.question-hero {
  padding-block: var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background:
    linear-gradient(90deg, rgba(217, 226, 243, 0.8) 1px, transparent 1px),
    linear-gradient(rgba(217, 226, 243, 0.8) 1px, transparent 1px),
    #eef3ff;
  background-size: 36px 36px;
}

.question-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
}

.question-bank-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: var(--space-5);
  align-items: start;
}

.question-nav,
.question-list-panel {
  border: 1px solid var(--color-border);
  border-radius: 18px;
  background: #fff;
  box-shadow: var(--shadow-sm);
}

.question-nav {
  position: sticky;
  top: 96px;
  padding: var(--space-4);
}

.question-nav h2 {
  font-size: 1.1rem;
}

.question-nav-group {
  margin-top: var(--space-3);
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-3);
}

.question-nav-group summary {
  display: flex;
  justify-content: space-between;
  gap: var(--space-2);
  cursor: pointer;
  font-weight: 900;
}

.question-nav-link {
  display: flex;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-2);
  padding: 0.45rem 0.6rem;
  border-radius: 10px;
  color: var(--color-muted);
}

.question-nav-link.is-active,
.question-nav-link:hover {
  background: #eef2ff;
  color: var(--color-primary-dark);
}

.unit-start {
  margin-top: var(--space-3);
  width: 100%;
}

.question-list-panel {
  padding: var(--space-4);
}

.question-list-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.question-list-heading h2 {
  margin-bottom: 0;
}

.question-list-view {
  display: grid;
  gap: var(--space-3);
}

.question-row-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-3);
  align-items: center;
  padding: var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  background: #fff;
}

.question-row-main h3 {
  margin: var(--space-2) 0 0.25rem;
}

.question-row-main p {
  margin-bottom: 0.2rem;
  color: var(--color-muted);
}

.question-card,
.question-main,
.question-side-card {
  border: 1px solid var(--color-border);
  border-radius: 18px;
  background: #fff;
  box-shadow: var(--shadow-sm);
}

.question-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  min-height: 240px;
  padding: var(--space-4);
}

.question-card p {
  margin-bottom: 0;
  color: var(--color-muted);
}

.question-card .button {
  margin-top: auto;
  width: fit-content;
}

.question-type,
.question-meta-pill {
  display: inline-flex;
  margin: 0 0.35rem 0.35rem 0;
  padding: 0.22rem 0.55rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 800;
}

.question-type {
  background: #eef2ff;
  color: var(--color-primary-dark);
}

.question-meta-pill {
  background: #ecfdf3;
  color: #067647;
}

.question-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: var(--space-5);
  align-items: start;
}

.unit-progress {
  display: inline-flex;
  margin-top: var(--space-2);
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  background: #fff;
  color: var(--color-primary-dark);
  font-weight: 800;
}

.question-main,
.question-side-card {
  padding: var(--space-4);
}

.question-stem {
  margin-bottom: var(--space-4);
}

.answer-card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.answer-card-grid.two {
  grid-template-columns: repeat(2, minmax(0, 220px));
}

.answer-card {
  display: grid;
  grid-template-columns: auto auto 1fr;
  gap: var(--space-2);
  align-items: start;
  padding: var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  background: #fff;
  cursor: pointer;
}

.answer-card.is-correct {
  border-color: #abefc6;
  background: #ecfdf3;
}

.answer-card.is-wrong {
  border-color: #fecaca;
  background: #fff1f1;
}

.option-id {
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: #eef2ff;
  color: var(--color-primary-dark);
  font-weight: 900;
}

.blank-answer {
  display: grid;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.blank-answer label {
  font-weight: 800;
}

.blank-answer input {
  min-height: 46px;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 0.7rem 0.85rem;
}

.blank-answer input.is-correct {
  border-color: #17a673;
  background: #ecfdf3;
}

.blank-answer input.is-wrong {
  border-color: #e44949;
  background: #fff1f1;
}

.answer-feedback {
  margin-top: var(--space-3);
  padding: var(--space-3);
  border-radius: 14px;
  font-weight: 800;
}

.answer-feedback.correct {
  border: 1px solid #abefc6;
  background: #ecfdf3;
  color: #067647;
}

.answer-feedback.wrong {
  border: 1px solid #fecaca;
  background: #fff1f1;
  color: #b42318;
}

.answer-panel {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.question-step-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.finished-pill {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  padding: 0.55rem 0.8rem;
  border-radius: 999px;
  background: #ecfdf3;
  color: #067647;
  font-weight: 800;
}

.answer-reference {
  margin-bottom: var(--space-4);
}

.answer-reference > strong {
  display: block;
  margin-bottom: var(--space-2);
}

.answer-markdown p {
  margin-bottom: var(--space-2);
}

.question-side {
  display: grid;
  gap: var(--space-4);
}

.question-side-card h2 {
  font-size: 1.1rem;
}

.ai-tutor-card p,
.ai-cache-meta {
  color: var(--color-muted);
  font-size: var(--font-sm);
}

.ai-explanation-card {
  border-color: #c8d5ff;
  background: #fbfcff;
}

.ai-explanation-card h3 {
  margin-top: var(--space-4);
  font-size: 1rem;
}

.ai-citation-list {
  display: grid;
  gap: var(--space-2);
  margin: 0;
  padding-left: 1.2rem;
  color: var(--color-muted);
  font-size: var(--font-sm);
}

.ai-citation-list span {
  display: block;
  color: var(--color-muted);
}

.ai-chat-history-label {
  justify-self: center;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  background: #e8eef8;
  color: var(--color-muted);
  font-size: 0.82rem;
  font-weight: 800;
}

.ai-workspace-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 420px;
  gap: var(--space-5);
  align-items: start;
}

.ai-workspace-stack {
  display: grid;
  gap: var(--space-5);
  max-width: 1380px;
  margin-inline: auto;
}

.ai-workspace-question,
.ai-workspace-chat {
  display: grid;
  gap: var(--space-4);
  width: 100%;
}

