@charset "UTF-8";

/* Page-owned styles for Colour Sorting page */

#colour-sorting-page {
  --cs-page-gap: var(--space-3xl);
  --cs-section-gap: var(--space-2xl);
  --cs-card-gap: var(--space-lg);
  --cs-accordion-gap: var(--space-md);
  --cs-stream-width: 3px;
  --cs-stream-color-start: #FF6B6B;
  --cs-stream-color-mid: #7B2CBF;
  --cs-stream-color-end: #00B4D8;
  position: relative;
  overflow: hidden;
}

#colour-sorting-page::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: var(--cs-stream-width);
  height: 100%;
  background: linear-gradient(
    to bottom,
    var(--cs-stream-color-start) 0%,
    var(--cs-stream-color-mid) 50%,
    var(--cs-stream-color-end) 100%
  );
  opacity: 0.2;
  pointer-events: none;
  z-index: 0;
}

#colour-sorting-page > * {
  position: relative;
  z-index: 1;
}

.cs-section {
  padding-block: var(--cs-page-gap);
}

.cs-section__inner {
  width: 100%;
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding-inline: var(--container-padding-mobile);
}

.cs-section__inner--full {
  max-width: var(--container-max-width);
}

.cs-section__inner--split {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: var(--space-2xl);
  align-items: start;
}

.cs-section__title {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-block-end: var(--space-xl);
}

.cs-droplet {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 50% 50% 50% 0;
  transform: rotate(-45deg);
  background-color: var(--color-cyan);
  flex-shrink: 0;
}

.cs-droplet--coral {
  background-color: var(--color-coral);
}

.cs-droplet--violet {
  background-color: var(--color-violet);
}

/* Hero */
.cs-hero {
  padding-block-start: var(--space-4xl);
  padding-block-end: var(--space-3xl);
}

.cs-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: var(--space-3xl);
  align-items: center;
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding-inline: var(--container-padding-mobile);
}

.cs-hero__text {
  max-width: 60ch;
}

.cs-hero__lead {
  font-size: 1.25rem;
  line-height: 1.5;
  margin-block-end: var(--space-lg);
}

.cs-hero__actions {
  margin-block-start: var(--space-xl);
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.cs-hero__media {
  position: relative;
  min-width: 0;
}

.cs-hero__media img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-glass-border);
  box-shadow: var(--shadow-glass);
  animation: cs-float 6s ease-in-out infinite;
}

@keyframes cs-float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* What is colour sorting */
.cs-rules-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--cs-card-gap);
}

.cs-rule-card {
  background-color: var(--color-white-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-lg);
  min-width: 0;
}

.cs-rule-card h3 {
  margin-block-end: var(--space-md);
}

.cs-rule-card p {
  margin-block-end: var(--space-md);
}

.cs-rule-card .content-list {
  margin-block-end: 0;
}

/* Mental model */
.cs-mental-block {
  margin-block-end: var(--space-xl);
}

.cs-mental-block:last-child {
  margin-block-end: 0;
}

.cs-mental-block h3 {
  margin-block-end: var(--space-sm);
}

.cs-mental-block p {
  margin-block-end: var(--space-sm);
}

.cs-mental-block p:last-child {
  margin-block-end: 0;
}

.cs-mental-visual {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  align-items: flex-end;
  background-color: var(--color-white-glass);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-xl);
  min-width: 0;
}

.cs-tube {
  display: flex;
  flex-direction: column-reverse;
  width: 60px;
  height: 180px;
  border: 2px solid var(--color-glass-border);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  background-color: rgba(255, 255, 255, 0.4);
  overflow: hidden;
  transition: transform var(--transition-fast);
}

