/* ======================================================================
   Reset + Base
   ====================================================================== */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 100%; -webkit-text-size-adjust: 100%; }

html, body {
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

body {
  background: #faf7f2;
  color: #1a1a1a;
  font-family: "Newsreader", Georgia, "Times New Roman", serif;
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Ensure [hidden] always wins over display properties set on element classes */
[hidden] { display: none !important; }

/* ======================================================================
   Layout Zones
   ====================================================================== */

/* Fixed top toolbar */
.toolbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  background: #faf7f2;
  padding: 0.75rem 1.5rem;
  padding-top: calc(0.75rem + env(safe-area-inset-top, 0px));
  border-bottom: 1px solid #e8e2d8;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: center;
}

/* Fixed bottom chrome: header bar + timeline */
.bottom-chrome {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 10;
  background: #faf7f2;
  border-top: 1px solid #e8e2d8;
}

/* Scrollable center panel fills remaining viewport space */
.center-panel {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  /* Dynamic offsets via JS (Sprint 3); static fallbacks below */
  padding: 0 1.5rem;
  padding-top: var(--center-padding-top, calc(3.5rem + env(safe-area-inset-top, 0px)));
  padding-bottom: var(--center-padding-bottom, calc(7rem + env(safe-area-inset-bottom, 0px)));
}

/* ======================================================================
   Timeline
   ====================================================================== */

.timeline {
  display: flex;
  border-top: 1px solid #e8e2d8;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding-bottom: env(safe-area-inset-bottom, 0px);
}
.timeline::-webkit-scrollbar { display: none; }

.timeline__tab {
  flex: 1 0 auto;
  min-width: 44px;
  min-height: 44px;
  padding: 0.75rem 0.5rem;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 500;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #5c544a;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.15s, border-color 0.15s;
}

.timeline__tab:hover { color: #1a1a1a; }

.timeline__tab[aria-selected="true"] {
  color: #8b6f47;
  border-bottom-color: #8b6f47;
}

.timeline__tab:focus-visible {
  outline: 2px solid #8b6f47;
  outline-offset: -2px;
}

/* ======================================================================
   Toolbar
   ====================================================================== */

.toolbar__toggle {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 0.22rem 0.65rem;
  border-radius: 999px;
  border: 1px solid #e8e2d8;
  background: transparent;
  color: #5c544a;
  cursor: pointer;
  white-space: nowrap;
  min-height: 30px;
  line-height: 1.3;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.toolbar__toggle:hover { border-color: #8b6f47; color: #1a1a1a; }

.toolbar__toggle[aria-pressed="true"] {
  background: rgba(139,111,71,0.12);
  border-color: #8b6f47;
  color: #8b6f47;
}

.toolbar__toggle[data-domain="motor"][aria-pressed="true"]              { background: rgba(139,111,71,0.14); border-color: #8b6f47; color: #8b6f47; }
.toolbar__toggle[data-domain="senses"][aria-pressed="true"]             { background: rgba(100,140,140,0.16); border-color: #3f6f6f; color: #3f6f6f; }
.toolbar__toggle[data-domain="social-cognitive"][aria-pressed="true"]   { background: rgba(160,120,160,0.16); border-color: #7b507b; color: #7b507b; }
.toolbar__toggle[data-domain="attachment"][aria-pressed="true"]         { background: rgba(180,130,130,0.16); border-color: #8a5555; color: #8a5555; }
.toolbar__toggle[data-domain="support"][aria-pressed="true"]            { background: rgba(130,160,130,0.16); border-color: #4f6f4f; color: #4f6f4f; }
.toolbar__toggle[data-domain="developmental-patterns"][aria-pressed="true"] { background: rgba(160,150,120,0.16); border-color: #7a704a; color: #7a704a; }
.toolbar__toggle[data-domain="sleep"][aria-pressed="true"]              { background: rgba(120,130,170,0.16); border-color: #4a548a; color: #4a548a; }
.toolbar__toggle[data-domain="feeding"][aria-pressed="true"]            { background: rgba(170,150,120,0.16); border-color: #8a6f45; color: #8a6f45; }
.toolbar__toggle[data-domain="leap-lens"][aria-pressed="true"]          { background: rgba(170,140,100,0.18); border-color: #8a6535; color: #8a6535; }

.toolbar__toggle:focus-visible {
  outline: 2px solid #8b6f47;
  outline-offset: 2px;
}