.ai-workspace-context-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4);
}

.ai-workspace-context-grid .ai-workspace-block:first-child {
  grid-column: 1 / -1;
}

.ai-workspace-chat-grid {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: var(--space-4);
  align-items: start;
}

.ai-page-chat-shell {
  max-width: none;
  min-height: 720px;
  margin-inline: 0;
  padding: 0;
  overflow: hidden;
  background: #fbfcfd;
}

.ai-page-chat-shell .ai-workspace-heading {
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: #fff;
}

.ai-page-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: #fff;
}

.ai-tool-runner {
  display: grid;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: #f8fbff;
}

.ai-tool-runner-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
}

.ai-tool-runner-head h3 {
  margin: 0;
  font-size: 1rem;
}

.ai-tool-runner-head span,
.ai-tool-runner-actions .muted {
  color: var(--color-muted);
  font-size: 0.9rem;
}

.ai-tool-runner-meta {
  display: grid;
  gap: 0.35rem;
  padding: 0.75rem;
  border: 1px solid #d9e1ff;
  border-radius: 10px;
  background: #fff;
}

.ai-tool-runner-meta strong {
  color: var(--color-primary-dark);
}

.ai-tool-runner-meta > span,
.ai-tool-runner-meta p,
.ai-tool-runner-meta dd {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.ai-tool-runner-meta dl {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--space-2);
  margin: 0;
}

.ai-tool-runner-meta dt {
  color: #334155;
  font-size: 0.82rem;
  font-weight: 900;
}

.ai-tool-runner-meta code {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  white-space: nowrap;
}

.ai-tool-runner-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.ai-tool-runner-links a {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0.28rem 0.6rem;
  border: 1px solid #c8d4ff;
  border-radius: 999px;
  background: #f7f9ff;
  color: var(--color-primary-dark);
  font-size: 0.82rem;
  font-weight: 900;
  text-decoration: none;
}

.ai-tool-runner-links a[hidden] {
  display: none;
}

.ai-tool-runner-grid {
  display: grid;
  grid-template-columns: minmax(180px, 0.36fr) minmax(0, 1fr);
  gap: var(--space-3);
}

.ai-tool-runner label {
  display: grid;
  gap: var(--space-1);
  color: #334155;
  font-weight: 700;
}

.ai-tool-runner select,
.ai-tool-runner textarea {
  width: 100%;
  box-sizing: border-box;
  border: 1px solid #ccd6e0;
  border-radius: 8px;
  padding: 0.65rem 0.75rem;
  background: #fff;
  color: #17242b;
  font: inherit;
}

.ai-tool-runner textarea {
  min-height: 132px;
  resize: vertical;
  font-family: "Cascadia Mono", "Consolas", monospace;
  font-size: 0.9rem;
}

.ai-tool-runner-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.ai-page-messages {
  display: grid;
  align-content: start;
  gap: var(--space-4);
  min-height: 460px;
  max-height: 58vh;
  overflow: auto;
  padding: var(--space-5);
  background: #fbfcfd;
}

.ai-page-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-2);
  margin: 0 var(--space-5) var(--space-5);
  padding: var(--space-2);
  border: 1px solid #ccd6e0;
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
}

.ai-page-form textarea {
  width: 100%;
  min-height: 74px;
  resize: vertical;
  border: 0;
  outline: 0;
  padding: 0.75rem;
  font: inherit;
}

.ai-page-form .button {
  align-self: end;
}

.ai-workspace-main,
.ai-dialog-panel {
  display: grid;
  gap: var(--space-4);
}

.ai-workspace-heading {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  align-items: center;
  margin-bottom: var(--space-3);
}

.ai-workspace-heading h2,
.ai-workspace-block h2,
.ai-workspace-block h3 {
  margin-bottom: var(--space-3);
  font-size: 1.12rem;
}

.ai-workspace-block {
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.ai-workspace-block:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.ai-followup-form {
  display: grid;
  gap: var(--space-2);
}

.ai-followup-form label {
  font-weight: 800;
}

.ai-followup-form textarea {
  width: 100%;
  min-height: 140px;
  resize: vertical;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 0.75rem 0.85rem;
  font: inherit;
}

.ai-answer-item,
.ai-conversation {
  display: grid;
  gap: var(--space-2);
  padding-block: var(--space-3);
  border-top: 1px solid var(--color-border);
}

.ai-answer-item:first-of-type,
.ai-conversation:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.ai-message {
  display: grid;
  gap: var(--space-2);
  padding: var(--space-3);
  border-radius: 12px;
  background: #f8fafc;
}

.ai-message-user {
  background: #eef2ff;
}

.ai-message-assistant {
  background: #f7fbf9;
}

.has-ai-modal {
  overflow: hidden;
}

.ai-modal[hidden] {
  display: none;
}

.ai-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
}

.ai-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.46);
}

.ai-modal-dialog {
  position: relative;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  width: min(1480px, calc(100vw - 20px));
  height: min(940px, calc(100vh - 20px));
  margin: 10px auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: #fff;
  box-shadow: 0 24px 80px rgba(15, 23, 42, 0.28);
  overflow: hidden;
}

.ai-modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
  background: #f8fafc;
}

.ai-modal-header h2 {
  margin: 0;
  font-size: 1.25rem;
}

.ai-modal-close {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--color-text);
  font-size: 1.6rem;
  line-height: 1;
  cursor: pointer;
}

.ai-modal-body {
  display: grid;
  grid-template-columns: minmax(300px, 0.72fr) minmax(0, 1.45fr);
  min-height: 0;
}

.ai-modal-context,
.ai-chat {
  min-height: 0;
  overflow: auto;
}

.ai-modal-context {
  display: grid;
  align-content: start;
  gap: var(--space-4);
  padding: var(--space-4);
  border-right: 1px solid var(--color-border);
  background: #fbfcfd;
}

.ai-context-block {
  display: grid;
  gap: var(--space-2);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}

