/* ============================================================
   SKILLS ISSUE — Global Stylesheet
   skillsissue.co.uk
   ============================================================ */


/* ------------------------------------------------------------
   1. FONTS
   ------------------------------------------------------------ */

@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;1,9..40,300;1,9..40,400&family=DM+Mono:wght@400;500&display=swap');


/* ------------------------------------------------------------
   2. DESIGN TOKENS
   ------------------------------------------------------------ */

:root {

  /* Colour palette */
  --si-ink:          #1a1a18;   /* near-black, primary text + dark surfaces */
  --si-ink-mid:      #2a2a28;   /* slightly lifted dark, hover states on dark bg */
  --si-ink-faint:    #333330;   /* borders on dark surfaces */
  --si-canvas:       #faf9f6;   /* warm off-white page background */
  --si-surface:      #ffffff;   /* card / component surface */
  --si-subtle:       #444441;   /* secondary text on light */
  --si-muted:        #888780;   /* tertiary text, metadata */
  --si-border:       #e8e4dc;   /* default border on light surfaces */
  --si-border-mid:   #d4cfc6;   /* slightly stronger border, hover emphasis */

  /* Amber — the accent, used sparingly */
  --si-amber:        #BA7517;
  --si-amber-tint:   #FAEEDA;   /* amber backgrounds, tags */
  --si-amber-deep:   #854F0B;   /* amber text on amber tint */
  --si-amber-darkest:#412402;   /* amber text on dark surfaces */

  /* Typography */
  --si-font-sans:    'DM Sans', sans-serif;
  --si-font-mono:    'DM Mono', monospace;

  /* Type scale */
  --si-text-xs:      11px;
  --si-text-sm:      13px;
  --si-text-base:    14px;
  --si-text-md:      16px;
  --si-text-lg:      18px;
  --si-text-xl:      22px;
  --si-text-2xl:     28px;
  --si-text-3xl:     36px;

  /* Leading */
  --si-leading-tight:  1.15;
  --si-leading-snug:   1.4;
  --si-leading-base:   1.7;
  --si-leading-loose:  1.85;

  /* Letter spacing */
  --si-tracking-tight:  -0.03em;
  --si-tracking-snug:   -0.02em;
  --si-tracking-normal:  0;
  --si-tracking-wide:    0.04em;
  --si-tracking-wider:   0.08em;

  /* Spacing */
  --si-space-1:   4px;
  --si-space-2:   8px;
  --si-space-3:   12px;
  --si-space-4:   16px;
  --si-space-5:   20px;
  --si-space-6:   24px;
  --si-space-8:   32px;
  --si-space-10:  40px;
  --si-space-12:  48px;

  /* Page gutters */
  --si-gutter:    1.5rem;

  /* Radius */
  --si-radius-sm:  4px;
  --si-radius-md:  6px;
  --si-radius-lg:  10px;
  --si-radius-xl:  14px;
  --si-radius-pill: 100px;

  /* Borders */
  --si-border-width: 0.5px;

  /* Transitions — specific curves, not generic ease */
  --si-transition-snap:    150ms cubic-bezier(0.4, 0, 1, 1);   /* filter clicks */
  --si-transition-smooth:  220ms cubic-bezier(0.4, 0, 0.2, 1); /* hovers */
  --si-transition-spring:  300ms cubic-bezier(0.34, 1.56, 0.64, 1); /* reveals */

  /* Nav height — used for sticky offset calculations */
  --si-nav-height: 52px;

  /* Max content width */
  --si-max-prose: 640px;
}


/* ------------------------------------------------------------
   3. RESET & BASE
   ------------------------------------------------------------ */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--si-font-sans);
  font-size: var(--si-text-base);
  font-weight: 400;
  line-height: var(--si-leading-base);
  color: var(--si-subtle);
  background-color: var(--si-canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, video, svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: var(--si-font-sans);
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}


/* ------------------------------------------------------------
   4. TYPOGRAPHY
   ------------------------------------------------------------ */

/* Display — hero headings */
.si-display {
  font-size: var(--si-text-3xl);
  font-weight: 500;
  letter-spacing: var(--si-tracking-tight);
  line-height: var(--si-leading-tight);
  color: var(--si-ink);
}