.toolbar__action {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: #5c544a;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  white-space: nowrap;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.toolbar__action:hover { color: #8b6f47; }

.toolbar__action:focus-visible {
  outline: 2px solid #8b6f47;
  outline-offset: 2px;
}

/* ======================================================================
   Card Design
   ====================================================================== */

/* Domain card */
.domain-card {
  background: #fff;
  border: 1px solid #e8e2d8;
  border-radius: 10px;
  margin-bottom: 0.75rem;
  overflow: hidden;
}

.domain-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 0.75rem 1rem;
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
  color: inherit;
  text-align: left;
  min-height: 44px;
}

.domain-card__header:focus-visible {
  outline: 2px solid #8b6f47;
  outline-offset: -2px;
}

/* Domain label pill inside card header */
.domain-label {
  display: inline-block;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 500;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #5c544a;
  padding: 0.15rem 0.6rem;
  border-radius: 3px;
}

/* Chevron icon */
.domain-card__chevron {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform 0.2s;
  flex-shrink: 0;
}

.domain-card__header[aria-expanded="false"] .domain-card__chevron {
  transform: rotate(-45deg);
}

/* Card body */
.domain-card__body {
  padding: 0 1rem 0.75rem;
  max-height: 800px;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.2s, padding 0.3s ease;
}

/* Collapse card body via :has() — modern CSS dependency (2023+).
   No polyfill provided; browsers without :has() support get the
   expanded (open) default state, which is a graceful degradation. */
.domain-card:has(.domain-card__header[aria-expanded="false"]) .domain-card__body {
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  opacity: 0;
}

/* Content inside card body */
.domain-card__body ul {
  padding-left: 1.25rem;
  margin-bottom: 0.5rem;
}

.domain-card__body ul li {
  margin-bottom: 0.4rem;
}

.domain-card__body p {
  margin-bottom: 0.5rem;
}

.domain-card__body p:last-child,
.domain-card__body ul:last-child {
  margin-bottom: 0;
}

/* ======================================================================
   Pastel Domain Colors
   ====================================================================== */

.domain-card[data-domain="motor"] .domain-label                { background: rgba(139,111,71,0.14); color: #8b6f47; }
.domain-card[data-domain="motor"] .domain-card__title          { color: #8b6f47; }
.domain-card[data-domain="senses"] .domain-label               { background: rgba(100,140,140,0.16); color: #3f6f6f; }
.domain-card[data-domain="senses"] .domain-card__title         { color: #3f6f6f; }
.domain-card[data-domain="social-cognitive"] .domain-label     { background: rgba(160,120,160,0.16); color: #7b507b; }
.domain-card[data-domain="social-cognitive"] .domain-card__title { color: #7b507b; }
.domain-card[data-domain="attachment"] .domain-label           { background: rgba(180,130,130,0.16); color: #8a5555; }
.domain-card[data-domain="attachment"] .domain-card__title     { color: #8a5555; }
.domain-card[data-domain="support"] .domain-label              { background: rgba(130,160,130,0.16); color: #4f6f4f; }
.domain-card[data-domain="support"] .domain-card__title        { color: #4f6f4f; }
.domain-card[data-domain="developmental-patterns"] .domain-label { background: rgba(160,150,120,0.16); color: #7a704a; }
.domain-card[data-domain="developmental-patterns"] .domain-card__title { color: #7a704a; }
.domain-card[data-domain="sleep"] .domain-label                { background: rgba(120,130,170,0.16); color: #4a548a; }
.domain-card[data-domain="sleep"] .domain-card__title          { color: #4a548a; }
.domain-card[data-domain="feeding"] .domain-label              { background: rgba(170,150,120,0.16); color: #8a6f45; }
.domain-card[data-domain="feeding"] .domain-card__title        { color: #8a6f45; }
.domain-card[data-domain="leap-lens"] .domain-label            { background: rgba(170,140,100,0.18); color: #8a6535; }
.domain-card[data-domain="leap-lens"] .domain-card__title      { color: #8a6535; }

/* ======================================================================
   Citation
   ====================================================================== */

.cite {
  font-family: "Newsreader", Georgia, "Times New Roman", serif;
  font-style: italic;
  font-size: 0.875rem;
  color: #5c544a;
  white-space: nowrap;
}

/* ======================================================================
   Leap Lens Sub-Tabs
   ====================================================================== */

.leap-lens-tabs {
  display: flex;
  gap: 0.25rem;
  margin-bottom: 0.75rem;
  border-bottom: 1px solid #e8e2d8;
  padding-bottom: 0.5rem;
}