.ai-context-block:last-child {
  border-bottom: 0;
}

.ai-context-block h3 {
  margin: 0;
  font-size: 1rem;
}

.ai-option-list {
  display: grid;
  gap: var(--space-2);
}

.ai-option-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-2);
  align-items: start;
  padding: var(--space-2);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: #fff;
}

.ai-chat {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  background: #fff;
}

.ai-chat-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.ai-chat-messages {
  display: grid;
  align-content: start;
  gap: var(--space-3);
  min-height: 0;
  padding: var(--space-4);
  overflow: auto;
  background: #f8fafc;
}
.ai-timeline-tools { display:flex; flex-wrap:wrap; align-items:end; gap:.55rem; padding:.6rem .75rem; border:1px solid var(--color-border); border-radius:10px; background:#fbfcff; }.ai-timeline-tools label { display:grid; gap:.2rem; color:var(--color-muted); font-size:.76rem; font-weight:800; }.ai-timeline-tools input,.ai-timeline-tools select { min-height:34px; border:1px solid #c7d2e5; border-radius:8px; background:#fff; color:var(--color-text); font:inherit; padding:.35rem .55rem; }.ai-timeline-tools input { width:min(280px,65vw); }.ai-timeline-result { margin-left:auto; color:var(--color-muted); font-size:.8rem; }
[data-ai-stop][hidden],.ai-chat-message[hidden] { display:none !important; }

.ai-chat-message {
  display: grid;
  gap: var(--space-2);
  max-width: 92%;
  padding: 0;
  border: 0;
  background: transparent;
}
.ai-message-avatar { display:grid; place-items:center; width:30px; height:30px; border-radius:50%; background:#e8efff; color:#2855d9; font-weight:800; }
.ai-chat-message { grid-template-columns:auto minmax(0,1fr); align-items:start; }
.ai-message-content { min-width:0; }
.ai-message-time { display:block; margin-top:.35rem; color:var(--color-muted); font-size:.75rem; }
.ai-message-actions { display:flex; gap:.25rem; margin-top:.4rem; }.ai-message-actions button{display:inline-grid;place-items:center;width:30px;height:30px;border:0;background:transparent;color:var(--color-muted);cursor:pointer;padding:.3rem;border-radius:7px}.ai-message-actions button:hover,.ai-message-actions button:focus-visible{background:#eef2ff;color:#1d4ed8;outline:0}.ai-message-actions button.is-success{color:#15803d;background:#dcfce7}.ai-message-actions .bi-icon{width:16px;height:16px;margin:0;pointer-events:none}
.ai-message-citations { margin-top:.55rem; padding:.45rem .65rem; border:1px solid #dbe4f4; border-radius:9px; background:#fbfcff; color:var(--color-muted); font-size:.83rem; }.ai-message-citations summary { cursor:pointer; color:#47617f; font-weight:800; }.ai-message-citations .ai-citation-list { margin-top:.45rem; }
.ai-message-editor { display:grid; gap:.55rem; }.ai-message-editor textarea { width:100%; min-height:88px; resize:vertical; padding:.65rem; border:1px solid #93a7d8; border-radius:10px; font:inherit; line-height:1.5; }.ai-message-editor > div { display:flex; justify-content:flex-end; gap:.45rem; }.ai-message-editor button { min-height:32px; padding:0 .7rem; border:1px solid #bfd0ff; border-radius:8px; background:#fff; color:#173d82; font-weight:800; cursor:pointer; }.ai-message-editor [data-ai-edit-submit] { border-color:#1d4ed8; background:#1d4ed8; color:#fff; }
.ai-thinking-dots { display:inline-flex; gap:.3rem; padding:.35rem 0; }
.ai-stream-complete { padding:0; }.ai-stream-tail { white-space:normal; color:var(--color-text); }
.ai-stream-display-math { overflow-x:auto; padding:.35rem 0; }
.ai-thinking-dots i { width:.45rem; height:.45rem; border-radius:50%; background:#5473df; animation:ai-dot 1s infinite ease-in-out; }
.ai-thinking-dots i:nth-child(2){animation-delay:.16s}.ai-thinking-dots i:nth-child(3){animation-delay:.32s}
@keyframes ai-dot { 0%,80%,100%{transform:translateY(0);opacity:.35}40%{transform:translateY(-.35rem);opacity:1} }

.ai-chat-message-user {
  justify-self: end;
  max-width: min(78%, 720px);
}

.ai-chat-message-assistant {
  justify-self: start;
  max-width: min(88%, 780px);
}

.ai-chat-message-tool {
  justify-self: stretch;
  max-width: min(100%, 860px);
  min-width: 0;
  width: 100%;
}

.ai-modal .ai-chat-message-tool {
  max-width: 100%;
}

.ai-modal .ai-chat-message-body,
.ai-modal .ai-tool-card,
.ai-modal .ai-tool-card-body {
  min-width: 0;
  max-width: 100%;
}

.ai-chat-message > strong {
  color: var(--color-muted);
  font-size: 0.86rem;
}

.ai-chat-message-user .ai-chat-message-body {
  padding: 0.78rem 0.95rem;
  border-radius: 16px 16px 4px 16px;
  background: #eef2ff;
}

.ai-chat-message-assistant .ai-chat-message-body {
  padding: 0.2rem 0;
}

.ai-stream-block + .ai-stream-block,
.ai-stream-committed + .ai-stream-block {
  margin-top: 0.75rem;
}

.ai-stream-block > :last-child {
  margin-bottom: 0;
}

.ai-tool-card {
  border: 1px solid #b6c5ff;
  border-radius: 12px;
  background: linear-gradient(180deg, #f7f9ff, #ffffff);
  box-shadow: 0 10px 22px rgba(71, 99, 255, 0.1);
  overflow: hidden;
}

.ai-tool-card.is-error {
  border-color: #fecaca;
  background: linear-gradient(180deg, #fff7f7, #ffffff);
  box-shadow: 0 10px 22px rgba(220, 38, 38, 0.08);
}

.ai-tool-card.is-error .ai-tool-card-head {
  border-bottom-color: #fecaca;
  background: #fff1f2;
  color: #991b1b;
}