.cs-tube:hover {
  transform: translateY(-4px);
}

.cs-tube__layer {
  flex: 1;
  min-height: 0;
}

.cs-tube__layer--cyan {
  background-color: var(--color-cyan);
}

.cs-tube__layer--violet {
  background-color: var(--color-violet);
}

.cs-tube__layer--coral {
  background-color: var(--color-coral);
}

.cs-tube__layer--yellow {
  background-color: var(--color-yellow);
}

.cs-tube--empty {
  border-style: dashed;
}

/* Patterns */
.cs-patterns-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--cs-card-gap);
}

.cs-pattern-card {
  background-color: var(--color-white-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-lg);
  min-width: 0;
}

.cs-pattern-card h3 {
  margin-block-end: var(--space-md);
}

.cs-pattern-card p {
  margin-block-end: var(--space-md);
}

.cs-pattern-card p:last-child {
  margin-block-end: 0;
}

/* Techniques accordion */
.cs-accordion-group {
  display: flex;
  flex-direction: column;
  gap: var(--cs-accordion-gap);
}

.cs-accordion {
  background-color: var(--color-white-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  overflow: hidden;
}

.cs-accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  width: 100%;
  padding: var(--space-lg);
  text-align: start;
  color: var(--color-ink);
  font-weight: 600;
  font-size: var(--text-body-size);
  line-height: var(--text-body-line-height);
  transition: background-color var(--transition-fast);
}

.cs-accordion__trigger:hover {
  background-color: rgba(0, 180, 216, 0.06);
}

.cs-accordion__trigger:focus-visible {
  outline: var(--focus-ring);
  outline-offset: -2px;
}

.cs-accordion__title {
  flex: 1;
  min-width: 0;
}

.cs-accordion__chevron {
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--color-cyan);
  border-bottom: 2px solid var(--color-cyan);
  transform: rotate(45deg);
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.cs-accordion.is-open .cs-accordion__chevron {
  transform: rotate(225deg);
}

.cs-accordion__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows var(--transition-fast);
}

.cs-accordion.is-open .cs-accordion__panel {
  grid-template-rows: 1fr;
}

.cs-accordion__panel > * {
  overflow: hidden;
}

.cs-accordion__panel p {
  padding-inline: var(--space-lg);
  margin-block-end: 0;
}

.cs-accordion__panel p:first-child {
  padding-block-start: var(--space-md);
}

.cs-accordion__panel p:last-child {
  padding-block-end: var(--space-lg);
}

/* Mistakes */
.cs-mistakes-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--cs-card-gap);
}

.cs-mistake-card {
  background-color: var(--color-white-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-lg);
  border-inline-start: 4px solid var(--color-coral);
  min-width: 0;
}

.cs-mistake-card h3 {
  margin-block-end: var(--space-md);
}

.cs-mistake-card p {
  margin-block-end: var(--space-md);
}

.cs-mistake-card p:last-child {
  margin-block-end: 0;
}

/* Walkthrough */
.cs-walkthrough-steps {
  padding-inline-start: var(--space-lg);
  margin-block-end: var(--space-md);
}

.cs-walkthrough-steps li {
  margin-block-end: var(--space-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
}

.cs-walkthrough-steps li:hover,
.cs-walkthrough-steps li.is-active {
  background-color: rgba(0, 180, 216, 0.08);
  color: var(--color-cyan);
}

.cs-walkthrough-solved {
  font-weight: 600;
  color: var(--color-turquoise);
}

.cs-walkthrough-visual {
  background-color: var(--color-white-glass);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-xl);
  min-width: 0;
}

.cs-walkthrough-tubes {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  align-items: flex-end;
}

.cs-walkthrough-tube {
  display: flex;
  flex-direction: column-reverse;
  width: 70px;
  height: 200px;
  border: 2px solid var(--color-glass-border);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  background-color: rgba(255, 255, 255, 0.4);
  overflow: hidden;
  transition: transform var(--transition-fast);
}

