*,
*::before,
*::after {
  box-sizing: border-box;
}

body.bd-with-nav.challenge-page {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  margin: 0;
  background: var(--bd-bg-secondary);
  color: var(--bd-text);
}

body.bd-with-nav.challenge-page .bd-topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--bd-border);
  background: var(--bd-bg);
}

body.bd-with-nav.challenge-page .bd-main {
  flex: 1;
  min-width: 0;
}

body.bd-with-nav.challenge-page .bd-main > .bd-container {
  max-width: 1040px;
}

body.bd-with-nav.challenge-page .bd-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--bd-border);
  background: var(--bd-bg);
  text-align: center;
}

.challenge-catalog-header {
  max-width: 740px;
}

.challenge-catalog-copy p,
.challenge-section p,
.challenge-stretch p {
  color: var(--bd-text-secondary);
  font-size: 14px;
  line-height: 1.65;
}

.challenge-catalog-header .bd-body {
  max-width: 700px;
}

.challenge-catalog-list {
  border-top: 1px solid var(--bd-border);
}

.challenge-catalog-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) auto;
  align-items: start;
  gap: 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--bd-border);
}

.challenge-number {
  margin: 3px 0 0;
  color: var(--bd-text-tertiary);
  font-size: 12px;
  font-weight: 600;
}

.challenge-catalog-copy h2 {
  margin: 0 0 6px;
  font-family: var(--bd-font-heading);
  font-size: 19px;
  font-weight: 600;
  line-height: 1.35;
}

.challenge-catalog-copy h2 a {
  color: var(--bd-text);
  text-decoration: none;
}

.challenge-catalog-copy h2 a:hover {
  color: var(--bd-primary-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.challenge-catalog-meta,
.challenge-catalog-copy .challenge-skills {
  margin: 0 0 5px;
  color: var(--bd-text-tertiary);
  font-size: 12px;
}

.challenge-catalog-copy > p:not(.challenge-catalog-meta):not(.challenge-skills) {
  margin: 0 0 7px;
}

.challenge-catalog-copy .challenge-skills {
  margin-bottom: 0;
}

.challenge-catalog-link {
  align-self: end;
  padding: 4px 0;
  color: var(--bd-primary);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
}

.challenge-catalog-link:hover {
  color: var(--bd-primary-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.challenge-brief {
  max-width: 960px;
}

.challenge-header {
  max-width: 780px;
  margin-bottom: 34px;
}

.challenge-meta {
  margin: 0 0 18px;
  color: var(--bd-text-tertiary);
  font-size: 13px;
  line-height: 1.5;
}

.challenge-intro {
  max-width: 720px;
}

.challenge-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
}

.challenge-page .bd-btn {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  justify-content: center;
  padding: 0 13px;
  border: 1px solid transparent;
  border-radius: var(--bd-radius-md);
  font: 500 13px/1 var(--bd-font);
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
}

.challenge-page .bd-btn-primary {
  border-color: var(--bd-primary);
  background: var(--bd-primary);
  color: #fff;
}

.challenge-page .bd-btn-primary:hover {
  border-color: var(--bd-primary-hover);
  background: var(--bd-primary-hover);
}

.challenge-page .bd-btn-secondary {
  border-color: var(--bd-border-strong);
  background: var(--bd-bg);
  color: var(--bd-text);
}

.challenge-page .bd-btn-secondary:hover {
  background: var(--bd-bg-tertiary);
}

.challenge-section {
  max-width: 960px;
  margin: 0 0 38px;
}

.challenge-section h2,
.challenge-stretch h2 {
  margin: 0 0 11px;
  color: var(--bd-text);
  font-family: var(--bd-font-heading);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -.015em;
  line-height: 1.35;
}

.challenge-section p {
  max-width: 780px;
  margin: 0 0 10px;
}

.challenge-grain {
  margin-top: 18px !important;
  padding-left: 13px;
  border-left: 2px solid var(--bd-border-strong);
}

.challenge-stats {
  display: grid;
  max-width: 760px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  margin: 18px 0 12px;
}

.challenge-stats div {
  min-width: 0;
}

.challenge-stats dt {
  margin-bottom: 4px;
  color: var(--bd-text-tertiary);
  font-size: 12px;
  line-height: 1.4;
}

.challenge-stats dd {
  margin: 0;
  color: var(--bd-text);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -.02em;
  line-height: 1.25;
}

.challenge-questions {
  max-width: 800px;
  margin: 17px 0 0;
  padding-left: 27px;
  color: var(--bd-text-secondary);
  font-size: 14px;
  line-height: 1.6;
  list-style-type: decimal-leading-zero;
}

.challenge-questions li {
  padding-left: 5px;
}

.challenge-questions li + li {
  margin-top: 10px;
}

.challenge-section-heading {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 18px;
  margin-bottom: 12px;
}

.challenge-section-heading h2 {
  margin: 0;
}

.challenge-section-heading a {
  color: var(--bd-primary);
  font-size: 13px;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.challenge-table-wrap {
  max-width: 100%;
  overflow-x: auto;
  border-top: 1px solid var(--bd-border);
  border-bottom: 1px solid var(--bd-border);
  scrollbar-width: thin;
}

.challenge-table-wrap table {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  color: var(--bd-text-secondary);
  font-size: 13px;
  line-height: 1.5;
  text-align: left;
}

.challenge-table-wrap th,
.challenge-table-wrap td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--bd-border);
  vertical-align: top;
}

.challenge-table-wrap thead th {
  color: var(--bd-text);
  font-size: 12px;
  font-weight: 600;
}

.challenge-table-wrap tbody tr:last-child th,
.challenge-table-wrap tbody tr:last-child td {
  border-bottom: 0;
}

.challenge-table-wrap th:first-child,
.challenge-table-wrap td:first-child {
  padding-left: 0;
}

.challenge-table-wrap th:last-child,
.challenge-table-wrap td:last-child {
  padding-right: 0;
}

.challenge-table-wrap th[scope="row"] {
  color: var(--bd-text);
  font-weight: 500;
  white-space: nowrap;
}

.challenge-table-wrap code {
  font-family: var(--bd-font-mono);
  font-size: 12px;
}

.challenge-table-wrap:focus-visible {
  outline: 2px solid var(--bd-primary);
  outline-offset: 3px;
}

.challenge-section .challenge-skills {
  margin-top: 14px;
  color: var(--bd-text-tertiary);
  font-size: 13px;
}

.challenge-stretch {
  max-width: 780px;
  margin: 0 0 38px;
  padding: 2px 0 2px 15px;
  border-left: 2px solid var(--bd-border-strong);
}

.challenge-stretch h2 {
  font-size: 16px;
}

.challenge-stretch p {
  margin: 0;
}

.challenge-back {
  margin: 44px 0 0;
  font-size: 13px;
}

body.bd-with-nav.challenge-page .bd-footer .bd-hint {
  margin: 0;
  color: var(--bd-text-tertiary);
  font-size: 12px;
}

body.bd-with-nav.challenge-page .bd-footer a {
  color: var(--bd-primary);
}

@media (max-width: 600px) {
  .challenge-catalog-item {
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 12px;
    padding: 20px 0;
  }

  .challenge-catalog-link {
    grid-column: 2;
    justify-self: start;
    align-self: start;
  }

  .challenge-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    row-gap: 16px;
  }

  .challenge-section {
    margin-bottom: 32px;
  }

  .challenge-section-heading {
    align-items: flex-start;
  }
}