.ai-tool-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: 0.55rem 0.75rem;
  border-bottom: 1px solid #d9e1ff;
  background: #eef2ff;
  color: var(--color-primary-dark);
  cursor: pointer;
}

.ai-tool-card-head:not(:has(.ai-tool-toggle))::after {
  content: "收起";
  flex: 0 0 auto;
  border: 1px solid #c8d4ff;
  border-radius: 999px;
  background: #fff;
  color: var(--color-primary-dark);
  font-size: 0.78rem;
  font-weight: 800;
  line-height: 1;
  padding: 0.35rem 0.55rem;
}

.ai-tool-card.is-collapsed .ai-tool-card-head:not(:has(.ai-tool-toggle))::after {
  content: "展开";
}

.ai-tool-card-title {
  display: inline-flex;
  min-width: 0;
  align-items: center;
  gap: var(--space-2);
}

.ai-tool-card-title strong {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.ai-tool-card-title span {
  display: inline-flex;
  min-height: 22px;
  align-items: center;
  padding: 0.12rem 0.45rem;
  border-radius: 999px;
  background: var(--color-primary);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 900;
}

.ai-tool-status-badge {
  display: inline-flex;
  flex: 0 0 auto;
  min-height: 22px;
  align-items: center;
  padding: 0.12rem 0.45rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-style: normal;
  font-weight: 900;
  white-space: nowrap;
}

.ai-tool-status-badge.is-ok {
  background: #ecfdf3;
  color: #067647;
}

.ai-tool-status-badge.is-failed {
  background: #fef2f2;
  color: #991b1b;
}

.ai-tool-card-actions {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 0.35rem;
}

.ai-tool-full-link,
.ai-tool-demo-button,
.ai-tool-toggle {
  flex: 0 0 auto;
  border: 1px solid #c8d4ff;
  border-radius: 999px;
  background: #fff;
  color: var(--color-primary-dark);
  cursor: pointer;
  font-size: 0.78rem;
  font-weight: 800;
  line-height: 1;
  padding: 0.35rem 0.55rem;
}

.ai-tool-full-link {
  color: var(--color-primary-dark);
  text-decoration: none;
}

.ai-tool-demo-button {
  border-color: #bbf7d0;
  color: #067647;
}

.ai-tool-demo-button:hover,
.ai-tool-full-link:hover,
.ai-tool-toggle:hover {
  background: #f7f9ff;
}

.ai-tool-demo-button:hover {
  background: #ecfdf3;
}

.ai-tool-card.is-collapsed .ai-tool-card-body {
  display: none;
}

.ai-tool-card.is-collapsed .ai-tool-card-head {
  border-bottom: 0;
}

.ai-tool-card-body {
  display: grid;
  gap: var(--space-2);
  padding: var(--space-3);
}

.ai-tool-latex,
.ai-tool-result {
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: #fff;
  overflow-x: auto;
}

.ai-tool-input-summary {
  margin: 0;
  padding: 0.55rem 0.7rem;
  border: 1px solid #d9e1ff;
  border-radius: 10px;
  background: #f7f9ff;
  color: var(--color-muted);
  font-size: 0.92rem;
  font-weight: 800;
}

.ai-tool-terms,
.ai-tool-steps {
  display: grid;
  gap: var(--space-2);
  margin: 0;
  padding: 0;
  list-style: none;
}

.ai-tool-step-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  align-items: center;
  justify-content: space-between;
  padding: 0.45rem 0.55rem;
  border: 1px solid #d9e1ff;
  border-radius: 10px;
  background: #f7f9ff;
  color: var(--color-muted);
  font-size: 0.84rem;
  font-weight: 800;
}

.ai-tool-step-controls button {
  border: 1px solid #c8d4ff;
  border-radius: 999px;
  background: #fff;
  color: var(--color-primary-dark);
  cursor: pointer;
  font: inherit;
  padding: 0.28rem 0.55rem;
}

.ai-tool-step-controls button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.ai-tool-term,
.ai-tool-step {
  display: grid;
  gap: 0.35rem;
  padding: 0.65rem 0.75rem;
  border-left: 3px solid var(--color-primary);
  border-radius: 10px;
  background: #fbfcff;
}

.ai-tool-term[hidden],
.ai-tool-step[hidden] {
  display: none !important;
}

.ai-tool-step-head {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.ai-tool-step-title,
.ai-tool-step-operation {
  min-width: 0;
}
.ai-tool-step-explain { margin-left:auto; border:1px solid #c8d4ff; border-radius:999px; background:#fff; color:var(--color-primary-dark); cursor:pointer; font:inherit; font-size:.78rem; font-weight:800; padding:.22rem .5rem; }.ai-tool-step-explain:hover,.ai-tool-step-explain:focus-visible { border-color:#1d4ed8; background:#eef2ff; outline:0; }

.ai-tool-step-operation {
  padding: 0.12rem 0.4rem;
  border-radius: 999px;
  background: #eef2ff;
  color: var(--color-primary-dark);
  font-size: 0.82rem;
  font-weight: 800;
  overflow-x: auto;
  white-space: normal;
}

.ai-tool-step-note {
  margin: 0;
  color: #52647d;
}

.ai-tool-term-index {
  color: var(--color-muted);
  font-size: 0.82rem;
  font-weight: 800;
}

.ai-tool-term-formula,
.ai-tool-minor {
  overflow-x: auto;
}

.ai-tool-minor {
  display: grid;
  gap: 0.25rem;
}

.ai-tool-minor span,
.ai-tool-term-note {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.ai-tool-final {
  margin: 0;
  padding: 0.65rem 0.75rem;
  border-radius: 10px;
  background: #ecfdf3;
  color: #067647;
  font-weight: 800;
}

.ai-tool-solution {
  display: grid;
  gap: 0.4rem;
}
.ai-tool-eigenvalues { margin: 0; padding-left: 1.25rem; color: var(--color-text); font-weight: 700; }
.ai-tool-subspace-result { display: grid; gap: .45rem; margin-top: .65rem; padding: .75rem; border-radius: 10px; background: #eef8ff; color: #173d82; }
.ai-tool-subspace-result p { margin: 0; }