/* Heading 1 */
.si-h1 {
  font-size: var(--si-text-2xl);
  font-weight: 500;
  letter-spacing: var(--si-tracking-tight);
  line-height: var(--si-leading-tight);
  color: var(--si-ink);
}

/* Heading 2 */
.si-h2 {
  font-size: var(--si-text-xl);
  font-weight: 500;
  letter-spacing: var(--si-tracking-snug);
  line-height: var(--si-leading-snug);
  color: var(--si-ink);
}

/* Heading 3 */
.si-h3 {
  font-size: var(--si-text-md);
  font-weight: 500;
  letter-spacing: var(--si-tracking-snug);
  line-height: var(--si-leading-snug);
  color: var(--si-ink);
}

/* Subheading / section title */
.si-subhead {
  font-size: var(--si-text-sm);
  font-weight: 500;
  letter-spacing: var(--si-tracking-snug);
  color: var(--si-ink);
}

/* Eyebrow label — amber, tracked out */
.si-eyebrow {
  font-size: var(--si-text-xs);
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  text-transform: lowercase;
  color: var(--si-amber);
}

/* Body — main prose */
.si-body {
  font-size: var(--si-text-base);
  font-weight: 400;
  line-height: var(--si-leading-loose);
  color: var(--si-subtle);
}

.si-body strong {
  font-weight: 500;
  color: var(--si-ink);
}

/* Body small */
.si-body-sm {
  font-size: var(--si-text-sm);
  line-height: var(--si-leading-base);
  color: var(--si-subtle);
}

/* Meta — dates, durations, secondary info */
.si-meta {
  font-size: var(--si-text-xs);
  color: var(--si-muted);
  line-height: var(--si-leading-snug);
}

/* Mono — code, timestamps */
.si-mono {
  font-family: var(--si-font-mono);
  font-size: var(--si-text-xs);
  color: var(--si-muted);
}

/* Intro deck — large article intro */
.si-deck {
  font-size: var(--si-text-md);
  font-weight: 300;
  line-height: var(--si-leading-loose);
  color: var(--si-subtle);
  letter-spacing: -0.01em;
}


/* ------------------------------------------------------------
   5. LAYOUT
   ------------------------------------------------------------ */

.si-page {
  min-height: 100vh;
  background: var(--si-canvas);
}

.si-container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--si-gutter);
}

.si-container--prose {
  max-width: var(--si-max-prose);
  margin: 0 auto;
  padding: 0 var(--si-gutter);
}

.si-section {
  padding: var(--si-space-6) var(--si-gutter);
}

.si-section--lg {
  padding: var(--si-space-10) var(--si-gutter);
}

/* Divider */
.si-divider {
  border: none;
  border-top: var(--si-border-width) solid var(--si-border);
  margin: var(--si-space-6) 0;
}

.si-divider--gutter {
  border: none;
  border-top: var(--si-border-width) solid var(--si-border);
  margin: 0 var(--si-gutter);
}


/* ------------------------------------------------------------
   6. NAVIGATION
   ------------------------------------------------------------ */

.si-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--si-nav-height);
  background: var(--si-canvas);
  border-bottom: var(--si-border-width) solid var(--si-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--si-gutter);
}

.si-nav__logo {
  display: flex;
  align-items: baseline;
  gap: var(--si-space-2);
  text-decoration: none;
}

.si-nav__wordmark {
  font-size: var(--si-text-md);
  font-weight: 500;
  color: var(--si-ink);
  letter-spacing: var(--si-tracking-snug);
}

.si-nav__tag {
  font-size: var(--si-text-xs);
  font-weight: 500;
  color: var(--si-amber);
  letter-spacing: var(--si-tracking-wide);
}

/* Back link variant — experiment / article pages */
.si-nav__back {
  display: flex;
  align-items: center;
  gap: var(--si-space-3);
}

.si-nav__back-link {
  font-size: var(--si-text-sm);
  color: var(--si-muted);
  transition: color var(--si-transition-snap);
}

.si-nav__back-link:hover {
  color: var(--si-amber);
}

.si-nav__divider {
  width: var(--si-border-width);
  height: 16px;
  background: var(--si-border);
}

