:root {
  --bg: #f2ebdf;
  --bg-soft: #fbf7f2;
  --surface: rgba(255, 255, 255, 0.9);
  --surface-strong: #fffdfa;
  --border: rgba(53, 44, 31, 0.12);
  --text: #2e2924;
  --muted: #73685f;
  --navy: #17354e;
  --orange: #d76d3f;
  --orange-soft: #f3d9c9;
  --green-soft: rgba(61, 118, 93, 0.12);
  --red-soft: rgba(215, 109, 63, 0.14);
  --shadow: 0 18px 40px rgba(64, 42, 18, 0.08);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --font-display: "Georgia", "Times New Roman", serif;
  --font-body: "Microsoft YaHei UI", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(circle at top left, rgba(215, 109, 63, 0.18), transparent 28%),
    linear-gradient(180deg, #f7f1e8, #eee5d7);
  color: var(--text);
  font-family: var(--font-body);
}

body {
  padding: 20px 28px 28px;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-family: var(--font-display);
}

a {
  color: inherit;
}

button,
input,
select {
  font: inherit;
}

.bank-shell {
  display: grid;
  gap: 16px;
}

.bank-header,
.stats-grid,
.workspace {
  display: grid;
  gap: 18px;
}

.bank-header {
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
}

.eyebrow {
  margin: 0 0 8px;
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: rgba(115, 104, 95, 0.88);
}

.lead {
  margin: 10px 0 0;
  max-width: 860px;
  line-height: 1.75;
  color: var(--muted);
}

.ghost-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.62);
  text-decoration: none;
}

.stats-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.panel,
.stat-card {
  padding: 22px;
  border-radius: var(--radius-lg);
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.55);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.stat-card {
  display: grid;
  gap: 8px;
}

.stat-value {
  font-size: 2rem;
  color: var(--navy);
  font-weight: 700;
}

.stat-label,
.helper-text {
  color: var(--muted);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.toolbar {
  display: grid;
  grid-template-columns: minmax(320px, 520px) auto;
  gap: 16px;
  justify-content: space-between;
  align-items: end;
}

.toolbar label {
  display: grid;
  gap: 8px;
  font-size: 0.92rem;
}

.paper-select-field {
  max-width: 520px;
}

.sidebar-toolbar {
  padding: 20px 18px;
  grid-template-columns: 1fr;
  align-items: stretch;
}

.sidebar-toolbar .paper-select-field {
  max-width: none;
}

.toolbar-random {
  display: flex;
  align-items: end;
  gap: 12px;
  justify-content: flex-start;
  flex-wrap: wrap;
}

.random-count-field {
  min-width: 140px;
}

.random-count-field-oj {
  min-width: 112px;
}

.sidebar-toolbar .toolbar-random {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.maintain-toggle-field {
  display: flex !important;
  align-items: center;
  gap: 10px !important;
  grid-column: 1 / -1;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.72);
  font-size: 0.92rem;
}

.maintain-toggle-field input[type="checkbox"] {
  width: 18px;
  height: 18px;
  min-height: 18px;
  margin: 0;
}

.sidebar-toolbar .random-count-field,
.sidebar-toolbar .random-count-field-oj {
  min-width: 0;
}

.sidebar-toolbar .secondary-button-inline {
  width: 100%;
  justify-content: center;
  grid-column: 1 / -1;
}

select,
input {
  width: 100%;
  min-height: 46px;
  padding: 10px 14px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.94);
}

.workspace {
  grid-template-columns: 280px minmax(0, 1fr);
  align-items: start;
}

.sidebar-column {
  position: sticky;
  top: 24px;
  align-self: start;
  display: grid;
  gap: 18px;
  overflow: visible;
}

.panel {
  min-width: 0;
}

.answer-card-panel,
.question-panel,
.question-list,
.option-list,
.answer-card-grid,
.answer-card-actions {
  display: grid;
  gap: 18px;
}

.answer-card-panel {
  padding: 28px 24px;
}

.panel-header,
.detail-title,
.question-header,
.paper-actions {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 14px;
}

.tag-row,
.meta-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag,
.source-link {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 12px;
  border-radius: 999px;
}

.tag,
.question-source-tag {
  background: #efe4d6;
  color: #8f4a24;
  font-size: 0.82rem;
}

.paper-item p,
.empty-state p,
.question-card p,
.question-source {
  margin: 0;
  line-height: 1.7;
  color: var(--muted);
}

.detail-head {
  display: grid;
  gap: 16px;
  margin-bottom: 18px;
}

.source-link {
  background: var(--orange-soft);
  color: #8f451f;
  text-decoration: none;
  white-space: nowrap;
}

