 43, 145, .28);
  }
  body.v11-app .review-heading {
    background: rgba(244,242,255,.94);
    border-bottom-color: #ded8ef;
  }
  body.v11-app.dark .review-heading { background: color-mix(in srgb, var(--bg) 94%, transparent); border-color: var(--line); }
}