/* Burger */
.si-burger {
  display: flex;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--si-space-1);
  background: none;
  border: none;
}

.si-burger__line {
  display: block;
  height: 1.5px;
  background: var(--si-ink);
  transition: width var(--si-transition-smooth),
              transform var(--si-transition-smooth),
              opacity var(--si-transition-smooth);
}

.si-burger__line:nth-child(1) { width: 20px; }
.si-burger__line:nth-child(2) { width: 20px; }
.si-burger__line:nth-child(3) { width: 13px; }

.si-burger:hover .si-burger__line:nth-child(3) {
  width: 20px;
}

/* Open state — JS adds .is-open to burger */
.si-burger.is-open .si-burger__line:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}
.si-burger.is-open .si-burger__line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.si-burger.is-open .si-burger__line:nth-child(3) {
  width: 20px;
  transform: translateY(-6.5px) rotate(-45deg);
}


/* ------------------------------------------------------------
   7. MENU OVERLAY
   ------------------------------------------------------------ */

.si-menu {
  position: fixed;
  inset: 0;
  background: var(--si-ink);
  z-index: 200;
  display: flex;
  flex-direction: column;
  padding: var(--si-space-4) var(--si-gutter) var(--si-gutter);

  /* Hidden by default */
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px);
  transition: opacity var(--si-transition-smooth),
              transform var(--si-transition-smooth);
}

.si-menu.is-open {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}

.si-menu__header {
  height: var(--si-nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--si-space-6);
}

.si-menu__close {
  font-size: var(--si-text-xl);
  color: var(--si-canvas);
  cursor: pointer;
  padding: var(--si-space-1);
  line-height: 1;
  opacity: 0.6;
  transition: opacity var(--si-transition-snap);
}

.si-menu__close:hover {
  opacity: 1;
}

.si-menu__links {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.si-menu__link {
  font-size: 26px;
  font-weight: 500;
  color: var(--si-canvas);
  letter-spacing: var(--si-tracking-snug);
  padding: var(--si-space-4) 0;
  border-bottom: var(--si-border-width) solid var(--si-ink-faint);
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-decoration: none;
  transition: color var(--si-transition-snap);
}

.si-menu__link:hover {
  color: var(--si-amber);
}

.si-menu__link-sub {
  font-size: var(--si-text-sm);
  color: var(--si-muted);
  font-weight: 400;
  letter-spacing: 0;
}

.si-menu__footer {
  font-size: var(--si-text-xs);
  color: var(--si-ink-faint);
  padding-top: var(--si-space-6);
  font-family: var(--si-font-mono);
}


/* ------------------------------------------------------------
   8. FOOTER
   ------------------------------------------------------------ */

.si-footer {
  background: var(--si-ink);
  padding: var(--si-space-8) var(--si-gutter);
}

.si-footer__logo {
  font-size: var(--si-text-md);
  font-weight: 500;
  color: var(--si-canvas);
  letter-spacing: var(--si-tracking-snug);
  margin-bottom: var(--si-space-1);
}

.si-footer__tag {
  font-size: var(--si-text-xs);
  color: var(--si-amber);
  font-weight: 500;
  letter-spacing: var(--si-tracking-wide);
  margin-bottom: var(--si-space-6);
}

.si-footer__links {
  display: flex;
  gap: var(--si-space-6);
  flex-wrap: wrap;
  margin-bottom: var(--si-space-6);
}

.si-footer__link {
  font-size: var(--si-text-sm);
  color: var(--si-muted);
  transition: color var(--si-transition-snap);
}

.si-footer__link:hover {
  color: var(--si-canvas);
}

.si-footer__copy {
  font-size: var(--si-text-xs);
  color: var(--si-ink-faint);
  font-family: var(--si-font-mono);
}


/* ------------------------------------------------------------
   9. CARDS
   ------------------------------------------------------------ */

/* Experiment card — left amber border */
.si-card {
  background: var(--si-surface);
  border: var(--si-border-width) solid var(--si-border);
  border-left: 3px solid var(--si-amber);
  border-radius: 0 var(--si-radius-lg) var(--si-radius-lg) 0;
  padding: var(--si-space-4) var(--si-space-5);
  cursor: pointer;
  transition: border-left-color var(--si-transition-snap);
  display: flex;
  flex-direction: column;
  gap: var(--si-space-2);
}