.meta-grid {
  gap: 10px;
}

.meta-card {
  min-width: 132px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface-strong);
}

.meta-card strong {
  display: block;
  margin-bottom: 6px;
  color: var(--navy);
}

.answer-card-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.answer-card-actions .primary-button,
.answer-card-actions .secondary-button-inline {
  width: 100%;
  justify-content: center;
}

.answer-card-actions {
  gap: 16px;
  margin-top: 6px;
}

.answer-card-button {
  min-height: 54px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.84);
  cursor: pointer;
  color: var(--text);
  transition: transform 0.16s ease, border-color 0.16s ease, background 0.16s ease;
}

.answer-card-button:hover {
  transform: translateY(-1px);
  border-color: rgba(23, 53, 78, 0.24);
}

.answer-card-button.answered {
  background: rgba(23, 53, 78, 0.08);
  border-color: rgba(23, 53, 78, 0.24);
}

.answer-card-button.correct {
  background: var(--green-soft);
  border-color: rgba(61, 118, 93, 0.36);
  color: #2d6b52;
}

.answer-card-button.incorrect {
  background: var(--red-soft);
  border-color: rgba(215, 109, 63, 0.34);
  color: #a14f2a;
}

.answer-card-button.pending {
  background: rgba(255, 255, 255, 0.82);
  color: var(--muted);
}

.question-card {
  padding: 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface-strong);
  transition: border-color 0.16s ease, background 0.16s ease, box-shadow 0.16s ease;
}

.question-card.answered {
  border-color: rgba(23, 53, 78, 0.22);
  background: rgba(23, 53, 78, 0.04);
}

.question-card.correct {
  border-color: rgba(61, 118, 93, 0.3);
  background: rgba(61, 118, 93, 0.06);
}

.question-card.incorrect {
  border-color: rgba(215, 109, 63, 0.3);
  background: rgba(215, 109, 63, 0.06);
}

.question-card.pending {
  border-color: rgba(115, 104, 95, 0.22);
  background: rgba(255, 255, 255, 0.94);
}

.primary-button,
.secondary-button-inline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border: none;
  border-radius: 999px;
  cursor: pointer;
  text-decoration: none;
}

.primary-button {
  background: var(--navy);
  color: #fff;
}

.secondary-button-inline {
  background: var(--orange-soft);
  color: #8f451f;
}

.student-mode .toolbar-random {
  display: none !important;
}

.locked-paper-mode .paper-select-field {
  display: none;
}

.student-mode.locked-paper-mode .sidebar-toolbar {
  display: none;
}

.question-card > * + * {
  margin-top: 12px;
}

.question-source-tag {
  display: inline-flex;
  margin-top: 10px;
  padding: 6px 10px;
  border-radius: 999px;
}

.question-type-tag {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.72);
  color: var(--muted);
  font-size: 0.82rem;
}

.question-maintain-link {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  background: rgba(23, 53, 78, 0.08);
  border: 1px solid rgba(23, 53, 78, 0.12);
  color: var(--navy);
  text-decoration: none;
  font-size: 0.82rem;
  white-space: nowrap;
}

.question-type-tag.objective {
  background: rgba(23, 53, 78, 0.08);
  color: var(--navy);
}

.question-type-tag.oj {
  background: rgba(215, 109, 63, 0.12);
  color: #8f451f;
}

.question-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0 10px;
  border-radius: 999px;
  background: var(--navy);
  color: #fff;
  font-weight: 700;
  flex-shrink: 0;
}

.question-title {
  flex: 1;
  line-height: 1.58;
  font-size: 1rem;
}

.question-heading-spacer {
  flex: 1;
  min-height: 8px;
}

.question-body {
  color: var(--text);
  line-height: 1.74;
}

.question-body > * + * {
  margin-top: 14px;
}

.question-body-empty {
  margin: 0;
  color: var(--muted);
}

.question-body img {
  display: block;
  max-width: 100%;
  height: auto !important;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.question-body pre,
.question-body code {
  font-family: "Consolas", "Courier New", monospace;
}

.python-code-block {
  overflow: hidden;
  border-radius: 16px;
  border: 1px solid rgba(23, 53, 78, 0.14);
  background: #1f2430;
}

.inline-code-line {
  margin: 0;
}

.inline-code-line code {
  display: inline-block;
  max-width: 100%;
  padding: 4px 10px;
  border-radius: 10px;
  background: rgba(23, 53, 78, 0.08);
  color: var(--navy);
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  font-family: "Consolas", "Courier New", monospace;
  font-size: 0.95rem;
  line-height: 1.7;
}