.cs-walkthrough-tube--empty {
  border-style: dashed;
}

.cs-walkthrough-layer {
  flex: 1;
  min-height: 0;
}

.cs-walkthrough-layer--red {
  background-color: var(--color-coral);
}

.cs-walkthrough-layer--blue {
  background-color: var(--color-cyan);
}

/* Satisfying */
.cs-satisfying-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--cs-card-gap);
  margin-block-end: var(--space-xl);
}

.cs-satisfying-grid article {
  background-color: var(--color-white-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-lg);
  min-width: 0;
}

.cs-satisfying-grid h3 {
  margin-block-end: var(--space-md);
}

.cs-satisfying-grid p {
  margin-block-end: var(--space-md);
}

.cs-satisfying-grid p:last-child {
  margin-block-end: 0;
}

.cs-pull-quote {
  max-width: 70ch;
  margin-inline: auto;
  text-align: center;
  font-size: 1.5rem;
  line-height: 1.4;
  border-inline-start: none;
  border-block-start: 4px solid var(--color-cyan);
  background-color: var(--color-white-glass);
  padding: var(--space-xl);
  border-radius: var(--radius-lg);
}

.cs-pull-quote p {
  margin-block-end: 0;
}

/* Advanced */
.cs-advanced-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--cs-card-gap);
}

.cs-advanced-card {
  background-color: var(--color-white-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass), var(--shadow-glass-inset);
  padding: var(--space-lg);
  border-inline-start: 4px solid var(--color-violet);
  min-width: 0;
}

.cs-advanced-card h3 {
  margin-block-end: var(--space-md);
}

.cs-advanced-card p {
  margin-block-end: var(--space-md);
}

.cs-advanced-card p:last-child {
  margin-block-end: 0;
}

/* Continue */
.cs-continue {
  text-align: center;
}

.cs-continue .cs-section__title {
  justify-content: center;
}

.cs-continue__content {
  max-width: 70ch;
  margin-inline: auto;
}

.cs-continue__actions {
  margin-block-start: var(--space-xl);
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* Responsive */
@media (max-width: 1023px) {
  .cs-section__inner--split,
  .cs-hero__inner {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .cs-hero__text {
    max-width: 70ch;
  }

  .cs-hero__media {
    max-width: 400px;
    margin-inline: auto;
  }

  .cs-rules-grid,
  .cs-patterns-grid,
  .cs-mistakes-grid,
  .cs-advanced-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .cs-satisfying-grid {
    grid-template-columns: 1fr;
  }

  .cs-mental-visual,
  .cs-walkthrough-visual {
    max-width: 400px;
    margin-inline: auto;
  }
}

@media (max-width: 767px) {
  .cs-section {
    padding-block: var(--space-2xl);
  }

  .cs-hero {
    padding-block-start: var(--space-3xl);
    padding-block-end: var(--space-2xl);
  }

  .cs-hero__inner {
    gap: var(--space-lg);
  }

  .cs-hero__lead {
    font-size: 1.125rem;
  }

  .cs-hero__media img {
    animation: none;
  }

  .cs-rules-grid,
  .cs-patterns-grid,
  .cs-mistakes-grid,
  .cs-advanced-grid {
    grid-template-columns: 1fr;
  }

  .cs-mental-visual,
  .cs-walkthrough-visual {
    padding: var(--space-lg);
  }

  .cs-tube {
    width: 48px;
    height: 150px;
  }

  .cs-walkthrough-tube {
    width: 56px;
    height: 160px;
  }

  .cs-pull-quote {
    font-size: 1.25rem;
    padding: var(--space-lg);
  }

  .cs-accordion__trigger {
    padding: var(--space-md);
  }

  .cs-accordion__panel p {
    padding-inline: var(--space-md);
  }
}

@media (prefers-reduced-motion: reduce) {
  .cs-hero__media img {
    animation: none;
  }

  .cs-tube,
  .cs-walkthrough-tube {
    transition: none;
  }

  .cs-accordion__panel {
    transition: none;
  }
}