/* Exercises override and page-specific tweaks (base.css provides shared layout + mobile nav) */

/* Utilities */
.clearfix::before,
.clearfix::after {
  content: '';
  display: table;
}

.clearfix::after {
  clear: both;
}

.pull-left {
  float: left;
}

.pull-right {
  float: right;
}

.item-page {
  background-color: transparent;
}

/* Grid (mobile-first) */
.row-fluid {
  display: flex;
  flex-wrap: wrap;
  margin-left: -8px;
  margin-right: -8px;
}

.row-fluid > [class*='span'] {
  box-sizing: border-box;
  flex: 0 0 100%;
  max-width: 100%;
  padding-left: 8px;
  padding-right: 8px;
}

@media (width >= 768px) {
  .row-fluid > .span2 {
    flex: 0 0 16.6667%;
    max-width: 16.6667%;
  }

  .row-fluid > .span8 {
    flex: 0 0 66.6667%;
    max-width: 66.6667%;
  }
}

/* Header basics */
.header {
  margin-bottom: 1rem;
}

.header .brand img {
  display: block;
  height: auto;
  max-width: 100%;
}

/* Pager */
.pager {
  align-items: center;
  display: flex;
  justify-content: space-between;
  list-style: none;
  margin: 1rem 0;
  padding: 0;
}

.pager li {
  align-items: center;
  display: inline-flex;
}

.pager li > a {
  align-items: center;
  color: var(--pager-text-color, var(--link-color));
  display: inline-flex;
  text-decoration: none;
}

.pager li > a:hover {
  color: var(--link-hover);
  text-decoration: none;
}

/* Breadcrumb */
.breadcrumb {
  align-items: center;
  color: var(--color-muted);
  display: flex;
  gap: 5px;
  list-style: none;
  margin: 1.25rem 0;
  padding: 0;
}

.breadcrumb > li {
  display: inline;
}

/* Breadcrumb modernization (wrapper + inline SVG separators) */
.breadcrumb-wrap {
  max-width: 100%;
  overflow: hidden;
}

.breadcrumb-wrap .breadcrumb {
  align-items: center;
  display: flex;
  flex-wrap: nowrap;
  gap: 0.4rem;
  list-style: none;
  margin: 1.25rem 0;
  overflow: hidden;
  padding: 0;
}

.breadcrumb-wrap .breadcrumb > li {
  align-items: center;
  display: inline-flex;
  flex-shrink: 0;
  min-width: 0;
  white-space: nowrap;
}

.breadcrumb-wrap .breadcrumb > li:last-child {
  flex: 1 1 auto;
  min-width: 0;
}

.breadcrumb-wrap .breadcrumb > li:last-child > span[itemprop='name'] {
  display: block;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.breadcrumb-wrap .breadcrumb > li > .divider {
  align-items: center;
  display: inline-flex;
  flex: 0 0 auto;
}

.breadcrumb-wrap .breadcrumb > li > .divider > svg {
  fill: #e0162b;
  height: 9px;
  width: 9px;
}

.quest-bg {
  background-color: var(--white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  display: block;
  margin-bottom: .75rem;
  padding: 1.25rem 1.25rem .01rem;
}

/* Exercise gating UI */
:root {
  --exercise-success: #166534;
  --exercise-success-glow: #4caf50;
  --exercise-success-bg: #e6f4ea;
  --exercise-error: #b3261e;
  --exercise-error-glow: #cf3b32;
  --exercise-error-bg: #fdecea;
  --exercise-pending: #b26a00;
  --exercise-pending-bg: #fff4e5;
}

.exercise-form {
  background-color: var(--surface-color, #fff);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  margin-bottom: 1.5rem;
  padding: 1.5rem;
}