.ai-tool-error {
  margin: 0;
  padding: 0.65rem 0.75rem;
  border-radius: 10px;
  background: #fef2f2;
  color: #991b1b;
  font-weight: 800;
}

.ai-tool-raw {
  margin: 0;
  padding: 0.65rem 0.75rem;
  border: 1px solid #fecaca;
  border-radius: 10px;
  background: #fffafa;
  overflow-x: auto;
}

.has-tool-demo-dialog {
  overflow: hidden;
}

.ai-tool-demo-dialog[hidden] {
  display: none;
}

.ai-tool-demo-dialog {
  position: fixed;
  inset: 0;
  z-index: 1200;
  display: grid;
  place-items: center;
  padding: var(--space-4);
  overflow: auto;
  overscroll-behavior: contain;
}

.ai-tool-demo-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.48);
}

.ai-tool-demo-panel {
  position: relative;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  width: min(920px, calc(100vw - var(--space-4) * 2));
  max-width: 100%;
  height: min(90vh, 780px);
  height: min(90dvh, 780px);
  max-height: min(90vh, 780px);
  min-height: 0;
  overflow: hidden;
  border: 1px solid #d9e1ff;
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 24px 80px rgba(15, 23, 42, 0.28);
}

.ai-tool-demo-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
  background: #f7f9ff;
}

.ai-tool-demo-header span {
  display: block;
  color: var(--color-muted);
  font-size: 0.8rem;
  font-weight: 800;
}

.ai-tool-demo-header h2 {
  margin: 0.15rem 0 0;
  font-size: 1.15rem;
}

.ai-tool-demo-close {
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  background: #fff;
  color: var(--color-text);
  cursor: pointer;
  font-size: 1.25rem;
  line-height: 1;
}

.ai-tool-demo-content {
  display: grid;
  min-height: 0;
  max-height: 100%;
  overflow: hidden;
}

.ai-tool-demo-scroll {
  display: grid;
  align-content: start;
  min-height: 0;
  max-height: 100%;
  gap: var(--space-3);
  overflow: auto;
  overscroll-behavior: contain;
  padding: var(--space-4);
}

.ai-tool-demo-scroll .ai-tool-card {
  box-shadow: none;
}

.ai-tool-demo-loading {
  margin: 0;
  color: var(--color-muted);
  font-weight: 800;
}

.ai-tool-demo-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-2);
  margin: 0;
}

.ai-tool-demo-meta div,
.ai-tool-demo-json {
  min-width: 0;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: #fbfcff;
}

.ai-tool-demo-meta div {
  padding: 0.65rem 0.75rem;
}

.ai-tool-demo-meta dt {
  color: var(--color-muted);
  font-size: 0.78rem;
  font-weight: 800;
}

.ai-tool-demo-meta dd {
  margin: 0.2rem 0 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 900;
}

.ai-tool-demo-json {
  overflow: hidden;
}

.ai-tool-demo-json summary {
  cursor: pointer;
  padding: 0.65rem 0.75rem;
  font-weight: 900;
}

.ai-tool-demo-json pre {
  margin: 0;
  max-height: 240px;
  overflow: auto;
  border-top: 1px solid var(--color-border);
  padding: 0.75rem;
  background: #fff;
}