.leap-lens-tab {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 0.3rem 0.75rem;
  border: 1px solid transparent;
  border-radius: 4px;
  background: transparent;
  color: #5c544a;
  cursor: pointer;
  min-height: 30px;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.leap-lens-tab:hover {
  border-color: #8a6535;
  color: #1a1a1a;
}

.leap-lens-tab[aria-selected="true"] {
  background: rgba(170,140,100,0.18);
  border-color: #8a6535;
  color: #8a6535;
}

.leap-lens-tab:focus-visible {
  outline: 2px solid #8a6535;
  outline-offset: 2px;
}

.leap-lens-panel__title {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #8a6535;
}

/* ======================================================================
   Masonry Layout
   ====================================================================== */

.age-panel { position: relative; }

.age-panel__sizer {
  width: 100%;
}

.masonry-ready .age-panel > .domain-card {
  width: 100%;
}

@media (min-width: 600px) {
  .age-panel__sizer,
    .masonry-ready .age-panel > .domain-card {
    width: calc(50% - 12px);
  }
}

/* ======================================================================
   Accessibility
   ====================================================================== */

.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: #8b6f47;
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 100;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.875rem;
  text-decoration: none;
}

.skip-link:focus {
  top: 0;
}

/* Reduced motion: disable transitions */
@media (prefers-reduced-motion: reduce) {
  .domain-card__body,
  .domain-card__chevron,
  .timeline__tab,
  .toolbar__toggle {
    transition: none;
  }
  /* MAINTENANCE: each new transition/animation added to the site must also be
     added to this block. Add the override at the same time you add the effect. */
}

/* ======================================================================
   Dark Mode (system preference)
   ====================================================================== */

@media (prefers-color-scheme: dark) {
  /* --- Base --- */
  body {
    background: #171412;
    color: #ebe4db;
  }

  /* --- Fixed chrome --- */
  .toolbar {
    background: #171412;
    border-bottom-color: #2e2924;
  }

  .bottom-chrome {
    background: #171412;
    border-top-color: #2e2924;
  }

  /* --- Timeline --- */
  .timeline {
    border-top-color: #2e2924;
  }

  .timeline__tab {
    color: #aea291;
  }

  .timeline__tab:hover {
    color: #ebe4db;
  }

  .timeline__tab[aria-selected="true"] {
    color: #c4a46c;
    border-bottom-color: #c4a46c;
  }

  .timeline__tab:focus-visible {
    outline-color: #c4a46c;
  }

  /* --- Toolbar --- */
  .toolbar__toggle {
    border-color: #2e2924;
    color: #aea291;
  }

  .toolbar__toggle:hover {
    border-color: #c4a46c;
    color: #ebe4db;
  }

  .toolbar__toggle[aria-pressed="true"] {
    background: rgba(196,164,108,0.15);
    border-color: #c4a46c;
    color: #c4a46c;
  }

  .toolbar__toggle[data-domain="motor"][aria-pressed="true"]              { background: rgba(196,164,108,0.14); border-color: #c4a46c; color: #c4a46c; }
  .toolbar__toggle[data-domain="senses"][aria-pressed="true"]             { background: rgba(130,180,180,0.18); border-color: #7fc4c4; color: #7fc4c4; }
  .toolbar__toggle[data-domain="social-cognitive"][aria-pressed="true"]   { background: rgba(200,160,200,0.18); border-color: #c79bc7; color: #c79bc7; }
  .toolbar__toggle[data-domain="attachment"][aria-pressed="true"]         { background: rgba(210,160,160,0.18); border-color: #d49b9b; color: #d49b9b; }
  .toolbar__toggle[data-domain="support"][aria-pressed="true"]            { background: rgba(160,200,160,0.18); border-color: #9bc79b; color: #9bc79b; }
  .toolbar__toggle[data-domain="developmental-patterns"][aria-pressed="true"] { background: rgba(200,190,155,0.18); border-color: #c7bc9a; color: #c7bc9a; }
  .toolbar__toggle[data-domain="sleep"][aria-pressed="true"]              { background: rgba(155,165,210,0.18); border-color: #9aa5d4; color: #9aa5d4; }
  .toolbar__toggle[data-domain="feeding"][aria-pressed="true"]            { background: rgba(210,190,155,0.18); border-color: #d4bd9a; color: #d4bd9a; }
  .toolbar__toggle[data-domain="leap-lens"][aria-pressed="true"]          { background: rgba(210,175,130,0.18); border-color: #d4b187; color: #d4b187; }