.exercise-form__intro {
  border: 0;
  margin: 0 0 1.25rem;
  padding: 0;
}

.exercise-form__intro-layout {
  display: grid;
  gap: 0.75rem;
}

.exercise-form__intro-fields {
  display: grid;
  gap: 0.5rem;
}

.exercise-form__intro-fields .exercise-form__email,
.exercise-form__intro-fields .exercise-form__student-id {
  margin-bottom: 0;
}

.exercise-form__email-label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.exercise-form__email {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.exercise-form__email-input {
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  font: inherit;
  max-width: min(320px, 100%);
  padding: 0.6rem 0.75rem;
  width: min(320px, 100%);
}

.exercise-form__email-input:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgb(224 22 43 / 15%);
  outline: none;
}

.exercise-form__email-input--invalid {
  border-color: var(--exercise-error);
  box-shadow: 0 0 0 3px rgb(179 38 30 / 20%);
}

.exercise-form__note {
  color: var(--color-muted);
  margin: 0 0 0.75rem;
}

@media (width >= 910px) {
  .exercise-form__intro-fields {
    gap: 0.75rem;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.exercise-form__progress {
  font-weight: 600;
  margin: 0 0 0.5rem;
}

.exercise-form__last-attempt {
  align-items: center;
  color: var(--exercise-success);
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0 0 0.75rem;
  min-height: 1.5rem;
}

.exercise-form__last-attempt-icon {
  font-size: 1.15rem;
  line-height: 1;
}

.exercise-form__feedback {
  border-radius: var(--radius);
  font-weight: 500;
  margin: 0;
  min-height: 1.5rem;
  padding: 0.25rem 0;
}

.exercise-form__feedback--error {
  color: var(--exercise-error);
}

.exercise-form__feedback--success {
  color: var(--exercise-success);
}

@media (width >= 640px) {
  .exercise-form__intro-fields {
    align-items: end; /* keep inputs aligned along their baselines */
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.exercise-submit-row {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: stretch;
  margin-top: 1.5rem;
}

.exercise-submit-button {
  background-color: var(--primary-color);
  border: none;
  border-radius: var(--radius);
  color: #fff;
  align-self: flex-end;
  cursor: pointer;
  font-weight: 600;
  padding: 0.75rem 1.75rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.exercise-submit-button:hover:not(:disabled) {
  box-shadow: 0 6px 18px rgb(224 22 43 / 18%);
  transform: translateY(-1px);
}

.exercise-submit-button:active:not(:disabled) {
  transform: translateY(0);
}

.exercise-submit-button:disabled,
.exercise-submit-button[aria-disabled="true"] {
  background-color: var(--border-color);
  box-shadow: none;
  color: var(--color-muted);
  cursor: not-allowed;
}

.exercise-response-field[hidden] {
  display: none !important;
}

.exercise-response-input--locked {
  cursor: not-allowed;
}

.exercise-response-input--locked:focus {
  outline: 2px solid var(--exercise-success);
  outline-offset: 2px;
}

.exercise-response-row--correct .exercise-response-input {
  background-color: var(--exercise-success-bg);
  border-color: var(--exercise-success);
}

.exercise-response-row--incorrect .exercise-response-input {
  background-color: var(--exercise-error-bg);
  border-color: var(--exercise-error);
}

.exercise-response-row--long {
  align-items: stretch;
}

.exercise-response-row--long .exercise-response-field {
  flex: 1 1 100%;
  max-width: none;
}

.exercise-response-input--textarea {
  line-height: 1.25;
  min-height: var(
    --exercise-textarea-min-height-field,
    var(--exercise-textarea-min-height, calc(1.25em + 0.35rem))
  );
  resize: vertical;
  width: var(
    --exercise-textarea-width-field,
    var(--exercise-textarea-width, 100%)
  );
}

/* Textarea width helpers (override via page-level or field-level vars) */
.sizeformtextarea {
  --exercise-textarea-width: var(--sizeformtextarea)!important;
}

.sizetextarea {
  --exercise-textarea-width-field: var(--sizetextarea)!important;
}