.has-process-demo { overflow: hidden; }
.ai-process-demo-dialog[hidden] { display: none; }
.ai-process-demo-dialog { position: fixed; inset: 0; z-index: 1250; display: grid; place-items: center; padding: var(--space-4); }
.ai-process-demo-backdrop { position: absolute; inset: 0; background: rgba(15, 23, 42, .58); }
.ai-process-demo-panel { position: relative; display: grid; grid-template-rows: auto minmax(260px, 1fr) auto auto auto; width: min(880px, calc(100vw - var(--space-4) * 2)); max-height: min(90vh, 780px); overflow: hidden; border: 1px solid #cbd5ff; border-radius: 18px; background: #fff; box-shadow: 0 28px 90px rgba(15, 23, 42, .34); }
.ai-process-demo-header { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); padding: var(--space-4); border-bottom: 1px solid var(--color-border); background: linear-gradient(110deg, #f7f9ff, #eef5ff); }
.ai-process-demo-header span { display: block; color: var(--color-muted); font-size: .78rem; font-weight: 800; }
.ai-process-demo-header h2 { margin: .15rem 0 0; font-size: 1.18rem; }
.ai-process-demo-close { width: 36px; height: 36px; border: 1px solid var(--color-border); border-radius: 50%; background: #fff; color: var(--color-text); font-size: 1.25rem; cursor: pointer; }
.ai-process-demo-stage { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; justify-items: center; gap: var(--space-5); min-height: 0; padding: clamp(1rem, 4vw, 3rem); overflow: auto; background: radial-gradient(circle at 50% 38%, #f7fbff, #fff 62%); }
.ai-demo-operation, .ai-demo-result { grid-column: 1 / -1; font-size: 1.12rem; font-weight: 800; color: #173d82; }
.ai-demo-matrix { position: relative; display: grid; gap: .32rem; padding: .7rem 1.15rem; border-inline: 3px solid #283d6e; border-radius: 6px; background: rgba(255,255,255,.86); }
.ai-demo-matrix-row { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(2.2rem, auto); gap: .35rem; padding: .18rem; border-radius: 8px; transition: background .2s ease; }
.ai-demo-matrix-row.is-focused { background: #dceeff; }
.ai-demo-matrix-row.is-source { background: #dbeafe; box-shadow: inset 0 0 0 2px #60a5fa; }
.ai-demo-matrix-row.is-target { background: #fef3c7; box-shadow: inset 0 0 0 2px #f59e0b; }
.ai-demo-matrix-cell { display: grid; min-width: 2.2rem; min-height: 2.2rem; place-items: center; padding: .15rem .4rem; border-radius: 7px; font-weight: 800; transition: background .2s ease, transform .2s ease; }
.ai-demo-matrix-cell.is-focused { background: #fff1bf; color: #8a5200; transform: scale(1.06); }
.ai-demo-matrix-cell.is-augmented { border-left: 2px solid #334155; border-radius: 0; }
.ai-demo-minor { display: grid; gap: .45rem; justify-items: center; color: var(--color-muted); font-size: .85rem; font-weight: 800; }
.ai-demo-factor { position: absolute; right: -4.4rem; top: 50%; z-index: 2; min-width: 3.2rem; padding: .35rem .5rem; border: 1px solid #7dd3fc; border-radius: 999px; background: #ecfeff; color: #075985; font-weight: 900; text-align: center; }
.ai-demo-row-ghost { position: absolute; z-index: 4; margin: 0; pointer-events: none; background: #dbeafe; box-shadow: 0 8px 18px rgba(30, 64, 175, .22); }
.ai-demo-solution { display: grid; gap: .4rem; padding: .8rem 1rem; border-radius: 10px; background: #ecfdf3; color: #067647; font-weight: 800; }
.ai-demo-vectors { display: grid; gap: .5rem; justify-items: center; }
.ai-demo-vectors > div { padding: .45rem .8rem; border-radius: 8px; }
.ai-demo-vectors > div.is-focused { background: #dbeafe; box-shadow: inset 0 0 0 2px #60a5fa; }
.ai-demo-geometry { display: grid; width: min(100%, 540px); gap: .65rem; }
.ai-demo-geometry > header { display: flex; align-items: center; justify-content: center; gap: .7rem; font-weight: 900; }
.ai-geometry-source-label, .ai-geometry-image-label { padding: .3rem .62rem; border-radius: 999px; font-size: .86rem; }
.ai-geometry-source-label { background: #dbeafe; color: #1d4ed8; }
.ai-geometry-image-label { background: #dcfce7; color: #15803d; }
.ai-geometry-arrow-label { color: #475569; font-size: 1.25rem; }
.ai-demo-geometry svg { width: min(100%, 420px); justify-self: center; border: 1px solid #cbd5e1; border-radius: 14px; background: linear-gradient(135deg, #f8fbff, #fff); }
.ai-geometry-grid-line { stroke: #dbe7f5; stroke-width: 1; }
.ai-geometry-axis { stroke: #64748b; stroke-width: 1.8; }
.ai-geometry-polygon { fill: rgba(34, 197, 94, .22); stroke: #16a34a; stroke-width: 3; }
.ai-geometry-vector line { stroke: #2563eb; stroke-width: 3; }
.ai-geometry-vector text { fill: #1e3a8a; font-size: 16px; font-weight: 800; paint-order: stroke; stroke: #fff; stroke-width: 4px; stroke-linejoin: round; }
.ai-demo-geometry marker path { fill: #2563eb; }
.ai-demo-geometry > p { margin: 0; color: var(--color-muted); font-size: .82rem; line-height: 1.55; text-align: center; }
.ai-tool-linear-result { display: grid; gap: .45rem; margin-top: .8rem; padding: .8rem; border: 1px solid #c7d2fe; border-radius: 10px; background: #f8faff; }
.ai-tool-linear-result p { margin: 0; }
.ai-tool-warnings { display: grid; gap: .3rem; margin: .8rem 0 0; padding: .65rem .8rem .65rem 1.8rem; border-radius: 10px; background: #fffbeb; color: #92400e; font-size: .9rem; }
.ai-process-demo-caption { display: grid; gap: .3rem; padding: .9rem var(--space-4); border-top: 1px solid var(--color-border); background: #fbfcff; }
.ai-process-demo-caption span { color: var(--color-muted); }
.ai-process-demo-controls { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: .55rem; padding: .85rem var(--space-4); }
.ai-process-demo-controls button, .ai-process-demo-controls select { min-height: 34px; border: 1px solid #bfd0ff; border-radius: 9px; background: #fff; color: #173d82; font-weight: 800; cursor: pointer; }
.ai-process-demo-controls button { padding: 0 .75rem; }
.ai-process-demo-controls button.is-primary { border-color: #1d4ed8; background: #1d4ed8; color: #fff; }
.ai-process-demo-controls label { display: inline-flex; align-items: center; gap: .35rem; color: var(--color-muted); font-size: .9rem; font-weight: 800; }
.ai-process-demo-controls select { padding: 0 .35rem; }
.ai-process-demo-timeline { display: flex; gap: .4rem; padding: 0 var(--space-4) var(--space-4); overflow-x: auto; }
.ai-process-demo-timeline button { flex: 0 0 30px; width: 30px; height: 30px; border: 1px solid #cbd5e1; border-radius: 50%; background: #fff; color: var(--color-muted); cursor: pointer; font-weight: 800; }
.ai-process-demo-timeline button.is-current { border-color: #1d4ed8; background: #1d4ed8; color: #fff; }
@media (prefers-reduced-motion: reduce) { .ai-process-demo-stage { animation: none; } }
@media (max-width: 640px) { .ai-process-demo-dialog { padding: .5rem; } .ai-process-demo-panel { width: 100%; max-height: 96dvh; } .ai-process-demo-stage { grid-template-columns: 1fr; padding: 1.2rem; } .ai-process-demo-controls { justify-content: flex-start; } }

.ai-chat-message-body p:last-child,
.ai-chat-message-body .markdown-body p:last-child {
  margin-bottom: 0;
}

.ai-chat-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-top: 1px solid var(--color-border);
  background: #fff;
}

.ai-chat-form textarea {
  width: 100%;
  min-height: 78px;
  resize: vertical;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 0.75rem 0.85rem;
  font: inherit;
}

.markdown-body.compact {
  padding: 0;
  border: 0;
  box-shadow: none;
}

@media (max-width: 840px) {
  .ai-modal-dialog {
    width: 100vw;
    height: 100vh;
    margin: 0;
    border-radius: 0;
  }