.si-card:hover {
  border-left-color: var(--si-ink);
}

.si-card--locked {
  border-left-color: var(--si-border);
  opacity: 0.45;
  cursor: default;
}

.si-card--locked:hover {
  border-left-color: var(--si-border);
}

/* Standard surface card */
.si-surface-card {
  background: var(--si-surface);
  border: var(--si-border-width) solid var(--si-border);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
}

/* Dark card */
.si-dark-card {
  background: var(--si-ink);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
}

/* Episode card */
.si-ep-card {
  background: var(--si-surface);
  border: var(--si-border-width) solid var(--si-border);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
  display: flex;
  gap: var(--si-space-4);
  align-items: flex-start;
  cursor: pointer;
  transition: border-color var(--si-transition-snap);
}

.si-ep-card:hover {
  border-color: var(--si-border-mid);
}

.si-ep-card.is-playing {
  border-color: var(--si-amber);
  border-left: 3px solid var(--si-amber);
  border-radius: 0 var(--si-radius-lg) var(--si-radius-lg) 0;
}


/* ------------------------------------------------------------
   10. TAGS & BADGES
   ------------------------------------------------------------ */

.si-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 500;
  padding: 2px 9px;
  border-radius: var(--si-radius-pill);
  line-height: 1.6;
}

.si-tag--amber {
  background: var(--si-amber-tint);
  color: var(--si-amber-deep);
}

.si-tag--grey {
  background: var(--si-border);
  color: var(--si-subtle);
}

.si-tag--dark {
  background: var(--si-ink-mid);
  color: var(--si-muted);
}

.si-tag--ink {
  background: var(--si-ink);
  color: var(--si-canvas);
}


/* ------------------------------------------------------------
   11. FILTER BAR
   ------------------------------------------------------------ */

.si-filter-bar {
  display: flex;
  gap: var(--si-space-2);
  overflow-x: auto;
  scrollbar-width: none;
  padding: var(--si-space-3) var(--si-gutter);
  border-bottom: var(--si-border-width) solid var(--si-border);
  background: var(--si-surface);
}

.si-filter-bar::-webkit-scrollbar {
  display: none;
}

.si-filter-btn {
  font-size: var(--si-text-sm);
  font-weight: 500;
  padding: 5px 13px;
  border-radius: var(--si-radius-pill);
  border: var(--si-border-width) solid var(--si-border);
  background: var(--si-surface);
  color: var(--si-subtle);
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
  transition: color var(--si-transition-snap),
              border-color var(--si-transition-snap),
              background var(--si-transition-snap);
}

.si-filter-btn:hover:not(.is-active) {
  border-color: var(--si-amber);
  color: var(--si-amber);
}

.si-filter-btn.is-active {
  background: var(--si-ink);
  border-color: var(--si-ink);
  color: var(--si-canvas);
}


/* ------------------------------------------------------------
   12. TABS
   ------------------------------------------------------------ */

.si-tabs {
  display: flex;
  border-bottom: var(--si-border-width) solid var(--si-border);
  background: var(--si-surface);
  overflow-x: auto;
  scrollbar-width: none;
}

.si-tabs::-webkit-scrollbar {
  display: none;
}

.si-tab {
  font-size: var(--si-text-sm);
  font-weight: 500;
  color: var(--si-muted);
  padding: 12px var(--si-space-5);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
  flex-shrink: 0;
  transition: color var(--si-transition-snap),
              border-color var(--si-transition-snap);
}

.si-tab:hover:not(.is-active) {
  color: var(--si-subtle);
}

.si-tab.is-active {
  color: var(--si-ink);
  border-bottom-color: var(--si-amber);
}

.si-tab-panel {
  display: none;
}

.si-tab-panel.is-active {
  display: block;
}


/* ------------------------------------------------------------
   13. PULL QUOTE & CALLOUT
   ------------------------------------------------------------ */