.exercise-response-input--textarea[data-autosize="true"] {
  overflow: hidden;
}

#exercise-status {
  align-self: stretch;
}

#exercise-status.status-ok {
  color: #0f6d2a;
}

#exercise-status.status-ok::before {
  content: "";
  display: inline-block;
  width: 1.05em;
  height: 1.05em;
  margin-right: 0.4em;
  vertical-align: -0.15em;
  background-color: currentcolor;
  mask: center / contain no-repeat url("../icons/svg/checkmark.svg");
}

.exercise-response-row--pending .exercise-response-input {
  background-color: var(--exercise-pending-bg);
  border-color: var(--exercise-pending);
}

.exercise-response-row--flash-success .exercise-response-input {
  animation: exercise-flash-success 1s ease-in-out infinite both;
}

.exercise-response-row--flash-error .exercise-response-input {
  animation: exercise-flash-error 1s ease-in-out infinite both;
}

@keyframes exercise-flash-success {
  0%,
  100% {
    border-color: var(--exercise-success);
    box-shadow: 0 0 0 0 rgb(46 125 50 / 0%);
  }

  50% {
    border-color: var(--exercise-success-glow);
    box-shadow: 0 0 8px 8px rgb(76 175 80 / 30%);
  }
}

@keyframes exercise-flash-error {
  0%,
  100% {
    border-color: var(--exercise-error);
    box-shadow: 0 0 0 0 rgb(179 38 30 / 0%);
  }

  50% {
    border-color: var(--exercise-error-glow);
    box-shadow: 0 0 8px 8px rgb(207 59 50 / 32%);
  }
}

@media (width <= 600px) {
  .exercise-form {
    padding: 1.125rem;
  }

  .exercise-submit-row {
    justify-content: stretch;
  }

  .exercise-submit-button {
    width: 100%;
  }
}

/* Developer QA helper: floating auto-fill control  box-shadow offset-x, offset-y, blur-radius, spread-radius, and color */
.exercise-devtools__fill-button {
  align-items: center;
  background: linear-gradient(135deg, rgb(224 22 43 / 92%), rgb(0 39 134 / 92%));
  border: 0;
  border-radius: 999px;
  box-shadow: 0 10px 24px rgb(0 0 0 / 18%);
  color: #fff;
  cursor: pointer;
  display: inline-flex;
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1;
  font-family: Inter, "Segoe UI", sans-serif;
  gap: 0.5rem;
  padding: 0.75rem 1.35rem;
  position: fixed;
  right: 1.75rem;
  bottom: 1.75rem;
  z-index: 12050;
  transition: transform 150ms ease, box-shadow 150ms ease, opacity 150ms ease;
}

.exercise-devtools__fill-button:hover,
.exercise-devtools__fill-button:focus-visible {
  box-shadow: 0 14px 28px rgb(224 22 43 / 28%);
  transform: translateY(-2px);
  outline: none;
}

.exercise-devtools__fill-button:active {
  transform: translateY(0);
  box-shadow: 0 8px 18px rgb(0 0 0 / 20%);
}

.exercise-devtools__fill-button:disabled {
  cursor: progress;
  opacity: 0.7;
}

.exercise-devtools__fill-button--busy::after {
  animation: exercise-devtools-spin 0.8s linear infinite;
  border: 2px solid rgb(255 255 255 / 60%);
  border-top-color: #fff;
  border-radius: 50%;
  content: "";
  height: 1rem;
  width: 1rem;
}

@keyframes exercise-devtools-spin {
  0% {
    transform: rotate(0deg);
  }

  100% {
    transform: rotate(360deg);
  }
}

@media (width <= 599px) {
  .exercise-devtools__fill-button {
    bottom: 1.1rem;
    right: 1.1rem;
    padding-inline: 1.1rem;
  }
}

@media screen and (width <= 767px) {
        :root {
          --sizeformtextarea: 100%;
        }
      }

      .resizable-both {
        resize:;
      }

      .resizable-none {
        resize: none;
      }