  .ai-modal-body {
    grid-template-columns: 1fr;
    overflow: auto;
  }

  .ai-modal-context {
    max-height: 42vh;
    border-right: 0;
    border-bottom: 1px solid var(--color-border);
  }

  .ai-chat {
    min-height: 58vh;
  }

  .ai-chat-form {
    grid-template-columns: 1fr;
  }

  .ai-page-chat-shell {
    min-height: auto;
  }

  .ai-page-chat-shell .ai-workspace-heading,
  .ai-page-toolbar,
  .ai-tool-runner,
  .ai-page-messages {
    padding-inline: var(--space-3);
  }

  .ai-tool-runner-grid {
    grid-template-columns: 1fr;
  }

  .ai-tool-runner-meta dl {
    grid-template-columns: 1fr;
  }

  .ai-page-form {
    grid-template-columns: 1fr;
    margin-inline: var(--space-3);
  }

  .ai-tool-demo-dialog {
    align-items: start;
    padding: var(--space-2);
  }

  .ai-tool-demo-panel {
    height: calc(100vh - var(--space-4));
    height: calc(100dvh - var(--space-4));
    max-height: calc(100vh - var(--space-4));
  }

  .ai-tool-demo-meta {
    grid-template-columns: 1fr;
  }
}

.tool-list {
  margin: 0;
  padding-left: 1.2rem;
}

@media (max-width: 980px) {
  .question-grid,
  .question-bank-layout,
  .question-layout,
  .ai-workspace-layout,
  .ai-workspace-context-grid,
  .ai-workspace-chat-grid,
  .answer-card-grid,
  .answer-card-grid.two {
    grid-template-columns: 1fr;
  }

  .question-nav {
    position: static;
  }

  .question-list-heading,
  .question-row-card {
    grid-template-columns: 1fr;
    display: grid;
  }
}

/* Question bank refactor */
.question-bank-hero {
  padding-block: var(--space-4);
  background: #eef3ff;
}

.question-bank-container {
  width: min(100% - 32px, 1480px);
}

.question-bank-hero h1 {
  margin-bottom: 0.35rem;
}

.question-bank-hero .lead {
  margin-bottom: var(--space-3);
}

.question-search {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-2);
  margin-block: var(--space-3);
  padding: var(--space-2);
  border: 1px solid #cbd6f0;
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 10px 24px rgba(54, 78, 140, 0.1);
}

.question-search input,
.ai-bank-controls input,
.question-filter-panel select {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 0.62rem 0.75rem;
  background: #fff;
  color: var(--color-text);
}

.question-search input {
  border-color: transparent;
  outline: 0;
}

.ai-bank-search {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--space-2);
  padding: var(--space-3);
  border: 1px solid #bfe7dd;
  border-radius: 12px;
  background: #f1fbf8;
}

.ai-bank-search h2 {
  margin-bottom: 0.2rem;
  color: #146c5a;
  font-size: 1.05rem;
}

.ai-bank-search p {
  margin-bottom: 0;
  color: var(--color-muted);
}

.ai-bank-controls {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-2);
}

.ai-bank-examples {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.ai-bank-examples button,
.active-filter-chip {
  min-height: 32px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: #fff;
  color: var(--color-primary-dark);
  font-weight: 800;
}

.ai-bank-examples button {
  padding: 0.28rem 0.65rem;
}

.ai-bank-status,
.question-toast,
.basket-note {
  color: #067647;
  font-weight: 800;
}

.ai-bank-status {
  padding: .65rem .8rem;
  border: 1px solid #b7e4d7;
  border-radius: 9px;
  background: #fff;
  white-space: pre-line;
}

.ai-bank-status[data-state="working"] { color: #2855d9; border-color: #cbd7ff; background: #f6f8ff; }
.ai-bank-status[data-state="error"] { color: #b42318; border-color: #f4c7c3; background: #fff7f6; }
.ai-bank-status[data-state="empty"] { color: #7a5b13; border-color: #ead9aa; background: #fffbeb; }

.question-bank-section {
  padding-block: var(--space-4);
}

.question-bank-layout {
  grid-template-columns: 250px minmax(0, 1fr) 290px;
  gap: var(--space-3);
}

.question-chapter-tree,
.practice-basket {
  position: sticky;
  top: 88px;
  max-height: calc(100vh - 108px);
  overflow: auto;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 10px 24px rgba(54, 78, 140, 0.08);
}

.question-chapter-tree {
  padding: var(--space-3);
}

.question-nav-all {
  margin-bottom: var(--space-2);
  font-weight: 900;
}

.question-nav-group {
  margin-top: 0;
  padding-top: var(--space-2);
}

.question-nav-group summary {
  display: block;
  list-style: none;
}

.question-nav-group summary::-webkit-details-marker {
  display: none;
}

.question-nav-group summary > a,
.question-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  min-height: 36px;
  margin-top: 0.15rem;
  padding: 0.4rem 0.55rem;
  border-radius: 8px;
}

.question-nav-group summary > a {
  color: var(--color-text);
  font-weight: 900;
}

.question-section-list {
  display: grid;
  gap: 0.1rem;
  margin-left: var(--space-3);
  padding-left: var(--space-2);
  border-left: 1px solid var(--color-border);
}

.question-results {
  padding: var(--space-3);
  border-radius: 12px;
}

.question-results-header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: var(--space-3);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}

.question-results-header h2 {
  margin-bottom: 0.2rem;
  font-size: 1.35rem;
}

.question-results-header p {
  margin-bottom: 0;
  color: var(--color-muted);
}

.question-filter-panel {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr)) auto;
  gap: var(--space-2);
  align-items: end;
  margin-block: var(--space-3);
}

.question-filter-panel label,
.question-feature-filters {
  display: grid;
  gap: 0.3rem;
}

.question-filter-panel label span,
.question-feature-filters legend {
  color: var(--color-muted);
  font-size: 0.84rem;
  font-weight: 800;
}

.question-feature-filters {
  grid-column: 1 / -2;
  grid-template-columns: repeat(4, max-content);
  align-items: center;
  border: 0;
  margin: 0;
  padding: 0;
}