.si-pullquote {
  border-left: 3px solid var(--si-amber);
  padding: var(--si-space-3) var(--si-space-4);
  margin: var(--si-space-6) 0;
  background: var(--si-canvas);
  border-radius: 0 var(--si-radius-md) var(--si-radius-md) 0;
}

.si-pullquote p {
  font-size: var(--si-text-md);
  font-weight: 400;
  font-style: italic;
  color: var(--si-ink);
  line-height: var(--si-leading-snug);
  margin: 0;
}

.si-callout {
  background: var(--si-amber-tint);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
}

.si-callout__label {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: var(--si-space-1);
}

.si-callout p {
  font-size: var(--si-text-sm);
  color: var(--si-amber-deep);
  line-height: var(--si-leading-base);
  margin: 0;
}


/* ------------------------------------------------------------
   14. TAKEAWAYS
   ------------------------------------------------------------ */

.si-takeaways {
  background: var(--si-surface);
  border: var(--si-border-width) solid var(--si-border);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
}

.si-takeaways__label {
  font-size: var(--si-text-xs);
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: var(--si-space-4);
}

.si-takeaway {
  display: flex;
  gap: var(--si-space-3);
  align-items: flex-start;
  margin-bottom: var(--si-space-3);
}

.si-takeaway:last-child {
  margin-bottom: 0;
}

.si-takeaway__bullet {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--si-amber);
  flex-shrink: 0;
  margin-top: 6px;
}

.si-takeaway p {
  font-size: var(--si-text-sm);
  color: var(--si-subtle);
  line-height: var(--si-leading-base);
  margin: 0;
}


/* ------------------------------------------------------------
   15. EXPERIMENT PLAY AREA
   ------------------------------------------------------------ */

.si-play-area {
  background: var(--si-ink);
  position: relative;
}

.si-play-toolbar {
  padding: var(--si-space-2) var(--si-gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: var(--si-border-width) solid var(--si-ink-faint);
}

.si-play-indicator {
  display: flex;
  align-items: center;
  gap: var(--si-space-2);
  font-size: var(--si-text-xs);
  color: var(--si-muted);
  font-family: var(--si-font-mono);
}

.si-play-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--si-amber);
}

.si-play-controls {
  display: flex;
  gap: var(--si-space-2);
}

.si-play-ctrl-btn {
  font-size: var(--si-text-xs);
  color: var(--si-muted);
  background: transparent;
  border: var(--si-border-width) solid var(--si-ink-faint);
  border-radius: var(--si-radius-sm);
  padding: 3px 10px;
  cursor: pointer;
  font-family: var(--si-font-sans);
  transition: color var(--si-transition-snap),
              border-color var(--si-transition-snap);
}

.si-play-ctrl-btn:hover {
  color: var(--si-canvas);
  border-color: var(--si-muted);
}

.si-play-frame {
  width: 100%;
  min-height: 280px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Iframe wrapper for embedded experiments */
.si-experiment-frame {
  width: 100%;
  height: 400px;
  border: none;
  display: block;
}


/* ------------------------------------------------------------
   16. ACHIEVEMENT BADGE
   ------------------------------------------------------------ */

.si-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--si-space-1);
  flex-shrink: 0;
}

.si-badge__icon {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: var(--si-border-width) solid var(--si-border);
  background: var(--si-canvas);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--si-text-md);
  transition: background var(--si-transition-smooth),
              border-color var(--si-transition-smooth);
}

.si-badge__icon.is-earned {
  background: var(--si-amber-tint);
  border-color: var(--si-amber);
}

.si-badge__name {
  font-size: 10px;
  color: var(--si-muted);
  text-align: center;
  max-width: 56px;
  line-height: var(--si-leading-snug);
}


/* ------------------------------------------------------------
   17. ACHIEVEMENT UNLOCK TOAST
   ------------------------------------------------------------ */

.si-unlock {
  background: var(--si-ink);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
  display: flex;
  align-items: center;
  gap: var(--si-space-4);

  /* Hidden by default — JS adds .is-visible */
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
  transition: opacity var(--si-transition-spring),
              transform var(--si-transition-spring);
}

.si-unlock.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.si-unlock__icon {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--si-amber);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--si-text-md);
  flex-shrink: 0;
}