.python-code-head {
  min-height: 34px;
  padding: 8px 14px;
  background: rgba(255, 255, 255, 0.06);
  color: rgba(231, 236, 243, 0.88);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.python-code-lines {
  list-style: none;
  counter-reset: python-line;
  margin: 0;
  padding: 12px 0;
  color: #e7ecf3;
}

.python-code-lines li {
  position: relative;
  counter-increment: python-line;
  padding: 0 16px 0 4.5rem;
  font-family: "Consolas", "Courier New", monospace;
  font-size: 0.94rem;
  line-height: 1.7;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.python-code-lines li::before {
  content: counter(python-line);
  position: absolute;
  left: 0;
  width: 3.1rem;
  padding-right: 0.8rem;
  text-align: right;
  color: rgba(231, 236, 243, 0.42);
}

.python-code-lines code {
  color: inherit;
}

.python-token-keyword {
  color: #ffb86c;
}

.python-token-string {
  color: #a3d977;
}

.python-token-number {
  color: #7ec8ff;
}

.python-token-comment {
  color: #93a0b5;
}

.oj-section {
  display: grid;
  gap: 10px;
  padding: 14px 16px;
  border-radius: 16px;
  border: 1px solid rgba(23, 53, 78, 0.1);
  background: rgba(255, 255, 255, 0.72);
}

.oj-section-title {
  font-weight: 700;
  color: var(--navy);
}

.oj-section-body {
  display: grid;
  gap: 10px;
}

.oj-text-line {
  margin: 0;
  color: var(--text);
  line-height: 1.8;
}

.oj-kv {
  display: grid;
  gap: 6px;
  padding: 10px 12px;
  border-radius: 12px;
  background: rgba(23, 53, 78, 0.05);
}

.oj-kv-label {
  font-weight: 700;
  color: var(--navy);
}

.oj-kv-value {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  color: var(--text);
}

.option-list {
  margin-top: 6px;
}

.option-item {
  display: grid;
  grid-template-columns: auto 64px minmax(0, 1fr);
  gap: 12px;
  align-items: stretch;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.76);
  cursor: pointer;
}

.option-item.selected {
  border-color: rgba(23, 53, 78, 0.28);
  background: rgba(23, 53, 78, 0.08);
}

.option-item.correct {
  border-color: rgba(61, 118, 93, 0.42);
  background: rgba(61, 118, 93, 0.1);
}

.option-item.incorrect {
  border-color: rgba(215, 109, 63, 0.42);
  background: rgba(215, 109, 63, 0.12);
}

.option-item input[type="radio"] {
  align-self: center;
  margin-top: 0;
}

.option-label {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100%;
  padding-right: 12px;
  font-weight: 700;
  color: var(--navy);
  border-right: 1px solid rgba(53, 44, 31, 0.12);
}

.option-text {
  display: flex;
  align-items: center;
  min-height: 100%;
  padding-left: 2px;
  color: var(--text);
  line-height: 1.68;
}

.question-feedback {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--muted);
}

.question-feedback.correct {
  background: var(--green-soft);
  color: #2d6b52;
}

.question-feedback.incorrect {
  background: var(--red-soft);
  color: #a14f2a;
}

.question-feedback.pending {
  background: rgba(255, 255, 255, 0.72);
  color: var(--muted);
}

.question-hint {
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px dashed var(--border);
  background: rgba(255, 255, 255, 0.46);
  color: var(--muted);
  line-height: 1.7;
}

.text-answer {
  width: 100%;
  min-height: 140px;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.94);
  resize: vertical;
  color: var(--text);
}

.question-body pre,
.question-body code,
.question-body blockquote,
.question-body ol,
.question-body ul,
.question-body p,
.question-body section,
.question-body div {
  max-width: 100%;
  overflow-wrap: anywhere;
}

.empty-state {
  display: grid;
  gap: 10px;
  padding: 28px;
  border-radius: var(--radius-md);
  border: 1px dashed var(--border);
  background: rgba(255, 255, 255, 0.48);
  text-align: center;
}

@media (max-width: 1320px) {
  .toolbar {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 1200px) {
  .stats-grid,
  .workspace {
    grid-template-columns: 1fr;
  }

  .bank-header {
    grid-template-columns: 1fr;
  }

  .sidebar-column {
    position: static;
    max-height: none;
    overflow: visible;
  }
}

@media (max-width: 860px) {
  .toolbar-random {
    flex-wrap: wrap;
  }

  .sidebar-toolbar .toolbar-random {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  body {
    padding: 14px 18px 18px;
  }

  .stats-grid,
  .workspace {
    grid-template-columns: 1fr;
  }

  .detail-title,
  .panel-header,
  .paper-actions,
  .question-header {
    flex-direction: column;
    align-items: stretch;
  }
}