.question-feature-filters label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  min-height: 36px;
  color: var(--color-muted);
}

.active-filter-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  margin-bottom: var(--space-3);
  color: var(--color-muted);
}

.active-filter-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.65rem;
  background: #eef2ff;
}

.clear-filter-link {
  color: var(--color-primary);
  font-weight: 900;
}

.question-compact-list {
  gap: var(--space-2);
}

.question-compact-card {
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  padding: var(--space-3);
  border-radius: 10px;
  box-shadow: none;
  transition: border-color var(--duration-fast), box-shadow var(--duration-fast), transform var(--duration-fast);
}

.question-compact-card:hover {
  border-color: #bdc9ff;
  box-shadow: 0 8px 20px rgba(54, 78, 140, 0.08);
  transform: translateY(-1px);
}

.question-card-content {
  min-width: 0;
}

.question-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.question-card-tags .question-type,
.question-card-tags .question-meta-pill {
  margin: 0;
}

.question-compact-card h3 {
  margin: 0.45rem 0 0.25rem;
  font-size: 1.04rem;
}

.question-preview.markdown-body {
  max-height: 5.9rem;
  overflow: hidden;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  color: #2e3b44;
}

.question-preview.markdown-body p {
  margin-bottom: 0.25rem;
}

.question-card-meta {
  margin: 0.45rem 0 0;
  color: var(--color-muted);
  font-size: 0.88rem;
}

.question-card-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.45rem;
  min-width: 220px;
}

.question-card-actions .button {
  min-height: 38px;
}

.question-pagination {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
}

.pagination-pages {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.pagination-pages a,
.pagination-pages span {
  display: inline-grid;
  place-items: center;
  min-width: 34px;
  min-height: 34px;
  border-radius: 8px;
  color: var(--color-muted);
  font-weight: 800;
}

.pagination-pages .is-current {
  background: #eef2ff;
  color: var(--color-primary-dark);
}

.is-disabled {
  opacity: 0.55;
  pointer-events: none;
}

.practice-basket {
  display: grid;
  gap: var(--space-3);
  padding: var(--space-3);
}

.practice-basket h2,
.practice-basket h3 {
  margin-bottom: 0.25rem;
  font-size: 1rem;
}

.practice-basket p {
  margin-bottom: 0;
}

.basket-stat-list,
.basket-items {
  display: grid;
  gap: 0.35rem;
}

.basket-stat-row,
.basket-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  min-height: 32px;
  color: var(--color-muted);
}

.basket-item {
  padding: 0.45rem 0;
  border-top: 1px solid var(--color-border);
}

.basket-item-title {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--color-text);
  font-weight: 800;
}

.basket-remove {
  border: 0;
  background: transparent;
  color: #b42318;
  font-weight: 900;
}

.basket-time {
  padding: 0.65rem 0.75rem;
  border-radius: 8px;
  background: #f7f9ff;
  color: var(--color-primary-dark);
}

.basket-actions {
  display: grid;
  gap: var(--space-2);
}

.question-preview-drawer[hidden],
.question-toast[hidden] {
  display: none;
}

.question-preview-drawer {
  position: fixed;
  inset: 0;
  z-index: 1000;
}

.question-preview-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.45);
}

.question-preview-panel {
  position: absolute;
  inset: 0 0 0 auto;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  width: min(680px, 100vw);
  border-left: 1px solid var(--color-border);
  background: #fff;
  box-shadow: -18px 0 48px rgba(15, 23, 42, 0.22);
}

.question-preview-panel > header,
.question-preview-panel > footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}

.question-preview-panel > footer {
  border-top: 1px solid var(--color-border);
  border-bottom: 0;
  justify-content: flex-end;
}

.preview-close {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: #fff;
  font-size: 1.5rem;
}

.question-preview-body {
  min-height: 0;
  overflow: auto;
  padding: var(--space-4);
}

.preview-options {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.preview-option {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-2);
  align-items: start;
  padding: var(--space-2);
  border: 1px solid var(--color-border);
  border-radius: 8px;
}

.question-toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 1100;
  max-width: min(420px, calc(100vw - 36px));
  padding: 0.75rem 0.9rem;
  border: 1px solid #abefc6;
  border-radius: 10px;
  background: #ecfdf3;
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.14);
}

@media (max-width: 1180px) {
  .question-bank-layout {
    grid-template-columns: 230px minmax(0, 1fr);
  }

  .practice-basket {
    position: fixed;
    inset: auto 12px 12px;
    z-index: 30;
    max-height: 46vh;
  }
}

@media (max-width: 900px) {
  .question-bank-layout,
  .question-filter-panel,
  .question-results-header,
  .question-compact-card {
    grid-template-columns: 1fr;
  }

  .question-chapter-tree {
    position: static;
    max-height: 42vh;
  }

  .question-feature-filters {
    grid-column: auto;
    grid-template-columns: 1fr 1fr;
  }

  .question-card-actions {
    min-width: 0;
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .question-bank-container {
    width: min(100% - 20px, 1480px);
  }

  .question-search,
  .ai-bank-controls {
    grid-template-columns: 1fr;
  }

  .question-feature-filters {
    grid-template-columns: 1fr;
  }

  .question-card-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .question-preview-panel {
    width: 100vw;
  }
}
.question-set-results {
  display: grid;
  gap: 1rem;
  margin-bottom: 1.25rem;
  padding: 1rem;
  border: 1px solid #c7d7fe;
  border-radius: 10px;
  background: #f8faff;
}

.question-set-results-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
}

.question-set-results-heading h3,
.question-set-card h3 {
  margin: 0;
}

.question-set-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.9rem;
}

.question-set-card {
  display: grid;
  gap: 0.75rem;
  padding: 1rem;
  border: 1px solid var(--color-border);
  border-radius: 9px;
  background: #fff;
}

.question-set-type {
  background: #ede9fe;
  color: #6d28d9;
}

.question-set-description {
  max-width: 820px;
  margin: 1rem 0;
}