.si-unlock__label {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: 2px;
}

.si-unlock__title {
  font-size: var(--si-text-sm);
  font-weight: 500;
  color: var(--si-canvas);
}


/* ------------------------------------------------------------
   18. PROGRESS BAR
   ------------------------------------------------------------ */

.si-progress-wrap {
  height: 2px;
  background: var(--si-border);
  position: sticky;
  top: var(--si-nav-height);
  z-index: 90;
}

.si-progress-bar {
  height: 2px;
  background: var(--si-amber);
  width: 0%;
  transition: width 80ms linear;
}


/* ------------------------------------------------------------
   19. GRIDS
   ------------------------------------------------------------ */

.si-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: var(--si-space-3);
}

.si-grid--wide {
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.si-grid--tight {
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: var(--si-space-2);
}


/* ------------------------------------------------------------
   20. HERO VARIANTS
   ------------------------------------------------------------ */

/* Dark hero — home, show, about */
.si-hero {
  background: var(--si-ink);
  padding: var(--si-space-8) var(--si-gutter);
}

.si-hero__eyebrow {
  font-size: var(--si-text-xs);
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: var(--si-space-2);
}

.si-hero__title {
  font-size: var(--si-text-2xl);
  font-weight: 500;
  letter-spacing: var(--si-tracking-tight);
  line-height: var(--si-leading-tight);
  color: var(--si-canvas);
  margin-bottom: var(--si-space-3);
}

.si-hero__title--amber span {
  color: var(--si-amber);
}

.si-hero__sub {
  font-size: var(--si-text-sm);
  color: var(--si-muted);
  line-height: var(--si-leading-base);
  max-width: 460px;
}

/* Light hero — article header */
.si-art-header {
  background: var(--si-surface);
  border-bottom: var(--si-border-width) solid var(--si-border);
  padding: var(--si-space-8) var(--si-gutter) var(--si-space-6);
}


/* ------------------------------------------------------------
   21. SECTION HEADER
   ------------------------------------------------------------ */

.si-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--si-space-5) var(--si-gutter) var(--si-space-3);
}

.si-section-header__title {
  font-size: var(--si-text-sm);
  font-weight: 500;
  color: var(--si-ink);
}

.si-section-header__link {
  font-size: var(--si-text-sm);
  color: var(--si-amber);
  font-weight: 500;
  cursor: pointer;
  transition: opacity var(--si-transition-snap);
}

.si-section-header__link:hover {
  opacity: 0.7;
}

/* Section label with line */
.si-section-label {
  display: flex;
  align-items: center;
  gap: var(--si-space-3);
  font-size: var(--si-text-xs);
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: var(--si-space-4);
}

.si-section-label::after {
  content: '';
  flex: 1;
  height: var(--si-border-width);
  background: var(--si-border);
}


/* ------------------------------------------------------------
   22. PLATFORM PILLS
   ------------------------------------------------------------ */

.si-platform-pill {
  font-size: var(--si-text-xs);
  font-weight: 500;
  padding: 4px 12px;
  border-radius: var(--si-radius-pill);
  cursor: pointer;
  transition: color var(--si-transition-snap),
              background var(--si-transition-snap),
              border-color var(--si-transition-snap);
}

.si-platform-pill--dark {
  background: var(--si-ink-mid);
  color: var(--si-muted);
  border: var(--si-border-width) solid var(--si-ink-faint);
}

.si-platform-pill--dark:hover {
  color: var(--si-canvas);
  border-color: var(--si-muted);
}

.si-platform-pill--amber {
  background: var(--si-amber);
  color: var(--si-canvas);
  border: none;
}


/* ------------------------------------------------------------
   23. READING CROSSLINK — field note ↔ experiment ↔ episode
   ------------------------------------------------------------ */

.si-crosslink {
  background: var(--si-surface);
  border: var(--si-border-width) solid var(--si-border);
  border-left: 3px solid var(--si-amber);
  border-radius: 0 var(--si-radius-lg) var(--si-radius-lg) 0;
  padding: var(--si-space-4) var(--si-space-5);
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--si-space-4);
  transition: border-left-color var(--si-transition-snap);
}

.si-crosslink:hover {
  border-left-color: var(--si-ink);
}

.si-crosslink__label {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: var(--si-space-1);
}