  .toolbar__toggle:focus-visible {
    outline-color: #c4a46c;
  }

  .toolbar__action {
    color: #aea291;
  }

  .toolbar__action:hover {
    color: #c4a46c;
  }

  .toolbar__action:focus-visible {
    outline-color: #c4a46c;
  }

  /* --- Domain cards --- */
  .domain-card {
    background: #1f1c18;
    border-color: #2e2924;
  }

  .domain-card__header:focus-visible {
    outline-color: #c4a46c;
  }

  .domain-label {
    color: #aea291;
  }

  /* --- Citations --- */
  .cite {
    color: #aea291;
  }

  /* --- Leap Lens Sub-Tabs (dark) --- */
  .leap-lens-tabs {
    border-bottom-color: #2e2924;
  }
  .leap-lens-tab {
    color: #aea291;
  }
  .leap-lens-tab:hover {
    border-color: #d4b187;
    color: #ebe4db;
  }
  .leap-lens-tab[aria-selected="true"] {
    background: rgba(210,175,130,0.18);
    border-color: #d4b187;
    color: #d4b187;
  }
  .leap-lens-tab:focus-visible {
    outline-color: #d4b187;
  }
  .leap-lens-panel__title {
    color: #d4b187;
  }

  /* --- Skip link --- */
  .skip-link {
    background: #c4a46c;
    color: #171412;
  }

  /* --- Pastel Domain Colors (dark) --- */
  .domain-card[data-domain="motor"] .domain-label                { background: rgba(196,164,108,0.14); color: #c4a46c; }
  .domain-card[data-domain="motor"] .domain-card__title          { color: #c4a46c; }
  .domain-card[data-domain="senses"] .domain-label               { background: rgba(130,180,180,0.18); color: #7fc4c4; }
  .domain-card[data-domain="senses"] .domain-card__title         { color: #7fc4c4; }
  .domain-card[data-domain="social-cognitive"] .domain-label     { background: rgba(200,160,200,0.18); color: #c79bc7; }
  .domain-card[data-domain="social-cognitive"] .domain-card__title { color: #c79bc7; }
  .domain-card[data-domain="attachment"] .domain-label           { background: rgba(210,160,160,0.18); color: #d49b9b; }
  .domain-card[data-domain="attachment"] .domain-card__title     { color: #d49b9b; }
  .domain-card[data-domain="support"] .domain-label              { background: rgba(160,200,160,0.18); color: #9bc79b; }
  .domain-card[data-domain="support"] .domain-card__title        { color: #9bc79b; }
  .domain-card[data-domain="developmental-patterns"] .domain-label { background: rgba(200,190,155,0.18); color: #c7bc9a; }
  .domain-card[data-domain="developmental-patterns"] .domain-card__title { color: #c7bc9a; }
  .domain-card[data-domain="sleep"] .domain-label                { background: rgba(155,165,210,0.18); color: #9aa5d4; }
  .domain-card[data-domain="sleep"] .domain-card__title          { color: #9aa5d4; }
  .domain-card[data-domain="feeding"] .domain-label              { background: rgba(210,190,155,0.18); color: #d4bd9a; }
  .domain-card[data-domain="feeding"] .domain-card__title        { color: #d4bd9a; }
  .domain-card[data-domain="leap-lens"] .domain-label            { background: rgba(210,175,130,0.18); color: #d4b187; }
  .domain-card[data-domain="leap-lens"] .domain-card__title      { color: #d4b187; }
}

/* ======================================================================
   Responsive Breakpoints
   ====================================================================== */

@media (max-width: 599px) {
  .center-panel { padding-left: 1rem; padding-right: 1rem; }
  .toolbar { padding: 0.5rem 0.75rem; gap: 0.3rem; }
  .toolbar__toggle { font-size: 0.65rem; padding: 0.2rem 0.55rem; }
  .timeline__tab { font-size: 0.65rem; padding: 0.6rem 0.4rem; }
  body { font-size: 17px; }

}

@media (min-width: 900px) {
  .age-panel__sizer,
  .masonry-ready .age-panel > .domain-card {
    width: calc(33.3333% - 8px);
  }
}

@media (min-width: 1200px) {
  .age-panel__sizer,
  .masonry-ready .age-panel > .domain-card {
    width: calc(25% - 9px);
  }
}