.si-crosslink__title {
  font-size: var(--si-text-sm);
  font-weight: 500;
  color: var(--si-ink);
  line-height: var(--si-leading-snug);
}

.si-crosslink__sub {
  font-size: var(--si-text-xs);
  color: var(--si-muted);
  margin-top: 3px;
}

.si-crosslink__arrow {
  font-size: var(--si-text-md);
  color: var(--si-border-mid);
  flex-shrink: 0;
  margin-top: 2px;
}


/* ------------------------------------------------------------
   24. EXPERIMENT CTA BLOCK
   ------------------------------------------------------------ */

.si-exp-cta {
  background: var(--si-ink);
  border-radius: var(--si-radius-lg);
  padding: var(--si-space-4) var(--si-space-5);
  display: flex;
  align-items: center;
  gap: var(--si-space-4);
  cursor: pointer;
  transition: background var(--si-transition-snap);
}

.si-exp-cta:hover {
  background: var(--si-ink-mid);
}

.si-exp-cta__icon {
  width: 38px;
  height: 38px;
  background: var(--si-amber);
  border-radius: var(--si-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: var(--si-text-md);
  color: var(--si-canvas);
}

.si-exp-cta__label {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: var(--si-tracking-wider);
  color: var(--si-amber);
  margin-bottom: 3px;
}

.si-exp-cta__title {
  font-size: var(--si-text-sm);
  font-weight: 500;
  color: var(--si-canvas);
}

.si-exp-cta__arrow {
  font-size: var(--si-text-md);
  color: var(--si-muted);
  flex-shrink: 0;
  margin-left: auto;
}


/* ------------------------------------------------------------
   25. UTILITY CLASSES
   ------------------------------------------------------------ */

/* Spacing helpers */
.si-mt-2 { margin-top: var(--si-space-2); }
.si-mt-4 { margin-top: var(--si-space-4); }
.si-mt-6 { margin-top: var(--si-space-6); }
.si-mb-2 { margin-bottom: var(--si-space-2); }
.si-mb-4 { margin-bottom: var(--si-space-4); }
.si-mb-6 { margin-bottom: var(--si-space-6); }

/* Colour helpers */
.si-text-ink    { color: var(--si-ink); }
.si-text-subtle { color: var(--si-subtle); }
.si-text-muted  { color: var(--si-muted); }
.si-text-amber  { color: var(--si-amber); }
.si-text-canvas { color: var(--si-canvas); }

/* Display helpers */
.si-flex        { display: flex; }
.si-flex-center { display: flex; align-items: center; }
.si-gap-2       { gap: var(--si-space-2); }
.si-gap-3       { gap: var(--si-space-3); }
.si-gap-4       { gap: var(--si-space-4); }

/* Screen reader only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}


/* ------------------------------------------------------------
   26. SCROLLBAR — minimal, on-brand
   ------------------------------------------------------------ */

::-webkit-scrollbar {
  width: 4px;
  height: 4px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--si-border-mid);
  border-radius: var(--si-radius-pill);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--si-muted);
}


/* ------------------------------------------------------------
   27. SELECTION
   ------------------------------------------------------------ */

::selection {
  background: var(--si-amber-tint);
  color: var(--si-ink);
}


/* ------------------------------------------------------------
   28. FOCUS — accessible, on-brand
   ------------------------------------------------------------ */

:focus-visible {
  outline: 2px solid var(--si-amber);
  outline-offset: 2px;
  border-radius: var(--si-radius-sm);
}


/* ------------------------------------------------------------
   29. RESPONSIVE — mobile first, one breakpoint
   ------------------------------------------------------------ */

@media (min-width: 640px) {

  :root {
    --si-gutter: 2rem;
    --si-text-2xl: 32px;
    --si-text-3xl: 42px;
  }

  .si-hero__title {
    font-size: var(--si-text-2xl);
  }

  .si-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  }

  .si-experiment-frame {
    height: 500px;
  }
}

@media (min-width: 960px) {

  :root {
    --si-gutter: 3rem;
  }

  .si-hero {
    padding: var(--si-space-12) var(--si-gutter);
  }
}
</style.css>